Wilson's Phalarope

Wilson's Phalarope is a small, elegant shorebird of interior North American wetlands, notable for its needle-thin bill and habit of spinning on the water surface to stir up prey. Unusually among birds, females are more brightly colored than males during the breeding season, a reflection of the species' reversed sex roles in which females compete for mates and males provide most parental care.

Breeding-plumage feathers show a pale gray back and crown contrasting with a bold black stripe through the eye that continues down the neck as chestnut on females, more muted gray-brown on males. Underparts feathers are clean white with little or no barring, distinguishing them from more heavily marked sandpipers. Nonbreeding plumage feathers are plain pale gray above and white below, lacking bold markings entirely, which can make loose feathers easy to overlook or misattribute to a generic small shorebird. Flight feathers are plain grayish-brown without a strong wing stripe, unlike the other phalarope species. The bill is notably thin and needle-like, longer and more slender than in Red-necked or Red Phalarope.

This species shows reversed sexual dichromatism: breeding females are more vividly patterned, with a rich chestnut stripe down the neck and gray crown, while breeding males are duller with muted brownish tones, consistent with their greater share of nest and chick care. Both sexes molt into a plain pale gray-and-white nonbreeding plumage. Juveniles resemble nonbreeding adults but show a buffier wash on the upperparts. Molt into nonbreeding plumage often begins before or during migration, with many individuals completing flight feather replacement at staging areas on saline lakes.

Breeds around shallow freshwater and alkaline wetlands, marshes, and wet meadows across the northern Great Plains and prairie provinces of North America. During migration, large numbers stage at hypersaline lakes rich in brine shrimp and alkali flies. Winters primarily on high-altitude saline lakes in the Andes of South America, making it one of the longer-distance migrant shorebirds of the interior flyways.

Wilson's Phalaropes are famous for a spinning feeding behavior, rapidly rotating on the water surface to create a small vortex that draws invertebrates upward, which they then pick from the surface with their needle-like bill. Nesting duties fall largely to males, who build the ground nest in vegetation near water and perform most incubation and chick care after females depart. The call is a low, nasal grunting note, less vocal than many other shorebirds. Conservation status is IUCN Least Concern, though the species depends heavily on a limited number of key staging wetlands during migration.