Wilson's Phalarope
Encyclopedia
The Wilson's Phalarope, Phalaropus tricolor, is a small wader
. This bird, the largest of the phalarope
s, breeds in the prairies of North America
in western Canada
and the western United States
. It is migratory
, wintering around the central Andes
in South America
. They are passage migrants through Central America
around March/April and again during September/October. The species is a rare vagrant to western Europe
.
This species is often very tame and approachable. Its common name commemorates the American ornithologist Alexander Wilson
. Sometimes, it is placed in a monotypic
genus
Steganopus.
Wilson's Phalarope is about 23 centimetres (9.1 in) in length, with lobed toes and a straight fine black bill. The breeding female is predominantly gray and brown above, with white underparts, a reddish neck and reddish flank patches. The breeding male is a duller version of the female, with a brown back, and the reddish patches reduced or absent.
Young birds are grey and brown above, with whitish underparts and a dark patch through the eye. In winter, the plumage is essentially grey above and white below, but the dark eyepatch is always present.
in California
and the Great Salt Lake
of Utah
, often with Red-necked Phalarope
s.
When feeding, a Wilson's Phalarope will often swim in a small, rapid circle, forming a small whirlpool. This behaviour is thought to aid feeding by raising food from the bottom of shallow water. The bird will reach into the outskirts of the vortex with its bill, plucking small insect
s
or crustacean
s caught up therein.
The typical avian sex roles are reversed in the three phalarope species. Females are larger and more brightly coloured than males. The females pursue males, compete for nesting territory, and will aggressively defend their nests and chosen mates. Once the females
lay their eggs, they begin their southward migration, leaving the males to incubate the eggs. Three to four eggs are laid in a ground nest near water. The young feed themselves.
Although very common, this bird's population may have declined in some areas due to the loss of prairie wetland habitat. A few staging areas are of critical importance during migration.
Wader
Waders, called shorebirds in North America , are members of the order Charadriiformes, excluding the more marine web-footed seabird groups. The latter are the skuas , gulls , terns , skimmers , and auks...
. This bird, the largest of the phalarope
Phalarope
A phalarope or wadepiper is any of three living species of slender-necked shorebirds in the genus Phalaropus of the bird family Scolopacidae. They are close relatives of the shanks and tattlers, the Actitis and Terek Sandpipers, and also of the turnstones and calidrids...
s, breeds in the prairies of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
in western Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
and the western United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. It is migratory
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
, wintering around the central Andes
Andes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...
in South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
. They are passage migrants through Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
around March/April and again during September/October. The species is a rare vagrant to western Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
.
This species is often very tame and approachable. Its common name commemorates the American ornithologist Alexander Wilson
Alexander Wilson
Alexander Wilson was a Scottish-American poet, ornithologist, naturalist, and illustrator.Wilson was born in Paisley, Scotland, the son of an illiterate distiller. In 1779 he was apprenticed as a weaver. His main interest at this time was in writing poetry...
. Sometimes, it is placed in a monotypic
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Steganopus.
Description
Young birds are grey and brown above, with whitish underparts and a dark patch through the eye. In winter, the plumage is essentially grey above and white below, but the dark eyepatch is always present.
Ecology and status
Wilson's Phalaropes are unusually halophilic (salt-loving) and feed in great numbers when on migration on saline lakes such as Mono LakeMono Lake
Mono Lake is a large, shallow saline lake in Mono County, California, formed at least 760,000 years ago as a terminal lake in a basin that has no outlet to the ocean...
in California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
and the Great Salt Lake
Great Salt Lake
The Great Salt Lake, located in the northern part of the U.S. state of Utah, is the largest salt water lake in the western hemisphere, the fourth-largest terminal lake in the world. In an average year the lake covers an area of around , but the lake's size fluctuates substantially due to its...
of Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
, often with Red-necked Phalarope
Red-necked Phalarope
The Red-necked Phalarope, Phalaropus lobatus, is a small wader. This phalarope breeds in the Arctic regions of North America and Eurasia. It is migratory, and, unusually for a wader, winters at sea on tropical oceans....
s.
When feeding, a Wilson's Phalarope will often swim in a small, rapid circle, forming a small whirlpool. This behaviour is thought to aid feeding by raising food from the bottom of shallow water. The bird will reach into the outskirts of the vortex with its bill, plucking small insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s
or crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s caught up therein.
The typical avian sex roles are reversed in the three phalarope species. Females are larger and more brightly coloured than males. The females pursue males, compete for nesting territory, and will aggressively defend their nests and chosen mates. Once the females
lay their eggs, they begin their southward migration, leaving the males to incubate the eggs. Three to four eggs are laid in a ground nest near water. The young feed themselves.
Although very common, this bird's population may have declined in some areas due to the loss of prairie wetland habitat. A few staging areas are of critical importance during migration.
External links
- Wilson's Phalarope - Phalaropus tricolor - USGS Patuxent Bird Identification InfoCenter
- Wilson's Phalarope Information and Photos - South Dakota Birds and Birding
- Oiseaux Photos
- Wilson's Phalarope photo gallery VIREO
- Avibase