HeronConservation

The IUCN-SCC Heron Specialist Group

Waterbird Population Estimates for Herons

Waterbird Population Estimates for Herons

Below are the latest estimates of the numbers of heron in various populations. Depending on the species, estimates may be for the entire species, a subspecies, or a geographic population. These estimates were derived by Wetlands International in partnership with HeronConservation and others. The entire report with information on the processes used may be obtained through the search page of Wetlands International.

Estimates are in all cases only that, and base on the best information available and best professional judgment of those who know the populations best. As information increases, estimates will be updated. HeronConservation will continue to partner with Wetlands International and the Ramsar Convention in periodically updating these estimates. All are invited to participate in making these estimates more accurate. Please communicate your data and suggestions to the HeronConservation Co-chairs or Steering Committee Members.

Heron Population Estimates

Scientific name English name Population Range Size - Year Size Trend - Year Trend Public-ation Note
Zonerodius heliosylus Forest Bittern New Guinea 2006 - 2006 1 - 10,000 1985 - 2005 Declining WPE5

  • References
  • Unpublished information supplied by Wetlands International Specialist Groups, 2006.
  • Notes
  • Very difficult to detect and invariably overlooked; thus virtually unknown in the wild (Bishop 2003).
Tigriornis leucolopha White-crested Tiger-heron W & C Africa 2006 - 2006 25,000 - 100,000 Unknown WPE5

  • References
  • Unpublished information supplied by Wetlands International Specialist Groups, 2006.
Tigrisoma lineatum Rufescent Tiger-heron lineatum 2005 - 2005 2,700 - 5,500 Unknown WPE5

  • References
  • Komar, O., Angehr, G., Eisermann, K., Herrera, N. and Zolotoff, J.M.. 2006. Waterbird Population Estimates for Central America. IV North American Ornithological Conference. unpublished report.
  • Notes
  • Estimate for whole of Central America.
marmoratum 2005 - 2011 25,000 - 100,000 2001 - 2010 Stable WPE5

  • References
  • Barrett R. T. 1997. Br?nnich?s Guillemot Uria lomvia. Pp 370 in: Hagemeijer E. J. M and Blair M. J. (Eds) 1997. The EBCC Atlas of European Breeding Birds: Their Distribution and Abundance. T and A D Poyser, London.
Tigrisoma fasciatum Fasciated Tiger-heron fasciatum 1 - 10,000 Unknown WPE5

  • References
  • Antas, P.T.Z. In litt. 1993. Unpublished data concerning South American waterbirds.
salmoni 2005 - 2005 2,520 - 5,050 Unknown WPE5

  • References
  • Komar, O., Angehr, G., Eisermann, K., Herrera, N. and Zolotoff, J.M.. 2006. Waterbird Population Estimates for Central America. IV North American Ornithological Conference. unpublished report.
  • Notes
  • Includes Tigrisoma fasciatum, bolivianum.
  • Estimate for whole of Central America.
pallescens 2004 - 2004 2,000 - 2,000 Unknown WPE5

  • References
  • Boyla, K. and Estrada, A. (Eds.) 2005. ?reas Importantes para la Conservaci?n de las Aves en los Andes Tropicales: Sitios prioritarios para la conservaci?n de la biodiversidad. Quito, Ecuador: BirdLife International and Conservation International (BirdLife Conservation Series No. 14).
Tigrisoma mexicanum Bare-throated Tiger-heron Colombia to Mexico 2005 - 2005 17,100 - 47,500 2005 - 2005 Increasing WPE5

  • References
  • Komar, O., Angehr, G., Eisermann, K., Herrera, N. and Zolotoff, J.M.. 2006. Waterbird Population Estimates for Central America. IV North American Ornithological Conference. unpublished report.
S Mexico Unknown WPE5

  • Notes
  • Sometimes ascribed to fremitus.
Agamia agami Agami Heron C & S America 2005 - 2011 10,000 - 25,000 Unknown WPE5

  • References
  • Komar, O., Angehr, G., Eisermann, K., Herrera, N. and Zolotoff, J.M.. 2006. Waterbird Population Estimates for Central America. IV North American Ornithological Conference. unpublished report.
  • Wetlands International Argentina (compiler). 2012. Unpublished information from the Neotropical Waterbird Census, 1990-2011, including contributions from Colombia (Asociaci?n Calidris in litt.), Paraguay (Guyra Paraguay in litt.), Uruguay (Averaves in litt.) and Venezuela (Uni?n Venezolana de Ornit?logos in litt.).
Cochlearius cochlearius Boat-billed Heron cochlearia 2011 - 2011 25,000 - 100,000 2001 - 2010 Declining WPE5

  • References
  • Boyla, K. and Estrada, A. (Eds.) 2005. ?reas Importantes para la Conservaci?n de las Aves en los Andes Tropicales: Sitios prioritarios para la conservaci?n de la biodiversidad. Quito, Ecuador: BirdLife International and Conservation International (BirdLife Conservation Series No. 14).
  • Wetlands International Argentina (compiler). 2012. Unpublished information from the Neotropical Waterbird Census, 1990-2011, including contributions from Colombia (Asociaci?n Calidris in litt.), Paraguay (Guyra Paraguay in litt.), Uruguay (Averaves in litt.) and Venezuela (Uni?n Venezolana de Ornit?logos in litt.).
zeledoni Unknown WPE5
phillipsi 2005 - 2005 14,800 - 46,300 Unknown WPE5

  • References
  • Komar, O., Angehr, G., Eisermann, K., Herrera, N. and Zolotoff, J.M.. 2006. Waterbird Population Estimates for Central America. IV North American Ornithological Conference. unpublished report.
  • Notes
  • Estimate for whole of Central America.
ridgwayi Unknown WPE5
panamensis Unknown WPE5
Zebrilus undulatus Zigzag Heron South America 2004 - 2004 1 - 10,000 Unknown WPE5

  • References
  • Boyla, K. and Estrada, A. (Eds.) 2005. ?reas Importantes para la Conservaci?n de las Aves en los Andes Tropicales: Sitios prioritarios para la conservaci?n de la biodiversidad. Quito, Ecuador: BirdLife International and Conservation International (BirdLife Conservation Series No. 14).
Botaurus stellaris Eurasian Bittern stellaris W Europe, NW Africa (bre) 2005 - 2012 7,150 - 9,100 2000 - 2012 Increasing CSR7

  • References
  • BirdLife International 2015. European Red List of Birds. Luxembourg: Office for Official Publications of the European Communities. http://datazone.birdlife.org/info/euroredlist
  • Notes
  • In WPE2 this population belonged to one single population (Europe (breeding)).
  • 2,375 - 3,013 pairs in BE, DE, DK, ES, FR, NL, PT, SE & UK (BirdLife International 2015). Less than 20 pairs in NW Africa (Dodman, 2014).
  • Increased both in the long- and the short-term.
C & E Europe, Black Sea & E Mediterranean (bre) 2000 - 2014 92,000 - 163,000 2000 - 2012 Increasing CSR7

  • References
  • BirdLife International 2015. European Red List of Birds. Luxembourg: Office for Official Publications of the European Communities. http://datazone.birdlife.org/info/euroredlist
  • Notes
  • In WPE2 this population belonged to one single population (Europe (breeding)).
  • 30,754 - 54,355 pairs in AL, AT, BA, BG, BY, CZ, EE, FI, GE, GR, HR, HU, IT, LT, LV, MD, ME, MK, PL, RO, RS, RU (assuming 70%), SI, SK, TR & UA (BirdLife International 2015).
  • The population has increased in the short-term, but the short-term trend is unknown in 7 of 26 breeding range states. The long-term trend is possibly stable, but unknown in 10 of 26 range states.
South-west Asia (win) 2006 - 2006 25,000 - 100,000 2003 - 2012 Unknown CSR7

  • References
  • Unpublished information supplied by Wetlands International Specialist Groups, 2006.
South Asia (non-bre) Unknown WPE5
S & E Asia (non-bre) 2001 - 2001 25,000 - 100,000 1981 - 1991 Declining WPE5

  • References
  • Chan, Simba, In litt,. 2002. Unpublished information on Asian waterbirds.
  • Notes
  • Sometimes ascribed to orientalis.
capensis Southern Africa 1980 - 2010 500 - 2,000 1980 - 2009 Declining CSR7

  • References
  • Animal Demography Unit (2017) Southern African Bird Atlas Project 2. SABAP1 vs SABAP2 reporting rates (QDGC). URL: http://sabap2.adu.org.za/index.php
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Notes
  • Fragmented population, only low numbers assumed from any site.
  • Dodman (2014) assumed decline based on fragmented population and habitat loss in many areas. ADU (2017) data confirms that that the species was absent in 16 quarter degree grid cells in SABAP2 where it was present during SABAP1, declined in one and occupied only 5 new ones.
Botaurus poiciloptilus Australasian Bittern SW Australia 2009 - 2010 60 - 230 2000 - 2010 Declining WPE5

  • References
  • Birds Australia. 2012. Bittern Survey (2009-10). Online http://www.birdsaustralia.com.au/our-projects/bittern-survey.html accessed April 2012.
  • Garnett, S.T., Szabo, J.K. and Dutson, G. 2010. The Action Plan for Australian Birds 2010. CSIRO Publishing, Melbourne.
  • Pickering, R. and Gole, C. 2008. Swan coastal plain Australasian Bittern surveys 2007-2008. Report to Birds Australia, Perth.
  • Notes
  • This species was included as one population in the first edition and has now been divided into 4 smaller populations. (WPE2)
  • Estimate derived by WPE method of number of mature birds x1.5 and based on systematic range-wide surveys in recent years coordinated by BirdLife Australia.
  • Trend is declining (20-30% within 2 generations (11 years)) due to loss of habitat.
SE Australia 2009 - 2010 310 - 960 2000 - 2010 Declining WPE5

  • References
  • Birds Australia. 2012. Bittern Survey (2009-10). Online http://www.birdsaustralia.com.au/our-projects/bittern-survey.html accessed April 2012.
  • Garnett, S.T., Szabo, J.K. and Dutson, G. 2010. The Action Plan for Australian Birds 2010. CSIRO Publishing, Melbourne.
  • Notes
  • This species was included as one population in the first edition and has now been divided into 4 smaller populations. (WPE2)
  • Estimate derived by WPE method of number of mature birds x1.5 and based on systematic range-wide surveys in recent years coordinated by BirdLife Australia.
  • Trend is declining (20-30% within 2 generations (11 years)) due to loss of habitat.
New Zealand 2011 - 2011 1,000 - 1,500 2001 - 2010 Declining? WPE5

  • References
  • O'Donnell, C. In litt. 30 March 2012 (advice from Department of Conservation, New Zealand).
  • Notes
  • This species was included as one population in the first edition and has now been divided into 4 smaller populations. (WPE2)
  • Estimate reflects better information arising from systematic investigation.
  • Trend assumed to be unchanged but requires confirmation.
New Caledonia 2011 - 2011 2001 - 2010 Extinct? WPE5

  • References
  • Dutson, G. In litt. 21 March 2012b (advice regarding Pacific Islands including New Guinea).
  • Notes
  • This species was included as one population in the first edition and has now been divided into 4 smaller populations. (WPE2)
Botaurus lentiginosus American Bittern North America 2000 - 2000 2,980,000 - 2,980,000 1966 - 2004 Declining? WPE5

  • References
  • Wiggins, D.A. (2006, September 6). American Bittern (Botaurus lentiginosus): a technical conservation assessment. [Online]. USDA Forest Service, Rocky Mountain Region.
  • Notes
  • Estimate from BBS 992,000 pairs (2,976,000 individuals). For populations over 2 million birds, Ramsar criterion 5 (20,000 or more waterbirds) applies.
Botaurus pinnatus Pinnated Bittern pinnatus 2005 - 2011 10,000 - 25,000 2001 - 2010 Stable WPE5

  • References
  • Franke, I. 2006. Waterbirds in Per?: Final report. Museo de Historia Natural de la Universidad Nacional Mayor de San Marcos. Lima (unpublished report to BirdLife International).
  • Unterkofler, D. and Blanco, D.E. 2012. Unpublished information on Argentine waterbirds.
  • Wetlands International Argentina (compiler). 2012. Unpublished information from the Neotropical Waterbird Census, 1990-2011, including contributions from Colombia (Asociaci?n Calidris in litt.), Paraguay (Guyra Paraguay in litt.), Uruguay (Averaves in litt.) and Venezuela (Uni?n Venezolana de Ornit?logos in litt.).
  • Notes
  • No new data other than estimate of 576-2,900 for Central America (Komar et al. 2006).
caribaeus Unknown WPE5
Ixobrychus involucris Stripe-backed Bittern N South America 1993 - 1993 100,000 - 1,000,000 1982 - 1992 Stable WPE5

  • References
  • Canevari, P. (pers. comm.). 1993. Unpublished information from Neotropical Wetlands Program.
  • Notes
  • In WPE2 this population belonged to one single population (South America).
S South America 2011 - 2011 10,000 - 25,000 2001 - 2010 Stable WPE5

  • References
  • Huanca Llanos, N.E. 2006. Reporte final, Aves Acu?ticas en Bolivia. Asociaci?n Armonia, Santa Cruz de la Sierra (unpublished report to BirdLife International).
  • Unterkofler, D. and Blanco, D.E. 2012. Unpublished information on Argentine waterbirds.
  • Notes
  • In WPE2 this population belonged to one single population (South America).
Ixobrychus exilis Least Bittern exilis 2000 - 2000 128,000 - 128,000 Unknown WPE5

  • References
  • Waterbird Conservation for the Americas. 2001. Continental Marshbird Conservation Planning Workshop, August 2001, Denver, Colorado.
  • Notes
  • No new data. 4,500 (1,500 Bpairs) in Canada (COSEWIC. 2009).
pullus Unknown WPE5
bogotensis 2011 - 2011 1,000 - 1,000 2001 - 2010 Declining WPE5

  • References
  • Asociaci?n Calidris. 2012. Unpublished information from the Neotropical Waterbird Census in Colombia, 1992-2011.
erythromelas 2005 - 2011 10,000 - 25,000 Unknown WPE5

  • References
  • Asociaci?n Calidris. 2012. Unpublished information from the Neotropical Waterbird Census in Colombia, 1992-2011.
peruvianus 2011 - 2011 1,000 - 5,000 2001 - 2010 Stable WPE5

  • References
  • Ottema, O. 2006. Waterbirds in Suriname: Final report. STINASU Foundation for Nature Conservation Suriname, Paramaribo (unpublished report).
  • Unterkofler, D. and Blanco, D.E. 2012. Unpublished information on Argentine waterbirds.
Ixobrychus minutus Common Little Bittern minutus W Europe, NW Africa/Subsaharan Africa 1997 - 2013 19,000 - 25,500 2000 - 2012 Stable CSR7

  • References
  • BirdLife International 2015. European Red List of Birds. Luxembourg: Office for Official Publications of the European Communities. http://datazone.birdlife.org/info/euroredlist
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Notes
  • In WPE2 this population belonged to one single population (Europe/Northern Africa (bre)).
  • 6,227-8253 pairs in BE, DE, ES, ESIC, FR, IT, LU, NL and PT (BirdLife International 2015). 100-200 pairs in NW Africa (Dodman, 2014).
  • Stable in the short-term but declined in the long-term.
C & E Europe, Black Sea & E Mediterranean/Sub-saharan Africa 1995 - 2014 168,000 - 298,000 2000 - 2012 Stable CSR7

  • References
  • BirdLife International 2015. European Red List of Birds. Luxembourg: Office for Official Publications of the European Communities. http://datazone.birdlife.org/info/euroredlist
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • 15. eu
  • Notes
  • In WPE2 this population belonged to one single population (Europe/Northern Africa (bre)).
  • 55,156 - 98,469 pairs in AL, AT, BA, BE, BG, BY, CH, CY, CZ, DE, ES, ESIC, FR, GE, GR, HR, HU, IT, LT, LU, LV, MD, ME, MK, NL, PL, PT, RO, RS, RU, SI, SK, TR, UA & XK (BirdLife International 2015). Further 1000 pairs in Egypt (Dodman, 2014).
  • Stable both in the long- and the short-term.
West & South-west Asia/Sub-Saharan Africa 1987 - 1991 25,000 - 100,000 2003 - 2012 Unknown CSR7

  • References
  • Perennou, C.P., Mundkur, T. and Scott, D.A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB Spec. Publ. No. 24; AWB Spec. Publ. No. 86. Slimbridge, UK and Kuala Lumpur, Malaysia.
South Asia 1987 - 1991 10,000 - 25,000 Unknown WPE5

  • References
  • Perennou, C.P., Mundkur, T. and Scott, D.A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB Spec. Publ. No. 24; AWB Spec. Publ. No. 86. Slimbridge, UK and Kuala Lumpur, Malaysia.
payesii Sub-Saharan Africa 1990 - 2000 25,000 - 100,000 2003 - 2012 Unknown CSR7

  • References
  • Fishpool, L.D.C. and Evans, M.I.,(Eds). 2001. Important Bird Areas in Africa and associated islands: Priority sites for conservation. Newbury and Cambridge, UK: Pisces Publications and BirdLife International (BirdLife Conservation Series No. 11).
podiceps 3,000 - 15,000 Unknown WPE5

  • References
  • Hawkins, F. In litt. 2002. Unpublished notes on waterbird population estimates of Madagascar.
Ixobrychus dubius Australian Little Bittern dubius 1994 - 2010 1 - 10,000 1982 - 2011 Declining? WPE5

  • References
  • Birds Australia. 2011. The Bittern Chronicle No. 3, September 2011. Online http://www.birdsaustralia.com.au/images/stories/current-projects/bittern/Bittern-Chronicle-Sep11.pdf accessed April 2012.
  • Christidis, L. and Boles, W.E. 2008. Systematics and taxonomy of Australian birds. CSIRO Publishing, Melbourne.
  • Clarke, A.G., Lane, J.A.K. and Jaensch, R.P. 2011. Surveys of waterbirds in selected wetlands of south-western Australia in spring-summer 2009-10, with further assessment of changes in habitat and waterbird usage over 2-3 decades. Western Australian Department of Environment and Conservation. 101pp.
  • Jaensch, R.P. 1995. Little Bitterns (Ixobrychus minutus) in the Middle Fly wetlands. Muruk 7 (3): 117-118.
  • Jaensch, Roger, August 2005. Detailed data and notes on numbers and distribution of waterbirds in Australia, updated from Jaensch, 2003, and derived from more than 90 Australian sources including Wetlands International, Birds Australia and Jaensch, 2003,
  • Jaensch, R. April 2012. Detailed data and notes on numbers and trends of waterbirds in Australia and other parts of the Oceania region, in a spreadsheet prepared for Wetlands International - Oceania for the 5th edition of WPE.
  • Notes
  • Now considered a distinct species, previously laced under Ixobrychus minutus
  • Data inadequate to derive a numerical estimate due to survey difficulties; numbers recorded support 1 - 10,000.
  • Trend is possibly declining due to loss of inland habitat.
Ixobrychus novaezelandiae New Zealand Little Bittern New Zealand 1982 - 1992 Extinct WPE5

  • References
  • Powlesland, R. (pers. comm.). 1993. New Zealand Department of Conservation unpublished data.
  • Notes
  • Treated as subspecies of L.minutus until WPE4.
Ixobrychus sinensis Yellow Bittern Seychelles 1 - 300 1991 - 2001 Declining WPE5

  • References
  • Rocamora, G. and Skerrett, A. 2001. Seychelles. Pp 751-768. In L.D.C. Fishpool and M.I. Evans, eds. Important Bird Areas in Africa and associated islands: Priority sites for conservation. Newbury and Cambridge, UK: Pisces Publications and BirdLife International
  • Skerrett, A., 2002. In litt.
South Asia Unknown WPE5
E & SE Asia 2006 - 2006 100,000 - 1,000,000 1985 - 2005 Increasing WPE5

  • References
  • Unpublished information supplied by Wetlands International Specialist Groups, 2006.
  • Notes
  • 42: Recently colonised New Caledonia.
Ixobrychus eurhythmus Schrenck's Bittern E & SE Asia 1 - 25,000 1985 - 1995 Declining WPE5

  • References
  • Lansdown, R.V. (pers. comm.) 1996. Data prepared for the Draft Ardeidae Action Plan.
Ixobrychus cinnamomeus Cinnamon Bittern South Asia 1987 - 1991 25,000 - 1,000,000 Unknown WPE5

  • References
  • Perennou, C.P., Mundkur, T. and Scott, D.A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB Spec. Publ. No. 24; AWB Spec. Publ. No. 86. Slimbridge, UK and Kuala Lumpur, Malaysia.
E, SE Asia 2006 - 2006 100,000 - 1,000,000 1985 - 2005 Stable WPE5

  • References
  • Unpublished information supplied by Wetlands International Specialist Groups, 2006.
Ixobrychus sturmii Dwarf Bittern Sub-Saharan Africa 1990 - 2000 25,000 - 100,000 2002 - 2013 Unknown CSR7

  • References
  • Fishpool, L.D.C. and Evans, M.I.,(Eds). 2001. Important Bird Areas in Africa and associated islands: Priority sites for conservation. Newbury and Cambridge, UK: Pisces Publications and BirdLife International (BirdLife Conservation Series No. 11).
Ixobrychus flavicollis Black Bittern flavicollis South Asia 1987 - 1991 25,000 - 100,000 Unknown WPE5

  • References
  • Perennou, C.P., Mundkur, T. and Scott, D.A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB Spec. Publ. No. 24; AWB Spec. Publ. No. 86. Slimbridge, UK and Kuala Lumpur, Malaysia.
  • Notes
  • Sometimes ascribed to genus Dupetor.
E, SE Asia 2006 - 2006 10,000 - 100,000 Unknown WPE5

  • References
  • Unpublished information supplied by Wetlands International Specialist Groups, 2006.
australis Australia, New Guinea 1999 - 2002 10,000 - 100,000 1991 - 2000 Declining WPE5

  • References
  • Bishop, K.D. 2003. A Review of the Avifauna of the TransFly Eco-region: the status, distribution, habitats and conservation of the region?s birds. Report to WWF South Pacific Program.
  • Green, A.J. 1992a. The status and conservation of the White-winged Wood Duck (Cairina scutulata). IWRB Special Publication No. 17. Slimbridge, UK. 115 pp.
  • Jaensch, R. April 2012. Detailed data and notes on numbers and trends of waterbirds in Australia and other parts of the Oceania region, in a spreadsheet prepared for Wetlands International - Oceania for the 5th edition of WPE.
  • Notes
  • Sometimes ascribed to gouldi.
  • Estimate based on previous information and extent of habitat across several countries.
Timor Unknown WPE5
Rennell Island 2001 - 2001 1 - 500 Unknown WPE5

  • References
  • Dutson, Guy, in litt. 2002.
  • Notes
  • Sometimes included in woodfordi, or as separate subspecies, pallidor.
New Britain, New Ireland 2001 - 2001 1 - 10,000 Unknown WPE5

  • References
  • Dutson, Guy, in litt. 2002.
  • Notes
  • Sometimes ascribed to nesophilus.
woodfordi 2001 - 2001 1 - 10,000 Unknown WPE5

  • References
  • Dutson, Guy, in litt. 2002.
Gorsachius magnificus White-eared Night-heron SE Asia 2000 - 2000 250 - 1,000 1995 - 2005 Declining WPE5

  • References
  • BirdLife International 2001. Threatened Bird of Asia: the BirdLife International Red Data Book. Cambridge, UK. BirdLife International.
  • BirdLife International. 2005. Threatened birds of the world 2005. Species factsheets available at?www.birdlife.org
  • Notes
  • M. Crosby in litt. (2005) estimates 250-999 individuals based on analysis of information presented in 66. Habitat detrimentally transformed at principal site, Shennongjia in Hubei province, China, in 1990s.
Gorsachius goisagi Japanese Night-heron E & SE Asia 2005 - 2005 250 - 1,000 1975 - 1995 Declining WPE5

  • References
  • BirdLife International. 2005. Threatened birds of the world 2005. Species factsheets available at?www.birdlife.org
Gorsachius melanolophus Malay Night-heron South Asia Unknown WPE5
SE Asia Unknown WPE5
Philippines Unknown WPE5

  • Notes
  • Sometimes ascribed to kutteri. Probably this subspecies on Ryukyu Is and Taiwan.
Palawan, Philippines 1 - 10,000 Unknown WPE5

  • References
  • Lansdown, R.V. (pers. comm.) 1996. Data prepared for the Draft Ardeidae Action Plan.
  • Notes
  • Sometimes ascribed to rufolineatus.
Nicobar Is 1 - 10,000 Unknown WPE5

  • References
  • Lansdown, R.V. (pers. comm.) 1996. Data prepared for the Draft Ardeidae Action Plan.
  • Notes
  • Sometimes ascribed to minor.
Calherodius leuconotus White-backed Night-heron Africa 25,000 - 100,000 1991 - 2001 Stable WPE5

  • References
  • Dodman, T. 2002. Waterbird Population Estimates in Africa. Unpublished report to Wetlands International.
  • Dodman, T., 2006. Status, estimates and trends of waterbird populations in Africa. Wetlands International, Dakar.
  • Notes
  • Sometimes included in genus Gorsachius.
Nycticorax duboisi Reunion Night-heron Reunion 2005 - 2005 1750 - 2005 Extinct WPE5

  • References
  • BirdLife International. 2005. Threatened birds of the world 2005. Species factsheets available at?www.birdlife.org
  • Notes
  • Population added in WPE3.
  • Described and last recorded in 1674 (BirdLife International. 2005).
Nycticorax mauritianus Mauritius Night-heron Mauritius 2005 - 2005 1750 - 2005 Extinct WPE5

  • References
  • BirdLife International. 2005. Threatened birds of the world 2005. Species factsheets available at?www.birdlife.org
  • Notes
  • Population added in WPE3.
  • Described and last recorded in 1693 (BirdLife International. 2005).
Nycticorax megacephalus Rodrigues Night-heron Rodrigues 2005 - 2005 1800 - 2005 Extinct WPE5

  • References
  • BirdLife International. 2005. Threatened birds of the world 2005. Species factsheets available at?www.birdlife.org
  • Notes
  • Population added in WPE3.
  • Described and last recorded in 1726 (BirdLife International. 2005).
Nycticorax nycticorax Black-crowned Night-heron nycticorax W Europe, NW Africa (bre) 2002 - 2012 46,000 - 51,000 1998 - 2012 Declining CSR7

  • References
  • BirdLife International 2015. European Red List of Birds. Luxembourg: Office for Official Publications of the European Communities. http://datazone.birdlife.org/info/euroredlist
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Notes
  • In WPE2 this population belonged to one single population (Europe/NW Africa (breeding)).
  • 14,836 - 15,596 pairs in BE, DE, ES, ESIC , FR, IT, NL and PT (BirdLife International 2015). Dodman (2014) estimated that 500-1500 pairs may breed in NW Africa.
  • The European part of the population has declined by 50-53% over the last decade.
C & E Europe/Black Sea & E Mediterranean (bre) 1990 - 2012 134,000 - 209,000 2000 - 2012 Stable CSR7

  • References
  • BirdLife International 2015. European Red List of Birds. Luxembourg: Office for Official Publications of the European Communities. http://datazone.birdlife.org/info/euroredlist
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Notes
  • In WPE2 this population belonged to one single population (Europe/NW Africa (breeding)).
  • 44,700 - 69,610 pairs in AL, AT, AZ, BA, BG, BY, GE, GR, HR, HU, MD, ME, MK, PL, RO, RS, RU, SI, SK, TR, UA& XK (BirdLife International 2015). In addition, less than 1000 birds in Egypt (Dodman, 2014).
  • Stable both in the short- and the long-term.
Western Asia/SW Asia & NE Africa 2002 - 2017 25,000 - 100,000 2000 - 2012 Unknown CSR7

  • References
  • Scott, D.A. in press, 2002. Report on the Conservation Status of Migratory Waterbirds in the Agreement Area. Update Report to African Eurasian Migratory Waterbird Agreement Secretariat
  • Sheldon, R. 2017. Estimates of breeding waterbird populations in Central/SW Asia, The Caucasus and the Arabian Peninsula.
Sub-Saharan Africa & Madagascar 1975 - 2014 100,000 - 300,000 2006 - 2015 Stable/ Increasing? CSR7

  • References
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • Widespread, with breeding colonies across sub-Saharan Africa
  • Dodman (2014) considered it to be at least stable. IWC trend analysis shows strong increase both in the long- and short-term, but this is driven by data from SN (Wetlands International 2017)
South Asia 100,000 - 150,000 1977 - 1991 Stable WPE5

  • References
  • Balachandran, S., in litt. 2005.
  • Perennou, C.P., Mundkur, T. and Scott, D.A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB Spec. Publ. No. 24; AWB Spec. Publ. No. 86. Slimbridge, UK and Kuala Lumpur, Malaysia.
  • Notes
  • 33: Population estimate for India 100,000.
E, SE Asia 2006 - 2006 100,000 - 1,000,000 1981 - 1991 Stable WPE5

  • References
  • Chan, Simba, In litt,. 2002. Unpublished information on Asian waterbirds.
  • Unpublished information supplied by Wetlands International Specialist Groups, 2006.
hoactii Caribbean 2006 - 2007 6,000 - 12,300 Unknown WPE5

  • References
  • Birdlife International. 2008a. Caribbean Waterbird Reports. Downloaded from: http://www.birdlife.org/action/science/species/waterbirds/downloads.html
  • Notes
  • In WPE2 this population belonged to one single population (N.n. nycticorax, North America/N Neotropics).
  • Total of data presented in BirdLife International 2008a.
northern South America (bre) 2005 - 2010 50,000 - 50,000 2001 - 2010 Stable WPE5

  • References
  • Huanca Llanos, N.E. 2006. Reporte final, Aves Acu?ticas en Bolivia. Asociaci?n Armonia, Santa Cruz de la Sierra (unpublished report to BirdLife International).
  • Unterkofler, D. and Blanco, D.E. 2012. Unpublished information on Argentine waterbirds.
  • Wetlands International Argentina (compiler). 2012. Unpublished information from the Neotropical Waterbird Census, 1990-2011, including contributions from Colombia (Asociaci?n Calidris in litt.), Paraguay (Guyra Paraguay in litt.), Uruguay (Averaves in litt.) and Venezuela (Uni?n Venezolana de Ornit?logos in litt.).
  • Notes
  • In WPE2 this population belonged to one single population (N.n. nycticorax, North America/N Neotropics).
North America (bre) 1999 - 2011 75,000 - 150,000 1990 - 2000 Stable WPE5

  • References
  • Butler, R.W., Kushlan, J.A. and Davidson, I.J. 2000. Herons in North America, Central America and the West Indies. Pp 151-175 in: Heron Conservation (James.A. Kushlan and Heinz Hafner, Eds.). Academic Press, London.
  • Schlatter, R. (In litt.). 2002. Unpublished information on Southern South American waterbirds.
  • Notes
  • Ascribed to subspecies hoactli (J. F. Gmelin, 1789) . In WPE2 this population belonged to one single population (N.n. nycticorax, North America/N Neotropics).
  • 2,500-5,000 breeding pairs estimated for Canada (Weseloh, C. In litt. 2012).
  • Ascribed to subspecies hoactli (J. F. Gmelin, 1789).
Mexico Unknown WPE5

  • Notes
  • In WPE2 this population belonged to one single population (N.n. nycticorax, North America/N Neotropics).
Central America 2005 - 2005 9,600 - 24,900 Unknown WPE5

  • References
  • Komar, O., Angehr, G., Eisermann, K., Herrera, N. and Zolotoff, J.M.. 2006. Waterbird Population Estimates for Central America. IV North American Ornithological Conference. unpublished report.
  • Notes
  • In WPE2 this population belonged to one single population (N.n. nycticorax, North America/N Neotropics).
obscurus 2001 - 2001 25,000 - 1,000,000 Unknown WPE5

  • References
  • Schlatter, R. (In litt.). 2002. Unpublished information on Southern South American waterbirds.
falklandicus Falkland Islands (Malvinas) 5,700 - 10,800 Unknown WPE5

  • References
  • Woods, R. and Woods, A. 1997. Atlas of the Breeding Birds of the Falkland Islands. Anthony Nelson, Oswestry, England.
  • Notes
  • 718 estimate 1,900-3,600 pairs (5,700-10,800 individuals).
Nycticorax caledonicus Rufous Night-heron caledonicus 2,000 - 4,000 1990 - 2000 Stable WPE5

