The IUCN-SCC Heron Specialist Group

Herons of World-wide Conservation Concern (2021)

Alphabetical list of abstracts for presentations

Bolded names are the presenters

Saving the critically endangered White-bellied Heron from extinction: two decades of conservation efforts and the way forward

Acharja, Indra; Tobgay, Tshering; Lungten, Lungten; Phuntsho, Thinley; Lhendup, Tshewang; Tshering, Sonam
Research Scientist, Royal Society For Protection Of Nature

The White-bellied Heron (Ardea insignis) is critically endangered and one of the rarest heron species in the world. While 50-249 adults are estimated to be surviving over the extent of 165,000 km2 of the Himalayan freshwater ecosystems, fewer than 60 are confirmed to exist today, spanned over Bhutan, India, Myanmar, and China. Since 2015, after the preparation of the conservation strategy and hosting of the first international conference for the species, range countries have been putting efforts to protect the fragmented populations and restore their habitats. In Bhutan, conservation started in 2003 soon after the discovery of the first active nest for the country and rediscovery for the world after more than 7 decades of the previous record. Over the last two decades, we have monitored the population trend, distribution & habitat use, nest, and active breeding population and mapped major threats to the bird and their habitats. In Bhutan, we conducted the annual population survey for the last nineteen consecutive years and recorded 28 ± 4.8 (n = 19) individuals. The average active nests (number of breeding pairs per year) of 2.6 ± 1.4 (n = 50) with an average clutch size of 2.7 ± 1.4 (n = 28), the hatch success rate of 1.9 ± 1.1(n =4 0) and 1.8 ± 1.1 (n = 42) of fledgling success per nest were recorded. While we observed a high nesting survival rate of 86% (n = 50), very little information is available on predators, fledgling survival post-fledging, dispersal, and mortality. Despite high breeding success and annual juvenile recruitment, considering the small overall population size, the population in Bhutan has remained low and potentially declining. The small and fragmented population with a restricted range and small gene pool is further threatened by habitat loss due to infrastructure development, hydropower dams, extractive industries, and climate change in the region. Our long-term monitoring and conservation filled many information gaps and provides important implications including the call for securing ex-situ gene pool, conservation breeding, more coordinated and impactful in-situ conservation efforts to save this species from extinction.

Agonistic behavior between Reddish Egrets Egretta rufescens in Northern Colombia

Ardila, Oscar Aldana1; Carlos, Caio2
1 Laboratório De Sistemática E Ecologia De Aves E Mamíferos Marinhos UFRGS;

The Reddish Egret Egretta rufescens inhabits shallow coastal flats, lagoons, and salt pans. It is distributed from the southern coast of the United States and the Pacific coast of Mexico, through the Caribbean islands and the Central American coast to northern Colombia, Ecuador, and Peru. Among the herons of the Americas, the Reddish Egret is the most solitary forager and the one that is most aggressive defending its feeding territories. Observations were made in a wetland habitat located in Laguna Buenavista (118340N, 728510W) in La Guajira state, Northern Colombia. This report describes the first observation of an adult Reddish Egret killing a juvenile conspecific. The possible reason for the killing was the invasion of the adult's foraging territory.

Setting up protocols to monitor the Critically Endangered White-bellied Heron, Ardea insignis, with focus on threats to the species in the changing landscapes around Namdapha Tiger Reserve, Arunachal Pradesh, India

Bida, Yumlam Benjamin1; George, Rohit1; Yomcha, Tajum2; Khaling, Sarala1
1 Ashoka Trust for Research in Ecology and the Environment, Regional Office, Eastern Himalaya-Northeast India, Gangtok, Sikkim, India;
2 Namdapha Tiger Reserve, Miao, Changlang District, Arunachal Pradesh, India

