The killdeer is North America’s most well-known plover, although many people know the killdeer without understanding its family affiliation. The killdeer can be common around human developments, frequently seen on playing fields, parking lots, and other unnatural habitats. Its “broken-wing” display is famous and known by many non-birders. The killdeer often forms flocks after breeding in late summer. It feeds in fields and in a variety of wet areas, but rarely along the ocean shore, and in general, it is not prevalent on mudflats. It is noisy. It reacts quickly to any perceived disturbance. Polytypic (3 ssp.; nominate in United States). Length 10.5".
The brown upperparts turn orange at the rump and uppertail coverts, but this only shows in flight, or during its “broken-wing” display. The forecrown is white, as is a short but distinct supercilium, and there is a white collar. The lores are dark; this coloration continues and broadens at the auriculars. The underparts are white, except for 2 bold black breast bands. The legs are pale, usually flesh tones, but sometimes with a yellow-green cast. The orbital ring is narrow, but a bright orange-red. The killdeer is the largest of the “ringed” plovers and looks long-tailed. The sexes generally look similar in adult plumage, and there is little seasonal change. Males average more black on the face than females, but this is variable. Fresh feathers, typically in late summer, have rusty edges to them. Juvenile: its plumage is paler than an adult’s, with pale edges to the upperparts. Downy young have only one breast band, but they quickly grow out of this plumage. Flight: a particularly bold white wing stripe marks the inner wing. In addition, the bright reddish orange rump is visible and the tail has obvious white corners, with dark central rectrices.
The killdeer’s double breast band is distinctive; as is its loud, piercing call. Downy young killdeer have one breast band and might be identified as Wilson’s Plovers by overeager birders.
Call: loud, piercing kill-dee or dee-dee-dee.
Status and Distribution
Common. Breeding: open ground, usually on gravel, including in cities. Migration: early spring migrants show up in the middle latitudes with the first bit of warmth after mid February. Peak in Great Lakes mid to late March, with most migrants having passed through by mid-April. In fall, numbers build July–August, sometimes as early as late June. Migration peaks August, with numbers decreasing during September. Many birds will linger until November, or later if warm weather persists. Winter: while most winter populations are well established, some vary according to the extent of snow cover. Vagrant: can occur north of breeding range.
Stable. The killdeer seems to adapt to human disturbance.
—From the National Geographic book Complete Birds of North America, 2006