Large (length 33 to 41 cm; mass 200 to 300 g), gray to brownish-gray sandpiper with white lower rump to base of tail and distinctive black and white wing pattern - "the Willet remains brown and inconspicuous until it opens its wings, displaying an unusually broad white wing-stripe that runs across the primaries and secondaries, bordered in black". Sexes similar in plumage and overall size, female slightly larger in mass. In Alternate plumage, head, neck, and remainder of body subtly barred and streaked darker, but Basic plumage largely plain brownish gray (Lowther et al. 2001).
For a comprehensive review of the conservation status, habitat use, and ecology of this and other Montana bird species, please see Marks et al. 2016, Birds of Montana.
Western Hemisphere Range
Willets migrate to California, the Gulf states and south in winter. The Bozeman migration occurs from May 6 to 25, with a peak on May 10. September numbers are less obvious.
Western breeding range on the prairies, uses short, sparse cover in wetlands and grasslands; on semiarid plains near bodies of water; in grasslands associated with shallow wetlands; to a lesser extent croplands (Lowther et al. 2001).
Insects, small crustaceans, mollusks, polychaetes; occasionally small fish (Lowther et al. 2001).
Nests on the ground, most frequently found in native grasslands, almost always in proximity to a piece of wood, dried cattle dung, stone, etc. Eggs usually ovate or ovate pyriform in shape; color varies from deep olive-buff to olive-buff, boldly marked. Clutch size typically 4 eggs (Lowther et al. 2001). Nesting is from mid-May to mid-June.