Saturday, 2 February 2013

Black Winged Stilt


order : Charadriiformes      Genus & Species : Recurvirostridae     Family : Himantopus himantopus

The black-winged stilt goes through a series of mysterious displays that observers have yet to explain; it “parachutes,” “butterflies” and performs a “grouping” ceremony. The black-winged stilt flies gracefully and walks slowly, raising its legs high and taking long steps in the flooded areas it inhabits. They found throughout Australia as well as coastal and inland regions of New Zealand; also in India, Sri Lanka, Southeast Asia, Africa, Europe, Mexico, Central and South America. 

Habitat : The black-winged stilt is most at home in extensive shallow wetlands, such as coastal wetlands and lagoons, which are full of insects, as well as small invertebrate prey. Stilts occur in both fast-flowing and still waters and prefer wetlands where there is adjacent open space that’s suitable for nesting and resting. The black-winged stilts also occupy other freshwater, estuarine and artificial environments, such as irrigated fields, and will move seasonally to find adequate wetlands. In areas heavily modified by human activity, stilts must depend upon artificial wetlands, such as scrapes, salt lakes, dams and drainage ponds, some of which are created expressly for wildlife conservation. 
Food & Hunting : Black-winged stilts tend to feed primarily on aquatic prey, especially beetles, mayflies and spiders, although mollusks, crustaceans, earthworms and small fish, as well as water plants and their seeds, are also part of the bird’s varied diet. The stilt usually hunts in shallow water or on damp land, but the bird also employs its unusually long legs, neck and bill to feed in deeper water as well. The stilt usually hunts by pecking at clearly visible prey in the water or on the ground. Grasping it with a slightly open bill and swallowing with a backward and forward jerk of the head, the food is quickly eaten.The bird then returns to its original position to search for more food. Larger prey, such as crabs, must be cut up by the bill into smaller pieces before they can be swallowed. Other visual methods commonly used by stilts are “plunging,” an underwater form of pecking or probing in which the bill and head are totally immersed, and “snatching,” which involves pecking at flying insects. 
Behavior : The black-winged stilt exhibits extremely unusual (and largely unexplained) behavior. For example, it often forms small groups of 3–4 and performs a “parachute display,” in which the birds leap high into the air and then parachute downward slowly on outspread wings. Some experts speculate that this may be a unique form of predator distraction. It also performs a “butterfly flight,” hovering 16–32' above a spot and then flying off quickly to another site to repeat the procedure. In the also unexplained “grouping ceremony,” 3–4 stilts gather together and spontaneously display mild aggression in the form of lunging and pecking at each other before dispersing. 
Breeding : Black-winged stilt courtship begins with preening and bill-dipping, followed by the female assuming a receptive posture. The male then moves from side to side in a semicircle behind the female several times before mating begins. Breeding pairs are most often found in colonies, typically ranging from between 2–50 pairs. Nests are built from flood debris, driftwood, grass, fine twigs and other vegetation, and shaped into a bowl, cone or mound up to 6" high. Nests are spaced widely on the ground, often among grasses and sedges, although some nests are made from well-lined masses of floating water weeds.The female usually lays four eggs in a 24-hour interval. Both parents take turns incubating the eggs from 22–26 days, when the downy young hatch. Fledging takes between 28–32 days, and the young are independent of their parents nearly 2–4 weeks after fledging. 

Bill : The black-winged stilt’s long, almost needlelike bill is aided by strong head muscles, which help provide quick jaw movement and give it a firm grip on prey. 
Neck : The stilt’s very long neck gives it an extended reach to capture prey, not only on the water’s surface but in deeper water as well. 
Plumage : The female black-winged stilt is mostly black on top, except for the grayish part of the tail, while the head, underside and rump are white.The back of the male’s head and neck become darker during the summer, unlike the female. 
Feet & Legs : The extremely long, pinkish-red legs of the stilt allow it to walk through much deeper water than other birds its size; it has no hind toe, but the others are unusually long, useful for walking on soft terrain. 

Weight : 6–7 oz.
Length : 13-14"
Wingspan : 24-28"
Sexual Maturity : 1-2 years
Breeding Season : Varies with location

The black-winged stilt is also known as the long-legged plover, longshanks, pied stilt, stilt-bird and dog-bird.