| White-bellied Heron | |
|---|---|
| Conservation status | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Pelecaniformes |
| Family: | Ardeidae |
| Genus: | Ardea |
| Species: | A. insignis |
| Binomial name | |
| Ardea insignis Hume, 1878 |
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| Synonyms | |
|
Ardea imperialis |
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The White-bellied Heron (Ardea insignis) is a species of large heron found in the foothills of the eastern Himalayas in India, northeastern Bangladesh, Burma and Bhutan. Records in the past have been from Nepal. It is mostly all dark grey with white throat and underparts. This heron is mostly solitary and is found on undisturbed riverside or wetland habitats. The global population has declined and the species is threatened by disturbance and habitat degradation.
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This large heron is plain dark grey above with a long neck. The crown is dark and there are no black stripes on the neck as in the Grey Heron. In breeding plumage, it has a greyish-white nape plume and elongated grey breast feathers with white centres. The bill is black, greenish near the base and tip and the face is greenish grey. The chin is whitish. The legs are dark. In flight, it has a uniform dark grey upperwing and white underwing-coverts contrasting with dark grey flight feathers. The rump appears paler grey.[2] At 127 cm (50 in), it is the largest Asian heron and the second largest heron on earth, after the Goliath Heron. On the ground it walks slowly, moving its neck slowly while looking from side to side. The Goliath Heron is larger and has a chestnut neck while the slightly smaller Sumatran Heron is grey necked with the underside of the wings all grey.[3]
The usual call given when disturbed is a deep croak.[3]
This heron was first noted as the "Great Indian Heron" in JE Gray's Zoological Miscellany of 1844 based on Brian Houghton Hodgson from Nepal.[4] Allan Octavian Hume noted its distinctiveness and pointed out the differences between it and Ardea sumatrana.[5] The alternate name of Ardea imperialis was suggested by Stuart Baker, since Hodgson's name was a nomen nudum and this was used in Peter's Checklist.[6] This was used until 1963, when Biswamoy Biswas commented on Sidney Dillon Ripley's synoptic list and noted:
[T]he name should be Ardea insignis Hume. Hume's name is available, since its citation as a synonym of Ardea nobilis Blyth and Ardea sumatrana Raffles are based on misidentification".[7]
The White-bellied Heron is found in the wetlands of tropical and subtropical forests in the foothills of the eastern Himalayas of India and Myanmar. It is also spotted in Himalayan Kingdom of Bhutan's sub tropical areas and was once found in Nepal. The major threats the heron faces are hunting (both the bird itself and its eggs) and habitat destruction (the cutting of nesting trees and the disappearance of wetlands).
This species is rarer than previously believed; indeed, it appears close to extinction. It has therefore been uplisted from Endangered to Critically Endangered status in the 2007 IUCN Red List.[1] In Bhutan, white bellied herons are found in the low elevation riparian habitat below 1700 m, particularly in the Punatsang Chhu (river)basin. About 32 individual birds are known within the river valley of Bhutan in the Punakha-Wangdiphodrang district in west central part of the country. It is under grave threat of extinction in Bhutan due to accelerated development of large-scale hydro-power projects in the basin. Rising water levels force the nesting birds to search extensively for fish, leaving the eggs or chicks exposed to predators such as the Crested Serpent Eagle.