The White-bellied Heron (WBH), Ardea insignis, is one of the most threatened birds in the world. India may host the largest population of WBH, but there have been limited population surveys. Namdapha Tiger Reserve (NTR), in the north-east of the Indian state of Arunachal Pradesh, has been noted as a strong-hold for the species where sightings have been recorded and estimates thus far are of 5-6 individuals remaining. However regular monitoring of the species has been a challenge due to lack of resources and with more attention being given to monitoring large and charismatic mammals found in the Tiger Reserve. 3 line transects measuring 1-2 km were identified in areas where there have been records through opportunistic sightings by tourists, wildlife enthusiasts and NTR staff. These will be used for monitoring White-bellied Heron in collaboration with the Reserve staff and local communities residing in the fringe area of the Reserve. As a trial measure these transects were monitored in the summer of 2021 by surveying along these trails in the mornings and evenings. Various environmental parameters, activities of the birds and habitat characteristics were recorded during these surveys. 2 pairs of birds were recorded in two of these transects during these surveys which are known WBH habitats. Anthropogenic activities like fishing, construction of temporary check dams, built up area, habitat being used as a thoroughfare and general presence of people were observed along all these known habitats. While areas in core areas of NTR may provide a better habitat for the species in terms of lesser threats and disturbances, it is imperative to monitor the species in its known habitats as establishing its presence in unknown areas will be challenging considering the terrain and the shy and elusive nature of the bird. We will continue to use the monitoring protocols by training the NTR staff and involving them in monitoring the species seasonally.

Observations of the largest known breeding colony of Agami Herons at Tapiche Reserve in the Northeastern Peruvian Amazon

Chen, Deborah1; Reis, Murilo1; Reintjes, Jana1; O'Donnell, Sean2
1 Tapiche Jungle Reserve, Peru;
2 Drexel University

The Agami Heron (Agamia agami) is widespread in the Neotropics but remains a poorly understood species; little has been confirmed regarding population sizes and trends, seasonal migration patterns, and the Agami's role in the wetland communities it inhabits. In this paper, we explore these topics through observations made from 2013 to 2021 of a large mixed-species heronry including Agami Herons located at the Tapiche Reserve in northeastern Peru. Situated in seasonally flooded forest at the edge of a lagoon, the two-hectare breeding ground is observable by eye and binocular via boat and was estimated to contain several thousand Agami nests in 2017 and 2019. As seasonal breeders, the Agami are typically present at this site between January and July, outside of which the rookery is deserted. The Agami were completely absent in 2018, when the nesting area did not flood, and 2020, when the flood was low and delayed. The Agami were the first to occupy the breeding ground during years of breeding success, with Boat-billed Herons arriving later in approximately equal numbers to the Agami. The Boat-billed Herons appeared to use existing Agami nests rather than building new structures, and, in the years that the Agami did not nest, the Boat-billed also failed to breed. Eight additional waterbird species are resident in the rookery area, some breeding concurrently with the Agami. Primates, raptors and reptiles were seen preying upon Agami eggs and young. Prior to reserve establishment in 2010, local people exploited the rookery by collecting eggs. The Agami responded rapidly and positively to protection of the rookery and showed resilience to isolated episodes of drought. Some observations suggest, however, that these birds are challenged by consecutive years of adverse climate conditions. An understanding of the Agami's foraging behavior and range while breeding, movement patterns outside the breeding season, and alternate breeding locations, if any, during atypical flood years would be of immense value to conservation efforts for this iconic heron species.

