Wilson's Phalarope

Steganopus tricolor

(c) Jim Fenton
  • PHALAROPODIDAE
  • Charadriiformes
  • Falaropo de pico largo; Falaropa de Wilson; Falaropo tricolor; Chorlillo nadador; Amacozque
  • Phalarope de Wilson
Introduction
The Wilson's Phalarope is a pretty shorebird with distinctive features–both physical and behavioral. Female phalaropes court males, display colorful plumage, and fight off rivals. A semi-colonial nester, this aquatic shorebird breeds in northern prairie wetlands, and winters on South American salt lakes. With fringes on their toes, they swim well, often whirling in circles as they feed.
(c) Jim Fenton
Appearance Description
The Wilson's Phalarope is a slender, delicately built shorebird with a small head, and thin, pointed bill. Breeding females are quite colorful, with a gray cap, white eyebrow, and dark crimson mask that extends from the bill to the back of the head and then swoops down the nape toward the back. The throat is white; a rusty wash colors the neck and chest. Otherwise, the female is whitish below and grey above. Males are pale grey above and whitish below, with a light rusty wash on the nape of the neck. In winter, both sexes have grey-white plumage without any warm colors. These medium-sized shorebirds average 2.1 ounces in weight and 8.5 inches in length, with pointed wings that span 17 inches. Females are substantially larger and can weigh as much as 40% more than males.
Range Map
Courtesy Kenn Kaufman
Range Distribution
Wilson's Phalaropes breed across the Great Plains of North America, and appear to be expanding their range south and east. The wintering range stretches from Peru to the tip of South America, with dense populations in Peru, Chile, Bolivia, and northwest Argentina.
 
A legend for the range map to the right can be found here.
Habitat
The Wilson's Phalarope breeds in the wetlands of North America's Great Plains and northern Rocky Mountains, favoring shallow water with adjacent mudflats and wet grasses. In migration and during winter, this shorebird prefers the shallows of salt lakes and ponds.
Feeding
Like other phalaropes, the Wilson's often spins on the water, at speeds of up to 60 turns per minute. The purpose of this whirling behavior may be to churn the muddy bottom, excite small aquatic creatures, and condense them in the swirls, where they can be picked off the surface. Wilson's phalaropes consume flies, beetles, brine shrimp, and other tiny marine creatures.
Reproduction
Compared to other shorebirds, the Wilson's Phalarope has reversed many typical sexual roles. Females display brighter plumage, court and defend mates, fight off other females, and provide almost no care for eggs or young. During migration and in loose breeding colonies, non-territorial females gather in small groups to court an available male. The females display with exaggerated postures and a "chug" call. After bonding, pairs stay together until the eggs are laid. Females are then free to court other males.
 
The pair begins construction on a simple nest, which the male completes. The female lays four buff-colored eggs, marked with brown. Under the male's care, they hatch in 18 to 27 days. During incubation, females defend the nest by pretending to incubate a false "nest." Males distract intruders by acting injured. Within an hour of hatching, the fully feathered chicks can walk, swim, and feed independently, but require brooding to keep them warm. Researchers have not yet observed the juvenile stages of Wilson's Phalaropes.
Migration
From the breeding grounds, Wilson's Phalaropes migrate in segregated groups: females depart first, followed by males, and finally, juveniles. All three groups stage at North American salt lakes before their non-stop flight to southern South America. Spring migration progresses through the mountains of South, Central, and North America to Cheyenne Bottoms, Kansas, where nearly all Wilson's Phalaropes stage.
  • 1,500,000
  • 1,500,000
  • Moderate population declines; very small winter range
Population Status Trends
The Wilson's Phalarope suffered significant losses in the early 20th century. Most recently, modest population increases have been recorded by Breeding Bird Surveys and Christmas Bird Counts; however, meaningful CBC counts have not been done on the bird's wintering grounds. From 1984 to 1993, Breeding Bird Surveys recorded a significant decline of 41%. The Canadian and U.S. Shorebird Conservation Plans regard the Wilson's Phalarope as a species of high concern.
Conservation Issues
The Wilson's Phalarope's breeding habitat has suffered significantly from agricultural development. The conversion of short-grass prairie to farmland, and subsequent urbanization have claimed about 38% of Wyoming's wetlands and 49% of North Dakota's. Wyoming lists the Wilson's Phalarope as deserving of "conservation actions," including habitat preservation, maintaining a diversity of wetland vegetation, securing buffer zones around breeding grounds, suspending grazing during breeding, and implementing controlled mowing or burning.
 
The bird's staging and wintering habitat depends on the health of a limited number of salt lakes, which have been altered by the diversion of water and the accumulation of pesticides and fertilizers. Key locations like Mono Lake in California, the Great Salt Lake in Utah, and Laguna Mar Chiquita, a saline lake in the Cordoba Province of Argentina have been added to the Western Hemispheric Shorebird Reserve Network.
What You Can Do
From mid-summer through early fall, look for Wilson's Phalaropes at a Western Hemisphere Shorebird Reserve.
 
Conduct and report a migratory shorebird survey. Visit the International Shorebird Survey website for their protocol and other information.
 

Advocate for the natural flow of fresh water into western salt lakes and ponds. Water diversion makes salt concentrations unnaturally high, and creates artificial drought conditions.
 
Find ways to conserve water—like growing a meadow rather than a lawn–particularly if you live near Wilson's Phalaropes.
 
For more actions you can take, including Audubon activities, please visit our resources page.
More Information
Visit your state's department of water conservation website, and the University of Nebraska at Lincoln website for water conservation and wetland management ideas.
 
Visit our resources page for more information about this species.
Natural History References
Colwell, M. A. and J. R. Jehl, Jr. 1994. Wilson's Phalarope (Phalaropus tricolor). In The Birds of North America, No. 83 (A. Poole and F. Gill, eds.). Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists' Union.
 
Dahl, Thomas E. 1990.  Wetlands losses in the United States, 1780's to 1980's. U.S. Department of the Interior, Fish and Wildlife Service, Washington, D.C. Jamestown, ND: Northern Prairie Wildlife Research Center Online. (Version 16JUL97).
 
Kaufman, Kenn. Lives of North American Birds. Houghton Mifflin Company, New York, 1996.
 
Nicholoff, S. H., compiler. 2003. Wyoming Bird Conservation Plan, Version 2.0. Wyoming Partners in Flight. Wyoming Game and Fish Department, Lander, WY.
 
Sibley, David Allen. 2000. The Sibley Guide to Birds. Alfred A. Knopf, New York.
Conservation Status References
Colwell, M. A. and J. R. Jehl, Jr. 1994. Wilson's Phalarope (Phalaropus tricolor). In The Birds of North America, No. 83 (A. Poole and F. Gill, eds.). Philadelphia: The Academy of Natural Sciences; Washington, D.C.: The American Ornithologists' Union.
 
Dahl, Thomas E. 1990.  Wetlands losses in the United States, 1780's to 1980's. U.S. Department of the Interior, Fish and Wildlife Service, Washington, D.C. Jamestown, ND: Northern Prairie Wildlife Research Center Online. (Version 16JUL97).
 
Kaufman, Kenn. Lives of North American Birds. Houghton Mifflin Company, New York, 1996.
 
Nicholoff, S. H., compiler. 2003. Wyoming Bird Conservation Plan, Version 2.0. Wyoming Partners in Flight. Wyoming Game and Fish Department, Lander, WY.
 
Sibley, David Allen. 2000. The Sibley Guide to Birds. Alfred A. Knopf, New York.