  • References
  • Barr?, N. and Dutson, G. 2000. Oiseaux de Nouvelle-Caledonie. Liste commentee. Suppl. Alauda (68), 3: 49pp.
manillensis Unknown WPE5

  • Notes
  • Includes former N.caledonicus minahassae.
pelewensis 2001 - 2001 1 - 10,000 Unknown WPE5

  • References
  • Dutson, Guy, in litt. 2002.
mandibularis 2001 - 2001 10,000 - 100,000 Unknown WPE5

  • References
  • Dutson, Guy, in litt. 2002.
  • Notes
  • Bismarck birds sometimes separated as cancrivorus.
hilli 2004 - 2011 25,000 - 1,000,000 1982 - 2011 Fluctuating WPE5

  • References
  • Jaensch, Roger, August 2005. Detailed data and notes on numbers and distribution of waterbirds in Australia, updated from Jaensch, 2003, and derived from more than 90 Australian sources including Wetlands International, Birds Australia and Jaensch, 2003,
  • Jaensch, R. April 2012. Detailed data and notes on numbers and trends of waterbirds in Australia and other parts of the Oceania region, in a spreadsheet prepared for Wetlands International - Oceania for the 5th edition of WPE.
  • Reid, J. and Jaensch, R. 2004. Aerial waterbird survey results. Section 4.7, pp 472-493 in, Costelloe, J.F., Hudson, P.J., Pritchard, J.C., Puckridge, J.T. and Reid, J.R.W. AridFlo Scientific Report: Environmental Flow Requirements of Arid Zone Rivers with Particular Reference to the Lake Eyre Drainage Basin. School of Earth and Environmental Sciences, University of Adelaide, Adelaide. Final Report to DLW and BC and DEH. Also available online at http://www.lebmf.gov.au/publications/aridflo.html
  • Reid, J.R.W., Kingsford, R.T. and Jaensch, R.P. 2009. Waterbird Surveys in the Channel Country Floodplain Wetlands, Autumn 2009. Report by Australian National University, Canberra, University of New South Wales, Sydney, and Wetlands International, Oceania, Brisbane, for the Australian Government Department of Environment, Water, Heritage and the Arts. 81 pp. Also available online at http://www.lebmf.gov.au/publications/pubs/waterbirds-report.pdf
  • Notes
  • Estimate based on numbers in colonies and consideration of survey difficulties and numbers outside Australia.
  • Trend is fluctuating; possible long-term decline due to loss of some breeding habitat in E Australia requires confirmation.
Nyctanassa violacea Yellow-crowned Night-heron violacea North America 75,000 - 150,000 1966 - 2000 Stable WPE5

  • References
  • Butler, R.W., Kushlan, J.A. and Davidson, I.J. 2000. Herons in North America, Central America and the West Indies. Pp 151-175 in: Heron Conservation (James.A. Kushlan and Heinz Hafner, Eds.). Academic Press, London.
  • Sauer, J. R., J. E. Hines, and J. Fallon. 2001. The North American Breeding Bird Survey, Results and Analysis 1966 - 2000. Version 2001.2, USGS Patuxent Wildlife Research Center, Laurel, MD.
  • Notes
  • Often placed in genus Nycticorax. In WPE2 this population belonged to one single population (N.v. violacea, North Am/Central America).
Mexico to Honduras Unknown WPE5

  • Notes
  • In WPE2 this population belonged to one single population (N.v. violacea, North Am/Central America).
  • No new data other than estimate of 1,400-1,900 for Central America (Komar et al. 2006).
gravirostris Unknown WPE5

  • Notes
  • Sometimes ascribed to bancrofti.
caliginis 2004 - 2004 900 - 900 1982 - 1992 Stable WPE5

  • References
  • Angehr, G. R. 2005. Waterbirds in Panama. Final report to BirdLife International.
  • Naranjo, L. (pers. comm.). 1993. Unpublished data summarised for IWRB.
cayennensis Unknown WPE5
bancrofti Unknown WPE5

  • Notes
  • No new data other than estimate of 2,203-7,603 for Caribbean (Birdlife International 2008a).
pauper Unknown WPE5
Butorides striata Green-backed Heron brevipes 1 - 25,000 Unknown CSR6

  • References
  • Jennings, M.C. 2010. Atlas of Breeding Birds of Arabia. Fauna of Arabia Vol. 25. Senckenberg Gesellschaft für Naturforschung and King Abdulaziz City for Science and Technology, Frankfurt, Germany and Riyadh, Saudi Arabia.
  • Notes
  • Jennings et al. estimated that the population is 2000 pairs in Arabia.
sundevalli Unknown WPE5

  • Notes
  • Sometimes considered separate species Butorides sundevalli.
albolimbata 1 - 10,000 Unknown WPE5

  • References
  • Lansdown, R.V. (pers. comm.) 1996. Data prepared for the Draft Ardeidae Action Plan.
chloriceps 25,000 - 25,000 1991 - 2001 Declining WPE5

  • References
  • Hoffman, T.W., Deepal Warakagoda, U. Sirivardena, 2002. Unpublished information on the birds of Sri Lanka.
spodiogaster Unknown WPE5
amurensis Unknown WPE5
actophila Unknown WPE5

  • Note
  • Includes "connectens". (WPE4)
javanica 2006 - 2006 10,000 - 100,000 Unknown WPE5

  • References
  • Unpublished information supplied by Wetlands International Specialist Groups, 2006.
  • Note
  • Split into a SE & S Asia population and a Mauritius, Reunion & Rodrigues population after WPE5.
moluccarum Moluccas Unknown WPE5
NW New Guinea Unknown WPE5

  • Notes
  • Sometimes ascribed to papuensis.
solomonensis 2001 - 2001 1 - 25,000 Unknown WPE5

  • References
  • Dutson, Guy, in litt. 2002.
atricapilla 2001 - 2001 100,000 - 1,000,000 1991 - 2001 Stable WPE5

  • References
  • Dodman, T. 2002. Waterbird Population Estimates in Africa. Unpublished report to Wetlands International.
idenburgi Unknown WPE5
flyensis Unknown WPE5
stagnatilis N Australia Unknown WPE5
NW Australia Unknown WPE5

  • Notes
  • Sometimes ascribed to rogersi.
NE Western Australia Unknown WPE5

  • Notes
  • Sometimes ascribed to cinereus.
patruelis 100 - 200 1971 - 1987 Declining WPE5

  • References
  • Thibault, J.C. and Guyst, I. 1993. Livre rouge des oiseaux menac?s des regions Francaises d'outre mer. ICBP Monograph No. 5. CIPO, Saint-Claude, France.
macrorhyncha E Australia Unknown WPE5
SC New Guinea, NE Queensland Unknown WPE5

  • Notes
  • Sometimes ascribed to littleri.
carcinophila Unknown WPE5
steini Unknown WPE5
rutenbergi 2001 - 2001 1 - 25,000 1991 - 2001 Stable WPE5

  • References
  • Dodman, T. 2002. Waterbird Population Estimates in Africa. Unpublished report to Wetlands International.
rhizophorae 2001 - 2001 1 - 10,000 1992 - 2002 Stable WPE5

  • References
  • Dodman, T. 2002. Waterbird Population Estimates in Africa. Unpublished report to Wetlands International.
  • Louette, M. 2004. Oiseaux. In: Louette, M., D. Meirte and R. Jocque (eds). La faune terrestre de l?archipel des Comores. Studies in Afrotropical Zoology (MRAC, Tervuren). 293: 89-196.
degens 2001 - 2001 1 - 10,000 Unknown WPE5

  • References
  • Dodman, T. 2002. Waterbird Population Estimates in Africa. Unpublished report to Wetlands International.
crawfordi 2001 - 2001 1 - 5,000 1991 - 2001 Stable WPE5

  • References
  • Dodman, T. 2002. Waterbird Population Estimates in Africa. Unpublished report to Wetlands International.
striata Central & South America Unknown WPE5
South America 2005 - 2011 100,000 - 1,000,000 2001 - 2010 Stable WPE5

  • References
  • Huanca Llanos, N.E. 2006. Reporte final, Aves Acu?ticas en Bolivia. Asociaci?n Armonia, Santa Cruz de la Sierra (unpublished report to BirdLife International).
  • Ottema, O. 2006. Waterbirds in Suriname: Final report. STINASU Foundation for Nature Conservation Suriname, Paramaribo (unpublished report).
  • Unterkofler, D. and Blanco, D.E. 2012. Unpublished information on Argentine waterbirds.
  • Wetlands International Argentina (compiler). 2012. Unpublished information from the Neotropical Waterbird Census, 1990-2011, including contributions from Colombia (Asociaci?n Calidris in litt.), Paraguay (Guyra Paraguay in litt.), Uruguay (Averaves in litt.) and Venezuela (Uni?n Venezolana de Ornit?logos in litt.).
  • Notes
  • Sometimes ascribed to cyanurus.
virescens Central & E North America 1966 - 2000 Declining WPE5

  • References
  • Sauer, J. R., J. E. Hines, and J. Fallon. 2001. The North American Breeding Bird Survey, Results and Analysis 1966 - 2000. Version 2001.2, USGS Patuxent Wildlife Research Center, Laurel, MD.
  • Notes
  • Butorides striata (del Hoyo and Collar 2014) was previously split as B. striata and B. virescens
Mexico Unknown WPE5

  • Notes
  • Butorides striata (del Hoyo and Collar 2014) was previously split as B. striata and B. virescens. Sometimes ascribed to maculatus. (WPE4)
Central America 2005 - 2005 23,000 - 60,000 Unknown WPE5

  • References
  • Komar, O., Angehr, G., Eisermann, K., Herrera, N. and Zolotoff, J.M.. 2006. Waterbird Population Estimates for Central America. IV North American Ornithological Conference. unpublished report.
  • Notes
  • Butorides striata (del Hoyo and Collar 2014) was previously split as B. striata and B. virescens
Caribbean 2006 - 2007 3,080 - 12,300 Unknown WPE5

  • References
  • Birdlife International. 2008a. Caribbean Waterbird Reports. Downloaded from: http://www.birdlife.org/action/science/species/waterbirds/downloads.html
  • Notes
  • Butorides striata (del Hoyo and Collar 2014) was previously split as B. striata and B. virescens
  • Total of data presented in BirdLife International 2008a
bahamensis Unknown WPE5

  • Notes
  • Butorides striata (del Hoyo and Collar 2014) was previously split as B. striata and B. virescens, though this population was considered Butorides striatus in WPE1.
anthonyi 1966 - 2000 Increasing WPE5

  • References
  • Sauer, J. R., J. E. Hines, and J. Fallon. 2001. The North American Breeding Bird Survey, Results and Analysis 1966 - 2000. Version 2001.2, USGS Patuxent Wildlife Research Center, Laurel, MD.
  • Notes
  • Butorides striata (del Hoyo and Collar 2014) was previously split as B. striata and B. virescens. This population was under Butorides striatus in WPE1.
frazari Unknown WPE5

  • Notes
  • Butorides striata (del Hoyo and Collar 2014) was previously split as B. striata and B. virescens. This population was considered Butorides striatus in WPE1.
Ardeola ralloides Squacco Heron ralloides SW Europe, NW Africa (bre) 2002 - 2013 9,000 - 11,000 2000 - 2012 Increasing CSR7

  • References
  • BirdLife International 2015. European Red List of Birds. Luxembourg: Office for Official Publications of the European Communities. http://datazone.birdlife.org/info/euroredlist
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Notes
  • 8,495-10,703 pairs in ES, FR, IT & PT (BirdLife International 2015). C. 100 pairs in N. Africa (Dodman, 2014).
  • Increased both in the short- and the long-term.
C & E Europe, Black Sea & E Mediterranean (bre) 1990 - 2012 29,000 - 52,000 2000 - 2012 Declining CSR7

  • References
  • BirdLife International 2015. European Red List of Birds. Luxembourg: Office for Official Publications of the European Communities. http://datazone.birdlife.org/info/euroredlist
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Notes
  • In WPE2 this population belonged to one single population (S&SW Asia/Black Sea (bre)).
  • 9,219-16,569 pairs in AL, BA, BG, CY, GE, GR, HR, HU, MD, ME, MK, RO, RS, RU, SK, TR & UA (BirdLife International 2015). In addition, over 600 breeding pairs in Egypt (Dodman, 2014).
  • Declining both in the long- and the short-term.
West & South-west Asia/Sub-Saharan Africa 1987 - 2017 25,000 - 100,000 2003 - 2012 Unknown CSR7

  • References
  • BirdLife International Website 2002
  • Perennou, C.P., Mundkur, T. and Scott, D.A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB Spec. Publ. No. 24; AWB Spec. Publ. No. 86. Slimbridge, UK and Kuala Lumpur, Malaysia.
  • Sheldon, R. 2017. Estimates of breeding waterbird populations in Central/SW Asia, The Caucasus and the Arabian Peninsula.
  • Notes
  • In WPE2 this population belonged to one single population (S&SW Asia/Black Sea (bre)).
paludivaga Sub-Saharan Africa & Madagascar 2006 - 2006 300,000 - 600,000 2006 - 2015 Increasing? CSR7

  • References
  • Dodman, T., 2006. Status, estimates and trends of waterbird populations in Africa. Wetlands International, Dakar.
  • Trolliet, B., in litt., 2006.
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • Sometimes ascribed to ralloides.
Ardeola grayii Indian Pond-heron grayii SW, S Asia 1987 - 1991 100,000 - 1,000,000 Unknown WPE5

  • References
  • Perennou, C.P., Mundkur, T. and Scott, D.A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB Spec. Publ. No. 24; AWB Spec. Publ. No. 86. Slimbridge, UK and Kuala Lumpur, Malaysia.
Myanmar, Bay of Bengal Unknown WPE5
phillipsi Unknown WPE5
Ardeola bacchus Chinese Pond-heron E, SE & S Asia 2001 - 2001 25,000 - 1,000,000 1981 - 1991 Stable WPE5

  • References
  • Chan, Simba, In litt,. 2002. Unpublished information on Asian waterbirds.
Ardeola speciosa Javan Pond-heron speciosa Unknown WPE5
continentalis 1987 - 1991 10,000 - 100,000 Unknown WPE5

  • References
  • Perennou, C.P., Mundkur, T. and Scott, D.A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB Spec. Publ. No. 24; AWB Spec. Publ. No. 86. Slimbridge, UK and Kuala Lumpur, Malaysia.
Ardeola idae Madagascar Pond-heron Madagascar & Aldabra/Central & Eastern Africa 2001 - 2001 2,000 - 6,000 2002 - 2013 Increasing? CSR7

  • References
  • BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 30/09/2017.
  • Dodman, T. 2002. Waterbird Population Estimates in Africa. Unpublished report to Wetlands International.
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • Significant long-term decline. BirdLife International (2017) suspects that the decline continues. However, IWC count data suggest modest increase after 2000 (Wetlands International 2017).
Ardeola rufiventris Rufous-bellied Heron Central, Eastern & Southern Africa 2006 - 2006 10,000 - 100,000 2006 - 2015 Stable/ Increasing? CSR7

  • References
  • Unpublished information supplied by Wetlands International Specialist Groups, 2006
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
Bubulcus ibis Cattle Egret ibis Southern Africa 1996 - 2001 100,000 - 1,000,000 2006 - 2015 Declining? CSR7

  • References
  • Animal Demography Unit (2017) Southern African Bird Atlas Project 2. SABAP1 vs SABAP2 reporting rates (QDGC). URL: http://sabap2.adu.org.za/index.php
  • Scott, D.A. in press, 2002. Report on the Conservation Status of Migratory Waterbirds in the Agreement Area. Update Report to African Eurasian Migratory Waterbird Agreement Secretariat.
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • Often placed in genus Ardea.
  • The short-term trend has a strong negative tendency. The long-term trend is also significant long-term decline (Wetlands International 2017). It has declined in three times more quarter degree grid cells than increased in ZA between the SABAP 1 and 2 (ADU 2017).
Caribbean 2006 - 2007 43,800 - 147,000 Unknown WPE5

  • References
  • Birdlife International. 2008a. Caribbean Waterbird Reports. Downloaded from: http://www.birdlife.org/action/science/species/waterbirds/downloads.html
  • Notes
  • In WPE2 this population belonged to one single population (B.i. ibis, Neotropics).Often placed in genus Ardea.
  • Total of data presented in BirdLife International 2008a and of which 25,000-100,000 estimated for Cuba (Acosta-Cruz, M. and Mugica-Vald?s, L. 2006.)
South America 1993 - 1993 1,000,000 - 1,000,000 1982 - 1992 Increasing WPE5

  • References
  • Canevari, P. (pers. comm.). 1993. Unpublished information from Neotropical Wetlands Program.
  • Naranjo, L. (pers. comm.). 1993. Unpublished data summarised for IWRB.
  • Notes
  • In WPE2 this population belonged to one single population (B.i. ibis, Neotropics).Often placed in genus Ardea.
Tropical Africa 1990 - 2001 1,000,000 - 10,000,000 2006 - 2015 Unknown CSR7

  • References
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Scott, D.A. in press, 2002. Report on the Conservation Status of Migratory Waterbirds in the Agreement Area. Update Report to African Eurasian Migratory Waterbird Agreement Secretariat.
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • Often placed in genus Ardea.
  • Population probably numbers 'several million' (Dodman, 2014).
  • IWC trend analysis produced uncertain results.
North-west Africa 1984 - 2000 100,000 - 150,000 2006 - 2015 Stable? CSR7

  • References
  • Hafner, H. 2000. Herons in The Mediterranean. Pp 32-54 in: Heron Conservation (James.A. Kushlan and Heinz Hafner, Eds.). Academic Press, London.
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • In WPE2 this population belonged to one single population (SW Europe/NW Africa).Often placed in genus Ardea.
  • Stable long-term trend.
South-west Europe 2002 - 2012 215,000 - 253,000 2000 - 2012 Declining? CSR7

  • References
  • BirdLife International 2015. European Red List of Birds. Luxembourg: Office for Official Publications of the European Communities. http://datazone.birdlife.org/info/euroredlist
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • In WPE2 this population belonged to one single population (SW Europe/NW Africa).Often placed in genus Ardea.
  • 71,770 - 84,193 pairs.
  • Both the breeding (BirdLife International 2015) and the IWC data (Wetlands International 2017) indicate long-term increase that turned into a decline in the short-term.
East Mediterranean & South-west Asia 2005 - 2017 10,000 - 100,000 2006 - 2015 Unknown CSR7

  • References
  • Sheldon, R. 2017. Estimates of breeding waterbird populations in Central/SW Asia, The Caucasus and the Arabian Peninsula.
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • Often placed in genus Ardea.
  • Although the trend analysis suggest steep decline, Hatzofe (pers. com) indicated that the species has exploded in IL.
North America 1,000,000 - 1,000,000 1966 - 2000 Stable WPE5

  • References
  • Kushlan, James, A., Melanie J. Steinkamp, Katharine Parsons, Jack Capp, Martin Acosta Cruz, Malcolm Coulter, Ian Davidson, Loney Dickson, Naomi Edelson, Richard Elliot, R. Michael Erwin, Scott Hatch, Stephen Kress, Robert Milko, Steve Miller, Kyra Mills, Richard Paul, Roberto Phillips, Jorge E. Saliva, Bill Sydeman, John Trapp, Jennifer Wheeler, and Kent Wohl. 2002. North American Waterbird Conservation Plan, Version 1. Waterbird Conservation for the Americas, Washington, DC, USA.
  • Sauer, J. R., J. E. Hines, and J. Fallon. 2001. The North American Breeding Bird Survey, Results and Analysis 1966 - 2000. Version 2001.2, USGS Patuxent Wildlife Research Center, Laurel, MD.
  • Notes
  • Often placed in genus Ardea.
  • Apparently does not breed in Canada anymore, certainly not in Ontario (Weseloh, C. In litt. 2012).
Mexico Unknown WPE5

  • Notes
  • In WPE2 this population belonged to one single population (B.i. ibis, Neotropics).Often placed in genus Ardea.
Central America 2005 - 2005 262,000 - 2,120,000 2005 - 2005 Increasing WPE5

  • References
  • Komar, O., Angehr, G., Eisermann, K., Herrera, N. and Zolotoff, J.M.. 2006. Waterbird Population Estimates for Central America. IV North American Ornithological Conference. unpublished report.
  • Notes
  • In WPE2 this population belonged to one single population (B.i. ibis, Neotropics).Often placed in genus Ardea.
coromanda South Asia 1987 - 1991 100,000 - 1,000,000 Unknown WPE5

  • References
  • Perennou, C.P., Mundkur, T. and Scott, D.A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB Spec. Publ. No. 24; AWB Spec. Publ. No. 86. Slimbridge, UK and Kuala Lumpur, Malaysia.
  • Notes
  • Often placed in genus Ardea.
E, SE Asia 2001 - 2001 100,000 - 1,000,000 1981 - 1991 Stable WPE5

  • References
  • Chan, Simba, In litt,. 2002. Unpublished information on Asian waterbirds.
  • Notes
  • Often placed in genus Ardea.
Oceania 1999 - 2011 25,000 - 1,000,000 1982 - 2011 Increasing WPE5

  • References
  • Chatto, R. 2000. Waterbird breeding colonies in the Top End of the Northern Territory. Technical Report 69, Parks and Wildlife Commission of the Northern Territory, Australia.
  • Jaensch, Roger, August 2005. Detailed data and notes on numbers and distribution of waterbirds in Australia, updated from Jaensch, 2003, and derived from more than 90 Australian sources including Wetlands International, Birds Australia and Jaensch, 2003,
  • Jaensch, R. April 2012. Detailed data and notes on numbers and trends of waterbirds in Australia and other parts of the Oceania region, in a spreadsheet prepared for Wetlands International - Oceania for the 5th edition of WPE.
  • Notes
  • Madsen, J., Reed, A. and Andreev, A. 1996. Status and trends of geese (Anser sp., Branta sp.) in the world: a review, updating and evaluation. In: Proceedings of Anatidae 2000. M. Birkan, J. van Vessem, P. Havet, J. Madsen, B. Trolliet, and M. Moser (eds.
  • Often placed in genus Ardea.
  • Estimate in broad range based on size of large colonies in far N Australia and status as common and locally breeding in coastal E Australia.
  • Ongoing, long-term trend of increase throughout population's range.
seychellarum 2001 - 2001 1 - 10,000 1991 - 2001 Stable WPE5

  • References
  • Dodman, T. 2002. Waterbird Population Estimates in Africa. Unpublished report to Wetlands International.
  • Notes
  • Often placed in genus Ardea.
Ardea cinerea Grey Heron cinerea Sub-Saharan Africa 1995 - 2014 100,000 - 300,000 2006 - 2015 Increasing? CSR7

  • References
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • approx 50,000 in Southern Africa, up to 100,000 in Eastern Africa, up to 100,000 in Western Africa, and up to 50,000 in Central Africa
Northern & Western Europe 2002 - 2013 347,000 - 712,000 2006 - 2015 Declining CSR7

  • References
  • BirdLife International 2015. European Red List of Birds. Luxembourg: Office for Official Publications of the European Communities. http://datazone.birdlife.org/info/euroredlist
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • Total number of breeding pairs is 115,754-237,071 pairs, i.e. 347,000-711,000 individuals BirdLife International 2015). Less than 300 birds breed in North Africa (Dodman, 2014).
  • Moderate decline in the short-term based on breeding numbers (BirdLife International 2015) and uncertain with a negative tendency based on mid-winter counts (Wetlands International 2017). Increased in the long-term according to both sources.
Central & Eastern Europe 2000 - 2014 322,000 - 459,000 2000 - 2012 Declining CSR7

  • References
  • BirdLife International 2015. European Red List of Birds. Luxembourg: Office for Official Publications of the European Communities. http://datazone.birdlife.org/info/euroredlist
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • In WPE2 this population belonged to one single population (E B Sea & W/SW Asia (bre)).
  • 107,317-153,025 pairs in Europe (BirdLife International 2015). Casual breeder in Egypt (Dodman, 2014).
  • BirdLife International (2015) estimates the trend to be negative in the short-term and stable in the long-term. Wetlands International (2017) has also found negative short-term trend and stable long-term one.
West & South-west Asia (bre) 2000 - 2017 25,000 - 100,000 2006 - 2015 Declining? CSR7

  • References
  • Sheldon, R. 2017. Estimates of breeding waterbird populations in Central/SW Asia, The Caucasus and the Arabian Peninsula.
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • In WPE2 this population belonged to one single population (E B Sea & W/SW Asia (bre)).
  • See CSR6 and Sheldon (2017).
  • Statistically uncertain short-term trend with a negative tendency. The long-term trend is stable.
South Asia 100,000 - 100,000 Unknown WPE5

  • References
  • Balachandran, S., in litt. 2005.
  • Notes
  • Sometimes assigned to rectirostris.
monicae 7,500 - 12,500 1984 - 1997 Stable WPE5

  • References
  • Campredon, P. 1987. La reproduction des oiseaux d'eau sur le Parc National du Banc d'Arguin (Mauritanie) en 1984-1985. Alauda 55: 187-210.
  • Hafner, H. 2000. Herons in The Mediterranean. Pp 32-54 in: Heron Conservation (James.A. Kushlan and Heinz Hafner, Eds.). Academic Press, London.
  • Notes
  • Sometimes considered a separate species.
firasa 2001 - 2001 5,000 - 5,000 1991 - 2001 Declining WPE5

  • References
  • Dodman, T. 2002. Waterbird Population Estimates in Africa. Unpublished report to Wetlands International.
  • Hawkins, F. In litt. 2002. Unpublished notes on waterbird population estimates of Madagascar.
jouyi E, SE Asia 1987 - 1991 100,000 - 1,000,000 Unknown WPE5

  • References
  • Perennou, C.P., Mundkur, T. and Scott, D.A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB Spec. Publ. No. 24; AWB Spec. Publ. No. 86. Slimbridge, UK and Kuala Lumpur, Malaysia.
Sumatra 1,000 - 2,000 Unknown WPE5

  • References
  • Lansdown, R.V. (pers. comm.) 1996. Data prepared for the Draft Ardeidae Action Plan.
  • Notes
  • Sometimes assigned to altirostris.
Ardea herodias Great Blue Heron herodias C & NE North America 124,000 - 125,000 1966 - 2000 Increasing WPE5

  • References
  • Kushlan, J. A. 2007. Conserving Herons, A Conservation Action Plan for the Herons of the World. Heron Specialist Group and Station Biologique de la Tour du Valat, Arles, France.
  • Sauer, J. R., J. E. Hines, and J. Fallon. 2001. The North American Breeding Bird Survey, Results and Analysis 1966 - 2000. Version 2001.2, USGS Patuxent Wildlife Research Center, Laurel, MD.
  • Notes
  • This estimate includes two other populations (W N Americas and W N Americas, N Mexico).
W North America 1966 - 2000 Stable WPE5

  • References
  • Sauer, J. R., J. E. Hines, and J. Fallon. 2001. The North American Breeding Bird Survey, Results and Analysis 1966 - 2000. Version 2001.2, USGS Patuxent Wildlife Research Center, Laurel, MD.
  • Notes
  • Sometimes ascribed to hyperonca.
  • The population estimate for C & NE N America includes the estimate for this population and also the W N Americas, N Mexico population.
W North America, N Mexico Unknown WPE5

  • Notes
  • Sometimes ascribed to treganzai. (WPE4)
  • The population estimate for C & NE N America includes the estimate for this population and also the W N Americas population.
Baja California, Mexico Unknown WPE5

  • Notes
  • Sometimes ascribed to sanctilucae.
cognata 2004 - 2004 1,000 - 1,000 Unknown WPE5

  • References
  • Boyla, K. and Estrada, A. (Eds.) 2005. ?reas Importantes para la Conservaci?n de las Aves en los Andes Tropicales: Sitios prioritarios para la conservaci?n de la biodiversidad. Quito, Ecuador: BirdLife International and Conservation International (BirdLife Conservation Series No. 14).
fannini 1997 - 2007 9,500 - 11,000 1997 - 2007 Declining WPE5

  • References
  • COSEWIC. 2008. COSEWIC assessment and update status report on the Great Blue Heron fannini subspecies Ardea herodias fannini in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vii + 39 pp.
  • Notes
  • Estimate refers to Nesting adults.
wardi 1966 - 2000 Increasing WPE5

  • References
  • Sauer, J. R., J. E. Hines, and J. Fallon. 2001. The North American Breeding Bird Survey, Results and Analysis 1966 - 2000. Version 2001.2, USGS Patuxent Wildlife Research Center, Laurel, MD.
occidentalis Florida 2006 - 2006 1,500 - 1,500 1980 - 2007 Declining WPE5

  • References
  • Kushlan, J. A. 2007. Conserving Herons, A Conservation Action Plan for the Herons of the World. Heron Specialist Group and Station Biologique de la Tour du Valat, Arles, France.
  • Vennesland, R.G. and Butler, R.W. 2011. Great Blue Heron (Ardea herodias), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology.
Caribbean Unknown WPE5

  • Notes
  • According to Birdlife International 2008a., occurs mainly as non-breeding migrant. Resident population presumably <100 individuals.
Central America 2005 - 2005 29,800 - 122,000 Unknown WPE5

  • References
  • Komar, O., Angehr, G., Eisermann, K., Herrera, N. and Zolotoff, J.M.. 2006. Waterbird Population Estimates for Central America. IV North American Ornithological Conference. unpublished report.
Ardea cocoi Cocoi Heron South America, Panama 2005 - 2011 100,000 - 1,000,000 2001 - 2010 Stable WPE5

  • References
  • Huanca Llanos, N.E. 2006. Reporte final, Aves Acu?ticas en Bolivia. Asociaci?n Armonia, Santa Cruz de la Sierra (unpublished report to BirdLife International).
  • Ottema, O. 2006. Waterbirds in Suriname: Final report. STINASU Foundation for Nature Conservation Suriname, Paramaribo (unpublished report).
  • Santander, T., J.R. Hidálgo and B. Haase. 2006. Reporte final Aves Acuáticas en Ecuador. Aves & Conservación, Quito (unpublished report).
  • Unterkofler, D. and Blanco, D.E. 2012. Unpublished information on Argentine waterbirds.
  • Wetlands International Argentina (compiler). 2012. Unpublished information from the Neotropical Waterbird Census, 1990-2011, including contributions from Colombia (Asociaci?n Calidris in litt.), Paraguay (Guyra Paraguay in litt.), Uruguay (Averaves in litt.) and Venezuela (Uni?n Venezolana de Ornit?logos in litt.).
Ardea pacifica White-necked Heron Australia 2004 - 2011 10,000 - 25,000 1982 - 2011 Fluctuating WPE5

  • References
  • Jaensch, Roger, August 2005. Detailed data and notes on numbers and distribution of waterbirds in Australia, updated from Jaensch, 2003, and derived from more than 90 Australian sources including Wetlands International, Birds Australia and Jaensch, 2003,
  • Jaensch, R. April 2012. Detailed data and notes on numbers and trends of waterbirds in Australia and other parts of the Oceania region, in a spreadsheet prepared for Wetlands International - Oceania for the 5th edition of WPE.
  • Notes
  • Estimate based on reassessment of previous information and recent information that suggests population level may reach or exceed 25,000 only briefly.
Ardea melanocephala Black-headed Heron Sub-Saharan Africa 1991 - 2001 100,000 - 500,000 2006 - 2015 Unknown CSR7

  • References
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
Ardea humbloti Madagascar Heron Madagascar 1,000 - 3,000 1990 - 2005 Declining WPE5

  • References
  • BirdLife International. 2005. Threatened birds of the world 2005. Species factsheets available at?www.birdlife.org
  • Hawkins, F. In litt. 2002. Unpublished notes on waterbird population estimates of Madagascar.
Ardea insignis White-bellied Heron S & SE Asia 2005 - 2005 250 - 1,000 1985 - 2005 Declining WPE5

  • References
  • BirdLife International. 2005. Threatened birds of the world 2005. Species factsheets available at?www.birdlife.org
  • Unpublished information supplied by Wetlands International Specialist Groups, 2006.
Ardea sumatrana Great-billed Heron SE Asia 10,000 - 100,000 1975 - 1985 Declining WPE5

  • References
  • Lansdown, R.V. 1986. The status and ecology of the Sumatran Heron (Ardea sumatrana). Interwader publ. No. 21. Kuala Lumpur.
Australia 1999 - 1999 7,500 - 7,500 1990 - 1999 Stable WPE5