Overview on the diversity, biogeography, and conservation of Herons in Ecuador

Cisneros-Heredia, Diego1; Peñaherrera-Romero, Emilia2
1 Professor, Universidad San Francisco De Quito USFQ, Colegio De Ciencias Biológicas Y Ambientales, Instituto IBIOTROP, Laboratorio De Zoología Terrestre & Museo De Zoología, Quito 170901, Ecuador;
2 Universidad San Francisco De Quito USFQ, Colegio De Ciencias Biológicas Y Ambientales, Instituto IBIOTROP, Laboratorio De Zoología Terrestre & Museo De Zoología, Quito 170901, Ecuador

Twenty-three species of herons have been reported in Ecuador, including Agami Heron (Agamia agami) classified under the IUCN threatened category of Vulnerable and Zigzag Heron (Zebrilus undulatus) considered as Near Threatened. Few studies have focused explicitly on the herons of the country, and little information is available about their current distribution, natural history and ecology, population trends, and conservation status. We produced an integrated and updated assessment of the species richness and biogeographic patterns for all species and subspecies of herons of Ecuador. This study is based on a large species occurrence dataset obtained from different sources, including fieldwork, scientific literature, grey literature, natural history museums, open data biodiversity databases, and private expert databases. Analyses emphasise on wetlands and other localities that are part of the National System of Protected Areas of Ecuador or are classified as Important Bird Areas or RAMSAR sites. We identified causes driving population changes (declines or increases), including habitat changes, illegal hunt, invasive species, or human-heron conflicts. Finally, we applied the IUCN Red List categories and criteria to evaluate the extinction risk for all species at the national level and provide suggestions for implementing research and conservation actions.

A coordinated response to the plight of the White-bellied Heron (Ardea insignis)

Goodman, Gemma
Head Of Conservation Programmes, Synchronicity Earth/White-bellied Heron Working Group

The Critically Endangered White-bellied Heron (Ardea insignis) is the one of the world's rarest birds and is the second largest heron. As such, a group of international and range-state based conservationists, government representatives and scientists, came together in Guwahati, India in December 2014 for a Conservation Strategy Workshop. As a result, the White-bellied Heron Working Group was formed under the IUCN SSC Heron Specialist Group; International and Regional Coordinators were appointed and a global Conservation Strategy was produced in November 2015. This was followed by a second International Workshop held in Bhutan in late November 2015. Survey work in China got underway in 2015 to try and understand the likelihood that a population still survived in China or not; while in India the White-bellied Heron Coordinator held national meetings and field work increased. Soon after, one of the top priority actions was implemented when two birds were fitted with satellite transmitters in Bhutan in June 2016. The IUCN SSC White-bellied Heron Working Group, has been working through its members to provide multi-pronged support at levels ranging from funding, to capacity support in satellite telemetry (since 2016), captive breeding (with training at international zoos starting in 2017, a breeding centre built in 2020 in Bhutan and birds brought into captivity in Bhutan in 2021) and assistance with identifying areas of survey priority and survey techniques (since 2018). This small yet committed community continues to strive to protect the species from the on-going and growing threats to the species. This talk explores the challenges and hope for such a species and attempts to centralise information and support through a Working Group model.

Reddish Egret Conservation: A 15-year history of the Reddish Egret International Working Group

Green, Clay
Texas State University

In 2005, a group of biologists met during the 29th Annual Meeting of the Waterbird Society to discuss conservation and research needs for Reddish Egrets (Egretta rufescens). Subsequent to that meeting, a species status review was conducted in 2006 and the Reddish Egret Working Group (REWG) was established. From 2006 – 2011, significant research was conducted on the species including establishment of long-term banding program, movement ecology studies using satellite telemetry and several range-wide population genetics study commenced. Also during this period, the REWG began capacity-building to establish a network of biologists, natural resource managers and other stakeholders invested in the conservation of Reddish Egrets and their associated habitats. In 2012, the REWG held its first meeting of the working group in Corpus Christi, Texas with stakeholders from U.S.A and Mexico. Using the Open Standards for the Practice of Conservation model, the REWG developed and drafted the first Conservation Action Plan for the species published in 2014. While various objectives of the Plan were being implemented, the REWG continued capacity-building to add partners and stakeholders from throughout the species range. During this period, ProNatura received funding from the Neotropical Migratory Bird Treaty Act Grant to conduct wintering surveys in Mexico and ultimately the completion of the Mexican Business Plan for Reddish Egret Conservation. The REWG also began meeting on annual basis to further advance conservation and research for the species. In 2018, the REWG secured funding from National Fish and Wildlife Foundation to update the Conservation Action Plan to include the development of range-wide strategies and objectives as well as the U.S. Business Plan for Reddish Egret Conservation. Various workshops were held during the drafting of these documents and included partners from U.S.A., Mexico, Cuba, Honduras, Belize, Bahamas and Colombia; at these workshops, the REWG officially changed its name to Reddish Egret International Working Group (REIWG). In 2021, the REIWG completed the range-wide Conservation Action Plan with seven over-arching conservation strategies for the next 10-year period.

