American avocet
Recurvirostra americana
SUBFAMILY
Recurvirostrinae
TAXONOMY
Recurvirostra americana Gmelin, 1789, North America. Monotypic.
OTHER COMMON NAMES
French: Avocette d'Amérique; German: Braunhals-Säbelschnäbler; Spanish: Avoceta Americana, Piqocurvo.
PHYSICAL CHARACTERISTICS
16.1–2.0 in (41–51 cm); 10.6–16.2 oz (302–461 g). Large, striking birds legs bluish, strongly upcurved black bill. The only avocet with annual color change, the head, neck, and breast change from gray to orange-brown in breeding season. Wings and back black, contrasting with white on wing coverts. Sexes similar in plumage, male often larger, bill shorter and more strongly recurved in female. Juvenile resembles adult but crown pale brown with dull chestnut nape and hindneck.
DISTRIBUTION
Southeastern British Columbia east to southwestern Ontario, south to northern Baja California east to central Texas, eastern United States, and central Mexico. Winters from California and south, Texas through Mexico to Guatemala and irregularly to northern Honduras, southeastern United States and Bahamas to Cuba.
HABITAT
Specializes in using ephemeral wetlands of arid western United States, breeds around sparsely vegetated saline lakes and ponds, in large numbers at marshes of Great Salt Lake, Tulare Basin of California and across northern Great Basin. Outside of breeding season occurs in freshwater habitats and coastal lagoons and estuaries.
BEHAVIOR
After flock arrives at breeding grounds, transition from flocking to territoriality. Territory defended by male and female. "Upright posture," where the bird faces its opponent with neck extended vertically, is used to threaten other birds.
FEEDING ECOLOGY AND DIET
Mostly feeds on aquatic invertebrates while wading or swimming, also crustaceans, worms, small fish, and seeds. Scything
is hallmark method, but also pecks, plunges, and snatches. Will forage in dense flocks.
REPRODUCTIVE BIOLOGY
Monogamous, though pair bond doesn't usually extend past one season. Semi-colonial nesting, nest is a grass-lined depression in soil. Usually four eggs, incubation 22–29 days by both sexes. Both adults care for chicks, fledging four to five weeks.
CONSERVATION STATUS
Not threatened. Before 1900s shooting and trapping led to population declines, particularly on the Atlantic coast. Many wetlands used by American avocets in western United States have been contaminated with selenium as a result of irrigation and other human activities, loss of wetland habitat has led to population declines. Operators of selenium-contaminated ponds in California's Tulare Basin now required to provide mitigation habitat for breeding recurvirostrids, and species response has been favorable.
SIGNIFICANCE TO HUMANS
Considerend a game bird in early 1900s in California.