  • References
  • Green, A.J. 1992a. The status and conservation of the White-winged Wood Duck (Cairina scutulata). IWRB Special Publication No. 17. Slimbridge, UK. 115 pp.
  • Notes
  • Sometimes ascribed to mathewsae.
  • Occurs at low density often in habitat remote from observation; thus, data deficient. Habitat is largely unchanged and not at high risk.
Ardea goliath Goliath Heron Sub-Saharan Africa 10,000 - 100,000 1991 - 2001 Stable WPE5

  • References
  • del Hoyo, J., Elliott A. and Sargatal, J. (eds). 1992. Handbook of the Birds of the World. Volume 1: Ostrich to Ducks. Lynx Editions, Barcelona.
  • Dodman, T. 2002. Waterbird Population Estimates in Africa. Unpublished report to Wetlands International.
SW Asia 1987 - 1991 50 - 50 Unknown WPE5

  • References
  • Perennou, C.P., Mundkur, T. and Scott, D.A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB Spec. Publ. No. 24; AWB Spec. Publ. No. 86. Slimbridge, UK and Kuala Lumpur, Malaysia.
S Asia 1987 - 1991 20 - 20 Unknown WPE5

  • References
  • Perennou, C.P., Mundkur, T. and Scott, D.A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB Spec. Publ. No. 24; AWB Spec. Publ. No. 86. Slimbridge, UK and Kuala Lumpur, Malaysia.
Ardea purpurea Purple Heron purpurea Tropical Africa 2001 - 2001 75,000 - 100,000 2005 - 2015 Declining? CSR7

  • References
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • According to the IWC trend analysis data, the population is possibly in significant long-term decline although only partial information is available (Wetlands International 2017).
West Europe & West Mediterranean/West Africa 2000 - 2012 32,000 - 38,000 2000 - 2012 Declining CSR7

  • References
  • BirdLife International 2015. European Red List of Birds. Luxembourg: Office for Official Publications of the European Communities. http://datazone.birdlife.org/info/euroredlist
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Notes
  • 10,802-12.400 pairs in CH, NL, DE, IT, FR, ES and PT (BirdLife International 2015). Less than 300 in North Africa (Dodman, 2014).
  • Declining in the short-term. Long-term trend appears to be stable (BirdLife International 2015).
East Europe, Black Sea & Mediterranean/Sub-Saharan Africa 2000 - 2013 61,000 - 99,000 2006 - 2015 Declining? CSR7

  • References
  • BirdLife International 2015. European Red List of Birds. Luxembourg: Office for Official Publications of the European Communities. http://datazone.birdlife.org/info/euroredlist
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Notes
  • 20,411-32,945 pairs (BirdLife International 2015). This estimate is without the estimate for SW Asian part of the population, which was split from.
  • Declining both in the short- and the long-term. Unknown breeding trends are reported from 7 of the 20 breeding range states (BirdLife International 2015).
SW Asia (bre) 2006 - 2006 10,000 - 25,000 2006 - 2015 Unknown CSR7

  • References
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • In WPE2 this population belonged to one single population (E Europe/SW Asia (breeding)).
  • WI/IUCN Heron SG (2005).
madagascariensis 5,000 - 10,000 1991 - 2001 Stable WPE5

  • References
  • Dodman, T. 2002. Waterbird Population Estimates in Africa. Unpublished report to Wetlands International.
  • Hawkins, F. In litt. 2002. Unpublished notes on waterbird population estimates of Madagascar.
bournei 1 - 50 1982 - 1992 Declining WPE5

  • References
  • Hazevoet, C.J. 1992. A review of the Santiago Purple Heron (Ardea purpurea bournei) with a report of a new colony. Bird Conservation International (1992) 2: 15-23.
  • Notes
  • May merit full specific status (del Hoyo et al. (1992)).
manilensis South Asia 1987 - 1991 25,000 - 25,000 1977 - 1991 Stable WPE5

  • References
  • Perennou, C.P., Mundkur, T. and Scott, D.A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB Spec. Publ. No. 24; AWB Spec. Publ. No. 86. Slimbridge, UK and Kuala Lumpur, Malaysia.
E & SE Asia 1987 - 1991 10,000 - 100,000 Unknown WPE5

  • References
  • Perennou, C.P., Mundkur, T. and Scott, D.A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB Spec. Publ. No. 24; AWB Spec. Publ. No. 86. Slimbridge, UK and Kuala Lumpur, Malaysia.
Ardea alba Great White Egret alba W, C & SE Europe/Black Sea & Mediterranean 2000 - 2014 61,000 - 99,000 2006 - 2015 Stable/ Increasing? CSR7

  • References
  • BirdLife International 2015. European Red List of Birds. Luxembourg: Office for Official Publications of the European Communities. http://datazone.birdlife.org/info/euroredlist
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • Often assigned to genus Casmerodius, occasionally Egretta.
  • 20,248-32,928 pairs in Europe (BirdLife International 2015). Possibly, some birds in the Volga delta belong to the Western Asia/South-west Asia population.
  • In the short-term, increased based on breeding numbers (BirdLife International 2015), but stabilized based on wintering numbers (Wetlands International 2017). In the long-term, increase based on both source.
Western Asia/South-west Asia 1990 - 2017 25,000 - 100,000 2006 - 2015 Stable/ Fluctuating CSR7

  • References
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • See CSR7 and Sheldon (2017).
  • Stable both in the short- and the long-term (Wetlands International 2017). The trend graph shows increase up to the late 1990s, followed by a rapid decline in the early 2000s and stabilisation in the last decade.
melanorhynchos Sub-Saharan Africa & Madagascar 2001 - 2001 100,000 - 500,000 2006 - 2015 Stable CSR7

  • References
  • Dodman, T. 2002. Waterbird Population Estimates in Africa. Unpublished report to Wetlands International.
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
    Notes
  • Notes
  • Stable both in the short- and the long-term.
egretta North America 270,000 - 270,000 1966 - 2000 Increasing WPE5

  • References
  • Kushlan, James, A., Melanie J. Steinkamp, Katharine Parsons, Jack Capp, Martin Acosta Cruz, Malcolm Coulter, Ian Davidson, Loney Dickson, Naomi Edelson, Richard Elliot, R. Michael Erwin, Scott Hatch, Stephen Kress, Robert Milko, Steve Miller, Kyra Mills, Richard Paul, Roberto Phillips, Jorge E. Saliva, Bill Sydeman, John Trapp, Jennifer Wheeler, and Kent Wohl. 2002. North American Waterbird Conservation Plan, Version 1. Waterbird Conservation for the Americas, Washington, DC, USA.
  • Sauer, J. R., J. E. Hines, and J. Fallon. 2001. The North American Breeding Bird Survey, Results and Analysis 1966 - 2000. Version 2001.2, USGS Patuxent Wildlife Research Center, Laurel, MD.
Mexico Unknown WPE5

  • Notes
  • Population added in WPE3.
Central America 2005 - 2005 52,500 - 180,000 2005 - 2005 Stable? WPE5

  • References
  • Komar, O., Angehr, G., Eisermann, K., Herrera, N. and Zolotoff, J.M.. 2006. Waterbird Population Estimates for Central America. IV North American Ornithological Conference. unpublished report.
  • Notes
  • Population added in WPE3.
Caribbean 2006 - 2007 11,100 - 30,500 Unknown WPE5

  • References
  • Birdlife International. 2008a. Caribbean Waterbird Reports. Downloaded from: http://www.birdlife.org/action/science/species/waterbirds/downloads.html
  • Notes
  • Population added in WPE3.
  • Total of data presented in BirdLife International 2008a.
South America 2005 - 2011 1,000,000 - 1,000,000 2001 - 2010 Stable WPE5

  • References
  • Huanca Llanos, N.E. 2006. Reporte final, Aves Acu?ticas en Bolivia. Asociaci?n Armonia, Santa Cruz de la Sierra (unpublished report to BirdLife International).
  • Ottema, O. 2006. Waterbirds in Suriname: Final report. STINASU Foundation for Nature Conservation Suriname, Paramaribo (unpublished report).
  • Santander, T., J.R. Hidálgo and B. Haase. 2006. Reporte final Aves Acuáticas en Ecuador. Aves & Conservación, Quito (unpublished report).
  • Unterkofler, D. and Blanco, D.E. 2012. Unpublished information on Argentine waterbirds.
  • Wetlands International Argentina (compiler). 2012. Unpublished information from the Neotropical Waterbird Census, 1990-2011, including contributions from Colombia (Asociaci?n Calidris in litt.), Paraguay (Guyra Paraguay in litt.), Uruguay (Averaves in litt.) and Venezuela (Uni?n Venezolana de Ornit?logos in litt.).
  • Notes
  • Population added in WPE3.
modestus South Asia (non-bre) 2001 - 2005 25,000 - 100,000 1977 - 1991 Stable WPE5

  • References
  • Asian Waterbird Census unpublished data. 2002.
  • Perennou, C.P., Mundkur, T. and Scott, D.A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB Spec. Publ. No. 24; AWB Spec. Publ. No. 86. Slimbridge, UK and Kuala Lumpur, Malaysia.
  • ul Islam, Zafar, in litt. 2005.
  • Notes
  • Sometimes considered as Ardea (Casmerodius, Egretta) modestus.
  • 20: 11,000 counted in South Asia in 2003.
E Asia (non-bre) 2001 - 2001 10,000 - 100,000 1987 - 1991 Declining WPE5

  • References
  • Asian Waterbird Census unpublished data. 2002.
  • Perennou, C.P., Mundkur, T. and Scott, D.A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB Spec. Publ. No. 24; AWB Spec. Publ. No. 86. Slimbridge, UK and Kuala Lumpur, Malaysia.
  • Notes
  • Sometimes considered as Ardea (Casmerodius, Egretta) modestus. Two forms are recognised by ornithologists in the region (one closely resembling alba) and research is needed on their taxonomy and distribution (Butler et al. (1992), Moores, N. in litt. (2005)).
  • 20: 16,800 counted in 2004.
Indonesia Unknown WPE5

  • Notes
  • Sometimes considered as Ardea (Casmerodius, Egretta) modestus.
Australia 1995 - 2011 25,000 - 100,000 1982 - 2011 Fluctuating WPE5

  • References
  • Jaensch, Roger, August 2005. Detailed data and notes on numbers and distribution of waterbirds in Australia, updated from Jaensch, 2003, and derived from more than 90 Australian sources including Wetlands International, Birds Australia and Jaensch, 2003,
  • Jaensch, R. April 2012. Detailed data and notes on numbers and trends of waterbirds in Australia and other parts of the Oceania region, in a spreadsheet prepared for Wetlands International - Oceania for the 5th edition of WPE.
  • Halse, S.A., Pearson, G.B., Jaensch, R.P., Kulmoi, P., Gregory, P., Kay, W.R. and Storey, A.W. 1996. Waterbird surveys of the Middle Fly River floodplain, Papua New Guinea. Wildlife Research 23 (5): 557-569. (CSIRO Publishing, Australia).
  • Notes
  • Sometimes considered as Ardea (Casmerodius, Egretta) modestus.
  • Estimate based on review of previous information and recent information that suggests total numbers remain between 25,000 and 100,000. Numbers in New Guinea can reach the same level but likely to be mostly migrants from Australia.
New Zealand 100 - 100 Unknown WPE5

  • References
  • Powlesland, R. (pers. comm.). 1993. New Zealand Department of Conservation unpublished data.
  • Notes
  • Sometimes considered as Ardea (Casmerodius, Egretta) modestus. Sometimes ascribed to maorianus.
Ardea brachyrhyncha Yellow-billed Egret Sub-Saharan Africa 2001 - 2001 25,000 - 100,000 2006 - 2015 Increasing? CSR7

  • References
  • Dodman, T. 2002. Waterbird Population Estimates in Africa. Unpublished report to Wetlands International.
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • Ardea intermedia, A. brachyrhyncha and A. plumifera (del Hoyo and Collar 2014) were previously placed in the genus Mesophoyx and lumped as M. intermedia (see BirdLife International (2016) Species factsheet: Ardea brachyrhyncha.)
Ardea intermedia Intermediate Egret intermedia South Asia 25,000 - 100,000 Unknown WPE5

  • References
  • Asian Waterbird Census unpublished data. 2002.
  • Notes
  • Often included in the genus Mesophoyx or Egretta.
  • 20: 22,000 counted in South Asia in 2004.
E, SE Asia 25,000 - 100,000 Unknown WPE5

  • References
  • Asian Waterbird Census unpublished data. 2002.
  • Notes
  • 20: >10,000 counted in 2002-2004.
Ardea plumifera Plumed Egret plumifera 1995 - 2011 100,000 - 1,000,000 1982 - 2011 Declining? WPE5

  • References
  • BirdLife International. 2012h. Important Bird Areas factsheet: Gwydir Wetlands. Downloaded from?http://www.birdlife.org?on 30/04/2012
  • Halse, S.A., Pearson, G.B., Jaensch, R.P., Kulmoi, P., Gregory, P., Kay, W.R. and Storey, A.W. 1996. Waterbird surveys of the Middle Fly River floodplain, Papua New Guinea. Wildlife Research 23 (5): 557-569. (CSIRO Publishing, Australia).
  • Jaensch, Roger, August 2005. Detailed data and notes on numbers and distribution of waterbirds in Australia, updated from Jaensch, 2003, and derived from more than 90 Australian sources including Wetlands International, Birds Australia and Jaensch, 2003,
  • Jaensch, R. April 2012. Detailed data and notes on numbers and trends of waterbirds in Australia and other parts of the Oceania region, in a spreadsheet prepared for Wetlands International - Oceania for the 5th edition of WPE.
  • Kingsford, R.T. and Johnson, W. 1998. Impact of water diversions on colonially-nesting waterbirds in the Macquarie Marshes of arid Australia. Colonial Waterbirds 21: 159-170.
  • Kingsford, R.T., Porter, J.L. and Halse, S.A. 2012. National waterbird assessment. Waterlines report, National Water Commission, Canberra. Available online at http://nwc.gov.au/publications/waterlines/74
  • Notes
  • Ardea intermedia, A. brachyrhyncha and A. plumifera (del Hoyo and Collar 2014) were previously placed in the genus Mesophoyx and lumped as M. intermedia (see BirdLife International (2016) Species factsheet: Ardea plumifera.)
  • Numbers clearly between 100,000 and 1,000,000 either in Australia or S New Guinea; probable migration precludes summation. Additional birds in Indonesia (no information) or failure to confirm migration would raise possibility of estimate in excess of 1,000,000.
  • In Australia, northern colonies secure but overall likely declining trend due to loss of southernmost colonies due to river regulation for irrigation.
Syrigma sibilatrix Whistling Heron sibilatrix 2005 - 2011 25,000 - 100,000 2001 - 2010 Stable WPE5

  • References
  • Huanca Llanos, N.E. 2006. Reporte final, Aves Acu?ticas en Bolivia. Asociaci?n Armonia, Santa Cruz de la Sierra (unpublished report to BirdLife International).
  • Unterkofler, D. and Blanco, D.E. 2012. Unpublished information on Argentine waterbirds.
  • Wetlands International Argentina (compiler). 2012. Unpublished information from the Neotropical Waterbird Census, 1990-2011, including contributions from Colombia (Asociaci?n Calidris in litt.), Paraguay (Guyra Paraguay in litt.), Uruguay (Averaves in litt.) and Venezuela (Uni?n Venezolana de Ornit?logos in litt.).
forstersmithi 2011 - 2011 10,000 - 10,000 2006 - 2010 Fluctuating WPE5

  • References
  • Uni?n Venezolana de Ornit?logos. 2012. Unpublished information from the Neotropical Waterbird Census in Venezuela, 2006-2011.
Pilherodius pileatus Capped Heron C & S America 2005 - 2011 10,000 - 25,000 2001 - 2010 Stable WPE5

  • References
  • Uni?n Venezolana de Ornit?logos. 2012. Unpublished information from the Neotropical Waterbird Census in Venezuela, 2006-2011.
Egretta picata (Pied Heron) Pied Heron Australia - Sulawesi 1995 - 2002 25,000 - 100,000 2000 - 2010 Stable WPE5

  • References
  • Bishop, K.D. 2003. A Review of the Avifauna of the TransFly Eco-region: the status, distribution, habitats and conservation of the region?s birds. Report to WWF South Pacific Program.
  • Chatto, R. 2000. Waterbird breeding colonies in the Top End of the Northern Territory. Technical Report 69, Parks and Wildlife Commission of the Northern Territory, Australia.
  • Halse, S.A., Pearson, G.B., Jaensch, R.P., Kulmoi, P., Gregory, P., Kay, W.R. and Storey, A.W. 1996. Waterbird surveys of the Middle Fly River floodplain, Papua New Guinea. Wildlife Research 23 (5): 557-569. (CSIRO Publishing, Australia).
  • Jaensch, Roger, August 2005. Detailed data and notes on numbers and distribution of waterbirds in Australia, updated from Jaensch, 2003, and derived from more than 90 Australian sources including Wetlands International, Birds Australia and Jaensch, 2003,
  • Jaensch, R. April 2012. Detailed data and notes on numbers and trends of waterbirds in Australia and other parts of the Oceania region, in a spreadsheet prepared for Wetlands International - Oceania for the 5th edition of WPE.
  • Notes
  • Sometimes placed in genus Ardea.
  • Estimate based on high counts in S New Guinea, and numbers breeding in far N Australia, which although not necessarily additive nevertheless suggest overall numbers in the range 25,000-100,000.
  • Trend assumed stable based on habitat in Australia and New Guinea being mostly near-natural.
Egretta novaehollandiae White-faced Heron novaehollandiae 2004 - 2008 10,000 - 100,000 Unknown WPE5

  • References
  • Jaensch, Roger, August 2005. Detailed data and notes on numbers and distribution of waterbirds in Australia, updated from Jaensch, 2003, and derived from more than 90 Australian sources including Wetlands International, Birds Australia and Jaensch, 2003,
  • Joseph, L. In litt. 4 April 2012 (CSIRO, Canberra).
  • Madsen, J., Reed, A. and Andreev, A. 1996. Status and trends of geese (Anser sp., Branta sp.) in the world: a review, updating and evaluation. In: Proceedings of Anatidae 2000. M. Birkan, J. van Vessem, P. Havet, J. Madsen, B. Trolliet, and M. Moser (eds.
  • Reid, J.R.W., Kingsford, R.T. and Jaensch, R.P. 2009. Waterbird Surveys in the Channel Country Floodplain Wetlands, Autumn 2009. Report by Australian National University, Canberra, University of New South Wales, Sydney, and Wetlands International, Oceania, Brisbane, for the Australian Government Department of Environment, Water, Heritage and the Arts. 81 pp. Also available online at http://www.lebmf.gov.au/publications/pubs/waterbirds-report.pdf
  • Notes
  • Considered to be monotypic by Marchant & Higgins (1990) & Boles & Walter, in litt. (2005).
  • Estimate based on summed maximum counts indicating at least 10,000 birds and common status (at low density) across dryland habitats; much habitat is not surveyed.
parryi Unknown WPE5

  • Notes
  • Population added in WPE3.
Egretta rufescens Reddish Egret rufescens S USA 1991 - 2006 5,000 - 7,000 1991 - 2006 Declining WPE5

  • References
  • Green, M.C. 2006. Status report and survey recommendations on the Reddish Egret (Egretta rufescens). U.S. Fish and Wildlife Service, Atlanta, GA. 37 pp.
  • Notes
  • In WPE2 this population belonged to one single population (S.h. rufescens, North America/Caribbean).
  • Green 2006. 1,215-1,330 breeding pairs in southern USA; 800-1,000 breeding pairs in Mexico (inc. dickeyi); 200 breeding pairs in Bahamas.
Mexico 1 - 10,000 Unknown WPE5

  • References
  • Scott, D.A. and Carbonnell, M. (compilers). 1986. A Directory of Neotropical Wetlands. IUCN, Cambridge, UK and IWRB, Slimbridge, UK.
  • Notes
  • Sometimes ascribed to colorata.
Central America 2006 - 2006 1 - 10,000 Unknown WPE5

  • References
  • Unpublished information supplied by Wetlands International Specialist Groups, 2006.
  • Notes
  • In WPE2 this population belonged to one single population (S.h. rufescens, North America/Caribbean).
  • Green, C. In litt. 2012. 282 breeding pairs in southern Mexico (Chiapas, Oaxaca in 2007-2008) and 95 breeding pairs in Tamaulipas (in 2008).
Caribbean 2006 - 2010 213 - 213 Unknown WPE5

  • References
  • Kushlan, J. A. 2007. Conserving Herons, A Conservation Action Plan for the Herons of the World. Heron Specialist Group and Station Biologique de la Tour du Valat, Arles, France.
  • Notes
  • In WPE2 this population belonged to one single population (S.h. rufescens, North America/Caribbean).
  • Data from Bahamas: 50 bp in Great Inagua, 19 bp in Grand Bahama, 2 bp in Bimini Island.
N South America 1 - 10,000 Unknown WPE5

  • References
  • Morales, G. 2000. Herons in South America. Pp 177-199 in: Heron Conservation (James.A. Kushlan and Heinz Hafner, Eds.). Academic Press, London.
  • Notes
  • In WPE2 this population belonged to one single population (S.h. rufescens, North America/Caribbean).
dickeyi 2007 - 2008 2,250 - 2,260 Unknown WPE5

  • References
  • Green, C. In litt. 2012.
  • Notes
  • 753 Breeding Pairs.
Egretta ardesiaca Black Heron Sub-Saharan Africa 1999 - 1999 25,000 - 100,000 2006 - 2015 Unknown CSR7

  • References
  • del Hoyo, J., Elliott A. and Sargatal, J. (eds). 1992. Handbook of the Birds of the World. Volume 1: Ostrich to Ducks. Lynx Editions, Barcelona.
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
Egretta vinaceigula Slaty Egret Central Southern Africa 2005 - 2005 3,000 - 5,000 1993 - 2013 Declining? CSR7

  • References
  • BirdLife International (2014) Species factsheet: Egretta vinaceigula. Downloaded from http://www.birdlife.org on 07/10/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 07/10/2014.
  • BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 30/09/2017.
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • No update to estimate in AEWA SSAP (Tyler 2013)
  • The population is suspected to be in decline owing to the effects of habitat conversion and degradation, and human disturbance. The likely rate of decline, however, has not been estimated (BirdLife International, 2017). Recent IWC trend analysis provides some week support to this assumption (Wetlands International 2017). Significant long-term decline maintained.
Egretta tricolor Tricolored Heron tricolor Unknown WPE5
ruficollis USA (bre) 293,000 - 293,000 1966 - 2000 Stable WPE5

  • References
  • Kushlan, James, A., Melanie J. Steinkamp, Katharine Parsons, Jack Capp, Martin Acosta Cruz, Malcolm Coulter, Ian Davidson, Loney Dickson, Naomi Edelson, Richard Elliot, R. Michael Erwin, Scott Hatch, Stephen Kress, Robert Milko, Steve Miller, Kyra Mills, Richard Paul, Roberto Phillips, Jorge E. Saliva, Bill Sydeman, John Trapp, Jennifer Wheeler, and Kent Wohl. 2002. North American Waterbird Conservation Plan, Version 1. Waterbird Conservation for the Americas, Washington, DC, USA.
  • Sauer, J. R., J. E. Hines, and J. Fallon. 2001. The North American Breeding Bird Survey, Results and Analysis 1966 - 2000. Version 2001.2, USGS Patuxent Wildlife Research Center, Laurel, MD.
  • Notes
  • In WPE2 this population belonged to one single population (E.t. ruficollis, North Am/NW Neotropics).
Mexico 2006 - 2006 1 - 1,500 Unknown WPE5

  • References
  • Kushlan, J. A. 2007. Conserving Herons, A Conservation Action Plan for the Herons of the World. Heron Specialist Group and Station Biologique de la Tour du Valat, Arles, France.
  • Notes
  • Sometimes ascribed to rufimentum.
  • No new data
Central America 2005 - 2005 3,350 - 6,800 Unknown WPE5

  • References
  • Komar, O., Angehr, G., Eisermann, K., Herrera, N. and Zolotoff, J.M.. 2006. Waterbird Population Estimates for Central America. IV North American Ornithological Conference. unpublished report.
  • Notes
  • In WPE2 this population belonged to one single population (E.t. ruficollis, North Am/NW Neotropics).
Caribbean 2006 - 2007 12,000 - 27,400 Unknown WPE5

  • References
  • Birdlife International. 2008a. Caribbean Waterbird Reports. Downloaded from: http://www.birdlife.org/action/science/species/waterbirds/downloads.html
  • Notes
  • In WPE2 this population belonged to one single population (E.t. ruficollis, North Am/NW Neotropics).
  • Total of data presented in BirdLife International 2008a and of which 10,000-25,000 estimated for Cuba (Acosta-Cruz, and Mugica-Vald?s 2006).
Egretta caerulea Little Blue Heron North America 225,000 - 300,000 1966 - 2000 Declining WPE5

  • References
  • Butler, R.W., Kushlan, J.A. and Davidson, I.J. 2000. Herons in North America, Central America and the West Indies. Pp 151-175 in: Heron Conservation (James.A. Kushlan and Heinz Hafner, Eds.). Academic Press, London.
  • Sauer, J. R., J. E. Hines, and J. Fallon. 2001. The North American Breeding Bird Survey, Results and Analysis 1966 - 2000. Version 2001.2, USGS Patuxent Wildlife Research Center, Laurel, MD.
  • Notes
  • In WPE2 this population belonged to one single population (North America/Neotropics).
Mexico 75,000 - 150,000 Unknown WPE5

  • References
  • Butler, R.W., Kushlan, J.A. and Davidson, I.J. 2000. Herons in North America, Central America and the West Indies. Pp 151-175 in: Heron Conservation (James.A. Kushlan and Heinz Hafner, Eds.). Academic Press, London.
  • Notes
  • In WPE2 this population belonged to one single population (North America/Neotropics).
Central America 2005 - 2005 701 - 1,500 Unknown WPE5

  • References
  • Komar, O., Angehr, G., Eisermann, K., Herrera, N. and Zolotoff, J.M.. 2006. Waterbird Population Estimates for Central America. IV North American Ornithological Conference. unpublished report.
  • Notes
  • In WPE2 this population belonged to one single population (North America/Neotropics).
Caribbean 2006 - 2007 12,300 - 35,900 Unknown WPE5

  • References
  • Birdlife International. 2008a. Caribbean Waterbird Reports. Downloaded from: http://www.birdlife.org/action/science/species/waterbirds/downloads.html
  • Notes
  • In WPE2 this population belonged to one single population (North America/Neotropics).
  • Total of data presented in BirdLife International 2008a.
South America 2005 - 2011 100,000 - 100,000 2001 - 2010 Stable? WPE5

  • References
  • Ottema, O. 2006. Waterbirds in Suriname: Final report. STINASU Foundation for Nature Conservation Suriname, Paramaribo (unpublished report).
  • Santander, T., J.R. Hidálgo and B. Haase. 2006. Reporte final Aves Acuáticas en Ecuador. Aves & Conservación, Quito (unpublished report).
  • Unterkofler, D. and Blanco, D.E. 2012. Unpublished information on Argentine waterbirds.
  • Wetlands International Argentina (compiler). 2012. Unpublished information from the Neotropical Waterbird Census, 1990-2011, including contributions from Colombia (Asociaci?n Calidris in litt.), Paraguay (Guyra Paraguay in litt.), Uruguay (Averaves in litt.) and Venezuela (Uni?n Venezolana de Ornit?logos in litt.).
  • Notes
  • In WPE2 this population belonged to one single population (North America/Neotropics).
Egretta thula Snowy Egret thula 215,000 - 215,000 1982 - 1992 Stable WPE5

  • References
  • Canevari, P. (pers. comm.). 1993. Unpublished information from Neotropical Wetlands Program.
  • Kushlan, James, A., Melanie J. Steinkamp, Katharine Parsons, Jack Capp, Martin Acosta Cruz, Malcolm Coulter, Ian Davidson, Loney Dickson, Naomi Edelson, Richard Elliot, R. Michael Erwin, Scott Hatch, Stephen Kress, Robert Milko, Steve Miller, Kyra Mills, Richard Paul, Roberto Phillips, Jorge E. Saliva, Bill Sydeman, John Trapp, Jennifer Wheeler, and Kent Wohl. 2002. North American Waterbird Conservation Plan, Version 1. Waterbird Conservation for the Americas, Washington, DC, USA.
  • Notes
  • In WPE2 this population belonged to one single population (E.t. thula, Neotropics).
thula Mexico 75,000 - 150,000 Unknown WPE5

  • References
  • Butler, R.W., Kushlan, J.A. and Davidson, I.J. 2000. Herons in North America, Central America and the West Indies. Pp 151-175 in: Heron Conservation (James.A. Kushlan and Heinz Hafner, Eds.). Academic Press, London.
  • Notes
  • In WPE2 this population belonged to one single population (E.t. thula, Neotropics).
Central America 2005 - 2005 11,300 - 26,900 Unknown WPE5

  • References
  • Komar, O., Angehr, G., Eisermann, K., Herrera, N. and Zolotoff, J.M.. 2006. Waterbird Population Estimates for Central America. IV North American Ornithological Conference. unpublished report.
  • Notes
  • In WPE2 this population belonged to one single population (E.t. thula, Neotropics).
Caribbean 2006 - 2007 12,500 - 36,100 Unknown WPE5

  • References
  • Birdlife International. 2008a. Caribbean Waterbird Reports. Downloaded from: http://www.birdlife.org/action/science/species/waterbirds/downloads.html
  • Notes
  • In WPE2 this population belonged to one single population (E.t. thula, Neotropics).
  • Total of data presented in BirdLife International 2008a.
South America 2005 - 2011 300,000 - 1,000,000 2001 - 2010 Stable WPE5

  • References
  • Huanca Llanos, N.E. 2006. Reporte final, Aves Acu?ticas en Bolivia. Asociaci?n Armonia, Santa Cruz de la Sierra (unpublished report to BirdLife International).
  • Ottema, O. 2006. Waterbirds in Suriname: Final report. STINASU Foundation for Nature Conservation Suriname, Paramaribo (unpublished report).
  • Wetlands International Argentina (compiler). 2012. Unpublished information from the Neotropical Waterbird Census, 1990-2011, including contributions from Colombia (Asociaci?n Calidris in litt.), Paraguay (Guyra Paraguay in litt.), Uruguay (Averaves in litt.) and Venezuela (Uni?n Venezolana de Ornit?logos in litt.).
  • Notes
  • In WPE2 this population belonged to one single population (E.t. thula, Neotropics).
brewsteri 2006 - 2006 100,000 - 1,000,000 1966 - 2000 Increasing WPE5

  • References
  • Sauer, J. R., J. E. Hines, and J. Fallon. 2001. The North American Breeding Bird Survey, Results and Analysis 1966 - 2000. Version 2001.2, USGS Patuxent Wildlife Research Center, Laurel, MD.
  • Unpublished information supplied by Wetlands International Specialist Groups, 2006.
Egretta garzetta Little Egret garzetta Sub-Saharan Africa 2001 - 2001 200,000 - 500,000 2006 - 2015 Increasing? CSR7

  • References
  • Dodman, T. 2002. Waterbird Population Estimates in Africa. Unpublished report to Wetlands International.
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • Trend analyses based on IWC July data suggest a significant increase, however data are rather limited to a few key countries.
Western Europe, NW Africa 2002 - 2013 106,000 - 116,000 2000 - 2012 Declining CSR7

  • References
  • BirdLife International 2015. European Red List of Birds. Luxembourg: Office for Official Publications of the European Communities. http://datazone.birdlife.org/info/euroredlist
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Notes
  • Population was omitted from WPE2.
  • 34,668-34,472 pairs in BE, ES, ESIC, FR, IE, IT, NL, PT & UK (BirdLife International 2015). 1500-3500 resident birds can be also added for NW Africa (Dodman, 2014).
  • Declines in the short-term but increased in the long one.
Central & E Europe, Black Sea, E Mediterranean 2000 - 2014 60,000 - 89,000 2000 - 2012 Stable CSR7

  • References
  • BirdLife International 2015. European Red List of Birds. Luxembourg: Office for Official Publications of the European Communities. http://datazone.birdlife.org/info/euroredlist
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Notes
  • 19,598-29,059 pairs in AL, AT, BA, BG, CY, CZ, GE, GR, HR, HU, MD, ME, MK, PL, RO, RS, RU, SK, TR, UA & XK (BirdLife International 2015) allocating 40% of the Russian population to this one. According to Dodman (2014), further 1000-2000 resident birds can be added for Egypt.
  • Stable in the short-term and stable/fluctuating in the long one.
Western Asia/SW Asia, NE & Eastern Africa 1987 - 2017 25,000 - 100,000 1988 - 2015 Stable/ Fluctuating CSR7

