Black-winged Stilt (Himantopus himantopus) is spindly legs that not only give the bird its apt name but also control its feeding. It is longer than those of other waders and only vestigially webbed. They enable the bird to wade out into shallows to find its food but not to swim or submerge for it as Banded Stilts and avocets do. As a result, it is limited to foraging in wet mud and shallow water up to 15 centimeters deep in still, freshwater, and brackish swamps.
There it stalks gingerly along, spaced out in ones, twos, and threes, picking up its food from the surface and in the mud with jabs and probes of its needle-like bill: molluscs, flies and aquatic insects, diatoms, and brine shrimps. Its mouth is tiny, allowing only minute organisms to be ingested.
Adults are more adept feeders than juveniles, walking more slowly and pecking more actively; in family parties, they may defend their feeding area from other birds. Often appearing sedentary, Black-winged Stilts nonetheless seem to be nomadic, often traveling to new feeding grounds at night, their movements tracked by their characteristic yelping barks. Their flight, on short-pointed triangular wings, is not fast, on deliberately pushed wing beats; long trailing legs may help in maneuvering.
They may be gregarious and gather in loose feeding assemblages of several hundred, but they never form compact flocks and nest in dispersed aggregations, each pair with its own moderate territory. Young hatch together is precocious and leaves the nest within hours. While still small they are brooded at night.
The other names of this bird are Pied Stilt, White-headed Stilt, Long-shanks, and Dog-bird. The size of Black-winged Stilt is about 365-390 mm. However, both adults’ sexes are similar, without eclipse plumage. Back of head and nape black, separated from black back and wings by a white-collar. The rest of the body is white, along with red eyes and a black bill.
The legs and feet are pink. The immature bird’s back and head are dull gray; dark grey patch around the eyes; the wings and back are grey-brown. The downy young are pale ochre above, dotted black that develops into pairs of broken lines down back and flanks; hindneck, underparts white.
The call of Black-winged Stilt is single yelping or puppy-like barking call, persistently repeated, in contact, sharper in alarm; higher-pitched warning piping notes in flight.
The nesting and breeding season is August-December. The bird builds a nest in the depression in the mud at the water’s edge, on an island in a swamp among damp vegetation, or at times a built-up structure in shallow water. Leaves and stalks of swamp plants, grasses, and small twigs were added for lining, often forming a platform.
Black-winged Stilt usually lays four eggs; that are dull green or stone-colored, heavily marked with purple-brown and black with underlying lavender lines; pyriform, about 45 x 29 mm. Moreover, the incubation period is about 23-25 days, for both sexes in short spells.
The distribution of Black-winged Stilt is edges of still, shallow, muddy surface waters, both fresh and brackish, throughout Australia, with outlying populations in southern New Guinea and Sunda arc to Philippines (Australian race, with white head and mantle, and black hind-neck).
It is nomadic but self-introduced in New Zealand where hybridizes and intergrades with endemic Black Stilt. Other races, sometimes regarded as separate species, in Afro-Eurasia (one), the Americas (three), and the Hawaiian islands (one); are those that meet intergrade.
Black-winged Stilt Facts – (Himantopus himantopus) is spindly legs that not only give the bird its apt name but also control its feeding. Photo Credit – Leo @ FlickrBlack-winged Stilt Facts – (Himantopus himantopus) is spindly legs that not only give the bird its apt name but also control its feeding. Photo Credit – Pixahive
