Willet Life History

Habitat

Habitat ShorelinesAlong both seacoasts, Willets inhabit open beaches, bayshores, marshes, mudflats, and rocky coastal zones. Their widespread wintering range makes them one of the easiest shorebirds to spot. During the breeding season, western Willets occur far inland, where they nest near marshes and other wetlands, prairie pothole ponds, and wet fields. Eastern birds seek saltmarshes, barrier islands, and barrier beaches for breeding.Back to top

Food

Food Aquatic invertebratesWestern Willets eat a variety of aquatic beetles on their freshwater feeding grounds, along with fish and spiders. In winter, Willets eat small crabs, worms, clams, and other invertebrates from saltwater marshes and along open coastlines. Eastern Willets also take fiddler and mole crabs. Back to top

Nesting

Nest Placement

Nest GroundWestern birds nest inland on the ground along pond edges and other seasonal wetlands, or on raised sites near water, often in native grasslands. In the Great Basin, nests are often built at the edge of sagebrush near ponds. In the East, Willets nest in cordgrass, saltgrass, and beachgrass near saltmarshes and on sand dunes, and on bare ground or in short vegetation sheltered by barrier dunes. A pair searches for nest sites together, typically with the male leading the female through the habitat and making trial scrapes for the female to evaluate.

Nest Description

The male Willet initiates nest building by scraping out a small depression with his feet and breast in the grass, on beach sand, or on bare ground. If nesting in grass, the female then pulls in surrounding vegetation to hide the nest site, lining the grass nest cup with finer grasses and pebbles. If built on bare ground, the birds bring grass from a distance to line the scrape. The finished nest is just over 6 inches across and 2 inches deep.

Nesting Facts
Clutch Size:4 eggs
Number of Broods:1 brood
Egg Length:1.9-2.4 in (4.9-6.2 cm)
Egg Width:1.3-1.6 in (3.4-4 cm)
Incubation Period:22-29 days
Nestling Period:1-2 days
Egg Description:Greenish or brownish, with bold, irregular dark brown spots.
Condition at Hatching:Eyes open, mobile, covered in buff or gray down, able to peck at vegetation.
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Behavior

Behavior ProbingFeeding both during the day and at night, Willets take most of their prey from the surface, using their sensitive bill tip to grab up worms, snails, and insects. They also probe for sand crabs and other prey on mudflats and beaches, and take shellfish and small fiddler crabs from rocky shorelines. You’ll usually see them on wetted shorelines or wading close to the water’s edge, but occasionally Willets paddle in shallow waters to chase down small fish and crabs. In spring, the pill-will-willet flight call marks the arrival of Willets on the breeding grounds. Willet pairs often remain together for several years and return to the same nest sites. Males loudly defend their nesting and feeding territories, challenging their neighbors with a ritualized walk along territorial boundaries that can escalate into physical attacks. Both parents incubate the eggs and teach the young to feed. The female Willet departs the nest site up to two weeks ahead of the male, leaving her mate to finish raising the chicks. Back to top

Conservation

Conservation DecliningThough Willets are common in some areas, they appear to have declined between 1966 and 2014, according to the North American Breeding Bird Survey. This species is on the 2014 State of the Birds Watch List, which lists bird species that are at risk of becoming threatened or endangered without conservation action. They can be found wintering on both coasts of the U.S. and in Mexico, and move to inland areas of the U.S. and Canada as well as to the N.E. coast of the U.S during the breeding season. The conversion of native grasslands and wetlands to agricultural use has decreased the amount of suitable breeding territory for the western subspecies. Coastal development in California has also degraded potential wintering sites for this population. Both adults and fledglings are also vulnerable to collisions with power lines built through wetland breeding sites. Willets were widely hunted for food in the nineteenth century; it took passage of the Migratory Bird Treaty Act in 1918 to begin the Willet’s comeback to its present numbers.Back to top

Credits

Ehrlich, P. R., D. S. Dobkin and D. Wheye (1988). The birder's handbook. A Field Guide to the natural history of North American birds, including all species that regularly breed north of Mexico. Simon and Schuster Inc., New York, USA.

Hayman, P., J. Marchant and T. Prater. 1986. Shorebirds: An identification guide to the waders of the world. Boston: Houghton Mifflin Company.

Lowther, Peter E., Hector D. Douglas III and Cheri L. Gratto-Trevor. 2001. Willet (Tringa semipalmata), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

Lutmerding, J. A. and A. S. Love. Longevity records of North American birds. Version 2015.2. Patuxent Wildlife Research Center, Bird Banding Laboratory 2015.

North American Bird Conservation Initiative. 2014. The State of the Birds 2014 Report. US Department of Interior, Washington, DC, USA.

O'Brien, M., R. Crossley and K. Karlson. 2006a. The shorebird guide. New York: Houghton Mifflin.

Sauer, J. R., J. E. Hines, J. E. Fallon, K. L. Pardieck, Jr. Ziolkowski, D. J. and W. A. Link. The North American Breeding Bird Survey, results and analysis 1966-2013 (Version 1.30.15). USGS Patuxtent Wildlife Research Center 2014b. Available from http://www.mbr-pwrc.usgs.gov/bbs/.

Sibley, D. A. (2014). The Sibley guide to birds, second edition. Alfred A. Knopf, New York, USA.

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