STILTS AND AVOCETS Recurvirostridae
The Stilts & Avocets are a small family of shorebirds with representatives found around the world. All taxa are essentially long-legged, long-billed, and dressed in patterns of black and white, presenting opportunities for classic reflections on calm shallow pools in which they feed, such as this Black-necked Stilt (left). All seven of the world's stilt have reddish legs, further adding to their bold appearance. While there is comparatively little debate about the taxonomy of the world's four avocets, there is little agreement about species-level taxonomy in the stilts. Leaving aside the unique Banded Stilt Cladorhynchus leucocephalus of Australia, some would lump all other stilts into a single species Himantopus himantopus, the name first in priority and which I prefer to restrict to the Black-winged Stilt of the Old World (below).

Sibley & Monroe (1990) note that "most allopatric forms [of stilts] differ in morphology, behavior or vocalizations" and they, followed by Clements (1991), divided Himantopus into five species of stilt: the widespread New World bird, Black-necked Stilt; the southern South American White-backed Stilt H. melanurus; the widespread Old World bird, Black-winged Stilt; the Malay/Australasian White-headed Stilt H. leucocephalus; and the endangered New Zealand Black Stilt H. novaezelandiae. Another group of ornithologists, including Bock & Farrand (1980) and Pierce (1996) in the Handbook of the Birds of the World series, lump all of these except Black Stilt together in one huge, polymorphic, cosmopolitan stilt ["Pied Stilt"]. In yet another approach, the A.O.U. (1998) separate the Old World and New World taxa, but lump the South American leucocephalus with mexicanus due to limited hybridization.  Assuming one is willing to separate the major allopatric taxa into species, by what criteria does one continue to lump the unique resident Hawaiian form with North American mainland birds? Yet that is the position taken by all the major recent authorities. The "Hawaiian Stilt" (below) differs from mainland birds in having more black to the neck and face; it is also an endangered taxa, now restricted to the few wetland locales remaining on the islands.

The world's four avocets -- genus Recurvirostra -- all have upturned bills and bluish legs. Two species, including the Pied Avocet of the Old World (left), have simple black-and-white patterns. The other two, including the American Avocet (above), have a distinctive breeding plumage with the head and neck washed with orange or rusty-red. This particular American Avocet in flight is a male with a comparatively shallow upturn to the long, thin bill; females are more decidedly upswept, more similar to their Old World counterpart.

Taxonomy aside, all members of this family are elegant and distinctive birds. Avocets scythe the murk in shallow ponds for invertebrate (often free-swimming) prey; stilts pick more daintily, both in the shallows and regularly along the edge. A number of species breed in loose colonies which can be impacted by mammalian ground predators. Here in Monterey County, the local species of stilt and avocet regularly nest at the Salinas River mouth. During the 1980s these populations were almost extirpated by non-native Red Foxes which had invaded this county. Our local Audubon Society vigorously supported a trapping program (now government funded after we got it off the ground) that controlled the predatory foxes. Local populations of stilts and avocets soon rebounded, and our local breeding Snowy Plovers -- a federally Endangered species -- were saved (details in Roberson & Tenney 1993).

Photos: The Black-necked Stilt Himantopus mexicanus was feeding at Merced NWR, Merced Co., California, on 26 Dec 1999. The Black-winged Stilt H. himantopus was in winter plumage at Lake Nakuru, Kenya, on 17 Nov 1981. The "Hawaiian Stilts" H. m. knudseni were at protected wetlands on Oahu I., Hawaii, on 9 Sep 1978. The Pied Avocet Recurvirostra avosetta was at Lake Nakuru, Kenya, on 17 Nov 1981. The American Avocet R. americana was in flight at the Salton Sea, Riverside Co., California, in May 1983. All photos © Don Roberson; all rights reserved.

Bibliographic essay

Family book: rating IIII [out of 5 possible]
Hayman, Peter, John Marchant & Tony Prater. 1986. Shorebirds: An Identification Guide to the Waders of the World. Croom Helm, London.

This book covers all the Charadriformes -- not just stilts & avocets -- and so includes plovers, sandpipers, jaçanas, thick-knees, and pratincoles. It is not a "family book" per se, since its focus is on identification problems, but it does include sections on "habits" and migratory or seasonal "movements." Breeding biology and similar topics are not covered here. John Marchant gets special credit for the text -- an upgrade from his 1977 guide (with Prater & Vuorinen) -- which surveys the literature well and is based on much original research. Hayman's paintings are just fine for stilts & avocets. However, for a real introduction to this small and separate family, see Pierce (1996).
Other literature cited:
American Ornithologists' Union. 1998. Check-list of North American Birds. 7th ed. A.O.U.,  Washington, D. C.

Bock, W. J., and J. Farrand, Jr. 1980. The number of species and genera of recent birds: a contribution to comparative systematics. Am. Mus. Novit., no. 2703.

Clements, J. F. 1991. Birds of the World: A Check-List. 4th ed. Ibis Publishing, Vista, CA.

Pierce, R. J. 1996. Family Recurvirostridae (Stilts and Avocets). Pp. 332-347 in del Hoyo, J., Elliott, A., & Sargatal, J., eds. Handbook of the Birds of the World. Vol. 3. Lynx Edicions, Barcelona.

Prater, A. J., J. H. Marchant, & J. Vuorinen. 1977. Guide to the Identification and Ageing of Holarctic Waders. BTO Guide 17. British Trust for Ornithology, Tring, England.

Roberson, D., and C. Tenney, eds. 1993. Atlas of the Breeding Birds of Monterey County, California. Monterey Pen. Audubon Soc., Carmel.

Sibley, C. G., and B. L. Monroe, Jr. 1990. Distribution and Taxonomy of Birds of the World. Yale Univ. Press, New Haven, CT.



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