Black-necked stilt

The black-necked stilt was formally described in 1776 as Charadrius mexicanus by the German zoologist Philipp Statius Müller. The species is now placed in the genus Himantopus that was introduced in 1760 by the French ornithologist Mathurin Jacques Brisson. Three subspecies are recognised: The black-necked stilt has often been treated as a subspecies of the common or black-winged stilt, using the trinomial name Himantopus himantopus mexicanus. However, the AOS has always considered it a species in its own right, and the scientific name Himantopus mexicanus is often seen. Matters are more complicated though; sometimes all five distinct lineages of the common stilt are treated as different species. The white-backed stilt from much of South America (H. melanurus when the species is recognized) is parapatric and intergrade to some extent with its northern relative where their ranges meet in northern Brazil and central Peru, would warrant inclusion with the black-necked stilt when this is separated specifically, becoming Himantopus mexicanus melanurus. Similarly, the Hawaiian stilt, H. m. knudseni, belongs to the (North) American species when this is considered separate; while it rarely has been treated as another distinct species, the AOS, BirdLife International and the IUCN do not. ==Description==

in Las Cruces, New Mexico Measurements: • Length: • Weight: • Wingspan: They have long pink legs and a long thin black bill. They are white below and have black wings and backs. The tail is white with some grey banding. A continuous area of black extends from the back along the hind neck to the head. There, it forms a cap covering the entire head from the top to just below eye-level, with the exception of the areas surrounding the bill and a small white spot above the eye. Males have a greenish gloss to the back and wings, particularly in the breeding season. This is less pronounced or absent in females, which have a brown tinge to these areas instead. Otherwise, the sexes look alike. actual trans-oceanic vagrants are nonetheless a rare occurrence. ==Distribution and habitat==

The black-necked stilt is found in estuarine, lacustrine, salt pond and emergent wetland habitats; it is generally a lowland bird but in Central America has been found up to ASL and commonly seen in llanos habitat in northern South America. They are known to prefer shallow, saline wetlands, including those which are soda or alkaline. This bird is locally abundant in the San Joaquin Valley, where it commonly winters. It is common to locally abundant in appropriate habitat in southern California from April to September. and elsewhere in the southern USA. In Arizona, black-necked stilts may be seen along artificially created lakes and drainage basins in the Phoenix metropolitan area, in remnant riparian habitat. For flocks that summer in the northern Central Valley of California, a migration occurs to the San Joaquin Valley to consolidate with flocks that were already summering there. In coastal areas flocks both summer and winter in these estuarine settings. Fall migration of the northernly birds takes place from July to September, and they return to the breeding grounds between March and May. Usually, the entire population breeding at any one site arrives, mates, incubates eggs for about a month, and protects and broods the young until they are capable of sustained flight (at 27–31 days old) and leaves again migrating in flocks of about 15 individuals sometimes juveniles congregating in small groups and other times siblings with family groups. There is some seasonal movement of the tropical populations, but this is not long-range and poorly understood. ==Behaviour==

This bird is considered to have a moderate tolerance for human disturbance. They are typically found at elevations below . Food and feeding mudflats The black-necked stilt forages by probing and gleaning primarily in mudflats and lakeshores, but also in very shallow waters near shores; it seeks out a range of aquatic invertebrates – mainly crustaceans (such as shrimp) and other arthropods (such as worms and flies), while tropical populations usually breed after the rainy season. The nests are typically sited within of a feeding location, and the pairs defend an extensive perimeter around groups of nests, patrolling in cooperation with their neighbors. Spacing between nests is approximately , but sometimes nests are within of each other and some nests in the rookery are as far as from the nearest neighbor. The black-necked stilt is actually classified as semicolonial since the nests are rarely found alone and colonies usually number dozens, rarely hundreds of pairs. The nests are frequently established rather close to the water edge, so that their integrity is affected by rising water levels of ponds or tides. This is particularly a hazard in the case of managed salt ponds where water levels may be altered rapidly in the salt pond flooding process. The clutch size generally is 3–5 eggs with an average of four. For 22–26 days both sexes take turns incubating the eggs. The young are so precocial that they are seen swimming within two hours after hatching and are also capable of rapid land velocity at that early time. In spite of this early development the young normally return to the nest for resting for one or two more days. They fledge after about one month but remain dependent on their parents for some more weeks. Birds begin to breed at 1–2 years of age. ==Conservation status==

Particularly the North American populations of the black-necked stilt have somewhat declined in the 20th century, mainly due to conversion of habitat for human use and pollution affecting both the birds directly as well as their food stocks. But altogether, the population is healthy and occurs over a large range. This stilt is therefore classified as a Species of Least Concern by the IUCN. ==Gallery==

File:Black-necked stilt exhibiting a "broken wing" display (6796573671).jpg|Stilts exhibit a weak or sick behavior in order to distract predators from the location of their young. File:WanderingStilt.jpg|Bolsa Chica Ecological Reserve File:Black-necked Stilt.jpg|The Hawaiian stilt is usually considered a subspecies of the black-necked stilt. ==References==