Plegadis chihi

P. falcinellus and P. chihi are sometimes considered conspecific (AOU 1998). Oberholser (1974) used the name P. mexicana, but P. chihi is the name accepted by others (Banks and Browning 1995).

Secure due mainly to large range; locally fairly common; relatively small number of breeding areas; vulnerable to habitat alteration, disturbance during nesting, and pesticide contamination.

BREEDING: locally from central California, eastern Oregon, southern Idaho (Taylor et al. 1989), Montana, southern North Dakota, and (formerly) southwestern Minnesota south into Mexico (to Colima, Zacatecas, state of Mexico, Veracruz), Texas, and southwestern Louisiana, southern Alabama, Florida (occasionally or formerly); also locally in South America in Bolivia, Paraguay, Uruguay, southern Brazil, northern and central Chile, and northern and central Argentina (AOU 1983). The world's largest nesting aggregation occurs probably in the marshes around the Great Salt Lake, Utah (D. Paul, in Paton et al. 1992). NON-BREEDING: north to southern California, Baja California, southern Texas, and Louisiana, south through lowlands to Guatemala and El Salvador, and in generally in breeding range in South America (AOU 1983). In the U.S., the highest winter densities occur near San Diego in California and on the coast of Texas and western Louisiana (Root 1988). Wanders outside usual range; rare straggler to Hawaii.

Limited number of breeding locations; vulnerable to fluctuating water levels. Susceptible to breeding failure in areas of pesticide contamination. Breeders in Nevada are still being contaminated with DDE-DDT in Mexican wintering areas (Henny and Herron 1989).