Asian Woolly-necked Stork

The woolly-necked stork is a medium-sized stork at 75–92 cm tall. The iris is deep crimson or wine-red. The stork is glistening black overall with a black "skull cap", a downy white neck which gives it its name. The lower belly and under-tail coverts are white, standing out from the rest of the dark coloured plumage. Feathers on the fore-neck are iridescent with a coppery-purple tinge. These feathers are elongated and can be erected during displays. The tail is deeply forked and is white, usually covered by the black long under tail coverts. It has long red legs and a heavy, blackish bill, though some specimens have largely dark-red bills with only the basal one-third being black. Sexes are alike. Juvenile birds are duller versions of the adult with a feathered forehead that is sometimes streaked black-and-white. The African birds are described as having the edges of the black cap diffused or with a jagged border compared to a sharp and clean border in the Asian birds. Sexes are identical, though males are thought to be larger. When the wings are opened either during displays or for flight, a narrow band of very bright unfeathered skin is visible along the underside of the forearm. …

It is a widespread tropical species which breeds in Asia, from India to Indonesia. It is a resident breeder building nests on trees located on agricultural fields or wetlands, on natural cliffs, and on cell phone towers. They use a variety of freshwater wetlands including seasonal and perennial reservoirs and marshes, crop lands, irrigation canals and rivers, but are mostly seen in agricultural areas and in wetlands outside protected areas across south Asia and Myanmar. They are attracted to fires in grasslands and crop fields where they capture insects trying to escape the fire. They use ponds and marshes inside forests in Asia, especially in south-east Asia where they use grassy and marshy areas in clearings in several forest types. In India, they are an uncommon species in coastal habitats. They use coastal areas in Asia with birds in Sulawesi observed to be eating sea snakes. In an agricultural landscape in north India, woolly-necked storks preferred fallow fields during the summer and monsoon seasons, and natural freshwater wetlands during the winter. Here, irrigation canals were preferentially used during winters when water levels were low, and birds avoided crop fields in all seasons. Assisted by construction of new irrigation canals, this species is spreading to arid areas like the Thar Desert in Rajasthan, India. …

Several calls by adult birds have been described including bisyllabic whistles given along with displays at the nest, and a fierce hissing sound when a bird was attacked by a trained falcon. The woolly-necked stork is a broad winged soaring bird, which relies on moving between thermals of hot air for sustained long-distance flight. Like all storks, it flies with its neck outstretched. It has also been observed to 'roll, tumble and dive at steep angles' in the air with the wind through its quills making a loud noise. Adult birds have also been observed diving from nests before flying away abruptly in a 'bat-like flight'. This species is largely seen as single birds, in pairs, or in small family groups of 4–5. While flocks are uncommon, they occur in all parts of the distribution range of the species and can be seen in all seasons. Flocking is affected by different factors in different areas. In more arid areas, most of the flocks occur in the summer when few wetlands are remaining, whereas in areas with more water, flocks occur largely in winter after chicks have fledged from nests. However, on agricultural landscapes, artificial irrigation introduces considerable complexity in providing water throughout the year, and flocks occur throughout the year. …