The Heron Specialist Group (HSG) of IUCN: an Open Discussion and Update

Green, Clay
Texas State University

The Heron Specialist Group (HSG, www.Heronconservation.org) is an independent, world-wide network of biologists, conservationists and others engaged in research and conservation of herons. This virtual open session is for all those interested in herons and provides an opportunity to learn about the HSG, its Heron Working Groups, our Journal of Heron Biology and Conservation, our past (HeronConservation » JHBC vol.3 art.5) and future (https://www.paoc15.org/programme) symposia and to discuss local heron research and conservation projects. If you have questions ahead of time, please contact: chip.weseloh@ec.gc.ca. See you there.

Targeted water management is key to recovery of the endangered Australasian bittern

Herring, Matthew
Murray Wildlife / Charles Darwin University

The Australasian bittern (Botaurus poiciloptilus) is a cryptic, globally endangered waterbird and the most threatened bittern in the world. Over the past decade, concerted efforts, including substantial public funding, have promoted the species as a flagship for wetland conservation and provided new insights into the conservation status, key threats and required conservation actions. The global population appears to be around 2,000 individuals and still in decline, particularly in New Zealand. The new Action Plan for Australian Birds (Garnett and Baker, Eds., CSIRO Publishing) estimates the national population at 1300 birds, concentrated in the Riverina region of New South Wales, where rice fields support 500-1,000 birds, with the most important natural wetlands comprising the Barmah-Millewa, Lowbidgee and Fivebough-Tuckerbil systems. Northern Victoria, especially around the Kerang region, contains several key wetlands, like Hird and Johnson Swamp, while south-western Victoria, including adjacent parts of south-eastern South Australia, can also support relatively large numbers, notably at Bool and Hacks Lagoon, and Pick Swamp. With the exception of rice fields, almost all of these occur in protected areas and game reserves. Tasmania and south-western Australia each support a small, relatively isolated subpopulation of less than 100. In Australia, the increasing severity and frequency of drought is now considered the key threat, emphasising the importance of drought refuges and impacts of climate change. Dry periods reduce the environmental water available for key bittern sites in the Murray-Darling Basin and amplify water-use efficiency measures in rice fields that are undermining successful breeding opportunities. Improved water management across all wetland types could maximise the benefits to bitterns. For example, providing a sufficient hydroperiod for successful breeding that also incorporates a drying phase can maintain the preferred early successional stages of vegetation and maximise prey abundance. Incentives for bittern-friendly rice farming and targeted environmental water management at key wetlands should be prioritised, while the potential impact of fox and cat predation needs to be assessed. Despite increased attention, the conservation status of the Australasian Bittern remains grave and greater management effort is urgently required.