  • References
  • Perennou, C.P., Mundkur, T. and Scott, D.A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB Spec. Publ. No. 24; AWB Spec. Publ. No. 86. Slimbridge, UK and Kuala Lumpur, Malaysia.
  • Sheldon, R. 2017. Estimates of breeding waterbird populations in Central/SW Asia, The Caucasus and the Arabian Peninsula.
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • Stable/fluctuating in the long-term. This overall trend confounds large long-term fluctuation.
West Indies 2006 - 2006 30 - 60 1991 - 2001 Increasing WPE5

  • References
  • Peterjohn, Bruce, in litt., April 2002.
  • Unpublished information supplied by Wetlands International Specialist Groups, 2006.
  • Notes
  • Population added in WPE3.
  • Colonised in early 1990s, (529). 10-20 pairs (30-60 individuals). See 336.
South Asia 100,000 - 200,000 Unknown WPE5

  • References
  • Asian Waterbird Census unpublished data. 2002.
  • Notes
  • 20: 48,000 counted in 2002.
E, SE Asia 2001 - 2001 100,000 - 1,000,000 1981 - 1991 Stable WPE5

  • References
  • Chan, Simba, In litt,. 2002. Unpublished information on Asian waterbirds.
nigripes 1987 - 1991 25,000 - 1,000,000 Unknown WPE5

  • References
  • Perennou, C.P., Mundkur, T. and Scott, D.A. 1994. The Asian Waterfowl Census 1987-1991: distribution and status of Asian waterfowl. IWRB Spec. Publ. No. 24; AWB Spec. Publ. No. 86. Slimbridge, UK and Kuala Lumpur, Malaysia.
immaculata 2002 - 2004 25,000 - 100,000 Unknown WPE5

  • References
  • Bishop, K.D. 2003. A Review of the Avifauna of the TransFly Eco-region: the status, distribution, habitats and conservation of the region?s birds. Report to WWF South Pacific Program.
  • Jaensch, Roger, August 2005. Detailed data and notes on numbers and distribution of waterbirds in Australia, updated from Jaensch, 2003, and derived from more than 90 Australian sources including Wetlands International, Birds Australia and Jaensch, 2003,
  • Notes
  • Included in nigripes by Marchant & Higgins (1990).
  • Estimate based on review of previous information and some recent information, which suggest that total numbers in Australia and S New Guinea are between 25,000 and 100,000, assuming most of the S New Guinea birds are immaculata. If immaculata and nigripes are combined as one population, estimate may be better expressed as a range of 25,000-1,000,000 in view of WPE4 data for nigripes.
Egretta gularis Western Reef-egret gularis West Africa 1991 - 2014 10,000 - 50,000 1997 - 2014 Stable/ Increasing? CSR7

  • References
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • van Roomen M., Nagy S., Foppen R., Dodman T., Citegetse G. & Ndiaye A. 2015. Status of coastal waterbird populations in the East Atlantic Flyway. With special attention to flyway populations making use of the Wadden Sea. Programme Rich Wadden Sea, Leeuwarden, The Netherlands, Sovon, Nijmegen, The Netherlands, Wetlands International, Wageningen, The Netherlands, BirdLife International, Cambridge, United Kingdom &, Common Wadden Sea Secretariat, Wilhelmshaven, Germany. URL: http://www.waddensea-secretariat.org/sites/default/files/downloads/status_coastal_birds_eaf_2014_1.pdf
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • This form and schistacea sometimes treated as separate species, Western Reef Heron.Sometimes assigned to Egretta garzetta.
  • Review of more recent data, including 2013 and 2014 counts
  • Van Roomen et al (2015) found increasing trend based on the IWC data. Wetlands International (2017) found that the long-term trend is stable/fluctuating, the short-term is uncertain. Wetlands International's assessment agrees well with Dodman (2014).
schistacea North-east Africa & Red Sea 1937 - 2011 10,000 - 15,000 2014 - 2014 Declining/ Stable CSR7

  • References
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Nagy, S., Alanazi, F., Almomen, A. Alsuhaibani, A, AlRashidi, M., Dereliev, S., Keijl, G. Ruiters, P. & Shobrak, M. 2014. Winter waterbird survey in the Kingdom of Saudi Arabia in January 2014. Wetlands International, Ede, The Netherlands.
  • Sheldon, R. 2017. Estimates of breeding waterbird populations in Central/SW Asia, The Caucasus and the Arabian Peninsula.
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • Sometimes assigned to Egretta garzetta schistacea.
  • See CSR6 and Sheldon (2017).
  • Dodman (2014) assumed that the population is stable in the absence of human impacts along the Red Sea coast. Reviewing of available IWC data and the formal trend analysis suggest that a steep decline might have taken place between 1990 and 2015 (Wetlands International 2017). This is probably driven by destruction of coastal wetlands and mangroves particularly along the northern coast of the Red Sea (Nagy et al. 2014).
South-west Asia & South Asia 1990 - 2012 10,000 - 25,000 2006 - 2015 Stable? CSR7

  • References
  • Sheldon, R. 2017. Estimates of breeding waterbird populations in Central/SW Asia, The Caucasus and the Arabian Peninsula.
  • Wetlands International (2017) Flyway trend analyses based on data from the African-Eurasian Waterbird Census from the period of 1967-2015. Ede, The Netherlands: Wetlands International. URL: http://iwc.wetlands.org/index.php/aewatrends
  • Notes
  • Sometimes assigned to Egretta garzetta schistacea. Sometimes assigned to asha.
  • See CSR6 and Sheldon (2017).
  • The short-term trend is uncertain but apparently stable.The long-term one is strong increase.
dimorpha Madagascar 6,000 - 20,000 Declining WPE5

  • References
  • Hawkins, F. In litt. 2002. Unpublished notes on waterbird population estimates of Madagascar.
Aldabra & Amirante Is 3,000 - 9,000 1991 - 2001 Stable WPE5

  • References
  • Dodman, T. 2002. Waterbird Population Estimates in Africa. Unpublished report to Wetlands International.
  • Rocamora, G. and Skerrett, A. 2001. Seychelles. Pp 751-768. In L.D.C. Fishpool and M.I. Evans, eds. Important Bird Areas in Africa and associated islands: Priority sites for conservation. Newbury and Cambridge, UK: Pisces Publications and BirdLife International
Coastal Eastern Africa 1996 - 1996 15,000 - 20,000 1991 - 2001 Stable? CSR7

  • References
  • Baker, N. (compiler). 1996. Tanzania Waterfowl Count, January 1995: The first coordinated count of the major wetlands of Tanzania. Wildlife Conservation Society of Tanzania. Dar es Salaam
  • Dodman, T. 2014. Status, Estimates and Trends of Waterbird Populations in Africa: AEWA-listed African populations. Wetlands International. (CSR6 African populations) URL: https://www.wetlands.org/publications/1304/
  • Notes
  • An earlier figure of 10,000 was erroneously used based on the same reference.
  • No monitoring data is available. Trend assessment is based on circumstantial evidence.
Egretta sacra Pacific Reef-egret sacra 2006 - 2006 100,000 - 1,000,000 1985 - 2005 Stable? WPE5

  • References
  • Unpublished information supplied by Wetlands International Specialist Groups, 2006.
  • Notes
  • Regarded as 'rapidly declining and very rare' in China (125).
  • Regarded as 'rapidly declining and very rare' in China (125).
albolineata 1,000 - 2,000 1990 - 2000 Stable WPE5

  • References
  • Barr?, N. and Dutson, G. 2000. Oiseaux de Nouvelle-Caledonie. Liste commentee. Suppl. Alauda (68), 3: 49pp.
  • Notes
  • Population added in WPE3.
Egretta eulophotes Chinese Egret E, SE Asia 2000 - 2010 3,000 - 4,100 Stable WPE5

  • References
  • BirdLife International 2001. Threatened Bird of Asia: the BirdLife International Red Data Book. Cambridge, UK. BirdLife International
  • Zhiying, D. 2009. The Chinese Egret, Feathers of snow in the summer sky. Chinese National Geography Vol. 1, Issue 2. Bulletin of Academy of Science Pyeongyang.
  • Notes
  • Hwang (2011) estimates 1,000-1,600 breeding individuals in South Korea from 2000 to 2010, 1,000-1,200 (Collar 2001) or 1,200-1,500 (BASP 2004) in DPRK, and 1,000 birds in China (Zhiying 2009).

Heron Red List

Heron Red List

The Heron Red List as of 2020 is shown below.

This authority for the global classification of the conservation status of species is the IUCN. It is published periodically as the IUCN Red List of Threatened Species. BirdLife International is the listing authority for birds. HeronConservation partners with BirdLife International on its periodic assessments for herons. The Heron Red List is the same as the IUCN list. Like all species, herons may be classified the following categories, LC = Least Concern, NT = Near Threatened, VU = Vulnerable, EN = Endangered, CR = Critically Endangered, EW = Extinct in the Wild, and EX =Extinct. More information on the meaning of these categories may be found in the IUCN Red List Categories & Criteria document.

The IUCN process is conducted at the species level, whereas HeronConservation does its assessments at a population level. So for some species the classification of a species may differ from that of one or more of its populations. For information on the listing assessment process, please see the IUCN Website.

The IUCN Assessment in some cases identifies species, uses a listing order, and uses scientific and English names that are at times deviant from those used by HeronConservation. There are a number of reasons for these differences, mainly that HeronConservation, being concerned only with one group of species can tracks and implement changes within its group more readily, whereas IUCN needs to maintain a more conservative approach to such changes across its periodic assessments and needs to maintain a common global process. As there is not a problem in identifying which species is being referred to, HeronConservation has chosen to retain the IUCN order and names to maintain its consistency with the Global Red List.

HeronConservation will continue to partner with BirdLife in its evaluation of the status of heron species. You are welcome to participate in this process by communicating your data and information to the HeronConservation Co-chairs or Steering Committee Members.

Status Trend Scientific Name English Name
EX Ixobrychus novaezelandiae New Zealand Little Bittern
Nycticorax duboisi Reunion Night-heron
Nycticorax mauritianus Mauritius Night-heron
Nycticorax megacephalus Rodrigues Night-heron
Nyctanassa carcinocatactes Bermuda Night-heron
CR Decreasing Ardea insignis White-bellied Heron
EN Decreasing Botaurus poiciloptilus Australasian Bittern
Gorsachius magnificus White-eared Night-heron
Gorsachius goisagi Japanese Night-heron
Ardeola idae Madagascar Pond-heron
Ardea humbloti Madagascar Heron
VU Decreasing Egretta vinaceigula Slaty Egret
Egretta eulophotes Chinese Egret
Unknown Agamia agami Agami Heron
NT Increasing Egretta rufescens Reddish Egret
Decreasing Zonerodius heliosylus Forest Bittern
Zebrilus undulatus Zigzag Heron
LC Increasing Bubulcus ibis Cattle Egret
Ardea herodias Great Blue Heron
Ardea cocoi Cocoi Heron
Ardea melanocephala Black-headed Heron
Egretta thula Snowy Egret
Egretta garzetta Little Egret
Stable Ixobrychus involucris Stripe-backed Bittern
Ixobrychus exilis Least Bittern
Ixobrychus cinnamomeus Cinnamon Bittern
Nycticorax caledonicus Rufous Night-heron
Nyctanassa violacea Yellow-crowned Night-heron
Ardeola bacchus Chinese Pond-heron
Ardea pacifica White-necked Heron
Ardea goliath Goliath Heron
Egretta picata Pied Heron
Egretta ardesiaca Black Heron
Egretta tricolor Tricolored Heron
Egretta gularis Western Reef-egret
Egretta sacra Pacific Reef-egret
Decreasing Tigriornis leucolopha White-crested Tiger-heron
Tigrisoma mexicanum Bare-throated Tiger-heron
Cochlearius cochlearius Boat-billed Heron
Botaurus stellaris Eurasian Bittern
Botaurus lentiginosus American Bittern
Ixobrychus minutus Common Little Bittern
Ixobrychus dubius Australian Little Bittern
Ixobrychus eurhythmus Schrenck's Bittern
Ixobrychus flavicollis Black Bittern
Calherodius leuconotus White-backed Night-heron
Nycticorax nycticorax Black-crowned Night-heron
Butorides striata Green-backed Heron
Ardea sumatrana Great-billed Heron
Ardea purpurea Purple Heron
Ardea intermedia Intermediate Egret
Ardea brachyrhyncha Yellow-billed Egret
Ardea plumifera Plumed Egret
Egretta caerulea Little Blue Heron
Unknown Tigrisoma lineatum Rufescent Tiger-heron
Tigrisoma fasciatum Fasciated Tiger-heron
Botaurus pinnatus Pinnated Bittern
Ixobrychus sinensis Yellow Bittern
Ixobrychus sturmii Dwarf Bittern
Gorsachius melanolophus Malay Night-heron
Ardeola ralloides Squacco Heron
Ardeola grayii Indian Pond-heron
Ardeola speciosa Javan Pond-heron
Ardeola rufiventris Rufous-bellied Heron
Ardea cinerea Grey Heron
Ardea alba Great White Egret
Pilherodius pileatus Capped Heron
Syrigma sibilatrix Whistling Heron
Egretta novaehollandiae White-faced Heron

List of Herons (IOC list ver. 10.1)

List of the Herons of the World (IOC List ver. 10.2, in 2020)

The following is a list of the herons of the world based on IOC World Bird List, Version 10.2 (July 25, 2020).

Scientific Name English Name Breeding Range (Non-breeding Range in parentheses)
Zonerodius heliosylus Forest Bittern AU: New Guinea
Tigriornis leucolopha White-crested Tiger Heron AF: Senegal to Central African Republic and DR Congo
Tigrisoma lineatum

  • T. l. lineatum Honduras south to ne Bolivia and Amazonian Brazil
  • T. l. marmoratum se Bolivia to s Brazil and n Argentina
Rufescent Tiger Heron MA, SA: widespread
Tigrisoma fasciatum

  • T. f. salmoni Costa Rica to n Bolivia
  • T. f. fasciatum se Brazil to n Argentina
  • T. f. pallescens nw Argentina
Fasciated Tiger Heron MA, SA: Costa Rica to n Bolivia, se SA
Tigrisoma mexicanum Bare-throated Tiger Heron MA, SA: Mexico to Colombia
Agamia agami Agami Heron MA, SA: e Mexico to Amazonia
Cochlearius cochlearius

  • C. c. zeledoni w Mexico
  • C. c. phillipsi e Mexico, Belize
  • C. c. ridgwayi s Mexico to Honduras
  • C. c. panamensis Costa Rica and Panama
  • C. c. cochlearius n and c South America
Boat-billed Heron MA, SA: wc Mexico to ne Argentina
Zebrilus undulatus Zigzag Heron SA: Amazonia
Botaurus stellaris

  • B. s. stellaris Europe to e Asia (Non-bre: n and c Africa, s Asia)
  • B. s. capensis southern Africa
Eurasian Bittern EU: widespread (Non-bre: AF, n OR)
Botaurus poiciloptilus Australasian Bittern AU: sw, se Australia, New Zealand
Botaurus lentiginosus American Bittern NA: widespread (Non-bre: MA, Caribbean)
Botaurus pinnatus

  • B. p. caribaeus se Mexico, Belize
  • B. p. pinnatus El Salvador and Nicaragua to n Argentina and s Brazil
Pinnated Bittern MA, SA: e Mexico to ne Argentina
Ixobrychus involucris Stripe-backed Bittern SA: Colombia to Suriname, s Bolivia and s Brazil to c Chile and c Argentina
Ixobrychus exilis

  • I. e. exilis e Canada, e and sw USA (Non-bre: Central America, West Indies)
  • I. e. pullus nw Mexico
  • I. e. erythromelas e Panama and n South America to n Bolivia and n Argentina
  • I. e. limoncochae e Ecuador
  • I. e. bogotensis c Colombia
  • I. e. peruvianus wc Peru
Least Bittern NA, MA, SA: e, sw USA to se Brazil
Ixobrychus minutus

  • I. m. minutus c and s Europe to c Asia and nw India (Non-bre: Africa)
  • I. m. payesii Africa south of the Sahara
  • I. m. podiceps Madagascar
Little Bittern EU, AF: s, c Europe to c Asia, nw India, Africa
Ixobrychus dubius Black-backed Bittern AU: e, sw Australia
Ixobrychus novaezelandiae extinct New Zealand Bittern AU: South I., New Zealand
Ixobrychus sinensis Yellow Bittern OR: widespread, also e Asia (Non-bre: AU)
Ixobrychus eurhythmus Von Schrenck's Bittern EU: se Siberia, Korea, Japan and e China (Non-bre: se Asia to the Sundas and Philippines)
Ixobrychus cinnamomeus Cinnamon Bittern OR: widespread, also e Asia
Ixobrychus sturmii Dwarf Bittern AF: widespread
Ixobrychus flavicollis

  • I. f. flavicollis India to Indochina, the Philippines, w and c Indonesia
  • I. f. australis e Indonesia, New Guinea, Bismarck Arch., Australia
  • I. f. woodfordi Solomon Is.
Black Bittern OR, AU: widespread
Gorsachius magnificus White-eared Night Heron OR: s, e China, n Vietnam
Gorsachius goisagi Japanese Night Heron EU: Japan (Non-bre: se China, Philippines)
Gorsachius melanolophus Malayan Night Heron OR: widespread
Gorsachius leuconotus White-backed Night Heron AF: widespread
Nycticorax nycticorax

  • N. n. nycticorax Eurasia s to Indonesia and Africa
  • N. n. hoactli s Canada to n Argentina and Chile, Hawaii
  • N. n. obscurus Chile, sw Argentina
  • N. n. falklandicus Falkland Is.
Black-crowned Night Heron Worldwide: except AU
Nycticorax olsoni extinct Ascension Night Heron AO: Ascension I.
Nycticorax duboisi extinct Reunion Night Heron IO: La Réunion
Nycticorax mauritianus extinct Mauritius Night Heron IO: Mauritius I.
Nycticorax megacephalus extinct Rodrigues Night Heron IO: Rodrigues I.
Nycticorax caledonicus

  • N. c. crassirostris extinct Bonin I. (Japan)
  • N. c. manillensis Philippines, n Borneo
  • N. c. australasiae Java east to New Guinea, Australia and New Zealand
  • N. c. pelewensis Palau and Caroline Is. (wc Pacific)
  • N. c. caledonicus New Caledonia
  • N. c. mandibularis Bismarck Arch. and Solomon Is.
Nankeen Night Heron AU: widespread
Nyctanassa violacea

  • N. v. violacea c and e USA to e Mexico and e Costa Rica
  • N. v. bancrofti w Mexico to w Nicaragua, Socorro I., West Indies
  • N. v. caliginis Panama and w Colombia to Peru
  • N. v. cayennensis Panama and ne Colombia to ne Brazil
  • N. v. pauper Galápagos Is.
Yellow-crowned Night Heron NA, MA, SA: e USA to Peru and e Brazil
Nyctanassa carcinocatactes extinct Bermuda Night Heron AO: Bermuda
Butorides virescens

  • B. v. anthonyi w USA, n Baja California (Mexico)
  • B. v. frazari s Baja California (Mexico)
  • B. v. virescens c and e USA and e Canada to Panama and the Caribbean
  • B. v. bahamensis Bahama Is.
Green Heron NA, MA: e and c USA to Panama
Butorides sundevalli Lava Heron SA: Galápagos Islands
Butorides striata

  • B. s. striata e Panama to n Argentina, Bolivia and Chile
  • B. s. atricapilla Africa south of the Sahara
  • B. s. brevipes Somalia and the Red Sea coasts
  • B. s. rutenbergi Madagascar, La Réunion
  • B. s. rhizophorae Comoros
  • B. s. crawfordi Aldabra Is. and Amirante Is.
  • B. s. degens Seychelles
  • B. s. albolimbata Chagos Arch. and Maldive Is.
  • B. s. spodiogaster Andaman Is., Nicobar Is. and islands off w Sumatra
  • B. s. amurensis se Siberia, ne China and Japan
  • B. s. actophila e China to n Myanmar and n Vietnam
  • B. s. javanica Pakistan, India and Sri Lanka to Thailand, the Philippines, the Greater Sundas and Sulawesi
  • B. s. steini Lesser Sundas
  • B. s. moluccarum Moluccas
  • B. s. papuensis nw New Guinea
  • B. s. idenburgi n New Guinea
  • B. s. flyensis sc, se New Guinea
  • B. s. macrorhyncha e and ne Australia, New Caledonia
  • B. s. patruelis Tahiti Is. (Society Is.)
  • B. s. solomonensis New Hanover to Solomons to Fiji
Striated Heron SA, EU, AF, AU: widespread
Ardeola ralloides Squacco Heron EU, AF: widespread
Ardeola grayii Indian Pond Heron EU, OR: Persian Gulf to Myanmar, Maldive Islands
Ardeola bacchus Chinese Pond Heron OR: widespread in the east
Ardeola speciosa

  • A. s. continentalis c Thailand through s Indochina
  • A. s. speciosa w and c Indonesia
Javan Pond Heron OR: se
Ardeola idae Malagasy Pond Heron AF: Madagascar, Aldabra Island (Non-bre: c, e AF)
Ardeola rufiventris Rufous-bellied Heron AF: Uganda and s Kenya to s Angola, n Botswana and e South Africa
Bubulcus ibis Western Cattle Egret EU, AF, NA, MA, SA: s Europe to Iran, Africa, Indian Ocean Is., North and Latin America
Bubulcus coromandus Eastern Cattle Egret OR: s, e Asia, Australasia
Ardea cinerea

  • A. c. cinerea w Europe to e Asia to India and Africa
  • A. c. jouyi n China, Korea and Japan to Sumatra and Java
  • A. c. monicae Banc d'Arguin (Mauritania)
  • A. c. firasa Madagascar, Comoros and Aldabra
Grey Heron EU, AF, OR: widespread
Ardea herodias

  • A. h. fannini nw North America
  • A. h. wardi w, sc, s USA to n Florida and w, ne Mexico
  • A. h. herodias s Canada to nc, e USA south to the n Carolinas
  • A. h. occidentalis s Florida (USA) through the West Indies
  • A. h. cognata Galápagos Is.
Great Blue Heron NA, MA: widespread
Ardea cocoi Cocoi Heron SA: widespread
Ardea pacifica White-necked Heron AU: Australia, s New Guinea
Ardea melanocephala Black-headed Heron AF: widespread south of the Sahara
Ardea humbloti Humblot's Heron AF: Madagascar
Ardea insignis White-bellied Heron OR: e Himalayas
Ardea sumatrana Great-billed Heron OR, AU: Southeast Asia to n Australia
Ardea goliath Goliath Heron AF, EU: widespread in Africa south of the Sahara, Iran and Iraq to India
Ardea purpurea

  • A. p. purpurea s and c Europe to c Asia and the Middle east, Africa south of the Sahara
  • A. p. bournei Cape Verde Is.
  • A. p. madagascariensis Madagascar
  • A. p. manilensis s and e Asia to the Philippines and Indonesia
Purple Heron EU, OR, AF: widespread
Ardea alba

  • A. a. alba c Europe to ne Asia south to n and c Africa and s Asia
  • A. a. melanorhynchos Africa south of the Sahara
  • A. a. egretta s Canada to s Argentina and s Chile
  • A. a. modesta s, e Asia to Indonesia and Australasia
Great Egret NA, SA, AF, EU, OR, AU: Worldwide
Ardea intermedia

  • A. i. brachyrhyncha Africa south of the Sahara
  • A. i. intermedia Japan to s India and Greater Sundas
  • A. i. plumifera e Indonesia, New Guinea, Australia
Intermediate Egret OR, AF, AU: widespread
Pilherodius pileatus Capped Heron MA, SA: e Panama to se Brazil
Syrigma sibilatrix

  • S. s. fostersmithi ne Colombia, nw Venezuela
  • S. s. sibilatrix e Bolivia and s Brazil to ne Argentina
Whistling Heron SA: n, sc, se
Egretta picata Pied Heron AU: Sulawesi to n Australia
Egretta novaehollandiae White-faced Heron AU: widespread
Egretta rufescens

  • E. r. rufescens s USA, West Indies, Mexico
  • E. r. dickeyi Baja California (Mexico)
Reddish Egret NA, MA: s USA, Caribbean
Egretta ardesiaca Black Heron AF: widespread south of the Sahara
Egretta vinaceigula Slaty Egret AF: Zambia to ne Namibia, n Botswana and w Zimbabwe
Egretta tricolor

  • E. t. ruficollis e and se USA and e, w Mexico to nw South America, West Indies
  • E. t. tricolor nc and ne South America
Tricolored Heron NA, MA, SA: se USA to n SA
Egretta caerulea Little Blue Heron NA, MA, SA: se USA to s Brazil
Egretta thula

  • E. t. brewsteri w North America
  • E. t. thula e and s North America to c Chile and n Argentina
Snowy Egret NA, MA, SA: widespread
Egretta garzetta

  • E. g. garzetta Europe to Japan south to Africa, India and the Philippines
  • E. g. nigripes Sundas to Australia and New Zealand
Little Egret EU, AF, OR, AU: widespread
Egretta gularis

  • E. g. gularis coastal w Africa
  • E. g. schistacea coastal ne Africa to w India, Sri Lanka
Western Reef Heron AF, EU, OR: w AF, ne AF to w India, Sri Lanka
Egretta dimorpha Dimorphic Egret AF: e, Madagascar
Egretta sacra

  • E. s. sacra coastal se Asia to Australia, Oceania
  • E. s. albolineata New Caledonia, Loyalty Is.
Pacific Reef Heron OR, AU: Southeast Asia to New Zealand
Egretta eulophotes Chinese Egret EU: e Asia (Non-bre: se OR)

Abstracts

The 1st Herons of the World Symposium (2016)
in New Bern, North Carolina, U.S.A.

Alphabetical list of abstracts for presentations

Bolded names are the presenters
——— Oral Presentation ———

Patterns of annual habitat utilization, spatial distribution, and migration by Great Egrets (Ardea alba)

Allen, Michael. C.1; Brzorad, John2; Elbin, Susan3; Kays, Roland4; Maccarone, Alan5; Schweitzer, Sara6; Tsipoura, Nellie1
1 New Jersey Audubon, Bernardsville, NJ 07924, USA;
2 Lenoir-Rhyne University, Hickory, NC 28601, USA;
3 New York City Audubon Society, New York, NY 10010, USA;
4 North Carolina State University, Raleigh, NC 27695, USA;
5 Friends University, Wichita, KS 67213, USA;
6 North Carolina Wildlife Resources Commission,Raleigh, NC 27606, USA

State-of-the-art satellite GPS transmitters (48-g Bird Solar; e-obs) are providingunprecedented details regarding movements and habitat utilization for birds heavier than 1 kg. We present current information on habitat utilization and the spatial distributions of 13 Great Egrets (Ardea alba) captured in various locations from 2013 to 2015. Nearly 560,000 GPS points were used to quantify the size of areas used by birds during 3694 observation-days by using LoCoH program in the R platform. The habitat size required for breeding (n = 10 birds), particularly when young require most food, islarger than that used for the post-breeding period (n = 7) and during winter (n = 5). All major migrations occurred at night, and we present details for post-breeding (n = 9) and Spring (n = 5) migration segments. Two young-of-the-year, non-breeding birdsdisplayed both conservative and exploratory use of habitat.


Estimating the breeding population of Great Blue Herons in Maine: what's not on our colony list?

D'Auria, Danielle E.1; Otto, Mark C.2
1 Maine Department of Inland Fisheries and Wildlife, Bangor, ME 04401, USA;
2 U.S. Fish and Wildlife Service, Patuxent Research Refuge, Laurel, MD 20708, USA

The Great Blue Heron (Ardea herodias) is listed in Maine as a Species of Special Concern due to a decline in nesting pairs and colonies along the coast since the mid-1980s. In order to determine whether the decline is limited to the coast, occurring statewide, or due to movement from the coast to inland sites, an aerial survey was conducted in 2015 to obtain an estimate for the statewide breeding population. Aerial surveys had been conducted previously, but this time a stratified dual-frame design accounting for imperfect detection of colonies was used. The strata were based on habitat and known colony densities. The area frame consisted of 10 km x 10 km plots; a sample of which was searched independently by front and rear observers for both new and known colonies. The list frame consisted of plots that contained known colonies and was only searched for known colonies. Detection of active nests within colonies and colonies themselves were accounted for in the estimation. The estimates of total nests and active nests were obtained from the number of colonies multiplied by the average colony size. The estimate of total colonies for the state is 336 (range = 261-455 colonies) and the estimate of active nests is 1,800 (range = 1,631-2,159 nests). Observer detection ranged from 31 to 95 percent. The list coverage, or the percentage of colonies included in the list frame, was 67 percent but varied widely among strata. By repeating these methods at future intervals (e.g., every 5 years), we plan to obtain population trends for each strata as well as the entire state of Maine.


Conservation status of herons in Paraguay: future scenarios in face of accelerated habitat degradation

del Castillo, Hugo1; Clay, Rob2; Lesterhuis, Arne1; Yanosky, Alberto1
1 Guyra Paraguay, Parque Ecológico del Rio, BioCentro, Avda. Carlos Bóveda s/n., CC 1132, Viñas Cue, Asunción, Paraguay;
2 Director of the Western Hemisphere Shorebird Reserve Network (WHSRN)

Paraguay’s five major ecoregions hold a total of 14 heron species. Currently, no species is considered threatened at a national or international level; in fact on the contrary, most species are common to abundant. Exceptions include the Boat-billed Heron, which is scarce and locally distributed, but probably overlooked due to its nocturnal habits; andthe three species of bittern (Pinnated, Least and Stripe-backed). Knowledge of the vocalizations of the two Ixobrychus bitterns has revealed them to be more widespread and abundant than previously thought, though they are still infrequently recorded and primarily found in wetlands within the Paraguay River valley. A recent increase in Pinnated Bittern records is likely related to the expansion of rice fields, and the relative ease of observing the species in such habitat. Capped Heron is the one species with a restricted distribution, limited to the Pantanal and associated wetlands in the north of the country. Little Blue Heron is a scarce vagrant to the country, though records appear to be increasing. Cattle Egret was already widespread in Paraguay by 1977, when first recorded by ornithologists. There is increasing evidence for seasonal movements by both that species and Striated Heron. While most herons remain common and widespread throughout the country, the increasing loss of wetland habitats, and their degradation through runoff and sedimentation (driven by massive deforestation and conversion to industrial agriculture) is of concern. Although the rapid and ongoing expansion of rice agriculture in Paraguay provides important foraging habitat for at least8 heron species, their populations depend on the survival of natural wetland and woodland habitats in surrounding areas for roosting and breeding.


Development of a survey protocol for monitoring Reddish Egrets in Florida

Cox, Andrew; Schwarzer, Amy
Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, Gainesville, FL, 32601, USA

The Reddish Egret (Egretta rufescens) is North America’s rarest heron and roughly 10% of its global population resides in Florida. The rarity of the species, its localized breeding distribution and a potential negative population trend have prompted the need to monitor thisspecies. However, standard aerial surveys performed from fixed-wing aircraft often implemented for colonial nesting wading birds are ineffectual for this dark-plumaged and sub-canopy nesting species, leading some researchers to use either direct counts or flight-line surveys. During the 2015 breeding season we compared the efficacy of flight-line surveys and direct counts using data collected by multiple observers during repeated visits to colonies located in three of Florida’s core breeding areas (Tampa Bay, Florida Bay, and the lower Florida Keys). Our objectives were to 1) determine the appropriate duration of flight-line surveys, 2) estimate variation between multiple flight-line surveys performed at the same sites, and 3) estimate the correlation between flight-line surveys and direct counts. Average variation between counts was high for a 1-hr flight line survey (60%), but more acceptable for 2-hr (20%) or 3-hr (16%) surveys. Flight-line surveys often produced abundance estimates that were biased high when compared to direct counts, likely because nest exchanges occurred >1 time per survey, violating a primary assumption of the method, or because breeding sites contained interior ponds used for foraging by adult birds breeding elsewhere. Nevertheless, some breeding sites were not amenable to direct counts and others are in areas where such access is prohibited. Ultimately, variation in habitat, site access, and breeding synchrony will necessitate the use of multiple approaches when conducting a statewide survey.


