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New Jersey Endangered and Threatened Species Field Guide
Species Group: Bird
State: Other Classification
Willets are large shorebirds with grey-brown plumage and a long, thick, grey bill. They have a white rump, a short white “eyebrow,” and a distinctive white wing stripe that is visible in flight. Willets also have long grey legs and slightly webbed toes. Plumage is similar for both sexes, but females are slightly larger. The eastern subspecies, the willets that can be seen in New Jersey, are slightly smaller and darker than their western cousins. Willets are named after their breeding display song: a steady, rolling “pill-will-willet” that can be heard in the spring. Recently, because of discoveries made by DNA analysis, the willet’s scientific name was changed from Catoptrophorus semipalmatus to Tringa semipalmata.
DISTRIBUTION AND HABITAT
Willets are commonly found on beaches and in saltmarshes along the coasts of North America. They primarily breed in grassy marshes in Canada and migrate south to winter on mudflats and beaches in northern South America. While willets are usually solitary, they may gather in flocks to migrate and roost.
Willets feed by probing with their bills into mud and sand flats, searching for a wide variety of invertebrates. They eat insects, crustaceans, mollusks, worms, grasses, seeds, and occasional fish. In the east, willets eat primarily marine coastal invertebrates, including fiddler and mole crabs. Aside from probing in the sand, willets also hunt by walking through shallow water and holding their bills open under the surface.
Each year, willets breed from May to July. They are monogamous each season, and males will even reunite with their previous mate if he can find her at their breeding grounds. To attract females, the males will fly with their wings high above their heads and use their “pill-will-willet” call. Females fly beneath them and sing back, before the pair flies to the ground together. Once a pair has formed, the willets stop displaying, mate, and search for a nest site together. Nests are simple scrapes in the grass. Females lay 3 to 4 eggs over the course of 6 days. Both parents incubate the eggs for slightly less than a month. Within hours of hatching, willet chicks are able to walk and feed themselves, and can fly within four weeks. Like many other shorebirds, the male, rather than the female, stays with the chicks longer.
CURRENT THREATS, STATUS, AND CONSERVATION
There is no current conservation status for willets, as they have had no significant declines in population recently. However, habitat degradation in willets’ breeding, wintering, and migration areas (such as Delaware Bay) may put this species at risk.
Text written by Taran Catania in 2013.
- Dewey, Tanya. "Catoptrophorus semipalmatus". 2009. Animal Diversity Web. University of Michigan. Accessed: July 31, 2013. Available at: http://animaldiversity.ummz.umich.edu/accounts/Catoptrophorus_semipalmatus/.
- Lowther, Peter E., Hector D. Douglass III, and Cheri L. Gratto-Trevor. "Willet (Tringa semipalmata)". Ithaca, NY, 2001. The Birds of North America Online (A. Poole, Ed.).Cornell Lab of Ornithology. Accessed: July 30, 2013. Available at: http://bna.birds.cornell.edu/bna/species/579.
- Message, Stephen, and Don Taylor. Shorebirds of North America, Europe, and Asia: A Guide to Field Identification. Princeton, NJ: Princeton University Press, 2005.
- Sibley, David Allen. The Sibley Field Guide to Birds of Eastern North America. New York, NY: Alfred A. Knopf, 2003.
- Stokes, Donald, and Lillian Stokes.Field Guide to Birds: Eastern Region. New York, NY: Little, Brown and Company, 1996.
Species: T. semipalmata
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