Nest predation of the critically endangered White-bellied Heron Ardea insignis by Masked Palm Civet Paguma larvata in Bhutan

Khandu, Pema
Teacher/Heron Biologist, Department Of Science, Biology And Environmental Sciences, Wangbama Central School, Thimphu 11001, BHUTAN

The White-bellied Heron Ardea insignis is verging extinction, but very little is known about their basic ecology and biology, hindering effective implementation of the conservation actions. Although the nesting failure rate of the White-bellied Heron recorded in Bhutan seems widespread, to date, nothing is known about the predators of this species, nor its causes sufficiently understood. We carried out a systematic survey method to locate the nests of the White-bellied Heron. The active nests were monitored continuously until the fate of the nests was confirmed. Then, the camera traps were set up on the failed and abandoned as well as the artificial nests baited with dyed chicken and dummy eggs. The evidence strongly suggests that Masked Palm Civet Paguma larvata is an egg predator of the White-bellied Heron responsible for a single nest failure at Burichu, Tsirang. Also, potential bird egg predators belonging to at least eight genera were documented. To this end, conservation management should implement evidence-based nest protection methods from their natural predators to reduce and prevent further nesting failures. Additionally, an intensive study is required to glean vital information on the causes of nesting failures, including the nesting predation from their breeding sites and its impacts on their nesting behavior.

Overview and wrap-up of Herons of World-wide Conservation Concern

Kushlan, James

This presentation will examine the papers presented in the symposium from the standpoint of the Working Group as well as the goals of the Heron Specialist Group, as part of the International Union for the Conservation of Nature (IUCN).

Observations and conservation implications of a newly discovered White-bellied Heron nesting site in India

Patgiri, Samiran
Ph.D. Candidate, Mizoram University

The White-bellied Heron, Ardea insignis, is on the verge of extinction, with residential populations presently distributed only in Central Bhutan, North-East India and Myanmar. The Namdapha Tiger Reserve is the only breeding site of the species in India, holding a population of at least 7-8 individuals. In India, there is a huge knowledge gap in understanding the occurrence and distribution pattern of the White-bellied Heron, due to limited survey efforts in probable areas. The majority of areas in Arunachal Pradesh remain largely unsurveyed for White-bellied Heron. Therefore, the recent discovery of its nesting site in Walong area of Arunachal Pradesh is significant. It is the second nesting record after Namdapha and the easternmost record of White-bellied Heron in India. Here we present the preliminary findings of our surveys in Walong which was carried out from April to August. The surveys were carried out to record their feeding sites, documentation of potential threats and disturbances, behaviour towards human and other relevant aspects. Our findings show differences in White-bellied Heron behaviour towards humans, contradictory to the established perceptions in the Indian context. The White-bellied Herons appeared tolerant to human presence. We conducted semi-structured questionnaire surveys with 64 respondents in nearby villages to understand the historical occurrence of the species in the area and also to document the demography of the fringe communities. The documentation of White-bellied Heron in Walong is important due to the strategic location of Walong with other key White-bellied Heron sites.

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

Rabarisoa, Rivo
Participant, Member

The Endangered species Madagascar Heron, Ardea humbloti breeds in Madagascar with a recent records in Mayotte. In order to strengthen its conservation, investigations were carried out through literature reviews and field expeditions undertaken from 1993 to 2020 for population assessment and trend evaluation. Trend analyses were conducted using Trends and Indices for Monitoring data (TRIM) software based on 25 years survey and population estimates from 2015 to 2020. The species occurred in various type of wetlands throughout Madagascar with higher concentration along the western coastal area, it becomes rare in the southern part and absent along the eastern part of the country. The current population was estimated between 1,300 and 1,500 individuals with a minimum of 750 breeding pairs. The species was recorded nesting in colony but most of the time seen alone with one record in Mayotte. The population showed a moderate declination, but significantly did not exceed 5% per year (95% CI , p < 0.01).The main threats are habitat destruction, disturbance and persecution at its breeding site. Action plan for conservation are needed to preserve this species.