Range-wide Survey of Inland Wading Bird Nest Colonies in North Carolina

Cook, K. L.1; Schweitzer S. H.1; Anderson S.1; Cameron, S. E.2; Shaiyen, M.1
1 N.C. Wildlife Resources Commission, Raleigh, NC 27606, USA;
2 U.S. Fish & Wildlife Service, Asheville, NC 28801, USA

Although fairly common in North Carolina, accurate estimates of Great Blue Heron (Ardea herodia) andGreat Egret (A. alba) abundance are poor. Since the 1970s, wading bird colony surveys have been conducted only for certain regions. From April to mid-May, 2008-2012, we completed a stratified aerial survey of all major waterways within the state breeding range. Goals were to design a repeatable survey accounting for detection probability using a double-observer method. We also wished to evaluate landscape characteristics associated with persistent and abandoned heronries to improve conservation recommendations. A total of 490 active heronries were detected ([192] Piedmont, [298] Coastal Plain), 80% of which had not been recorded previously. Heronry size was not correlated with detection probability and detection probability did not differ between observers (0.9, 95% credible interval [CI] [0.8-1.0]). Along our flight route, the Bayes estimate of total heronry abundance incorporating detection probability was 548 heronries (95% CI [535–561]). We estimated 533 heronries that included GBHE (95% CI: [520–546]) and 38 heronries with GREG (95% CI: [37–39]). Nest abundance estimates were 8,306 GBHE nests (95% CI [7,963–8,660]) and 4,963 GREG nests (95% CI [4,963–5,406]). Other species had low counts and or detectability and so are not reported.


Hydrologic fluctuations influence dailysurvival rates of small herons and Great Egrets in a subtropical littoral wetland

Essian, David A.1; Chastant, Jennifer1; May, Jenna2; Gawlik, Dale E.2
1 Biological Sciences, Florida Atlantic University, FL, USA;
2 Environmental Science Program, Florida Atlantic University, FL, USA

Subtropical freshwater wetlands in South Florida USA, support large populations of wading birds that are thought to be food-limited. The production of many wading bird prey species is controlled by hydrological variation, which is increasingly regulated by human activities through water management regimes. Thus, we expected that water management regimes on Lake Okeechobee, Florida USA would also influence wading bird reproduction. We use a model selection approach to investigate the influence of hydrological parameters on the daily nest survival rates (DSR) of wading birds. We pooled Tricolored Heron (Egretta tricolor) and Snowy Egret (Egretta thula) nests since they are indistinguishable during the incubation period. Because lake stage and water level recession rates, in particular, can be adjusted by water managers, we focused on the influence of those parameters on the DSR of Great Egrets (Ardea alba; n=298) and small herons (n=1,524). Nest survival for all species was highest when lake stage was below 4.0 m and above 3.6 m. Lake stage was the only important parameter that influenced DSR of Great Egrets, but this model was only marginally better than the null model. Water level recession rate, lake stage, and their interaction were important parameters for predicting DSR of small herons, regardless of nesting stage. These species were more sensitive to lake stage and water level recession rate than were Great Egrets. Our results suggest that water management strategies could be designed to benefit species sensitive to hydrologic constraints such as small herons without hindering the reproductive success of less sensitive species.


Current Status, ecological characteristics and conservation of Family Ardeidae in natural and disturbed forests of urban area, Korea

Eun-Jae, Lee1; Kim, In-Kyu2; Cho, Hae-Jin2; Lim, Eun-Hong2; Shin, Man-Seok3; Jung, Hwan-Do1; Lee, Jae-Geun1; Moon, Choong-Man1; Lee, Yohan4
1 Urban Planning Research Group, Daejeon Development Institute, 34863 Daejeon, Korea;
2 Korea Institute of Environmental Ecology Inc., 34014 Techno 1-ro, Yusunggu, Dajeon, Korea;
3 National Institute of Ecology, 33657,Geumgang-ro, Maseo-myeon, Seocheon-gun, Chungcheongnam-do, Korea;
4 Department of Sustainable Development, Yeungnam University, 712-749, Gyeongsan, Korea

Of 72 egret species recorded in the world, 18 species were observed in Korea. According to the nationwide census conducted by the National Institute of Environmental Research between 2011 and 2012, 35,512 breeding pairs at the 148 sites were recorded in Korea. We found 142 breeding pairs of 5 species at 3 sites in Daejeon in 2016. 10 individuals (5 gray herons, 4 great egret and 1 intermediate egret) were tagged with GPS-Mobile based Telemetry (WT 300; 35 x 63 x 14 mm, >27 g, Korea) and released. Some of them (5 gray herons, 2 great egret) were successfully tracked by now. Their home-range sizes were about 20-25 km2 (100% Minimum Convex Polygon Method, 95% Kernel Density Estimation) in breeding season. They moved down to the southern part of China and Vietnam on October 2015. As a result of analyzing potential habitats using 12 variables selected by Maxent model, 106.68 km2 (19.7%) were extracted in Daejeon, Korea. Among them, we selected Wolpyung Park as compensatory habitat, and placed 20 decoys with nests anda recorder stored breeding song on the top of trees to induce egret breeding on January 2016, but failed. More effective long-term plan should be needed to solve the conflict between residents and breeding egrets.


Dry rice paddies cause a decline of the breeding herons and egrets in Italy

Fasola, Mauro1; Imperio, Simona2; Ranghetti, Luigi3; Cardarelli, Elisa1; Boncompagni, Eleonora1
1 Dipartimento Scienze Terra Ambiente, Pavia, Italy;
2 IGG-CNR, Pisa, Italy. 3IREA-CNR, Milano, Italy

After a period of strong increase since 1980, and a peak around 2000, the breeding herons and egrets in Northwestern Italy entered a phase of decline. The population fluctuations were affected by several climatic factors, but the main cause for the increase was reduced human-induced mortality. The recent decline, however, occurred following the expanding practice of rice cultivation on dry paddies that during 2015 reached 80% of the rice surface in some areas. The dry paddies are not flooded for more than a few days, and become unsuitablefor the herons and egrets, except for the Cattle Egret, the only one of the seven species that is adapted to forage on dry lands and that is still increasing in our study area. In the paddies that remain flooded, prey availability for herons has changed dramatically due to arrival of alien species and to the decreased water level compared to the traditional practices. In the other European areas of rice cultivation, in Spain, France, and Greece, cultivation without submersion has not been adopted yet, but in Italy the new practices are undermining the value of rice cultivation for waterbirds. The monitoring of the 200 heronries in our study area, now in its 45th year, is continued thanks to a group of 100+ volunteer collaborators.


Representing hydrologic variability in heron models: key processes for wetland ecosystem management

Gawlik, Dale E.
Environmental Science Program, Florida Atlantic University, Boca Raton, FL 33431, USA

The response of herons and other wading birds to hydrologic variability has been studied for over 50 years in the Florida Everglades (USA) and globally. Collectively, these studies illustrate a variety of mechanisms through which hydrologic variability affects nesting and foraging, and how this variability can be represented in ecological models that have application to wetland restoration and management. In wetlands with a pronounced seasonal water cycle, herons and other wading birds often initiate nesting when water levels are dropping and aquatic animals are concentrated into shallow water. The success of nesting is dependent on the rate of receding water being at an optimal level, with rates above andbelow the optimum causing lower nest survival. When water levels stop receding and rise suddenly due to rain or inflows, birds will abandon their nests. This pattern contrasts with that of floodplain wetlands where wading birds often initiative nesting when water levels are rising and prey are dispersing rather than being concentrated. Juvenile aquatic animals disperse out of river channels to the floodplain where they experience a rapid growth rate leading to an increase in prey biomass for birds. The parameters hydroperiod and minimum water level affect the production of prey populations, establishing the upper limit to subsequent foraging conditions, with the actual value being lowered by the degree to which deep water levels restrict access to prey by birds. The range in water level fluctuations defines the spatial extent of habitat that becomes suitable for foraging. In floodplain systems this variable is often the primary determinant of numbers of nests.


Characterization of Ardeid assemblages on the southern coast of Cuba

González, Alieny1; Mugica, Lourdes1; Acosta, Martín1; Aguilar, Susana2; Hernández, Noel3; Pérez, Alina4; de la Cruz, José M.5; Hernández, Zaimiuri6; Castro, Rodolfo7; Navarro, Dunia8; Inguanzo, Raúl8; Rodríguez, Alberto9; Labrada, Omar10; López, Manuel11
1 Facultad de Biología, Universidad de La Habana;
2 Centro Nacional de Áreas Protegidas;
3 Empresa para la Protección de la Flora y Fauna, Reserva Ecológica “Los Pretiles”;
4 Centro de Investigación y Servicios Ambientales, ECOVIDA;
5 Museo de Historia Natural “Tranquilino Zandalio de Noda”;
6 Empresa para la Protección de la Flora y Fauna, Refugiode Fauna “Punta Caribe”;
7 Instituto Nacional de Ciencias Agrícolas “Los Palacios”;
8 Empresa para la Protección de la Flora y Fauna, Refugio de Fauna “Canales del Hanábana”;
9 Empresa para la Protección de la Flora y Fauna, Refugio de Fauna “Tunas de Zaza”;
10 Empresa para la Protección de la Flora y Fauna, Refugio de Fauna “Delta del Cauto, Granma”;
11 Empresa para la Protección de la Flora y Fauna, Refugio de Fauna “Delta de Cauto, Las Tunas”, Cuba

Cuba has 12 species of herons distributed throughout the national territory, with exception of American Bittern, all breeding in Cuba and has migrant populations from North America. The group is well represented in natural and anthropic wetlands, however little has been published about their status and distribution. In this work weevaluated the ardeidos assembly in nine Cuban natural wetlands distributed along the southerncoast of Cuba from May 2011 to March 2013,and one ricefield between 1992 and 1995. Of the 12 species represented in the archipelago, nine were presentin 100% of observations in nine of the wetlands studied. Here were included all representatives of genusEgrettain Cuba. The highest values of abundance were recorded in Los Palacios (1,188 individuals); Delta del Cauto (958 individuals) and Canales Hanábana (924 individuals). In more than 50% of the sites Snowy Egret, Little Blue Heron, Tricolored Heron and Great Egret were identified as the most abundant species. In Punta Caribe and Tunas de Zaza, the highest values of abundance were recorded in the period of Permanent Residence (May-June), while in Los Palacios y Monte Cabaniguán was during the fall migration (October-November). In the remaining sites these higher abundance values were reported during the spring migration (February-March). Meanwhile, in the ricefield 12 species of herons were identified. Of these, the most abundant were Cattle Egret, Snowy Egret, Little Blue Heron and Great Egret. In general,the results support the importance of natural and anthrogenic wetlands in Cuba for ardeidos.


Clinal variations in dark morph proportion of Reddish Egret (Egretta rufescens) in Cuba

González, Alieny1; Jiménez, Ariam1; Acosta, Martín1; Mugica, Lourdes1; García-Lau, Ianela2
1 Departamento Biología Animal y Humana, Facultad de Biología, Universidad de La Habana;
2 Museo de Historia Natural Felipe Poey, Facultad de Biología, Universidad de La Habana, Cuba

The Reddish Egret presents a polymorphic plumage that is independent of age and sex. According to information from the ratio of dark morph in some areas of its range, the species appears to exhibit a cline variation, with dark individuals predominating in the most western populations (e.g., Baja California, ~100% dark morph), while the eastern populations contain a small proportion of these (e.g., Great Inagua, ~12% dark morph). An analysis of the proportion of dark individuals over 20 Cuban wetlands revealed a consistent pattern of geographic variation with apparent cline described in the global distribution of the species. In turn, the proportion of dark individuals was higher in the N coast than in the S, but in both cases the probability of observing a dark individual decreased with distance from the western end of Cuba (cline west-east, coast N: 92 50%, S coast: 80-9%). A case study in three wetlands of the south coast distributed throughout Cuba confirm the results found for this coast. The study included systematically sampled in these wetlands for two years.


A decade of Reddish Egret research: looking back and moving forward

Green, M. Clay1; Ballard, Bart M.2
1 Department of Biology, Texas State University, San Marcos, Texas 78666, USA;
2 Caesar Kleberg Wildlife Research Institute, Texas A&M University-Kingsville, Kingsville, Texas 78363, USA

In 2006, the US Fish and Wildlife Service published a species status report for the Reddish Egret (Egretta rufescens), the first status review of the species in 15 years. From that report, it was evident that knowledge gaps on the ecology and limitingfactors of the species remained. Since 2006, we have conducted research in Texas and various parts of the species’ range on 1) movement ecology, 2) nesting and foraging ecology, 3) juvenile and adult survival and 4) genetic differentiation and gene flow. Juvenile Reddish Egrets exhibit nomadic behavior during post-fledging dispersal before showing little movement during first winter and subsequent breeding season, whereas roughly 60% of adult Reddish Egrets nesting in Texas exhibit migratory behavior overwintering in Mexico and as far south as El Salvador. While annual survival of adult birds is high, survival of juvenile Reddish Egrets is low (~25%) and potentially as low as 10% during first 3-6 months post hatch. Low juvenile survival is in contrast to high nesting survival (~80-90%) from incubation through 4-5 weeks post hatch. Within Texas, we found little genetic differentiation (mtDNA and microsatellites) geographically or between color morphs. Across the range, we found significant differentiation along a longitudinal gradient with genetically isolated population centers in Baja California, Chiapas and Bahamas. Populations in Louisiana, Texas, eastern Mexico and Florida appear to be transitional between the extremes of Baja and Bahamas. Our research fills many information gaps for this little studied species, provides important implications for future research, and informs resource managers for more directed and impactful conservation for the Reddish Egret.


HeronryMAP:Africa — mapping the distribution and status of ardeid (and other waterbird) breeding colonies in Africa

Harebottle, Doug M.
School of Natural and Applied Sciences, Sol Plaatje University, Kimberley, South Africa

Colonial breeding waterbirds are spread across seven bird families — Laridae, Phalacrocoracidae, Ardeidae, Phoenicopteridae, Threskiornithidae, Pelecanidae and Ciconidae. Due to their conspicuous behavior and often socio-economic and ecological impacts, most taxa have been well studied. In Africa, information on the status and distribution of breeding colonies in the Ardeidae is severely lacking which provides a gap in the knowledge of how important these sites are in terms of location and productivity. HeronryMAP: Africa is a citizen science initiative that aims to address this gap through the systematic collection of long-term dataon inter alia where ardeid breeding sites occur, their species composition, nest abundance and site tenureship. Preliminary results are presented from 2013, and challenges identified and discussed regarding data mobilization and sustainability. Future objectives such as the assessment of priority sites, and identification of conservation action for colonies under threat are discussed and the impact of climate and landscape changes are briefly highlighted.


Rice fields support the largest known breeding population of the endangered Australasian Bittern

Herring, Matthew W.1,2; Zander, Kerstin K.2; Garnett, Stephen T.2
1 Bitterns in Rice Project, Leeton, NSW 2705, Australia;
2 Charles Darwin University, Darwin, NT 0909, Australia

The Australasian Bittern (Botaurus poiciloptilus) is a poorly known, globally endangered species with a total population of just 1,000-2,499 mature individuals. The Riverina region of New South Wales is recognised as a stronghold. It supports around 95% of Australia’s rice production, which constitutes approximately 100,000 hectares in years of 100% water allocation. Despite this, little was known about the Australasian Bittern population found in these rice fields. From 2012-2016, standardised surveys of rice crops on randomly selected farms in two of the three main rice-growing areas wereused to estimate the population size and determine the extent of breeding. Occupancy at the 23-30 hectare sites ranged 0.23-0.29, depending on the year and region. Most observations were of one or two birds, but up to four were recorded during a single survey. Habitat occupancy modelling, accounting for the unsurveyed third region and substantial detectability issues, suggests that in most years these rice fields attract approximately 500-1,000 mature individuals. This represents around 43% of the estimatedglobal population. Nests found at the randomly selected farms indicate widespread breeding and observations of fledged young confirm that some nests succeed before harvest. The results highlight the overlooked conservation role of agricultural wetlands inAustralia and the potential for dual-purpose water use. Bitterns showed a strong preference for more traditional rice growing methods of aerial sowing with early inundation, as opposed to direct-drill sowing with delayed inundation. However, driven by water savings, an increasing number of rice growers are altering their sowing methods and water management. Development of bittern friendly rice growing incentives will be discussed.


Impacts of a road construction on water bird populations and first regional rehabilitation actions at Asunción Bay Ecological Reserve (Paraguay)

Lesterhuis, Arne; Yanosky, Alberto; Zárate, Rodrigo
Guyra Paraguay, Parque Ecológico del Rio, BioCentro, Avda. Carlos Bóveda s/n., CC 1132, Viñas Cue, Asunción, Paraguay

The Asunción Bay, is a relatively small bay (c.600 ha in total) located along the northern outskirts of Asunción, the capital of Paraguay. Although a relatively small area, more than 290 species of birds have been recorded in the bay, including 89 waterbird. Families represented by most species include Scolopacidae (18 species), Anatidae (15 species), Rallidae (13 species) and Ardeidae (11 species). 34 of the recorded waterbirds are migratory species, including 21 Nearctic migrants and 13 Austral migrants. Due to its importance for migrants in particular, the bay has been designated as an IBA and WHSRN site, and in 2005 was declared as an Ecological Reserve. The recent development of a coastal road has presented important opportunities for the urban population of Asunción to reconnect with its natural heritage, but unfortunately dredging to create the embankment for this road in 2010 destroyed about 70% of the habitat in the bay. The disappearance of muddy beaches on the bay caused drastic reductions of the total number of Nearctic shorebirds that regularly visited the Bay, but also caused changes in abundance and diversity of resident waterbird populations. The Municipality of Asunción and the Ministry of Public Works have been working together with Guyra Paraguay on the implementation of a series of habitat recuperation and management measure to improve remnants habitats for both waterbirds in general and shorebirds in particular.


Intraspecific and Intersexual Variation in Three Species of Wading Birds

Maccarone, Alan D.1; Brzorad, John N.2
1 Biology Department, Friends University, Wichita, Kansas, USA;
2 Reese Institute for Conservation of Natural Resources, Lenoir-Rhyne University, Hickory, North Carolina, USA

Intraspecific and intersexual morphological variation is common in many groups of birds, but few data regarding such differences exist for Ardeids. Since 2008, we have trapped long-legged wading birds in Kansas and along the East Coast for telemetry studies. Captured individuals are weighed and several measurements taken before they are released. Beginning in 2013, a blood sample was collected from each bird, which was used to determine its sex. Measurements of 103 birds of three species were used to examine relationships among mass, culmen length, and tarsus length, and to determine whether males of each species differ from females in these values. Great Blue Herons (1,702-2,859 g), Great Egrets (1,769-1,300 g), and Snowy Egrets (349-539 g) all showed high variation both in body weights and morphometric measurements. For all three species, weight was correlated significantly both with culmen and tarsus lengths, which were themselves strongly associated. For Great Egrets and Snowy Egrets, males were significantly heavier than females and also had longer culmen and tarsus lengths (all P <0.003). Sample size for Great Blue Herons was not large enough to compare male and female birds. We discuss the possible implications of intraspecific variation and sexual differences in Ardeids.


Foraging Microhabitat Selection by Long-legged Wading Birds at an Artificial Weir

Maccarone, Alan D.; Renken, Rachel C.; Thompson, Jeane A.
Biology Department, Friends University, Wichita, Kansas, USA

To better understand how wading birds select among different foraging microhabitats that show spatial heterogeneity, we divided a 100-m-long concrete weir located at the terminus of the Little Arkansas River in Wichita into 10 patches based on water depth. We observed four species of wading birds during 60 1-h periods from 12 June-28 July 2015 to document microhabitat use and feeding behavior. The independent variables collected before each session were time of day, date, water level, water clarity, and flow velocity. We documented capture efficiency, prey length (relative to bill length), and aggressive interactions for Black-crowned Night-Herons (n = 396), Great Egrets (n = 54), Snowy Egrets (n = 36), and Great Blue Herons (n = 30). Time of day and water level were the only significant predictors of weir attendance. A total 348 fish were captured, of which 108 were 3/4 bill length or greater. Wading bird species differed in capture efficiency, mean prey lengths, and the primary patch use. Great Blue Herons and Black-crowned Night-Herons captured mainly large fish (gizzard shad, catfish, and freshwater drum); Great Egrets captured both large and small fish, and Snowy Egrets captured mainly small fish (minnows). Overall aggression rate was correlated with the number of large fish captured but not with total fish, whereas the per capita aggression rate was correlated with the number of birds at the weir. Electro-fishing showed a non-uniform distribution of fish among the 10 patches. The pattern of fish spatial distribution was reflected in prey-capture patterns, where mean fish length differed significantly by patch and ranged from 2.8 cm to 11.9 cm.


Recent trends of the nesting location of Grey Herons in Hokkaido, northern Japan

Matsunaga, Katsutoshi
Hokkaido Grey Heron Research Group, 5-4-8-103, Hachiken 8-jo Higashi, Nishi-ku, Sapporo, Hokkaido 063-0868, Japan

The nesting location of Grey Herons (Ardea cinerea) in Hokkaido (83,450 km2), northern Japan was documented from 1960 to 2016. During the study period, 152 colonies were confirmed to be exist, though some of them have been already abandoned. All herons were observed to nest at trees in the inland area until the early 1990s. After the mid-1990s, however, 10 colonies were confirmed in unusual locations: an islet, flooded trees and buoys in reservoirs, and offshore rocks. These type of locations could be considered to be selected to defend their eggs and chicks against terrestrial predators by being surrounded with water area. In fact, in Hokkaido, Brown Bears (Ursus arctos) and Common Raccoons (Procyon lotor) were observed to eat chicks in conventional colonies in 1994 and 2012, respectively. Moreover, some colonies were recently established in isolated groves in towns and others adjacent to houses despite the presence of vast woodlands around. It would be another strategy to prevent bears and raccoons from approaching the colony. The number of colonies had increased, at least until 1999, and raccoons, which are alien species, have rapidly expanded their range until now. These situations would increase the encounters between herons and predators, and therefore, herons may be forced to nest in unusual locations.


The effects of colony structure and nest position on the reproductive success of small herons

May, Jenna C.; Essian, David A.; Gawlik, Dale
E. Florida Atlantic University, Boca Raton, FL 33431, USA

When food is not limiting, competition for high quality nesting sites can limit the density of breeding birds. Quality nesting sites must provide structural support for nests as well as to offer effective protection against predators and unfavorable weather. Anthropogenic influences can alter the structure and composition of vegetation available for nest sites, thereby providing birds with novel habitat. During the 2015 breeding season, we examined the effects of colony structure and nest position on the reproductive success of Tricolored Herons (Egretta tricolor) and Snowy Egrets (Egretta thula) nesting at Lake Okeechobee, Florida USA, to determine if colonies in anthropogenic habitat (spoil islands) had lower reproductive rates than colonies in natural habitat (willow, Salix sp.; islands). Daily survival rate (DSR) of nests did not differ significantly between the two colony types. The best model predicting DSR included nest height, distance to canopy, and type of substrate species (invasive or noninvasive). Apparent survival was higher for nests placed farther from the canopy edge, higher from the ground, and in noninvasive substrate. Results indicate that spoil islands are capable of providing nesting habitat comparable to natural islands in some years. However, factors that led to a lower DSR, (e.g., invasive plants and short vegetation), also tended to be more prevalent on spoil islands, so over a longer time we would expect to see differences in DSR emerge.


Diversity of waterbirds in Periyakulam Lake, Tiruchirappalli District, Tamil Nadu, Southern India

Mohanraj, Sivanantham; Pandiyan, Jeganathan
PG Research Department of Zoology and Wildlife Biology, AVC College (Autonomous), Mannampandal – 609 305, Mayiladuthuari, Tamil Nadu, India

The bird community of Periyakulam wetlands in Tiruchirapalli District, Tamil Nadu, Southern India was studied during January 2011 to December 2012. The methodology followed was mainly observations using binoculars, andthe site was done by direct count. A total of 35 species belongingto 7 orders and 18 families, including 14 resident species, 16 resident-migrant species, and 5 migrant species. Thirty species of Least Concern and 5 Near Threatened species were recorded in the area during the period. Little egret, Little Cormorant, Purple Moorhen, Purple Heron, Little Grebe, Spot billed duck, Black crowned Night Heron, Indian Pond Heron, Common coot, River tern, White breasted Kingfisher, and Whiskered Tern were the most abundant resident and migrant species foundin the Periyakulam wetlands.


Foraging strategy and prey-handling time in White-bellied heron Ardea insignis in Namdapha Tiger Reserve, Arunachal Pradesh, India

Mondal, Himadri Sekhar; Maheswaran, Gopinathan
Zoological Survey of India, M-Block, New Alipore, Kolkata-700053, West Bengal, India

The White-bellied heron (Ardea insignis) is Critically Endangered and no detailed studies have been carried out prior to ours across the species’ range. Studies on the foraging behavior and prey handling time of the heron were undertaken from November 2013 to March 2016 in Namdapha. Focal animal sampling was used to record the foraging behaviour of herons. The major fish species of the reserve were used for length (cm) and wet weight (g) estimates. The White-bellied heron is a visual forager and adapts to forage amidst fast-flowing freshwater rivers in India, especially within Namdapha. Number of foraging attempts and number of fish caught while ‘facing water current’ (FWC) and ‘against water current’ (AWC) was studied during different months in three seasons. Though the mean number of foraging attempts during FWC (Mean±SD;0.80±1.04)and AWC (0.85±1.05) did not vary significantly (t=-0.63; d.f. 558; n.s.) during three seasons, the number of fish caught did (FWC: 0.34±0.60) (AWC: 0.26±0.51; t=-2.13; d.f, 558; p<0.03). The fish eaten ranged in length from 3-60 cm (mean±SD) (12.9±6.8; n=335) in Namdapha. Fishes of 7 cm were more (11.1%) in the diet of WBH followed by 25 (9%) and 26 cm (9%). As the size of the fish increased in the diet of WBH corresponding prey-handling time also increased.


Status assessment and population trends of the Madagascar Pond Heron, Ardeola idea (Hartlaub, 1860)

Rabarisoa, Rivo1; Ramanampamonjy, Julien R.1; Razafindrajao, Felix2; De Rolland, Lily3
1 Asity Madagascar, BP 1074, Antananarivo 101, Madagascar;
2 Durrell Wildlife Conservation;
3 The Peregrine Fund

The Madagascar Pond Heron, Ardeola idea, is a migratory species breeds exclusively in Madagascar and related islands such as Europa, Aldabra, Mayotte and Comoros. Changes in the population of this species were investigated over the last 20 years through literature reviews, field monitoring and surveys undertaken from 1993 to 2016. Data from 108 localities including the seven known breeding sites were collected and analyzed for the species population assessment. The species occurs to all types of wetlands including lakes, ponds, marshes, rivers, mangroves and also rice field. During the non-breeding season, May-October, birds migrate to eastern and central Africa but some population, with 911 records, remain in Madagascar spent austral winter. Data shows that the current population is evaluated at 2,200 breeding birds remaining into its entire breeding areas. The populations are rapidly declining particularly at its main breeding sites. The main threats are the habitat destruction, collect of eggs and fledgling birds, predation and disturbance at its breeding sites.


Current status of the Madagascar Heron, Ardea humbloti (Milne-Edwards and Grandidier, 1885) in Madagascar

Rabarisoa, Rivo1; Razafindrajao, Felix2; De Rolland, Lily3
1 Asity Madagascar, BP 1074, Antananarivo 101Madagascar;
2 Durrell Wildlife Conservation.;
3 The Peregrine Fund.rivo.

The Madagascar Heron, Ardea humbloti, is endemic to Madagascar and Comoros. The species breeds in Madagascar, with recent records in Mayotte.Distribution and status of the species was investigated over the last 23 years through literature reviews and surveys undertaken from 1993 to 2016 in Madagascar. During this period, 374 records from 108 localities were collected and analyzed. Bird occurs to all type of wetlands habitat with higher concentration recorded to site along the coastal area in western Madagascar; Mangoky Ihotry wetland complex (+100 individuals), Tsiribihina River & delta (+20 individual), Manambolomaty Lakes complex (+300 individual), Baly Bay wetlands (+100 individual), and Mahavavy Kinkony wetland complex (+40 individual). The current population was evaluated at 1,470 individual breeding birds remaining into its entire distribution areas. The population is in declining. The main threats are habitat destruction, disturbance and persecution at its breeding site. Action plan for conservation are needed to preserve this species.


Morphological trade-offs and recursive plumage patterns as indicators of integrated evolutionary dynamics in the Ardeidae

Riegner, Mark F.
Environmental Studies Program, Prescott College, Prescott, AZ 86301, USA

The ultimate form an organism attains is based, in large part, on the rate and timing of developmental trajectories and on compensatory relationships between anatomical structures. For example, there is often an inverse correlation between the size of an organism’s head and the length of its legs. To determine whether a compensatory relationship exists between relative head size and leg length in Ardeidae, I measured skull dimensions (length, width, and height of cranium, and total length including bill) and skeletal limb dimensions (femur, tibiotarsus, and tarsometatarsus) of the 12 North American species as well as 10 other taxa, including the morphologically divergent Cochlearius. In addition, plumage pattern was tabulated across Ardeidae to assess whether an association exists between various patterns and specific morphological traits. My comparisons show that, in general, there is a negative association between proportionate head size and leg length. Ardea species exhibit the smallest relative head size while Cochlearius, Nycticorax, and Nyctanassa have the relatively largest heads. Similarly, Butorides and Ixobrychus have disproportionately large heads compared to leg length, but since their intracranial proportions are average for the family, the relatively large size of the head results from disproportionately short legs. I propose that the long legs of Ardea derive from hypermorphosis while the short legs of Butorides and Ixobrychus are paedomorphic features, which, in compensation, permit the feet to evolve a specialized prehensile function for grasping branches and reeds. Regarding plumage pattern, there are identifiable trends; for example, smaller species and those that forage in enclosed habitats tend toward cryptic patterns. Additionally, specific plumage patterns are not restricted to closely related taxa but recur in diverse genera across Ardeidae.


Prey Consumed by Wading Birds in Mangrove Swamps of Colombia Caribbean Coast

Ruiz-Guerra, Carlos1,2; Echeverry-Galvis, María Á.1
1 Departamento de Ecología y Territorio, Facultad de Estudios Rurales y Ambientales, Transversal 4 #42-00, piso 8 Bogotá, Colombia;
2 Asociación Calidris, Carrera 24 # 4-20, Santiago de Cali, Colombia

Understanding the diet of wading birds can act as an instrument to study relations of key ecosystems, such as mangroves. Although the diet of various species has been studied due to their tendency to regurgitate upon capture, for many species their food requirements are still unknown. In 2015, from May until December, we studied the diet composition of wading birds in the best-conserved area of mangrove swamps of Northwestern Caribbean coast of Colombia, This study encompass both non-breeding season for Little Blue Heron, Tricolored Heron and Snowy Egret and breeding season for Agami Heron, Cocoi Heron, Boat Billed Heron and Bare Throated Tiger Heron. For all species, except Little Blue Heron, fish was the most common prey, with guppies as the most common item followed by gambusia; even with in reduced samples for some egret species. Samples from Agami Heron and Bare-Throated Tiger Heron were too difficult to obtaining for both adults and nestlings, proving them still the most poorly known diet of wading birds in the area and in general in the Neotropic. Based on this information, we are assembled a trophic network to better understand the role of wading birds in mangrove areas, and how this can be affected or not due to human intervention. We found out two families of fish, Engraulidae and Poecilidae are the most vulnerable resource of the trophic network, which are used as bait by artisanal fishermen and are also preys eaten by wading birds.


Herons in Colombia; status, knowledge gaps and conservation

Ruiz-Guerra, Carlos; Estela, Felipe; Cifuentes-Sarmiento, Yanira
Asociación Calidris, Carrera 24 # 4-20, Santiago de Cali, Colombia

Colombia is host of 24 species of herons including both migrant and breeding populations. This significant diversity is due to the geographical position that includes a large number of biomes and wetlands complex in the country, such as Orinoco floodplains, Amazon forests, and Pacific and Caribbean coasts. However, few studies have focused on herons in this country and information about genera Syrigma, Tigrisoma, Agamia, Cochlearius, Ixobrychus, Botaurus and Zebrilus is scarce. The vast majority of this species inhabits on mangrove forest, swampy forest and natural grasslands that are being profoundly transformed by legal and illegal mining, urbanization, agriculture development, and infrastructure. We made and analysis of risks for herons in Colombia, crossing species distribution and national scale threads. As a result of this analysis we propose two heron species to be included in the Colombian Red List: Zig-zag heron and Agami heron.


