The Black-necked Stilt, Himantopus mexicanus, is a locally abundant resident of North American wetlands and coastlines, including the coastal areas of California and Mexico, much of the interior western United States, and along the Gulf of Mexico as far east as Florida D. A. Sibley, The Sibley Field Guide to Birds of North America, Alfred A. Knopf, 472pp (2003). This slender bird has black and white body markings, resembling tuxedo attire. Chicks are known for their ability to swim two hours after hatching, and to move quickly on land.

Range and habitat

The Black-necked Stilt is found in estuarine, lacustrine, salt pond and emergent wetland habitats over the range noted above. It is also found in seasonally ponded wetlands. This bird is locally abundant in the San Joaquin Valley, where he commonly winters.G. McCaskie, D. DeBenedictus, R. Erickson and J. Morlan, Birds of Northern California, an annotated field list, 2nd ed. Golden Gate Audubon Society, Berkeley 84pp (1979) This species is common to locally abundant in these same habitats in Southern California from April to September. In the Salton Sea locale, the Black-necked Stilt is resident year-round. The species also breeds along lake shores in northeastern California and southeastern Oregon as well as along the Colorado River.K. Garrett and J. Dunn, Birds of Southern California, Los Angeles Audubon Society, 408pp (1981) Use of salt evaporation ponds has increased significantly since 1960 and may now be the primary wintering habitat; these salt ponds are especially prevalent in southern San Francisco Bay. This species rarely breed inland outside of California, but is known as a breeding bird in riparian locales in Arizona T. Corman and C. Wise-Gervais, Arizona Breeding Bird Atlas, University of New Mexico Press, 646pp (2005).

Specific locations where one would expect to view the Black-necked Stilt in the San Francisco Bay Area are Richardson Bay (especially, according to mudflat bird sightings, the mouth of Picklewood Creek)Kay Ransom, C. M. Hogan et al., Environmental Impact Report for the Corinthian Villas Project on Richardson Bay, prepared for the city of Mill Valley by Earth Metrics Inc., (1984), mudflats of Belmont Slough, mudflats of Seal Slough in San Mateo , salt ponds in Hayward, California and exposed bay muds on the Burlingame, California estuarine shore.

For the populations that summer in the Sierra Nevada of northeast California and southeastern Oregon as well as the plateau lakes of those areas, breeding occurs after those flocks migrate to lowland and coastal areas each August or September. 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.

In Arizona, Black-necked Stilts may been seen along artificially-created lakes and drainage basins in the Phoenix metropolitan area, in remnant riparian habitat along the Salt and Gila Rivers, and at the Riparian Preserve in Gilbert, Arizona where it is a confirmed breeding bird.

This species forages by probing and gleaning primarily in mudflats and lakeshores, but also in very shallow waters near shores; he seeks out crustaceans, arthropods mollusks, aquatic invertebrates and small fish. For feeding areas the Black-necked Stilt prefers coastal estuaries, salt ponds, lakeshores, alkali flats and even flooded fields.K. Garrett and J. Dunn, Birds of Southern California, Los Angeles Audubon Society, 408pp (1981) For roosting and resting needs, this bird selects alkali flats (even flooded ones), lake shores, and islands surrounded by shallow water.

Breeding

This species of stilt chooses mudlats, desiccated lacustrine verges, and levees for nest locations, as long as the soil is friable. Reproduction occurs from late April through August, with peak activity in June.A. C. Bent, Life Histories of North American Shorebirds, Part I, U.S. National Museum Bulletin 142 (1927) The nests are typically sited within one kilometer of a feeding location, and the Black-necked Stilt defends an extensive perimeter around groups of nests, patrolling in cooperation with its neighborsR.B. Hamilton, Comparative Behavior of the American Avocet and the Black-necked Stilt (Recurvirostridae), Ornithology Monogr. No. 17 (1975) Spacing between nests is approximately 20 meters, but sometimes nests are within two meters of each other and some nests in the rookery are as far as 40 meters from the nearest neighbor. The species is actually classified as semicolonial since the nests are scattered in loose clusters.California Wildlife, Volume II, Birds, ed. by David C. Zeiner, William F. Laudenslayer and Kenneth E. Meyer, published by the California Department of Fish and Game, November 1988. 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.M. Rigney and T. Rigney, A breeding bird survey of the south San Francisco Bay salt pond levee system, U.S. Dept. of Interior, Fish and Wildlife Service, San Francisco Bay National Wildlife Refuge, special report 130pp

The clutch size generally is three to five eggs with an average of four. For three and one half weeks both sexes take turns incubating the eggs. The young are so precocial that they are seen swimming within two hours after hatchingA field guide to the nests, eggs and nestlings of North American birds, W. Collins and Company, Cleveland, OH 416pp (1978) and are also capable of rapid land velocity at that early time. In spite of this early development the young normally continue to reside in the nest for two days.

Comparison to other stilts

Some sources believe that there are as many as five distinct species of stilt, though others consider them to be all subspecies of the Black-winged Stilt. The North American variant, the Black-necked Stilt, has a dark head as well with a white spot over the eye. It is recorded as Himantopus mexicanus in the Sibley-Monroe checklist. The North American Black-necked Stilt is migratory and moves to the Pacific coast or San Joaquin Valley to winter.

A relative, the Black-winged Stilt, Himantopus himantopus, is a large wader in the avocet and stilt family, Recurvirostridae. Adults are 33 to 36 centimeters long, have long pink legs, a long thin black bill and are mainly white with a dark cap and a dark back. Its breeding habitat is marshes, shallow lakes and ponds. Black-winged Stilts are found in southern and southeastern Europe, central Asia, northern Africa, Australia, Central and South America, Hawaii, the Philippines, south central Canada and the western and southeastern United States. They may even stray well outside these areas. The nest site is a bare spot on the ground near water. These birds often nest in small colonies, sometimes with avocets. Like the Black-necked Stilt, this bird extracts insects and crustaceans from sand or water.

In Hawaii, the Hawaiian Stilt (ae`o) is endangered due to habitat loss. This bird is considered by some to be a subspecies of the Black-necked Stilt and by others to be a distinct species. The stilt is the only shorebird to breed in the Hawaiian Islands .

References

Recurvirostridae | Shorebirds | Avifauna of Oregon | Avifauna of Arizona | Avifauna of Florida | Avifauna of California | Avifauna of Mexico | Avifauna of the United States

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