Yellow Bittern (Ixobrychus sinensis) walking on lilypads for feeding
Ixobrychus bitterns are a genus of eight small tropical bitterns. The Yellow Bittern (Ixobrychus sinensis) ranges from southern China to New Guinea and Oceania. It usually feeds on invertebrates and fish in reed beds or other forms of cover either by climbing on the vegetation or by walking along the ground (del Hoyo et al. 1992).
I observed the feeding behavior of at least one Yellow Bittern at Pulau Samosir (2° 35′ N, 98° 49′ E), a large island with an area of 630 km2 which occupies just over a third of the total surface area of the volcanic Lake Toba in northern Sumatra. In the grounds of my hotel, there was a small area of reed beds near the shore of the lake. Nearby there was a small pond (1 ha) that was covered by the leaves of waterlilies. Two adult White-breasted Waterhens (Amaurornis phoenicurus) with four black chicks and a Moorhen (Gallinula chloropus) were also present. On a number of occasions during 28-30 October 2014, a single Yellow Bittern was observed in the late afternoon to come 10 m out of the reed beds and walk around on the lilypads for ten minutes or so. It was further observed taking something off the leaves either standing or by actively running. The bird(s) spent much of the time inside the reed beds so whether it was the same bird is unknown. But the bitterns did not interact with the rails present.
This is the first time I had observed such behavior in this species or any Ixobrychus in wide field experience of the Old World species in Africa and Asia. Apparently this is the first report of this method of feeding in this species and genus (c.f. Kushlan and Hancock 2005).
Kushlan, J. A. and J. A. Hancock. 2005. The Herons. Oxford University Press, New York, New York, U.S.A.
del Hoyo, J., A. Elliott and J. Sargatai. 1992. Handbook of the birds of world. Lynx Editions, Barcelona, Spain.