A hop, skip and a jump: The use of long-term banding datato understand movement and survivorship of the Reddish Egret in Texas and Mexico

Rylander, Rebekah J.1; Palacios, Eduardo2; Duarte, Adam3; Green, M. Clay4
1 Aquatic Resources PhD Program, Texas State University, San Marcos, Texas, USA;
2 Centro de Investigación, Científica y de Educación Superior de Ensenada, (CICESE), Unidad La Paz, BCS, México;
3 Department of Fisheries and Wildlife, Oregon State University, Corvallis, Oregon, USA;
4 Department of Biology, Texas State University, San Marcos, Texas, USA

Understanding a species’ dispersal and movement behavior is critical when developing a conservation strategy at local and global scales. Without knowledge of the species’ life history in regards to movement patterns, it can be difficult to create an appropriate management plan across and within its range, especially if the species in question travels great distances. The Reddish Egret (Egretta rufescens, REEG) is a medium-sized heron that displays plumage-dimorphism (dark and white). Its range is along the coast of the Gulf of Mexico, Pacific coast of Mexico, as well as portions of Central American and the Caribbean islands. The primary objective of this research was to estimate survivorship of juvenile REEG through long-term color banding, as well as analyze the movement ecology of individually marked birds across Texas and Mexico. During the breeding seasons between 2006-2016, we color banded REEGs in Texas/Tamaulipas (n=628), Yucatan (n=105), Chiapas (256), and Baja California Sur (n=220). Using multi-state models, we analyzed the movement between color morphs (dark and white), sexes (when known), and the four target breeding regions mentioned above. Variation in movement measurements and juvenile dispersal behaviors was seen among individual birds and within different regions. Our results also suggest that juvenile REEG suffer from high mortality rates, which leads us to believe that this life stage is possibly a limiting factor on the growth of the population across its range. Therefore,our research targets the importance of long-term color banding, yielding to considerable insight on survivorship and movement of a species. As more band-resight data is gathered, our ongoing research of REEG will hopefully contribute to the conservation of one of North America’s rarest herons.


Response of Avian Communities to Water Management in the Floodplain Grasslands of the Mekong Delta

Senner, Paul1; Silbernagel, Janet1; Barzen, Jeb2
1 Nelson Institute for Environmental Studies, University of Wisconsin-Madison, WI 53703, USA;
2 International Crane Foundation, Baraboo, WI 53913, USA

Critically important to waterbirds, wetlands in the world’s deltas are disappearing at an alarming rate. In locations such as the Vietnamese Mekong Delta, the loss of natural wetlands is almost complete, necessitating research into the restoration and conservation of the remaining remnants. At Tram Chim National Park (TCNP), a restored floodplain grassland in the Mekong Delta, managers use water control structures to conduct season long draw-downs, mimicking the flood pattern of the Mekong River. Few publications have studied avian communities in Southeast Asian floodplain grasslands or evaluated the success of season long draw-downs in maintaining these communities. At TCNP, changes in water management coincided with two surveys of bird and plant communities, one during a period of dry-season water draw-downs (1986-1995) and another following a period where high water levels were maintained year-round (1996-2005). In the spring of 2016, we repeated these surveys to assess the status of TCNP’s floodplain grassland communities following the resumption of draw-downs in 2006. Using results from the previous surveys as a reference, we assessed species turnover and used taxonomic and functional diversity indices to compare the avian and vegetative communities present during different water management regimes. In 2016, we recorded 33 plant species and 2,241 individuals of 46 bird species. We found that grassland plant communities remained stable across all three surveys. In contrast,avian species diversity was lowest when high water levels were maintained year-round. Grassland specialists (e.g., Megalurus sp. and Anthus sp.) were most abundant in draw-down years, while Ardea sp. and Phalacrocorax sp. were more abundant with high water. As currently implemented, dry-season draw-downs are an effective management technique to maintain floodplain grassland communities at TCNP.


Distribution and Temporal Trends of Western Reef Heron (Egretta gularis) Populationsalong the Arabian Gulf Coast, United Arab Emirates

Shah, Junid N.1; Javed, Salim1; Ahmed, Shakeel1; Khan, Shahid B.1; Al Hammadi, Abdullah1; Soorae, Pritipal Singh1; Al Dhaheri, Shaikha Salem1; Durham, Sarah E.2; Green, M. Clay2
1 Terrestrial & Marine Biodiversity Sector, EAD -Abu Dhabi, Abu Dhabi, UAE;
2 Department of Biology, Texas State University, San Marcos, Texas 78666, USA

The Arabian Gulf of the United Arab Emirates contains highly productive mangrove and seagrass habitats that are essential breeding and non-breeding areas for vast numbers of waterbirds. Unfortunately, both mangroves and seagrasses are declining in this area due to anthropogenic disturbances such as pollution, development, and commercial and recreational activities. Due to their dependence on these coastal habitats, waterbirds such as the western reef heron (Egretta gularis) can act as important bioindicators of ecosystem health. The estimated global population size of E. gularisis roughly 10,000 to 100,000 individuals. While populations are considered stable, many important breeding and overwintering areas of the western reef heron remain unprotected. We performed line transect counts at fifteen sites along the Arabian GulfCoast of the U.A.E. monthly from 2006-2015. Using a mixed effects model, we found that counts varied by both month and year independently, suggesting no interaction between the two fixed factors. Our model analysis also suggested a decline in annual abundance by approximately three birds per year, but lacked statistical significance. We found significant inverse relationships between year and count at the Al Aryam and Abu Al Abyad sites, suggesting annual abundance may be decreasing in these areas. Furtherresearch and monitoring of the U.A.E. western reef heron population is recommended due to habitat loss and potential declines of the species.


From Argos to conservation: reporting 4 years of action for the Agami Heron

Stier, Anna
GEPOG Association, 15 Ave. Pasteur, 97300, Cayene, French Guiana

The Agami Heron is ranked 13th among the world’s conservation priority heron species, and 2nd for the Americas. In French Guiana, which holds the world’s largest Agami Heron colony (representing over 95% of the known population), knowledge was lacking until recently to be able to evaluate the threats on the species and develop an effective conservation plan both for French Guiana and throughout its distribution in South and Central America. To achieve this objective, GEPOG (Group for the Study and Protection of Birds in French Guiana) used the results of two years of Argos tracking of 8 individuals and built up a working group under HeronConservation (Agami Heron Working Group -AHWG), including several experts and natural protected area managers across South America and beyond. To be effective to serve conservational purposes, research results need to be set in perspective with local and regional environmental, economic, social and political conditions, before being declined in concrete and adapted actions.


Abundance and distribution patterns of two heron species in multiple agricultural landscapes of south Asia

Sundar, K. S. Gopi1,2; Kittur, Swati2
1 International Crane Foundation, Program SarusScale, E-11376, Shady Lane Road, Baraboo, WI 53913, USA;
2 Nature Conservation Foundation, Cranes and Wetlands Programme, 3076/5, 4th Cross, Gokulam Park, Mysuru 570002, India

Multi-cropped agricultural landscapes in South Asia have recently been discovered to host surprisingly high bird diversity despite a very long history of cultivation and high human density. Nuanced understanding of how herons interact with the seasonal crops and persisting wetlands is absent. Comparisons across landscapes with different levels of cultivation and human densities are also absent. We systematically collected information on seasonal abundance and distribution of two heron species, the Grey Heron Ardea cinerea and the Purple Heron Ardea purpurea, simultaneously in five agricultural landscapes in lowland Nepal and north-central India during 2014-2016. This project is part of a long-term monitoring framework developed to track the status of large waterbirds in south Asia. We also generated detailed wetland maps for each landscape to determine if abundance and distribution of the two heron species was influenced by wetland extent and position. Both heron speciesshowed: (1) significant spatial and temporal variations in both abundance and distribution in all five landscapes, and (2) considerable complexity in their associations with wetlands varying between landscapes and seasons. Agricultural landscapes showed considerable variations in their utility as heron habitat, with strong evidence of cropping patterns, agricultural intensity, and human population density influencing observed patterns. This is the first assessment carried out simultaneously in multiple landscapes and covering all three seasons for herons in agricultural landscapes. We will discuss the conservation implications of the findings, and future research needs.


Making a case for long-term monitoring of large waterbirds inagricultural landscapes: preliminary findings from south Asia

Sundar, K. S. Gopi1,2; Kittur, Swati2
1 International Crane Foundation, Program SarusScale, E-11376, Shady Lane Road, Baraboo, WI 53913, USA;
2 Nature Conservation Foundation, Cranes and Wetlands Programme, 3076/5, 4th Cross, Gokulam Park, Mysuru 570002, India

Scientific attention to large waterbird ecology outside of the United States and Europe, unfortunately, continues to be low. Understanding of large waterbird needs is therefore biased, with literature frequently suggesting that intensively-cultivated agricultural landscapes have poor utility as large waterbird habitat. Assumptions regarding the impact of areas with high human densities and long agricultural histories on waterbird populations drive global status assessments despite lack of empirical evidence. In south Asia, agriculture is the dominant land use with some areas experiencing cultivation for several centuries. In other areas, government policies are driving increases in cultivation with concomitant alterations in land use, particularly wetland persistence. These landscapes remain largely unexplored for biodiversity, with meagre to no information existing on large waterbirds in these areas. In 2012, as part of Program SarusScape,we instituted a systematic, spatially-explicit, landscape-scale, long-term monitoring program focusing on large waterbirds (cranes, storks, ibis, spoonbills and herons) in seven areas in lowland Nepal and north-central India. These areas were chosen to represent variations in cropping history, agricultural intensity, crop species, human population density, rainfall patterns, and wetland persistence. The effort has yielded: (1) new populations of species of global conservation concern (Sarus Crane, Lesser Adjutant, Asian Woolly-neck); (2) novel information on heronry ecology; (3) evidence for landscape-scale effects of croplands on large waterbird distribution; and (4) a high value of agricultural landscapes as habitat for several large waterbird species. Weposit therefore that assumptions regarding status of large waterbird species using land use alone require to be revisited. Evidence-based understanding of the utility of different habitats and land uses to large waterbirds is critical to obtain realistic large waterbird status assessments.


Collective Colony Formation Algorithm

Toquenaga, Yukihiko1; Tornero, Luis Carrasco2; Mashiko, Miyuki3; Fasola, Fasola, Mauro4
1 University of Tsukuba, Japan;
2 Center for Ecology and Hydrology, UK;
3 Wildlife Management Office, Inc., Japan;
4 University of Pavia, Italy

Colonies of breeding herons and egrets should be located so as to maximize individual resource intake. Food spectra of these species are relatively strict, and their colony sites are restricted to wood and wetlands, so it is relatively easy to specify their habitat requirements. But simple calculation of availability of food and nesting habitats often fails to explain why colonies were formed at specific locations. We tackled this problem by a different analysis of heronry locations, using long-term data for large study areas in Italy and Japan. First we incorporated not only favorable resource sites, such as nesting and foraging sites, but also unfavorable sites, such as urban and bare ground, for evaluating probability of colony formation. Second we incorporated site fidelity, or tendency to reuse the same places as colonial sites. The second aspect was inspired by the fact that nearly two thirds of colonies formed in the past 30 years in our study area in Japan, and in the past 43 years in Italy, were located exactly at the same or at nearby sites. We applied the random forest analysis to create the collective brain, or colony locating algorithms. Their collective brains show that they used specific scale and land use combinations for colony formation, avoiding urban or bare fields at the 10 km scale, but favoring ever green forest at the 4 km scale. Importance of site fidelity constantly increased after 1995 in Italy, and after 2005 in Japan. We discuss the change in colony formation algorithms according to the change of member species in colonies.


Potential Impacts in heron populations due to scenarios of climate change in South America: focus in Paraguay and bordering countries

Yanosky, Alberto1; Pasten, Max2; Arévalos, Fabiano1; Ortiz, Edder1; del Castillo, Hugo1
1 Guyra Paraguay, Parque Ecológico del Rio, BioCentro, Avda. Carlos Bóveda s/n., CC 1132, Viñas Cue, Asunción, Paraguay;
2 Facultad Politécnica, Universidad Nacional de Asunción, San Lorenzo, Paraguay

Climate change affects ecosystems, habitats and species with increasing velocity and continuity. Climate change is expected to cause shifts in the geographic distribution of species worldwide as species track their optimal habitat which will likely shift as a result of rearrangement of climate zones. Water and wetlands are very linked to heron populations and severe extreme conditions such as drought and flooding may affect these populations in light of the different future scenarios related to shifts in temperature and rainfall. We here analyze the historical information on climate for Paraguay and the distributional ranges for the 14 Ardeidae species occurring in the Paraguayan territory and their contribution to the 57 country’s Important Bird and Biodiversity Areas (IBAs). Though most of the Paraguayan heron species may not be severely affected by the different climate change scenarios, this contribution highlight some of the threats and identify strategies for creating conditions towards more resilient heron populations which will serve to decision makers for improving their response andsupport for natural resource management.

——— Poster Presentation ———

Importance of Costa Rican Conservation Areas and IBAS for Ardeidae conservation and management

Alvarado Quesada, Ghisselle M.
National Museum of Costa Rica

Costa Rica has 350 documented wetlands (350,000 ha) in the National Wetland Inventory; all them administrated by Conservation Areas (Environmental Ministry). However the diversity of more of them is poorly known (except Ramsar Sites). Ardeidae species liveand move along the country. I used 55,000 electronic recordsfrom the National Museum and Global biodiversity information facility (GBIF) to create Conservation Areas and IBAS ardeidae species lists and prioritize them by species diversity, vulnerability and future needs. I applied ecological niche modelling for Costa Rica threatened or sensible species: Agami Heron, Least Bittern, Pinnated Bittern and Rufescent Tiger-Heron.


Great Egret roosting dynamics along the North Carolina coast

Andersson, Annika G.; Kornegay, M. Edye; Schweitzer, Sara H.
North Carolina Wildlife Resources Commission, New Bern, NC 28562, USA

To understand more about the habits, habitat preferences, species composition, abundance trends and overall importance of Great Egret (Ardea alba) roosting sites, we monitored eight roosts along the North Carolina Coast from 2015–2016. These roost locations, in Carteret County and at Lake Mattamuskeet National Wildlife Refuge, were obtained through reported observations of tagged egrets from concerned citizens and from a separate radio-telemetry project. Only two of the eight roosting sites have been used consistently by Great Egrets throughout the year; these roosts are on suburban, privately-owned land and are at risk of development or other manipulation. Three roosts are used on a short-term basis (≤3 consecutive months), two sites have been deemed inactive, and we lost access to another. Roost size ranged from 0–259 Great Egrets. High counts of other colonial waterbirds at these roosts include 6 Snowy Egrets (Egretta thula), 46 Cattle Egrets (Bubulcus ibis), 20 Black-crowned Night Herons (Nycticorax nycticorax), 15 Little Blue Herons (Egretta caerulea), 7 Green Herons (Butorides virescens), 7 Great Blue Herons (Ardea herodias), 1 Tri-colored Heron (Egretta tricolor), 383 White Ibis (Eudocimus albus), 18 Glossy Ibis (Plegadis falcinellus) and 1097 Double-crested Cormorants (Phalacrocorax auritus). Our data collection is ongoing and will supplement other roost monitoring projects in North America.


The correlation between prey item distribution and Reddish Egret (Egretta rufescens) foraging behavior

Daigneault, Beau J.1; Green, M. Clay1; Bonner, Timothy H.1; Jensen, Jennifer2
1 Department of Biology, Texas State University, San Marcos, Texas 78666, USA;
2 Department of Geography, Texas State University, San Marcos, Texas 78666, USA

The Reddish Egret is a coastal wading bird with an IUCN conservation status of near threatened, and is listed as threatened in Texas where much of its breeding population occurs. We utilized a Texas Parks and Wildlife Department coastal fisheries database to examine spatial and temporal factors driving prey community structure in the Laguna Madre of Texas. We divided the Laguna Madre into three regional zones: Upper Laguna, Landcut, and Lower Laguna. The fisheries data was collected from 1976-2014 and consisted of multiple seine hauls each month. Environmental data including salinity, turbidity, and temperature were also collected corresponding to each seine haul collection event. We limited the fisheries data to only include those species either known to be prey of Reddish Egrets or were members of the same genus as known prey species. The dataset was also broken into breeding, post-breeding, and migration-wintering seasons based on Reddish Egret life history. We used multivariate analysis to determine what biotic and abiotic factors influenced prey species distribution. This multivariate analyses showed prey varied by both season and region within the Texas Laguna Madre. Future analysis will examine the relationship of prey distribution to known Reddish Egret colony site location and nest initiation date.


Population Viability of the Reddish Egret (Egretta rufescens) in Texas: An Analysis of Management Actions and Implications

Durham, Sarah; Green, M. Clay
Wildlife Ecology Program, Department of Biology, Texas State University, San Marcos, TX 78666, USA

Reddish egrets are a threatened waterbird species that inhabit the Gulf Coast of the U.S. and Mexico, as well as, the Bahamas, Cuba, the Mexican Pacific Coast, and the Yucatan peninsula. The plume trade of the late 1800s drastically reduced global population numbers of reddish egrets. By the 20th century, the species was decimated and possibly extirpated in many parts of its range. While much of the historical range has been recolonized, the reddish egret remains North America’s least abundant heron species. An estimated one-third to one-half of the global reddish egret population occurs in the United States, with Texas having approximately 75% of the breeding pairs. While egret population numbers may be increasing throughout portions of the range, many factors continue to threaten the persistence of the species. Population viability analyses (PVAs) are a common method of predicting a species’ persistence into some future time. The purpose of developing a population viability analysis for E. rufescensis to identify possible factors impeding the growth of Texas populations. By assessing the relative threat of each contributing factor and identifying vulnerable life stages, a robust PVA can estimate how different management actions will affect population demographics. The outcome of this analysis will help guide the management of Texas populations of E. rufescens. Using population and demographic data from the Texas population of E. rufescens, our model will serve as the backbone for the creation of a range-wide PVA.


Status and Conservation of White-eared Night Heron in Vietnam

Hung, Le Manh1; Manh, Vuong Tien2
1 Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet st, Caugiay dis, Hanoi, Vietnam;
2 Vietnam CITES Management Authority, 02 Ngoc Ha st, Ba Dinh dist, Hanoi, Vietnam

For the last ten years, several works have been done for the little known and endangered White-eared Night Heron Gorsachius magnificus in Northern Vietnam. From direct field surveys and interview the local hunters, we confirmed the records of this species at three different sites in two provinces in Northern Vietnam including (Cho Don and Ba Be districts of Bac Kan province), Trung Khanh district of Cao Bang province. We have also confirmed the occurrence of 8 breeding pairs and estimated the population size in Northern Vietnam is under 100 individuals. The main threats to the species have been identified including habitat loss and hunting. Several conservation works have been done such as setting up the nest protecting group at Xuan Lac and Ba Be sites and the species action plan have been made. Particularly, this species was included in the 160 Degree of Vietnam Government in 2013 which is used as the mainreference for Vietnam penal code and Biodiversity Law.


Changes in populations of colonial herons and egrets in Japan

Mashiko, Miyuki1,2; Toquenaga, Yukihiko1
1 University of Tsukuba. 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8572, Japan;
2 Current address: Wildlife Management Office, Inc. 1-10-13 Oyamagaoka, Machida, Tokyo 194-0215, Japan

Rice is the most important crop in Japan, and large areas of rice paddies support large populations of colonial herons and egrets. Japanese people have traditionally worshiped herons and egrets as gods protecting crops from pest bugs and locusts. But population sizes of herons and egrets are thought to be declining after World War II due to the decline of areas of rice fields. Here we report colony dynamics around Ibaraki Prefecture, eastern Japan. First, 10-year population dynamics from 2002to 2011 were addressed by censuses based on a combination of aerial photography and ground surveys. Population changes differed among the six constituent species: Great Egret (Ardea alba) and Black-crowned Night Heron (Nycticorax nycticorax) remained relatively constant, while Grey Heron (A. cinerea) and Intermediate Egret (Egretta intermedia) increased, but Little Egret (E. garzetta) and Cattle Egret (Bubulcus ibis) decreased. The marked increase of the Grey Herons contributed to the increasing temporal variation in colony size and in species composition ratio. Second, whether the addition of Grey Herons has affected colony persistence was examined. After the increase of Grey Herons in 2005, colonies with Grey Herons had a greater propensity to persist. Grey Herons began to take the initiative in establishing colonies, and other species began to follow them in colony site selection. The expansion of Grey Herons into mixed-species colonies has promoted the persistence of colonies, and local populations of colonial herons and egrets seemed to gain the benefit of colony sustainability.


Distribution and abundance of egret and night-heron species in Pennsylvania, past and present

Master, Terry L.
Department of Biological Sciences, East Stroudsburg University of Pennsylvania, East Stroudsburg, PA 18301, USA

Of the egret and night-heron species inhabiting Pennsylvania before the turn of the 20thcentury, only the Black-crowned Night-Heron was reported reasonably often as a breeding species. Yellow-crowned Night-Herons and Great Egrets were recognized only as stragglers and post breeding wanderers. At the turn of the 20thcentury, a few nests were reported in southeastern Pennsylvania, also the focus of Black-crowned Night-Heron nesting at the time. Nests of all three species increased in number through the mid 20thcentury, likely a response to recovery from plume hunting and subsequent range expansion. At this time major colony location switched to the lower Susquehanna Valley and environsfrom the southeast, perhaps due to increasing development in this most populated corner of Pennsylvania. In the mid 20thcentury, the three species were joined by relatively short-lived colonies of Snowy and Cattle Egrets, also nesting in the lower Susquehanna Valley. Beginning in the early 1970s, colony locations and numbers were documented routinely and, with the advent of two state-wide atlas efforts spanning 25 years and eBird, a continuous and accurate record of population status has been available since then. Interestingly, throughout this entire period, few individuals and almost no nesting have occurred in the western half of the state. The number of colonies and current population levels of all three species warrant endangered status within the state.


Mitochondrial and Nuclear Phylogenies of the Herons

McCracken, K.1; Sheldon, F.2; Lavretsky, P.3; DaCosta, J.4
1 Department of Biology, University of Miami;
2 Musuem of Natural Science, Louisiana State University;
3 University of Texas El Paso;
4 Department of Organismic and Evolutionary Biology, Harvard University

Systematic relationships of the herons (Aves: Ardeidae) are of strong interest to ornithologists. Here we present phylogenies derived from both mitochondrial (cytochrome b) DNA and next-generation sequencing of nuclear DNA, encompassing most of the world's heron species. Phylogenies from both genomic regions were largely concordant with similar structures confirming the monophyly of five main heron groups: (1) Cochlearius (Tigriornis, Tigrisoma); (2) Agamia; (3) Zebrilus (Ixobrychus, Botaurus); (4) Syrigma, Pilherodias, (Egretta), (5) (Butorides, Ardeola) (Ardea, Casmerodius, Mesophoyx, Bubulcus). The night-herons Nycticorax, Nyctanassa, and Gorsachius appear to be polyphyletic.


Effects of hydroelectric generation on foraging in Great Blue Herons (Ardea herodias)

Scarlett, Todd L.
University of South Carolina Lancaster, Lancaster, SC 29720, USA

Tailwater streams below hydroelectric dams are subject to drastic changes in water depth and velocity over short periods of time. The effects of altered flow regimes on macroinvertebrates and fish have received significant study, but the effects on other wildlife have received virtually no attention at all. I examined the effects of altered flow regimes on foraging success and bird abundance of great blue herons (Ardea herodias) at the Lake Wylie Dam near Rockhill, South Carolina, USA. Heron foraging was observed from the dam structure to a distance of 850 m downstream of the dam. During periods of no generation foraging rates were highest at shallow areas 500-850 m below the dam and lowest near the dam. During generation foraging rates were highest immediately downstream of the dam near the outflow of the generators and foraging in the shallows downstream was very low. Censuses conducted every thirty minutes during foraging observations show that significantly more herons were present near the dam during generation than in periods of no generation. Conversely, in the shallow areas 500-850 m below the dam, more heronswere present during periods of no generation than during generation, though the differences at this location were not significant. Great blue herons generally forage solitarily but hydroelectric dams concentrate foraging great blue herons into much greater densities than they are found elsewhere. This may impact breeding colony size and the distance travelled between foraging and nesting sites, particularly during the breeding season when adults are feeding young.


Survival and movements of Black-crowned Night-Herons in Lake Erie, Ohio

Stein, Kristie; Tonra, Christopher
The Ohio State University, Columbus, OH, USA

Located 9 miles due north of the Ohio mainland, West Sister Island is home to 40% of the nesting herons and egrets in the U.S. Great Lakes. One such species of heron, Black-crowned Night-Heron, has experienced a decline in breeding pairs from 3,000 in 1977 to 387 pairs in 1999 and is currently listed as threatened in Ohio (Hothem et al. 2000). Understanding factors influencing movements of individuals across spatial and temporal scales is critical to the preservation of populations threatened by environmental change. Using this information, in accordance with survivorship estimates, is important in understanding population dynamics and the conservation needs of species. To estimate post-fledging survival and examine dispersal patterns, Black-crowned Night-Herons (n=15 fledglings) were marked with coded nanotags in Lake Erie, Ohio, in 2015. Adult night-herons (n=5) were captured at local marinas near public-use fish-cleaning stations using a baited woosh net technique. In combination with active hand tracking, automated telemetry towers were used to passively monitor movement activity of marked birds. During the 2016 nesting season, we will use the same techniques to deploy coded nanotags (n=60) and ARGOS satellite transmitters (n=15 adults). I will present preliminary results on fledging rates, survival, recruitment, and movements of juvenile and adult Black-crowned Night-Herons. Incorporating knowledge of night-heron movement and population demographics may help guide future management decisions to maintain a viable population.


ARGOS tracking to understand the ecology and behavior of Agami Herons

Stier, Anna
GEPOG Association, 15 Ave. Pasteur, 97300 Cayene, French Guiana

The Agami Heron is ranked 13th among the world’s conservation priority heron species, and 2nd for the Americas. Until recently, nothing was known about the feeding grounds of this species during the breeding season, or about areas used during the nonbreeding season. In French Guiana, which holds the world’s largest Agami Heron colony (representing over 95% of the known population), the location and characterization of these habitats as well as the identification of the geographic location and routes travelled by breeding and non-breeding individuals has been crucial to evaluate the threats on the species and develop an effective conservation action plan both in French Guiana and throughout its distribution in South and Central America. To achieve this objective, GEPOG (Group for the Study and Protection of Birds in French Guiana) tracked 8 Agami Herons in 2012 and 2013 via the European LIFE+ Cap DOM program. Data from 4 individuals show that this species migrates north and south along the coast (Brazil, Suriname and Venezuela) and is able to cover up to 1,300 km within two months, including several stop-overs. Sizes and habitats of the breeding season home ranges are determined.


Seasonal variation of Reddish Egret movement along the Gulf of Mexico

Walker, Isabelle; Green, M. Clay
Department of Biology, Texas State University, 601 University Drive, San Marcos, TX 78666, USA

Understanding seasonal variation in waterbird movement is essential for conservation management of key habitats used during breeding, post-breeding and wintering seasons. Reddish egrets (Egretta rufescens) are a near threatened waterbird species with the breeding population primarily occurring along the Texas coast. There has been limited knowledge on their movement especially changes in movement from juvenile dispersal to breeding adult. In this study, we estimate seasonal variation in home range size and site fidelity of reddish egrets. Data was analyzed from five years of satellite telemetry data collected during 2010-2015 from 25 individuals along the Texas Coast in the Laguna Madre. Our results show individual home range sizes were the largest during the 2010 breeding season 3,825 km2 (n=20) and decreased to 145 km2 (n=19) in the 2010 winter season. Home range size varied between age and season with an overall decrease during the study. During 2013-2015, home range size significantly decreased to <3 km2 suggesting further evidence for weak long distance migration in this species. Of the remaining tagged birds from 2013-2015, there was no evidence of site fidelity to the natal colony. All of these birds settled in the southern tip of Texas and the Laguna Madre y Delta del Río with the largest dispersal of 165 km. Our study is the first study to track individual Reddish Egret movement from juvenile age class to breeding age class.


Habitat characteristics and seasonal numbers of Great Egrets at 70 roost sites in the area of Southern Ontario, Canada

Weseloh, D. V. Chip1; Moore, Dave2; Knezevic, Tina1
1 Canadian Wildlife Service, 4905 Dufferin St., Toronto, Ontario M3H 5T4, Canada;
2 Canada Centre for Inland Waters, Box 5050, Burlington, Ontario L7R 4A6, Canada

Roosting sites of Great Egrets (Ardea alba) away from breeding colonies are little known and studied. Our objective was to identify roosting sites,their size and habitat, annual usage and rarity, and to answer the question of whether roost sites should be Important Bird Areas (IBAs). We searched for and monitored roosting sites annually, 2008-15; 70 confirmed roosting sites were located in southern Ontario and adjacent U.S. states; 18 other sites were suspected of being roosts. All roosts were located in wetlands where microhabitat included: adjacent to water in trees on mainland (40%) or islands (11%), shallow water or mudflats (25%), trees in water (11%), bushes in water (7%) and herbaceous vegetation in water (6%). The most common size categories were 6-15 birds (30%) and 16-40 birds (24%) but individual roosts ranged in size from 1 to 816 birds. Most roosts consisted of a single site in a wetland,however, at 38% of the wetlands, egrets roosted sequentially at 2 or more sites within the wetland, i.e. they moved to a 2nd site within the wetland, often within the same season. They often moved from trees to mudflats as water levels receded. Roosts usually became active during mid-June to early August, had peak numbers in late August-early September and declined in numbers during late September–late October. Not all roosts are worthy of IBA designation.


Long Term monitoring of egrets and herons in Hong Kong (1989–present)

Wong, L. C. Captain; Woo, C. K. Luke; Wong, Y. P. Josephine; Fung, C. L. Louis; Tam, Y. S.; Young, Llewellyn
The Hong Kong Bird Watching Society. 7C, V Ga Building, 532 Castle Peak Road, LaiChi Kwok, Kowloon, Hong Kong

Systematic, territorial-wide monitoring of egrets and herons has been conducted in Hong Kong since 1989. Through the population change, this monitoring could reveal how egrets and herons make use of fragmented wetlands and adapt dynamic change in urbanized landscapes. In recent years, the annual population of five species (Great (Ardea alba), Little (Egretta garzetta) and Cattle Egrets (Bubulcus coromandus), Black-crowned Night Heron (Nycticorax nycticorax) and Chinese Pond Heron (Ardeola bacchus)) fluctuated around 1,000-1,400 nests, with Little Egret and Chinese Pond Heron were the dominant species. The Great Egret exhibited a long term increasing trend (from zero in 1989 to 283 nests in 2015, while Cattle Egret showed a long term decline in the number of nests (from 118 nests in 1989 to 54 nests in 2015). Although pond type wetlands, and farmlands in Hong Kong were degraded in terms of fragmentation and shrinking in area during the period, both the total number of nests and the number of colonies in 2015 are higher than 1989. This may imply that nesting birds tend to split into more small colonies, and these coloniescould be situated in close proximity to feeding habitats. This may help reducing energetic costs. Also, their feeding habitat use pattern may shift to coastal wetlands in order compensate to the loss of pond type wetlands and farmlands. Pollution control in coastal areas, and better management of protected wetlands (for instance the Mai Po Nature Reserve and Hong Kong Wetland Park) may also provide prime feeding habitats although the wetland area was shrinking.

JHBC vol.4 art.1

Journal of Heron Biology and Conservation
Volume 4, Article 1 (2019)

HeronryMAP:Africa - Mapping the distribution and status of breeding sites of Ardeids and other colonial waterbirds in Africa #

Douglas M. HarebottleDepartment of Biological and Agricultural Sciences, School of Natural and Applied Sciences, Sol Plaatje University,
Private Bag X5008, Kimberley, South Africa; doug.harebottle@spu.ac.za

Abstract

Heronries in Africa are poorly studied and many data gaps are evident in terms of occurrence, species composition and productivity of these colonial breeding sites. This paper introduces HeronryMAP:Africa, a citizen-science project started in 2014 that aims to systematically collect long-term data on location, size and composition, site fidelity, longevity and conflict scenarios of heronries in Africa. Preliminary results are presented for current and historical sites sourced over a three year period (2014-2016). Three hundred and thirty-six colony sites were identified and mapped in 14 (25.9%) African countries; 72.6% of sites have no formal protection, 18.8% were subject to at least one human conflict scenario with ‘cutting of trees’ and ‘removal of trees’ being the most common human disturbances. A first, but presumably grossly underestimated total of 35,000 breeding pairs of colonial waterbirds in Africa is provided from available data. No species-specific nest data are given due to the tendency to report total nest numbers in mixed colonies rather than species-specific numbers. The study revealed a general paucity of data for heronries in Africa (there was no response from 74.1% of African countries), but also the challenges faced in collecting adequate scientific data for these sites. It did, however, show how citizen-science can make significant contributions to research projects that are poorly funded or have limited resources. Human-wildlife conflicts were highlighted as an area that is poorly understood for heronries but has important conservation outcomes. Future objectives include identification of species composition, assessment of priority sites, identification of conservation action for colonies under threat and production of an Atlas of African Heronries.

