Black-necked stilt

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Black-necked stilt
Adult near Corte Madera, California
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Charadriiformes
Family: Recurvirostridae
Genus: Himantopus
Species:
H. mexicanus
Binomial name
Himantopus mexicanus
(P.L.S.Müller, 1776)
(but see text)
Range of black-necked stilt (including white-backed stilt of most of South America, see text)
Synonyms

Himantopus himantopus mexicanus (Müller, 1776)
but see text

The black-necked stilt (Himantopus mexicanus) is a locally abundant

Himantopus himantopus.[2]

Taxonomy

Black-necked stilt of Quintana, Texas

It is often treated as a

IUCN
do not.

Description

Flying in California, USA
Black-necked stilt calls
Calls from an agitated black-necked stilt in Palo Alto, California
Problems playing this file? See media help.

Measurements:[4]

  • Length: 13.8–15.3 in (35–39 cm)
  • Weight: 5.3–6.2 oz (150–180 g)
  • Wingspan: 28.1–29.7 in (71–75 cm)

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.[5]

Downy young are light olive brown with lengthwise rows of black speckles (larger on the back) on the upperparts – essentially where adults are black – and dull white elsewhere, with some dark barring on the flanks.[5]

Where their ranges meet in northern Brazil and central Peru, the black-necked and white-backed stilts intergrade. Such individuals often have some white or grey on top of the head and a white or grey collar separating the black of the hindneck from that of the upper back.

The black-necked stilt is distinguished from non-breeding vagrants of the black-winged stilt by the white spot above the eye. Vagrants of the northern American form in turn are hard to tell apart from the resident Hawaiian stilt, in which only the eye-spot is markedly smaller. But though many stilt populations are long-distance migrants and during their movements can be found hundreds of miles offshore,[6] actual trans-oceanic vagrants are nonetheless a rare occurrence.[5]

Distribution and habitat

The black-necked stilt is found in

ASL and commonly seen in llanos habitat in northern South America.[5] It is also found in seasonally flooded wetlands. Use of salt evaporation ponds has increased significantly since 1960 in the US, and they may now be the primary wintering habitat; these salt ponds are especially prevalent in southern San Francisco Bay. At the Salton Sea, the black-necked stilt is resident year-round.[7]

This bird is locally abundant in the San Joaquin Valley, where it commonly winters.[8] It is common to locally abundant in appropriate habitat in southern California from April to September.[7]

It also breeds along lake shores in northeastern California and southeastern

riparian locales in Arizona[9] 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.

tropical populations, but this is not long-range and poorly understood.[5]

The

Allopyge, found in Old World cranes.[12]

  • Stilts exhibit a weak or sick behavior in order to distract predators from the location of their young.
    Stilts exhibit a weak or sick behavior in order to distract predators from the location of their young.
  • Bolsa Chica Ecological Reserve
    Bolsa Chica Ecological Reserve
  • The Hawaiian stilt is usually considered a subspecies of the black-necked stilt.
    The Hawaiian stilt is usually considered a subspecies of the black-necked stilt.

Food and feeding

Black-necked stilts foraging on Richardson Bay 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

alkali flats and even flooded fields.[7] For roosting and resting needs, this bird selects alkali flats (even flooded ones), lake shores, and islands surrounded by shallow water.[5]

Breeding

Black-necked stilt eggs Quintana, Texas

This stilt chooses mudflats, desiccated

tropical populations usually breed after the rainy season. The nests are typically sited within 1 km (0.62 mi) of a feeding location, and the pairs defend an extensive perimeter around groups of nests, patrolling in cooperation with their neighbors.[15] Spacing between nests is approximately 65 ft (20 m), but sometimes nests are within 7 ft (2.1 m) of each other and some nests in the rookery are as far as 130 ft (40 m) 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.[16] 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.[5][17]

The

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.[5]

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

IUCN.[2] The Hawaiian stilt, which on occasionally has been separated as a distinct species, is very rare however and numbers less than 2,000 individuals.[5] Predation by the small Indian mongoose (Urva auropunctata), introduced to hunt rats, is suspected to have contributed to its decline.[19]

Notes

  1. ^ Pierce (1996), Sibley (2003)
  2. ^
    doi:10.2305/IUCN.UK.2019-3.RLTS.T22727969A155440465.en
    . Retrieved 9 December 2023.
  3. ^ E.g. Pierce (1996)
  4. ^ "Black-necked Stilt Identification, All About Birds, Cornell Lab of Ornithology". www.allaboutbirds.org. Retrieved 2020-09-30.
  5. ^ a b c d e f g h i Pierce (1996)
  6. ^ E.g. as a casual visitor on Clarión in the Revillagigedo Islands: Brattstrom & Howell (1953)
  7. ^ a b c Garrett & Dunn (1981)
  8. ^ McCaskie et al. (1979)
  9. ^ Corman & Wise-Gervais (2005)
  10. ^ Robinson, Julie A., J. Michael Reed, Joseph P. Skorupa and Lewis W. Oring. 1999. "Black-necked Stilt (Himantopus mexicanus)", The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from The Birds of North America Online: bna.birds.cornell.edu/bna/species/449
  11. ^ Sordahl, T. A. 1980. Antipredator behavior and parental care in the American Avocet and Black-necked Stilt (Aves: Recurvirostridae). Ph.D. thesis. Utah State Univ. Logan.
  12. ^ Dronen et al. (2006)
  13. ^ a b Himantopus mexicanus (Black-necked Stilt) The Online Guide to the Animals of Trinidad and Tobago. Retrieved 16 March 2023
  14. ^ Bent (1927)
  15. ^ Hamilton (1975)
  16. ^ Zeiner et al. (1988)
  17. ^ Rigney & Rigney (1981)
  18. ^ Harrison (1978)
  19. ^ Hays & Conant (2007)

References

Further reading

External links

Wikimedia Commons has media related to Black-necked Stilt.
Wikispecies has information related to Himantopus mexicanus.
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