Habitat requirement of the Madagascar Pond-heron Ardeola idea in Madagascar

Rabarisoa, Rivo1; Rakotomanana, Hajanirina2
1 Participant, Member;
2 Co-author

Foraging habitat of the Madagascar Pond-heron, Ardeola idae, were investigated in Madagascar using data collected over the last 23 years through literature reviews, field monitoring and surveys undertaken from 1993 to 2016. Data from 220 localities were collected and analyzed for the study using bird abundance and habitat characteristics variables to determine foraging habitat needs. Madagascar pond-heron was present at 106 localities (48.18% of the visited localities). Based on wetlands classification used by the Ramsar convention, the species occurs at nine types of wetlands out of 32 identified in Madagascar. The habitat indices of frequentation (IhabM ) by the pond-heron were determined and the result show that the species give priorities to freshwater lakes (IhabM = 2.61) rice field (IhabM =1.06), and rivers (IhabM = 0.50), with significant difference between habitat types (Levene test: α = 0.05, p < 0.0001). In terms of abundance, freshwater lakes and rice field were the most frequented by the bird with respectively 21.11 and 10,47 bird per km2. Principal Components Analysis revealed that positive correlation exists between bird density and the height of vegetation at habitat shore, the vegetation cover on watershed, and the water pH, and inversely correlated to aquatic vegetation cover and altitude. Pond-heron were absent or had no preference for both non-vegetated wetlands and wetland with high level of human activities. The main threats of the species are habitat destruction such as conversion of wetlands for agricultural land, watershed deforestation, and urbanization at all its foraging area. Urgent actions are needed to reinforce action to limit wetland degradation especially at species foraging area.

An update on the status of Slaty Egrets in southern Africa

Tyler, Stephanie
National Waterbird Count Organiser Botswana, Birdlife Botswana

A single species action plan was produced for Slaty Egret Egretta vinaceigula in 2005. This paper updates the known distribution of Slaty Egrets to 2020 and provides information on recently discovered breeding sites. Since the first record in Angola - four specimens in the Lubango Bird collection - there have been 11 sightings of Slaty Egrets during May 2015 and August 2018, all in the Okavango catchment. Further surveys have been carried out in Zambia notably in the Barotse floodplains in Liuwa National Park where birds are not uncommon. Large counts of up to 100 birds have also come from the Kafue Flats and the Simungoma area of the Zambezi floodplain with recent sightings too from Bangweulu in the Zambian Congo system. However, there is no evidence of breeding in Zambia. Regular wanderers occur in South Africa, Namibia and Zimbabwe, with breeding only very rarely recorded in the former two countries. The presence of the species in Mozambique and the DCR is discussed.

In Botswana where the main population of Slaty Egrets occur, three breeding sites were known up to 2000 but since then a further nine colonies have been located. The locations of these are described and threats to the species are described. Some information is provided on roosting behaviour.

Update of the conservation status and distribution of herons in Paraguay

Yanosky, Alberto1; Selich, Tatiana Galluppi2; Irala, Rebeca3
1 Independent Research, Pronii-CONACYT;
2 Asociacion EcoPantanal Bahia Negra;
3 Wildlife Paraguay

Herons are closely related to humid environments, and are bioindicators of the quality of their habitats, mainly because of their fidelity to their nesting sites and being predictable in their reproductive phenology. Paraguay holds 14 species of herons, which occur in wetlands of local and international importance such as those found in the south of the country, the capital, the Central Chaco and the Paraguayan portion of the pantanal, thus embracing diverse ecosystems at the national level. The status of conservation and distribution of the herons was updated, using as a basis data collected in the free platforms eBird (www.ebird.org) at national level, Heron Conservation (https://www.heronconservation.org/) and Waterbird population estimates (http://wpe.wetlands.org/) at regional level, complemented by a revision of threat categories at national and international level. Currently, no species is under a threat category at the national or international level, with all species being recorded in the last two years. However, there are increasing threats such as the conversion of wetlands to rice crops and other uses, and the construction of infrastructure works that directly affect the ecosystems used by the Ardeidae family. Species such as Egretta caerulea, Ixobrychus involucris and Cochlearius cochlearius are the less recorded and more range-restricted species where a focus should be placed on.