Key words: Africa; colonial waterbirds; heronries; HeronryMAP:Africa; human-wildlife conflict; monitoring.

# This paper was presented at the 1st Herons of the World Symposium at the 40th Anniversary Meeting of the Waterbird Society at New Bern, North Carolina, USA, 21-23 September 2016. Other papers from that Symposium have appeared in past (or will appear in future) issues of the Journal of Heron Biology and Conservation, and Waterbirds.


Introduction

Waterbirds that breed communally in freshwater or coastal systems are spread across eight bird families: Phalacrocoracidae, Anhingidae, Pelecanidae, Ardeidae, Ciconiidae, Threskiornithidae, Phoenicopteridae and Laridae (Perennou et al. 1996, Clements et al. 2017). Most of these waterbirds breed in large colonies, either loosely or in close association; however, some species are solitary nesters, e.g. Goliath Heron (Ardea goliath) and White-backed Night Heron (Gorsachius leuconotus) (Hancock and Kushlan 1984, del Hoyo et al. 1992). Colonies may be largely discrete (e.g., pelicans, gulls, terns and cormorants) or mixed (e.g., ibises, herons, egrets and spoonbills) (Hancock and Kushlan 1984, Perennou et al. 1996). However, some species such as the White-breasted Cormorant (Phalacrocorax lucida) and Reed Cormorant (Microcarbo africanus) are also known to frequently nest in extensively mixed flocks with Ardeids and Threskiornithids (DMH pers. obs.). The term ‘heronry’ usually refers to breeding sites where Ardeid species nest in mixed colonies (British Trust for Ornithology 2018); however, for the purpose of this paper, I will use this term to refer to breeding colonies for the colonial species concerned.

Due to their conspicuous behavior, abundance and often socio-economic and ecological impacts, the general distribution and basic biology of most of these taxa have been well studied globally (Hancock and Kushlan 1984, Brooke and Birkhead 1991, Kushlan and Hafner 2000, Kushlan and Hancock 2005). Continentally, studies are generally well distributed: in Europe (Hafner and Fasola 1997, Marchant et al. 2004, British Trust for Ornithology 2018), Asia (Hong Kong Bird Watching Society 2016, Mashiko and Toquenaga 2018, Matsunaga 2018) North America (Gawlik et al. 1998, Spies and Weingartner 2007, Maccarone et al. 2010, Rush et al. 2015, Cox et al. 2017), South America (Kushlan et al. 2002, Stier 2018, Yanosky 2018) and Australia (Maddock and Baxter 1991, Richardson et al. 2001, McKilligan 2005). However, gaps do exist and in Africa, information on the status and distribution of heronries is severely lacking; it is limited mainly to Southern and Eastern Africa (Tarboton 1977, Underhill et al. 2009, Turner 2011, Kopij 2014). Some data have been collected through atlas projects (Tanzania Bird Atlas; N. Baker in litt.), waterbird surveys (Botswana; Tyler 2001, Madagascar; Wetlands International 2012, Dodman 2014, Rabarisoa et al. (in review)) and some dedicated efforts of individual researchers (Turner 2002, J. Agutu unpubl. data, C. Barlow in litt.). However, most of these studies were short-term or of an irregular nature. Currently, only a single long-term monitoring program (1993 to present) for heronries in Africa is known to the author (Rabarisoa et al. (in review)). As a result, there is a gap in the knowledge of the importance of these African sites in terms of location, species composition, abundance, breeding productivity and site management (Perennou et al.1996, Kushlan et al. 2002).

HeronryMAP:Africa was born out of a heron banding project that started in 2002 in Cape Town, South Africa (Harebottle and Gibbs 2004, 2006) and the general paucity and limited nature of information on heronries in South Africa (Tarboton 1977, Perennou et al. 1996, Veen et al. 2011). The project was officially launched on 1 August 2014 through social media with the creation of a web page via Facebook - ‘HeronryMAP:Africa’.

The objective of this paper is to introduce HeronryMAP:Africa as a continent-wide, citizen-science based monitoring project for African heronries; preliminary results on the status and distribution of current and historical heronries in Africa are presented for 31 species (Appendix 1) and gaps in research and conservation interventions are identified and discussed.

Appendix 1
Appendix 1. The 31 colonial waterbird species that were considered in determining colonial sites for this study. Nomenclature after Gill and Donsker (2018); global status taken from IUCN (2017). LC = Least Concern, VU = Vulnerable, EN = Endangered. Country codes: BW – Botswana, CV – Cape Verde, GM – The Gambia, KE – Kenya, LS – Lesotho, MG – Madagascar, ML – Mali, NA – Namibia, SZ – Eswatini (formerly Swaziland), TZ – Tanzania, UG – Uganda, ZA – South Africa, ZW – Zimbabwe. Heronries in Senegal and Mauritania did not report any species specific information and are therefore not included here.

Methods

The study area for this paper was the entire continent of Africa, the island of Madagascar and smaller offshore islands including Cape Verde, Madeira Islands, Zanzibar, Comoros, Sao Tome and Principe. Data were collected from various sources including surveys from ornithologists, heron researchers and bird club members; additional information was sourced from nest record cards (Animal Demography Unit, University of Cape Town; unpubl. data), academic or popular literature and from personal observations. The HeronryMAP:Africa web page was used extensively to request data and collate records and information about heronries throughout Africa, especially South Africa; all researchers and observers were encouraged to post records and upload images of active heronries. Standardized datasheets, available on the site, were provided for participants to use in uploading their data in a standardized format (Appendix 2). Any incidental information relating to breeding sites that was posted directly on the page was transferred to a database.

Appendix 2
Appendix 2. Sample data Excel forms that were made available to observers for the collection of heronry data for this study: (a) The first version of the data form that was used in the early part of the study; (b) A streamlined modified version of (a) and is the current version that is used.

Data were grouped into current sites, 2012-2016, which had census data and historical sites, pre-2012 which included sites with census data and those which were reported as active but lacking census data. The reason for selecting 2012 as a cut-off to separate ‘current’ from ‘historical’ heronries is based on heronry dynamics; natural heronry sites generally persist for a few (2-3) years (due to natural variable landscape fluctuations or changes) before being abandoned (Perennou 1996, Underhill et al. 2009), therefore five years (prior to the final year of data gathering for this study, 2016) would be a reasonable amount of time to isolate recent, active colonies from older colonies that may have abandoned preferred sites and moved to other optimal sites.

Additional site protection status information and/or human-related conflict issues were sourced by the author where these were not or could not be provided by the respondent or observer.

Results

Spatial distribution and numbers

A total of 336 heronry sites was mapped from 14 countries across Africa (Table 1, Fig. 1); no distinction was made between colonies being mixed or discrete. Most records (n=238, 70.8%) were from southern Africa. Almost a quarter of the sites (n=73, 21.7%) were located in East Africa (including Madagascar), while 24 sites (7.1%) occurred in West Africa, including the Cape Verde Islands. Only one site (0.3%) was reported for Northern Africa (Mauritania, Table 1). No data were received from central Africa. Nearly half (45.8%) of localities (154/336) were recorded from South Africa; the next largest representations were from Kenya (32 sites), Uganda (29), Botswana (26), Lesotho (22), Zimbabwe (21) and The Gambia (21) (Table 1, Appendix 3).

Table 1
Table 1. Summary of the status of heronry sites in Africa based on submitted and additionally sourced data to HeronryMAP:Africa. The estimated number of breeding pairs is based on available nest count data for active sites only and should be regarded as preliminary estimates. Regions are based on those defined by the African Union (http://www.west-africa-brief.org/content/en/six-regions-african-union): N = Northern, S = Southern, E = Eastern and W = Western. Data sourced over a three-year period, 2014-2016.

Figure 1
Figure 1. Spatial distribution and protective status of 336 heronry sites throughout Africa based on HeronryMAP:Africa data. Protected sites are those located in formally protected areas; partially protected sites are those which are or form part of Important Bird Areas or Ramsar Sites; Unprotected sites are those sites which are known to occur outside of formally protected areas; Unknown refers to sites for which no information was available to determine protective status. Dashed lines indicate boundaries separating the five regions in Africa (see Table 1). The numerical values refer to the number of sites in each region.

Appendix 3
Appendix 3. Photos of selected colonies included in the HeronryMAP:Africa database.

Based on available data from submitted and sourced records for active heronries, a preliminary estimate of 35,000 breeding pairs was calculated from the 319 sites (out of 336 total sites) for which there were numerical data (Table 1); the estimate assumes that all historical sites (i.e. prior to 2012; n=162) have remained active with similar colony sizes that were initially reported. Seventeen sites were shown to be active prior to 2012 but lacked actual nest data. Most survey responders did not indicate any species specific numbers within a heronry; unfortunately, no verified species-specific breeding numbers are yet available in this study.

Protection status

Of the breeding colonies, 72.6% (244/336) were located in unprotected areas; 16.4% (55/336) of the sites were located in formal conservation areas (e.g. national parks or nature reserves) or included in Important Bird Areas and/or Ramsar Sites (Table 1, Fig. 1). The protection status for 37 colonies (11.1%) was ‘Unknown’.

Human-conflict coverage

Of the 336 sites, 81.3% (n=273) did not report any known human-wildlife conflicts; the remaining 63 sites (18.7%) had at least one known conflict (Table 1). From these 63 sites, the most frequently recorded conflicts included ‘cutting of trees’ and ‘removal of trees’. The distribution of human-conflict issues across all sites is given in Fig. 2; the current data indicate that Kenya and South Africa recorded most of the conflict scenarios identified.

Figure 2
Figure 2. Spatial distribution and type of human-wildlife impacts of 336 heronry sites throughout Africa based on HeronryMAP:Africa data. Hunting refers to killing of adult birds at nest sites; Mixed impacts refers to any combinations of known impacts and Unknown refers to colonies where there are no data available on conflict scenarios. Dashed lines indicate boundaries separating the five regions in Africa (see Table 1). The numerical values refer to the number of sites in each region.

Discussion

The results presented here are based on data sourced over a three year period and represent at least an initial attempt to document and quantify the numbers and distribution of heronries in Africa. However, it can be assumed that this is a gross under-estimation and under-representation of the real situation given the number of African countries (40 out of 54) for which no data were submitted in HeronryMAP:Africa but which probably have breeding colonies (see Clancey 1997 for Mozambique; Borrow and Demey 2010 for Ghana; and Redman et al. 2011 for Ethiopia, Eritrea, Djibouti and Somalia). This study also highlighted the challenges in collecting large-scale data on nesting colonial waterbirds across the African continent. Data are often insufficient or difficult to source, particularly when sites are known from personal experience (but not documented) or personal communication but where exact details cannot be ascertained in a timely manner. These gaps, as well as the identification of the species composition and updated status of historical sites with no data available, need to be filled in order to present a clearer and more holistic picture of the status, content and distribution of heronries across Africa. Dodman (2014) does include some information on breeding colonies for some species listed in this study but often locality details are lacking or information is vague. These data will need to be sourced so that these sites can be included in HeronryMAP:Africa and any future reviews of the dataset. Ongoing assessments and conservation measures remain limited without this information. The Heron Specialist Group of the International Union for the Conservation of Nature (IUCN) Species Survival Commission recognizes these gaps and has initiated an effort to establish a list of heron researchers in Africa in order to start building a database of heron researchers and to stimulate further development of research and projects on herons (C. King in litt.).

Although the distribution of documented heronries covers only a small number of African countries (n=14, 25.9%), the majority of records stem from southern Africa, and South Africa in particular. This has largely been due to the strong citizen-science networks in the region and the response of these volunteers to requests for information on heronries in the region. Most of these volunteers used social media to supply relevant information. Eastern Africa is the region which has the second largest number of documented heronries. There have been ongoing efforts there to document and update the status of herons in the region. Turner (2011) provided detailed accounts of the status of 19 Ardeidae in eastern Africa. The Tanzanian Bird Atlas (http://tanzaniabirdatlas.net/start.htm), which has now been underway since 1985, is providing valuable high-quality data for ardeid distributions and seasonality and has recently incorporated mapping active heronries into its volunteer operations (N. Baker in litt.). There are an estimated 50+ sites that have already been documented as part of the Tanzanian Bird Atlas with increasing numbers projected in the next five years (N. Baker in litt.). Western Africa has some data on heronries available through their coordinated waterbird monitoring programs (e.g. waterbird counts in Senegal and Mauritania, Veen et al. 2007) and through ex-patriots stationed in certain countries such as The Gambia (C. Barlow in litt.). Data are severely lacking from the rest of Africa, notably northern and central Africa, where up to nine and 26 species of ardeids, respectively, are known to breed (Hancock and Kushlan 1984, Brown et al. 2002).

This analysis has highlighted that only a small percentage (16.4%) of colonies are located in protected areas where sites can be protected from general human disturbance. Sites located on private land or public open spaces (e.g. parks and gardens) are subject to unpredictable threats such as human disturbance, including destruction of nests, egg predation and cutting or removal of trees. Considering most sites lack formal protection, conservation efforts for colonial waterbirds may need to be focused on private landowners in order to secure breeding sites across Africa and which may include landowner stewardship (https://www.capenature.co.za/care-for-nature/stewardship/) and custodianship programs (Little and Theron 2014).

The results of this study explicitly show that human-wildlife conflict scenarios are generally poorly understood or recognized for colonial waterbirds in the African landscape. Expansion of species and breeding sites into urban, suburban and rural areas often bring them into close contact with people and their associated activities (Telfair et al. 2000). These species/colony-human associations regularly lead to confrontation resulting mainly from the birds’ nesting and breeding activities and guano deposits posing nuisance factors and potential health risks. Many colonies are at risk; some are labelled nuisance sites due to excessive noise of breeding birds and potent guano smell (Grant and Watson 1995, Whittington-Jones 2014), while others are located close to airports or airfields creating potential collisions with aircraft as birds traverse the airfield to and from the colony (A. Froneman in litt.). Consequences of this are that colonies are usually destroyed (either through nest removal or tree cutting) without proper intervention or guidance from relevant authorities. There are no formal regulations or systematic guidelines in place to ensure that these situations are handled in a proper manner. In South Africa, however, Harebottle et al. (2019) have developed national guidelines to assist affected parties and provincial authorities in identifying and mitigating problematic colonies. Similar initiatives in other African countries, particularly where large heronries are under threat from human disturbance, should be considered. Nesting habitat enhancement has been carried out in South Africa (Harrison et al. 2001, Harrison 2005), by building artificial platforms for colonially nesting waterbirds. These have been constructed to replace natural sites that were not being used or were destroyed, and to attract species to breed in new areas. The platforms have been used to varying degrees of success but generally birds respond positively to these artificial nesting structures (Harrison et al. 2001, Harrison 2005). Management and maintenance of the platforms or structures are required to ensure sustainability of breeding populations on an annual basis. Mitigating human-wildlife conflict situations for colonial waterbirds may involve increased focus on constructing artificial breeding sites, particularly where threatened species are present and/or large, natural sites are under increasing threat (Perennou et al. 1996, Harrison et al. 2010).

The breeding pair estimates across all species within each country gleaned from this study should be interpreted cautiously. They are based solely on submitted information, and in light of missing data from other colonies, are gross under-estimations. At best, the figures given in this study should be regarded as an initial attempt to gauge the relative importance of breeding sites and abundance in each country. For colonial waterbirds, numbers of nests per active colony usually relate to breeding success (Perennou et al. 1996). This is driven largely by the number of pairs (within species and across species) that can build nests (nest site availability) and raise chicks. HeronryMAP:Africa will attempt to monitor breeding numbers and output as part of its long-term objectives.

Continued data collection, analysis and site assessments are critical to identify and document additional sites, determine their status and potential productivity, and assess the degree of risk to the future of the sites from habitat loss, climate change, human-wildlife-conflict and other conservation threats. The use of modern technology is crucial to collect high-quality data rapidly; this is important given the real possibility that, in the absence of any formal regulations, large and potentially important colony sites may be subject to disturbance and destruction. In South Africa, the development of mobile applications, such as BirdLasser (https://www.birdlasser.com) allows for project specific data to be collected; BirdLasser incorporates a HeronryMAP:Africa function which prompts users to add additional information (including colony name, breeding status of each species, etc.) when they log any of the species listed in Appendix 1.

Future long-term priorities for HeronryMAP:Africa will be to identify, census and prioritize sites at national and regional levels. This should be based on a set of criteria that will include the number of each species at the colony, conservation status of the site, species of greatest conservation need and threats to the colony. This will focus attention on important colonies and particularly those threatened by human disturbance. In addition, prioritization of heronries will enable conservation authorities to include these nesting sites in national or regional conservation planning programs. Kushlan et al. (2002) and Kushlan (2007) emphasize that where nesting habitat for colonial waterbirds is limiting, these habitats need to be protected and managed effectively to ensure survival of healthy populations. A broader landscape-habitat approach may need to be considered as part of the HeronryMAP:Africa project to ensure habitats and sites can be identified and managed, which may include the need to set up alternative, man-made sites; Perennou et al. (1996) and Kushlan et al. (2002) stress that the importance of artificial nesting sites should not be underestimated. In addition, the impact of climate change on wetland hydrology needs to be investigated as it may affect habitat quality, availability of nest sites and the timing of nesting and migration (Kushlan et al. 2002). Climate change may ultimately impact negatively on priority sites and birds may be forced to source alternative, potentially inferior sites as future breeding colonies. Kushlan (1993) identified colonial waterbirds as effective bioindicators of environmental change and HeronryMAP:Africa could be an effective data source to further elucidate how colonial waterbirds will respond to environmental change.

This study has highlighted the power of citizen-science and the use of social media in creating awareness and garnering biodiversity data for conservation outcomes. McKinley et al. (2017) and Sullivan et al. (2017) both highlight the importance of citizen-science and open access data in providing adequate information for species conservation action and natural resource management. Newman et al. (2017) argue that growth in technologies, particularly mobile applications, has the potential to expand the frontiers of social media and citizen-science to advance scientific research programs; they further elaborate that socio-cultural issues will likely influence citizen-science programs in the future as more biodiversity issues become linked to landscape and habitat changes. This is particularly relevant to this project as breeding sites may increasingly occur in local villages or areas of higher population densities resulting in potential human-wildlife conflict but also in opportunities for local citizen-science participation. In addition, access to social media platforms and technologies may be limited in parts of Africa (e.g. central and northern Africa) and which resulted in a lack of response and hence no data submissions for this study. Ultimately, long-term funding is pivotal to ensure that the HeronryMAP:Africa project can be effectively coordinated and managed into the future, where new or existing technologies for data collection can be implemented and coverage widened to include gap areas.

A long term outcome for HeronryMAP:Africa will be the production of an ‘Atlas of African Heronries’ which can serve as a valuable conservation resource. HeronryMAP:Africa, however, should be seen as an ongoing, long-term initiative to monitoring breeding populations of colonial waterbirds and species as well as implementing conservation action at both local and regional scales. The project also has the potential to provide improved species population estimates at country or regional levels which can contribute to Wetlands International’s Waterbird Population Estimates (Wetlands International 2012).

Acknowledgements

I am grateful to Dalton Gibbs for the inspiration during our early heronry ringing expeditions in Cape Town; this is where thoughts and ideas germinated. To all the people who responded to my requests for information, I am indebted to their input and timely response; without their submissions, data would be severely limited and outputs hampered. A special thanks to Don Turner for allowing access to his data and reports for eastern Africa, and Clive R. Barlow and The Gambian Department of Wildlife for data and information from The Gambia. I am extremely thankful to all the citizen-scientists who have joined the Facebook group, submitted photos, data and information and share a passion for heronries and heronry conservation; without their support this paper would not have been possible. Tabaro Kabanda kindly assisted with the production of the final maps. Lastly, I am indebted to Clay Green, Katsutoshi Matsunaga, Chip Weseloh and two anonymous reviewers for their input and comments that vastly improved the quality of the manuscript.

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Black Bittern

Black Bittern

Ixobrychus flavicollis (Latham)

Ardea flavicollis Latham, 1790. Index orn., 2, p. 701: India.

Subspecies: Ixobrychus flavicollis australis (Lesson), 1831: Timor; Ixobrychus flavicollis woodfordi (Ogilvie-Grant), 1888: Solomon Isles, Aloa.

Other names: Yellow-necked Bittern, Mangrove Bittern in English; Avetorillo Negro in Spanish; Blongios à cou jaune in French; Schwarzdommel in German; Takasago-kuro-sagi in Japanese; Mangansile in Pilipino (Philippines); Kokokan sungai in Indonesian; Hei Yan in Chinese.

Description

The Black Bittern is a medium black or dark brown heron with a brown and white striped throat bordered by yellow.

Adult: In the male, the head and hind neck are dark grey black with a blue sheen. The relatively long bill is dark but variable. The upper bill is dark brown to red brown. The lower bill is pale green or purple below, but sometimes suffused with a reddish tinge with a yellowish tip. The irises are yellow to red brown and the skin around the eye is variable, dusky to green or pink. The chin, throat, neck and upper breast are deep buff streaked with black and white and bordered on each side by a paler gold yellow band from the chin to the base of the neck. A loose tuft of elongated feathers on the foreneck overhangs the upper breast. The back, tail and upper wing are grey black, with the wing coverts tipped in buff. The under parts are dark grey brown, often with a yellow wash. The legs are variable black, dark brown, or olive green with yellow green soles.

Variation: The female is slightly paler, generally brown grey instead of dark grey black, with more yellow wash to under parts. The female also has throat, foreneck, upper breast streaked with yellow, white and black with yellow breast plumes.

Birds vary individually and geographically. Individual variation is great. In Australasia, six plumage morphs have been recognized (Mayr 1945). All black and mostly white individuals have also been found (Payne and Risley 1978).

Described geographic variation is ascribed to three subspecies. Flavicollis, as described above, has the least amount of plumage variation. Compared to flavicollis, australis tends to be larger and variable. Males from Bismarck archipelago are mostly black with brown streaking on the throat and some females have brown grey under parts. Other morphs have been reported within this subspecies’ range. Compared to australis, woodfordi is slightly smaller, has a relatively longer bill, and males are darker below with narrow white streaks on breast and foreneck. Patterns of geographic variation are not clear given the vast amount of individual variation in the species.

Juvenile: The immature bird has a grey black crown, but appears duller with a rufous wash. The breast is brown streaked in yellow. Back feathers are edged in buff. Lores are green brown. Irises are yellow. Legs and feet are brown grey.

Chick: The downy chick is white with light brown tinge to neck and rump. The irises are black brown becoming dark brown. Bill, lores, legs and feet are light pink.

Voice: The “Whoo” is a low booming drum like call, a peculiarity of this species among the Ixobrychus bitterns. It is long, drawn out, rendered “ wh, o, o, o, o, o, o”, given at 15 s intervals and answered by neighboring birds. It undoubtedly is a territorial and advertising call. A soft “coo-oorh” call is given approaching the nest. Other calls have been reported but need to be clarified.

Weights and measurements: Length: Very variable, 55-65 cm. Weight: 275-358 g.

Field characters

The Black Bittern is identified by its size, dark back, striped neck bordered by a striking yellow streak, and its long bill. It is usually seen flying away into thick cover. It is distinguished from the other Ixobrychus bitterns by its dark back color with yellow neck and its larger size. It is distinguished from the Gorsachius night herons and the New Guinea Tiger-Heron by its uniformly dark plumage and disproportionately long dagger-like bill. It is distinguished from the Green Backed Heron by its uniformly dark upper parts, yellow patch and breast stripes.

Systematics

The Black Bittern is one of the Ixobrychus bitterns, but is the largest of the group. It is similar morphologically but uniquely has a booming call (Payne and Risley 1976). It also has a distinctive skull shape, related to its very long bill. It was previously assigned its own genus. Its skull and color pattern are most similar to the Dwarf Bittern.

Range and status

RANGE: The Black Bittern occurs in India, Southeast Asia, Indonesia, Philippines, Australia, New Guinea to the Solomon Islands.

Breeding range: The breeding range of flavicollis is Pakistan (Sindh), India (Jamdar and Srivastava 1990), Maldives, Nepal, Sri Lanka, Bangladesh, Myanmar, Thailand (Round 1992b, 1995, Lansdown et al. 2000), Cambodia, Vietnam, to central and south China (Yunnan, Hainan, Guangdong, Fujian, Taiwan, Hubei, Anhui, Shanxi), Malaysia (Sabah, Sarawak, Indonesia (Sumatra, Timo), Philippines. Australis occurs in Indonesia (Moluccas, Irian Jaya), Papua-New Guinea (including Bismarck archipelago), coastal Australia (north Queensland to New South Wales – Morris 1971). Woodfordi is confined to the Solomon Islands.

Nonbreeding range: Northern populations in China are migratory, wintering in western Malaya (peninsular, Sarawak), through Indonesia (Lesser Sunda Islands), and Philippines. There has been no recorded breeding in south west Western Australia since the 1950’s (Marchant and Higgins 1990).

Migration: Chinese birds move south in October to peninsular Malaysia, Greater Sundas and Philippines. Return is April- May. Post-breeding dispersal occurs and is likely the origin of island populations of this species. In India post breeding dispersal and drought based movements occur. A Malaysian bird has been recovered in India (Manipur) and an Indian bird was recovered in Maldives. Australian birds appear to be sedentary, but some regional movements occur. Dispersal records include Japan (Fukumoto et al. 1992), Christmas Island (Indian Ocean), Mollucas, Guam (United States).

Status: The status of the species is unclear. It is common in Pakistan, parts of India, and Sri Lanka. It is common and abundant in Myanmar and southeast China (Lansdown et al. 2000). It is widespread and not uncommon in east Australia but has declined over the past 50 years due to destruction of river edge habitat for farming, pastures and also because of salinization (Marchant and Higgins 1990, Maddox 2000). It is common in winter in Sarawak (Malaysia). It is uncommon in winter in Sumatra (Indonesia) and Philippines. It is widespread in New Guinea.

distribution map

Habitats

This species typically uses thick scrubby vegetation, particularly forested streams and pools in permanent wetlands. But it uses a variety of habitats including swamps, mud flats, reed beds, wet forests, flooded bushy areas, marshes, forested streams, Pandanus fringed channels in swamps, Melaleuca swamps and coastal mangroves in Australia. Although primarily a lowland species, it occurs up to 1,200 m in India. It winters in reed beds around lagoons, pools and reservoirs in peninsular Malaysia and Borneo. It uses trees and reeds to rest and roost.

Foraging

The Black Bittern forages singly or as a pair in thick vegetation. It feeds by Standing with its neck and head pulled in and by Walking Slowly in Crouched or Upright postures (Recher et al. 1983). It also can scuttle agilely along mangrove roots and creep stealthily in a distinctive crouch. It feeds crepuscularly and also during the day when it is overcast or rainy.

They are seldom seen because they hunt in densely vegetated marshes and creek edges. When disturbed, it runs into cover or flies away. They roost when not foraging in reeds, trees or on the ground.

Food items recorded include relatively large fish, 12 to 115 cm long (Perca, Amniataba, Gobiomorphus), frogs, lizards, crabs, crayfish, shrimp, mussels, and insects including dragonflies, beetles, and flies.

Breeding

Nesting timing differs geographically. In the north, breeding is triggered by the advent of the monsoon, at any time between May and September. In Sri Lanka nests have been found in April, May in Java, February in New Guinea, and September to January In Australia. Overall it breeds in densely vegetated, secluded wetlands. But its nesting habitat is surprisingly diverse, depending mostly on having dense cover near water. In India and Sri Lanka, it nests in reeds, thorn bush or cane breaks low over water. In China, it nests in bamboo and trees as high as 6 m. In Australia nests are located in gums standing in water and in mangroves. It occasionally nests away from water and is it not unusual to nest close to human habitation.

Black Bitterns nest solitarily or in loose nesting groups. At places the nest interspersed in mixed colonies with other herons. The nest is a platform, 23-35 cm wide and 7.5 cm, with a shallow central depression. It is made of twigs or reeds. The nest is built by both birds. Its placement is variable, from 1 to 15 m above the water or ground.

Little is known about the courtship of this species. It adopts the Bittern posture when disturbed and when alarmed, raises and lowers its crest. It is likely that the plumes at the base of the neck are used during courtship display, but there is no information.

The eggs are white, although there have been reports of a blue tinge to some. As recorded, they vary in size averaging 41.6 x 31.4 mm in India and Myanmar, 45 x 35 mm in Australia, and 43 x 34 mm in New Guinea. Clutch size is 3-6 eggs. Although it is probably usually single brooded, double broods occur. Incubation is by both sexes. Both sexes feed the chicks regurgitated food. The incubating bird sits very tightly and the chicks. The chicks soon leave the nest if disturbed.
Nothing is known about late nesting.

Population dynamics

Nothing is known of the population biology and demography of this species.

Conservation

In Australia the species has declined owing to clearing for agriculture and the increasing salinity of the rivers. It was once common in southwest Western Australia but is not known to have bred there in 50 years. It is widespread elsewhere in Australia, but Garnett (1992) listed it under Taxa of Special Concern. In NSW it is listed (updated 1999) as Vulnerable under the NSW Scientific Committee Threatened Species Conservation Act 1995 and in Victoria its conservation status is classified as Critically Endangered (NRE 2000). The actual breeding distribution is little understood and not quantified. In many cases the range is based on a few observations. A basic conservation need is to clarify the breeding locations and distribution of the species and to locate the most important breeding areas.

Research needs

Patterns of geographic and individual variation are not clear. The variation in plumage and size in this species needs to be re-examined. There also is a need to clarify the status of the species throughout its range.

Overview

The Black Bittern is a forest bittern, a bird of thick cover, generally scrubby vegetation along mangrove shores and other watercourses. It is not a river heron in the sense of using running water, but thick vegetation along water courses appears to be a habitat requirement. It feeds in normal bittern fashion, but is relatively large for a ‘small' bittern. With its long bill and neck, it appears to be a fishing heron, working along the banks of watercourses from vegetation. It appears to take relatively large prey, and so may not eat large numbers of prey items per day. It likely feeds from territories, which it knows well and undoubtedly defends. Much remains to be learned about this heron.

Malayan Night-Heron

Malayan Night-Heron

Gorsachius melanolophus (Raffles)

Ardea melanocephala Raffles, 1822. Trans. Linn. Soc. London 13, p. 326: western Sumatra (Probably near Bengkulu).

Other names: Malay Tiger Bittern in English; Martinete Malayo in Spanish; Bihoreau malais in French; Wellenreiher in German; Zuguro-mizo-goi in Japanese; Bakaw-gabi in Pilipino (Philippines); Kowak melayu in Indonesian; Helguan yan in Chinese.

Description

The Malayan Night-Heron is a small chestnut and brown nocturnal heron of low to mid elevation wet forests.

Adult: The crown and nape are black, ending in a long black crest. The bill is stocky, down-curved, dark brown above and green below. The lores and orbital skin are blue green. The irises are green yellow. The sides of the face and neck are rufous. The chin is white with a central row of black streaks. The back and upper wings are chestnut finely barred with black. The flight feathers are brownish-black with white tips, visible in flight. The tail is black. The underparts are dark brown finely speckled with black. Flanks and undertail-coverts mottled brown and white. The legs and feet are olive. During breeding the lores become blue. The males change well in advance of nesting whereas the female’s change during courtship (Chang 2000). After courtship the lores faded to blue green, green, to grey green.

Variation: The sexes are alike, but the male may have a longer crest and bluer lores in courtship (Tsao 1998). The species shows a high degree of individual variability in plumage. Previously three subspecies differing in plumage color were recognized, but their variability appears to be within the overall range of individual variation of the species. Geographic variation does occur however. Immature birds of the herons breeding on Palawan are buff heavily overlaid with black. Herons from the Nicobar Islands are small.

Juvenile: The immature is cryptically colored, strikingly different from the adult. Upper parts are dull grey to brown spotted and barred with white and buff. Under parts are white, spotted and barred brown. The crown is blackish barred and spotted with white.

Chick: The chick has not been described.

Voice: “Arh” call, rendered “arh, arh, arh” is the flight and interaction call. It also has hoarse croaks that are not yet characterized.

Weights and measurements: Length: 49 cm, Weight: 417-450 g.

Field characters

The Malayan Night-Heron is identified by its rufous neck, barred chestnut back, black cap with crest, and white tipped primaries. The Malaysian Night-Heron is distinguished from the Japanese Night-Heron by its chestnut brown (not darker body color), Black (not tawny) crown and longer crest, slightly longer thinner bill, and white (not tawny) tips on primaries. It is distinguished from the Cinnamon Bittern by its short stubby (not long and pointed) bill, black crown, blue green lores, larger size, barred cinnamon back (not plain cinnamon or brown with buff spots), black and cinnamon wings with white flight feather tips (not uniformly cinnamon). It is distinguished from all bitterns by its white wing tips and stout bill.

The immature Malayan Night-Heron is distinguished from the immature Rufous and Black Crowned Night-Herons by its short, stubby and downward-arched bill, smaller size, finer spotting on the back and wings, and mottled (not stripped) under parts. It is distinguished from the immature Striated Heron by its slightly smaller size, spotted (not plain) back, shorter stubbier bill, and green (not yellow) legs and feet.

Systematics

The Malayan Night-Heron is closely related to the Japanese Night-Heron. The relationships among the night herons are unsettled. Patterns of individual and geographic variation as is the appropriate subspecific taxonomy need to be clarified.

Range and status

The Malayan Night-Heron occurs in India, south east Asia, Philippines and the east Indies.

Breeding range: The Malayan Night-Heron breeds in India (west India, Assam and Manipur, Nicobar islands), Nepal, Thailand (north), Laos, Cambodia, Vietnam, (Cambodia not certain), south China (Hainan, Guangzhou, Taiwan – Sykes 1996, Yunan, Gaunxi, Kwangsi, Guangdong (Lansdown pers. comm.), the Philippines (including Palawan), and Japan (Ryukyu Islands). Recent information reporting immature birds in Malaysia (Peninsular, Taman Negra), Java, and Borneo suggests nesting, but this needs to be confirmed (Perennou et al. 2000, R. Lansdown pers. comm.).

Nonbreeding range: It occurs during non-breeding in west India (Perennou et al. 2000), Sri Lanka, Thailand, Laos, Cambodia, Vietnam, south China (Hainan, Guangzhou, Taiwan), Malaysia (Malay Peninsula, Sarawak), Indonesia (Sumatra, Java, Kalimatan, Halmahara, Talaud) (Coates et al. 1997), the Philippines (to Palawan), and Japan (Ryukyu Islands).

Migration: Because of it is a solitary species in difficult habitat away from surveys and bird watchers; its migration is not very well understood. Evidence exists for both migratory and sedentary habit in most populations, including west India, Nicobar, Indochina, south China, Taiwan, Philippines (including Palawan), and south Japan. It is likely that partial migration is the rule for the species, even in northern populations such as Taiwan and India, but this needs to be confirmed. Some west India birds migrate south in November–December through Sri Lanka (which is not the important wintering ground it once was thought to be), to Nicobar, Malaysia and across the Straits of Malacca, to Indonesia. East India, north Myanmar, and Thailand birds migrate south in August–October, presumably through Myanmar also to and through Malaysia to Sumatra, Java, and Borneo. Return migration through the Malay Peninsula is in April.

Whether post-breeding dispersal occurs in unclear. Birds have been seen outside the usual range, but not very far, (Shikoku Island), Palau Island, Indonesian islands (Bandai) and Christmas Island.

Status: No data are available on population sizes. Recent information suggests that the stronghold of the eastern population is in North Thailand, Vietnam and Laos (Perennou et al. 2000). It is uncommon throughout much of its range. It is uncommon and local in both seasons in Japan (Ryukyu Islands) (Wild Bird Society 1982), uncommon in nonbreeding season in Sri Lanka (Perennou et al. 2000), uncommon in both seasons in China (mainland, Taiwan – Sykes 1996), breeds throughout the Philippines but is uncommon in both seasons, rare in nonbreeding season in Java (McKinnon 1993).

distribution map

Habitats

This is a heron of mature moist forests. It occurs in dense, high rainfall, subtropical forests ranging from the low wetlands, where it uses streams, marshes, and swamps, to moderate elevations, where it uses evergreen forests, secondary scrub and reservoirs. It occurs as high as 800 m in west India, 1,200 m in Thailand, 1,800 m in Sri Lanka, and 2,300 m in east India. It uses reed beds in migration and is often reported as making use of human environments, particularly flooded rice fields, pastures, and vegetable gardens and nesting near houses.

Foraging

The Malayan Night-Heron is nocturnal, although it feeds readily crepuscularly and by day as well. It is solitary forager that feeds by Walking slowly at the edges of water, fields and other feeding areas. Most observations are of its feeding in the open, but it is likely it feeds primarily unobserved under cover. In feeding on earthworms, it Probes them from the soil (Chang 2000). Little is reported on the details of its feeding behavior. It defends itself with Forward consisting of raised crest, open wings, and stabbing at the opponent. During the day, it roosts well hidden in reed, bamboo, and other dense vegetation. The diet is little studied. It eats terrestrial food, particularly earthworks and beetles but also mollusks, lizards, frogs, rarely small fish (Shen and Chen 1996).

Breeding

It nests in May–August during the big rains in west India, May–June in Assam, April–September in Taiwan. The night heron nests in lowland forests of tall trees and bamboo, usually near or over water. It nests in trees and also in reed beds. It is a colonial nester, with 20 nests close together. It also nests solitarily. The nest is a small fragile platform of sticks, sometimes lined with leaves and grass. Nests are placed well concealed in a fork of branches in trees, 5-10 m high over the water or bare ground. It occasionally nests in reed beds. Both birds of a pair build nests.

Nothing is known of the courtship and little is known of the nesting biology of this species. It appears to be typical that juvenile birds nest while still in juvenile plumage (Chang 2000).

The eggs are chalky-white with a slight greenish tinge and a single measurement was 46 x 37 mm. Clutch is usually 3, range 3-5. In Taiwan, a second clutch is laid after the first nesting is completed. Both parents incubate, which starts before the clutch is completed. Both parents also attend and feed the young. Young birds have been reported as helping at the nest in feeding the young, an unusual behavior in herons (Chang 2000). Young fledge at 43 days. Brood reduction occurred in Taiwan, with the youngest two chicks being ejected from the nest by the first hatched chick (Chang 2000). No quantitative information is available on nesting success.

Population dynamics

Birds in juvenile plumage nest, perhaps typically (Chang 2000). The observed nesting was in the months prior to molting in to adult plumage, so the birds were probably two years old, however the sequence of juvenile molts is not known. Nothing is known about the population biology of this species.

Conservation

Populations, except that of Nicobar, are vulnerable due to habitat loss (Heinz et al. 2000). The deficiency of data on this species is a critical impediment to conservation action. No doubt its habitat, like that of other Gorsachius herons, has been reduced due to deforestation and degradation. But the habitat needs of the species are not well understood, given that it is often reported to be using human-made habitats, and on Taiwan it nests in parks and near human residences (Chang 2000). It has been proposed that the species might be an indicator of environmental quality in wet tropical and subtropical forests, but this needs to be demonstrated (Perennou et al. 2000). Given its inaccessible habitat and secretive habits, it may be that the species is much more widespread and abundant than thought, particularly if it is accustomed to human-managed habitat as now is becoming clear in Taiwan. Intensive year-round surveys need to be conducted in suitable habitat in order to determine its status in various places.

Research needs

Much of the basic biology of the species remains to be determined. Information coming out of recent observations hints that the species may be of considerable biological interest. Nesting in juvenile plumage, helpers at the nest, and multiple clutches within a season are all very unusual among herons. This is a species that could reveal new elements of heron behaviour. Range-wide, year-round surveys of its annual occupancy of potentially suitable habitat need to be carried out to provide the basis for a conservation strategy.

Overview

The situation is much like that in the Japanese Night-Heron. So little is known of this heron that much of its basic biology is speculative and it is not certain what constitutes the essential characteristics of a nocturnal low- to mid-elevation wet forest heron.

Japanese Night-Heron

Japanese Night-Heron

Gorsachius goisagi (Temminck)

Nycticorax goisagi Temminck, 1835. Pl. Col. Livr. 98, pl. 582: Japan.

Other names: Japanese Bittern in English; Martinete Japonés in Spanish; Bihoreau goisagi in French; Rotscheitelreher in German; Mizo-goi in Japanese; Bakaw-gabi in Pilipino (Philippines); Litou Yan in Chinese.

Description

The Japanese Night-Heron is a small, small billed chestnut and buff heron.

Adult: The Japanese Night-Heron has a chestnut cap with a short chestnut crest. The bill is relatively short and stout for a heron. The upper bill is dark brown; the lower bill is yellow. The irises are yellow and the lores are green yellow, forming a notable patch in front of the eye. The sides of the neck are buff brown. The upper parts are pale chestnut. The darker wings have blackish primaries with prominent broad tawny tips, giving the appearance of a black wing bar on an otherwise tawny wing. A pale patch on the forewing can be seen in good light. The under sides are brown with darker streaking and the flanks are slightly mottled. The legs are black green. In breeding, lores turn blue, and the bill turns green black.

Variation: The sexes are alike.

Juvenile: The immature is similar to the adult with a black brown crown and less chestnut head. Its neck is more spotted and streaked. Upper wings are paler.

Chick: The appearance of the chick has not been recorded.

Voice: A croaking “Buo” call, rendered “buo, buo” is the principal call in feeding and breeding. It is probably a contact and identification call.

Weights and measurements: Length: 49 cm.

Field characters

The Japanese Night-Heron is identified by its small size, tawny cap, short stout bill, and red brown upper parts. It is distinguished from the Malayan Night-Heron by its chestnut (not black) cap, shorter crest feathers, shorter and stouter bill, and tawny (not white) tips on primaries. It is distinguished from the Cinnamon Bittern by its bicolored back, chestnut wings and thicker bill.

Systematics

The Japanese Night-Heron is closely related to the Malayan Night-Heron. The relationships among these night herons are unclear.

Range and status

This night heron occurs in Japan, south China, and the Philippines.

Breeding range: The Japanese Night-Heron breeds only in Japan in Honshu, Shikoku, Kyusgu and on the Izu Islands.

Nonbreeding range: The overall range in spring and or summer is larger, but breeding has not been proven. It has bred in small numbers on Taiwan (Severinghaus 1989) but without recent record. Birds occur in spring and summer in east Russia (Primorye, Sakhalin) and South Korea (Gore and Won 1971). Some birds remain in Philippines in summer (Rand and Rabor 1960). These various spring and summer records suggest the possibility of breeding, but this needs to be proven.

In the northern winter, the heron occurs in south Japan (south Kyushu, Ryukyu Islands) and southeast China (Guangxi, Fujian, Zhejiang, Taiwan). Its principal wintering range appears to be the Philippines (Luzon, Semirara, Leyte, Negros, Panay, Siquijor, Mindanao, Palawan).

Migration: The Japanese Night-Heron is highly migratory. They move south at the end of October and occur widely trough Japan on passage. Some may remain in Kyushu but most move south through the Ryukas to and through China to the Philippines. Return is in March–May.

The species has some dispersal tendencies, possibly overshooting on southward or northward migration. It has occurred on Palau, Indonesia (Sulawesi, Halmahera), and Brunei (Borneo) (Elkin 1993). Given the paucity of records and difficulty of observing it, it should be sought after in these areas to determine if it might not be more regular than thought.

Status: The species is rare and extremely local in Japan. There is no population estimate available and it is not counted on surveys due to its secretive nature. Only 6 nesting sites are known (Lansdown et al. 2000). It is likely that the population numbers less than a few thousand birds (BirdLife 2001).

At the beginning of 20th century it was common and remained relatively common into the 1940’s and 1950's. It disappeared from many traditional areas in the 1980’s and 1990's. Although it was reported to have bred in Taiwan, it is now a rare as a winter visitor and passage migrant there and in south China (Sykes 1996). It is rare but regular in South Korea. It is uncommon in the Philippines, which is probably its main wintering area (Dickinson et al. 1991).

distribution map

HABITATS

This is a nocturnal forest heron. It is occurs in heavily forested rivers, streams, and swamps, in the low mountains. This habitat is now extremely scarce in Japan. Similar habitats appear to be used in the nonbreeding range (Sykes 1996). It occurs generally from 50-240 m in elevation, but has been reported as high as 1,500 m in Japan and 1,350 m in Philippines (with two records from as high as 2,400 m).

Foraging

The Japanese Night-Heron is primarily crepuscular, feeding solitarily or in small groups. It feeds by Walking slowly within the dense vegetation presumably along watercourses and pools but also on dry ground. It forages more rarely in the open. Habitats used include swamps, forest, farms, and rice paddies.

The diet appears to consist mainly of crabs and possibly other crustaceans, insects, earthworms, and small fish.

Breeding

The Japanese Night-Heron breeds in May–July. It nests in tall trees, 7-20 m tall. Species include cedar (Cryptomeria), cypress (Chamaecyparis), oaks (Quercus), zelkovi (Zelkova), and chestnut (Castanea). On migration in China it occurs in tall trees and bamboo forests along rivers and in the hills. The species nests solitarily. However in favorable situations these nests can be gathered within relatively close proximity (250-500 m), although not truly a colony. Nests are flimsy, crude platforms of sticks, placed on more or less horizontal and usually densely foliaged boughs, 7-20 m above ground.

Nothing is known of courtship display in this species, and little of its nesting habits. Incubating bird will adopt the Bittern Posture when alarmed. Eggs are dull white and measure on average 47.5 x 37 mm. The clutch is 3-4. The incubation period was estimated to be 17-20 days. Nothing is known about the hatching, growth, or breeding success of this species other than fledging occurs in 35-37 days. Late eggs found in July suggest renesting.

Population dynamics

Nothing is known of the population dynamics of the species.

Conservation

The Japanese Night-Heron is endangered (IUCN 2003). With only six confirmed and 15 possible breeding sites (Lansdown et al. 2000), the species is certainly under threat of extinction. If the 21 sites in Japan each supported 10 pairs, which is unrealistically high, the total known breeding population could be as few as 200 birds. It is certainly less than a thousand birds. Conservation of this species faces two great challenges: lack of information and destruction of the species’ habitat. The lack of information on the species constrains conservation action. The present status and distribution of the species must be determined as rapidly as possible. The 21 identified active and possible breeding sites should be re-examined for nesting, and those supporting nesting birds should be protected in a reserve system (Hafner et al. 2000). Threats to the known habitat of the species, both during breeding and non-breeding, are the principal conservation issues facing this species. In Japan, hill forests have been and continue to be deforested and converted to plantations. Remaining forests have developed a scrubby undergrowth (BirdLife 2001). Very little pristine forest habitat remains in Japan. Remnant stands need to be protected. Although the species is now found in degraded habitat, thoughts that this is an adequate habitat are probably incorrect. In the Philippines, lowland primary forest is similarly threatened by deforestation, rendering some areas totally unsuitable for the species. Protection of habitat on the wintering grounds is essential to the species’ conservation. Hunting may in the past have been a factor in its conservation. They have been found for sale in Taiwan in the 1970’s and Gorsachius herons have been confiscated in trade in the 1980’s. Introduced predators have led to its decline on islands.

A species action plan covering both breeding and non-breeding areas is desperately needed for the species.

Research needs

Research is difficult given the secretive nature and tenuous status of the species. None the less, much could be learned from observational study. So little is known about the biology of this species, which represents an adaptive arm of the herons—a small nocturnal upland forest heron, that its basic biology needs to be understood and related to both conservation needs and heron biology. Surveys need to be conducted to locate breeding and wintering areas. Given the apparently small population size, any site with a few birds constitutes an important area for this species. These sites need to be identified and placed in a range-wide reserve network to be monitored, protected, and managed. The taxonomy of the night herons is not well understood, and a thorough analysis is needed.

Overview

Nearly nothing is known about the ecology of this rare and declining species. In fact, it is not understood what constitutes the basic ecological characteristics of a nocturnal forest heron. It is certainly a very rare species that has depended on a forested habitat that has been under severe threat on both the breeding and wintering areas.

White-eared Night-Heron

White-eared Night-Heron

Gorsachius magnificus (Ogilvie-Grant)

Nycticorax magnifica Ogilvie-Grant, 1899. Ibis, p. 586: Five Finger Mountain, Hainan.

Other names: Magnificent Night-Heron in English; Martinete Magnifico in Spanish; Bihoreau superbe in French; Hainanreiher in German; Hainan yan in Chinese.

Description

The White-eared Night-Heron is a medium brown heron with a brown streaked breast and a white patch on the side of the head.

Adult: The adult male has a black crown with a brown black crest. The rest of the head is distinctly patterned in white and brown patches. A brown black cheek patch extending from the crown to the bill is separated from the cap by a white wedge extending back from the eye - the white ear of the species’ common English name. A smaller white line descends diagonally from the eye. The chin is white and the upper throat also is white, but dusky centres to the feathers results in a mottled appearance. The irises are yellow, and the lores and skin around the eye are yellow green forming a conspicuous pale patch in front of the eye. The bill is basically dark, the upper bill being black and lower bill having a green yellow tinge at the base.

The front of the throat is vertically streaked down the middle, blacker towards the head and browner onto the breast. Three broad vertically oriented patches cover the area of the side to back of the neck: lateral to the dark-mottled central throat stripe is a white line descending from the white of the lower cheek, lateral to that is a broad black brown line ascending from the dark shoulder, and lateral to that is a broad buff yellow patch merging to chestnut orange at the back.

The upper parts are dark grey brown with a purple tinge, sometimes with a few white spots on the lower back. Flight feathers are slate. The brown stripe on the foreneck merges on the breast onto the mottled brown and white undersides. Thighs are dark reddish-brown. The legs are green.

Variation: In the female, the color of the head and neck is less prominent; the back and wings are more mottled, streaked, and spotted with white especially on the upper wing. The crest feathers are shorter than the male's

Juvenile: The immature has brown instead of brown black feathering spotted with buff or white. The back and upper wings are brown with heavy buff or white spotting.

Chick: The chick is undescribed.

Voice: Nothing is known of the voice of this species

Weights and measurements: Length: About 54 cm.

Field characters

The White-eared Night-Heron is identified by its dark base color contrasting with white ears and white throat, and by its short bill. It is distinguished from the Malayan Night-Heron by its tricolored neck (not rufous), dark (not chestnut) sides, and slate (not black) flight feathers. It is distinguished from the Black Bittern by shorter, thicker bill, stouter appearance, and shorter neck.

Systematics

The White-eared Night-Heron is related to the Japanese Night-Heron, Malayan Night-Heron, and the larger night herons. The relationships among the night herons remain unclear.

Range and status

The present known range of this species is confined to China,

Breeding range: This is a species with the most restricted known breeding range of any heron. Surveys conducted in 1999-2001 have clarified the current status. These have been organized through the collaboration of the Heron Specialist Group and Kadoorie Farm & Botanic Garden (KFBG), a conservation charity based in Hong Kong (KFBG, H. Hafner, and O. Pineau pers. comm.). Based on these surveys at present, there are known two breeding site in the world, both located in south Guangxi Province, and one other area where breeding is strongly suspected, located in neighbouring Guangdong Province.

Migration: It is most likely that this species is sedentary (BirdLife 2001). However information is very uncertain. There are winter and spring records from its most recent breeding area in south China (Hubei, Fujian, Guangdong, Guangxi). There also is a suggestion that dispersal occurred to the north prior to southern movement and that Hainan is or was once a wintering area for birds from further north. Of course given the population’s precarious position, its presence in Hainan has not been documented in recent years. There is one record from north Vietnam, which is either a straggler or an indication of prior wintering area.

Status: Very few individuals have been reported over the past 30 years. Of the two known breeding sites, one near Fusui is highly degraded and is unlikely to support the heron for much longer. In the early 1990’s the species was present in Hubei Province, in the Shennongjia Nature Reserve, but a re-examination of the site in 2001 revealed that what was prime habitat has been converted into a reservoir, and both the habitat and species have disappeared (KFBG, O. Pineau, and H. Hafner pers. comm.). In 2000 and again in 2001, the bird was seen in Guangdong Province in the Chebaling Nature Reserve suggesting another breeding site exists there. Since 1990, there have been only 7 confirmed observation locations; but, other than noted above, it has not been observed in recent years in other parts of its historic range in south China or Hainan (Zhou 1996, Fellows et al. 2001, Gao et al. 2000, BirdLife International 2001, Hafner pers. comm.). There are no population figures, but the world population numbers fewer than 20-50 birds. Certain remote areas in south China not yet surveyed need to be visited in a near future. In these forested mountain habitats difficult to access, isolated breeding sites may have gone unnoticed so far. This is the most endangered of all the herons (Kushlan and Hafner 2000).

distribution map

Habitats

The White-eared Night-Heron is a forest bird. Optimal habitat appears to be extensive, dense, primary forests with streams and adjacent marshes. It currently is observed only in mid-altitude mountains and has not been found higher than 1,300 m. However, it likely was originally also a lowland species, and its current restriction to hilly areas is probably because there are no remaining lowland forests (Fellowes et al. 2001).

Given that very little pristine habitat remains within the historic range of the species, it is observed primarily in degraded habitats in and near forest reserves. Recent observations have been near streams, a reservoir, and rice fields, all feeding sites located within 40 km of subtropical forests. These observations do not necessarily suggest that it can survive long term in altered environments, but rather that it has been forced into these sites as more appropriate habitat is now lacking (BirdLife 2001).

Foraging

This is a very poorly known species. Observations of the species’ foraging are few (Caldwell and Caldwell 1931). Herons have been reported as feeding singly or in isolated pairs feeding on the ground in ways likened to a bittern. They roost high in trees. All evidence suggests that it feeds primarily at night, as it has been observed flying from roosts in the evening (Fellowes et al. 2001.). However daytime activity has also been reported (Zhou 1994). The diet includes fish, shrimp and insects, but is very little documented (Zhou 1994).

Breeding

Nearly nothing is known about the breeding biology of this species. Various records of nesting activity indicate it nests in trees including oaks (Quercus), pines (Pinus), bamboo (although a nest was not found) and, likely, broad leafed trees (Caldwell and Caldwell 1931, BirdLife 2001). Information on nesting by this species is confounded by indications that it nested with Malayan Night-Herons. Presumed nests were very near the tops of the trees, 4-10 m above the ground near the trunks. Presumed nests were simple flat platforms (Fellows et al. 2001).

Population dynamics

With nothing known about nesting, there is also no information on population biology.

Conservation

The White-eared Night-Heron is the world’s most endangered heron; immediate action is required for its conservation. It is clearly endangered (Kushlan and Hafner 2000 IUCN 2003). Fortunately, Guangxi and Guangdong Forestry Departments and county governments are strongly committed to conserving the species (Fellowes et al. 2001). In Guangxi, the Fusui White-eared Night-Heron reserve was declared in 1999. In that only two breeding sites are known thorough surveys need to continue and expand. The recent surveys in southeast China were important first steps in identifying locations where birds remain (Fellowes et al. 2001). The surveys began by canvassing the local population, gaining public involvement, providing publicity, and following this with ground surveys. This model could be followed to great benefit in other areas where the species is expected. Where sightings occur, immediate protection of the area should be envisaged. Specific conservation issues include hunting, deforestation, reintroduction, and education. Hunting is a threat to this species, apparently even in nature reserves. Young herons are captured for the market. In fact, discovering an animal for sale in a Nanning market sparked the current conservation effort (Lee 1998). Hunting pressure of all kinds is intense in the rural agricultural areas that constitute the species’ current range. Night herons (including both this and the Malayan Night-Heron) are trapped, shot, and noosed (Fellowes et al. 2001). In Fusaui, where empty night heron nests were found, villagers have reported that they killed adult birds at the nesting site the year before (BirdLife 2001). An immediate conservation effort should be undertaken to eliminate the use of this and other rare species to meet the strong local market demand for birds. This practice threatens all the herons in the area, especially those that nest colonially. The optimal approach would be to attempt to divert hunting from all the colonial species. The night heron is a nationally protected species in China.

The principal habitat threat to the species, in fact to other Gorsachius herons as well, is habitat loss, including deforestation, reforestation with pine monoculture, reservoir construction, and gold mining. Deforestation has been underway for centuries, and the remaining diverse forests are very confined, mostly in reserves. Most of the existing forest in the area is monoculture pine plantation. This species occurs in areas of south China recognized for their importance to a collection of endemic species, many of which are now endangered. Even in reserves, degradation and disturbance continue. Tourism is increasing in remaining reserved areas, also posing threats for this heron’s well-being. Another very important threat, especially to this nocturnal species, is the numerous electric power lines concentrated usually along streams because the streams provide openings in the forest facilitating the erection of the lines. To provide habitat, truly protected forest areas are essential. At the nature reserves where the species still occurs, specific management plans are needed, including control of tourism effects, forest management and restoration, management of river bottoms and marshes as feeding habitat, realignment of reserve borders, creation of reserve corridors, and protection from hunting. When new breeding sites are found, they and the feeding habitat will require absolute protection. These qualify as Important Bird Areas for the species and need to serve as the basis of a network of reserves, managed sites and other conservation efforts aimed to protect the remaining birds. To the extent possible, a captive breeding programme should be considered. Fellowes et al. (2001) recommended that no more birds be taken from the wild. However, birds that are rescued from market could form the core of a captive population which could be used to re-establish or enhance the wild stock as sites are protected. Educational awareness of the existence and plight of the species among local populations is essential. The campaign that accompanied recent field surveys leading to the establishment of a reserve is an excellent example of meeting such needs. The species will not likely be saved except by local people.

Research needs

Clearly, with nothing known about the biology of the species, observational studies should be undertaken at every opportunity, particularly focusing on establishing the habitat requirements of the species. Surveys of known and suspected areas used by the species need to be undertaken to identify additional important areas. In order to render these surveys more efficient in the future, any opportunity should be taken to record vocalizations, for instance by captive birds. Once vocalizations are known, the periodicity of calls during the year, the day, and the night should be established in the known breeding areas. Surveys of this secretive bird in other forest habitat could then focus on the periods and hours with the highest probability of hearing a call. It is essential that the migratory status and year-round habitat needs of the species be understood. The potential feeding sites within flying distance of possible colony sites need to be determined.

Overview

The White-eared Night-Heron is the most endangered of all the herons, and biologically nearly unknown. Only a few have been seen and reported in recent years, and the world population likely numbers not many more than are presently known. This is fundamentally a lowland forest heron, which occurred in dense, wet, primary lowland forests with streams and adjacent wetlands and rice paddies. This habitat hardly exists at present. Herons that persist due so at the edge of their ecological tolerances in secondary forest in hills and mountains near residual forests. This is a species that seems to not tolerate disturbance well, and so requires reserves. Where found now it feeds in rice fields and irrigation systems. When rediscovered, the birds were in demand for the market in the area they are found, and their rarity did not provided much protection. The only hope for the species is for its welfare to become a concern of the local human population, its nesting sites be completely protected from disturbance, and feeding sites secured. The only successful conservation for this species will be that provided by and in cooperation with the local people.

White-backed Night-Heron

White-backed Night-Heron

Nycticorax leuconotus (Wagler)

Ardea leuconotus Wagler, 1827. Syst. Av., Ardea, No.3: Senegambia.

Other names: Martinete Encapuchado in Spanish; Bilhoreau à dos blanc in French; Weißrückenreiher in German.

Description

The White-backed Night-Heron is a nocturnal medium dark heron with a large white eye ring on a dark head and white plumes on an otherwise dark back.

Adult: The White-backed Night-Heron has a black head and a short, thick crest, strikingly setting off a large white patch around a relatively huge eye. The bill is black, with yellow its lower base. Irises are dark brown and the lores are green yellow. The chin is white and the neck is rufous brown. The back is black brown with white lanceolate plumes forming the dorsal patch, which is conspicuous at times and inconspicuous at others, probably related to breeding. The upper wings are brown; flight feathers are slate. Tail is black brown. The under parts are pale buff and brown; belly is white brown. Legs and feet are green to orange yellow. In breeding, irises turn red, chestnut, amber, yellow, probably in a sequence not yet described. The lores are lemon yellow.

Variation: The sexes are alike. Geographic variation is unclear, but South Africa birds have been described as natalensis.

Juvenile: Immature birds have dark brown streaked crown and forehead. Body is buff brown with heavy white streaking and speckling.

Chick: The chick is covered in olive brown down with buff feather tips. Bill is green grey. Irises are brown. Legs are green grey. Feet are yellow green.

Voice: The species is generally quiet. The growling “Taash” call, rendered “taash, taash, taash” is the disturbance call. The “Kroak” call is the alarm and flight call.

Weights and measurements: Length: 50-55 cm.

Field characters

The White-backed Night-Heron is identified by its relatively large, dark head and huge eyes

accentuated by the white eye ring and its white back patch. It is distinguished from immature Black Crowned Night-Herons by its smaller size, large head, white back patch, and more spotting on the back and wings.

Systematics

The generic identity of the species is not well settled. It has been variously assigned to Nycticorax and Gorsachius. The taxonomy of these night herons need to be further examined to determine both genus and species limits.

Range and status

The White-backed Night-Heron occurs in Africa, south of the Sahara.

Breeding range: It breeds widely from Senegal, Gambia, Guinea-Bissau, Cote d'Ivoire, Nigeria, Gabon, Sudan, Ethiopia, Congo, Tanzania, Uganda, Botswana, Zambia, Zimbabwe (Jonasi 1994), Malawi (Nyirenda 1992), Mozambique, north Angola, and east South Africa (Raymakers 1992).

Migration: The species appears to be sedentary, although it is likely that they undertake movements correlated with the onset of rains, but more information is needed on this secretive species.

Status: It is widely distributed through central and southern Africa but rare to uncommon. It may be most abundant in the Congo swamp forests and upper Zambezi in Zambia (Turner 2000).

distribution map

Habitats

The White-backed Heron is a forest heron. It occurs in densely vegetated forests near water, especially along with tree-fringed streams, on islands in large rivers and lakes (Jonasi 1994), mangrove swamps along both African coasts, and forested lakes. It does also uses reed beds and dry forests. In places (Gabon) it is found close to human habitations, but this is not general.

As a nocturnal species, requiring secure day resting spots. It roosts in very dense marsh or forest vegetation, often high in trees.

Foraging

This appears to be very much a strictly nocturnal species. It has been observed feeding primarily at the water’s edge, along muddy banks, and in the reeds along water courses. It feeds by Walking slowly along and in shallow water and by Standing on vegetation such as rafts o floating reeds. It feeds alone or in pairs in and near dense vegetation. Both adults and young assume a bittern posture on disturbance (James 1988, Bock and Medland 1988). Its diet is little known but it does consume fish (Blasdale 1984), amphibians, mollusks, and insects.

Breeding

Breeding season is variable, usually at the height of the local floods, which varies from place to place, and time to time. It nests in July–January and also March–April in South Africa, August–December and also January–June in Tanzania, May–June in Kenya, September–October in Nigeria.

The White-backed Night-Heron nests low in trees, bushes, reed beds, and on rocky shores in caves (Edwards1988). It nests solitarily and nests are placed close to the water or ground. They are large and bulky platforms made of sticks or reeds lined with smaller pieces of the same material. They are 25-30 cm across. Nests are generally close to the water, usually within 1 m but sometimes 3 m. It also nests on the ground in reed beds.

Nothing is known about the courtship or nesting behavior. The eggs are green white, 45.7 x 35.1 mm. The are probably laid at intervals of 48 hours or more. Clutch is 2-3 eggs; range is 2-5. The herons will sometimes double clutch. Incubation is 24-26 days. The often young grow to considerable size before leaving the nest at 6-7 weeks old.

Population dynamics

Nothing is known about the population dynamics and conservation of this species.

Conservation

The White-backed Night-Heron is a widespread but scarce bird, and is secretive, making surveys and monitoring difficult. A first step in conservation is to determine the species’ distribution, habitat needs, and population status. This will require surveys throughout its range. The dependence of the species on swamp and riparian forests makes it vulnerable to the effects of harvesting of such forests throughout its range.

Research needs

Owing to its secretiveness, dispersed range, and difficult habitat this is one of the least understood herons. Studies are needed of its basic biology, including nesting, courtship (including the function of the dorsal plumes), foraging, food selection, dispersal, and habitat requirements. The evolutionary relationships of the night herons are not clear and a comparative study of the species is needed.

Overview

This night heron is a nocturnal, forest dweller that feeds secretively on the edges of cover tending to nest in the local flood season. Little is known about its feeding behaviours, food taken, or environmental correlates of foraging or nesting success.