About the American Kestrel
The American kestrel is usually found in close proximity to open fields, either perched on a snag or telephone wire or hovering in search of prey. The typical falcon-shaped wings are slim and pointed; the tail long and square-tipped. Sexes are of similar size. Adult male plumage is easily told from adult females and juveniles of both sexes. All have 2 bold, dark moustache marks framing white cheeks on the face and have the dark eyes typical of falcons. It hunts insects, small mammals, and reptiles from a perch or on the wing. Will hover above a field on rapidly beating wings, or soar in place in strong winds above a hillside. Flight style is quick and buoyant, almost erratic, with wings usually swept back. Polytypic (New World 17 ssp.; 2 in North America). Length 10.5"; wingspan 23".
Adult male: head has gray crown, rufous nape with black spot on either side, dark moustaches around white cheeks. Back is bright rufous with black barring on lower back. The tail is patterned with highly variable amounts of black, white, or gray bands. Wings are blue-gray with dark primaries. Underparts are white, washed with cinnamon. Adult female: head similar pattern to male, but more brown on crown. Back, wings, and tail are reddish brown with dark barring; subterminal tailband much wider than other bands. Underparts are buffy-white with reddish streaks. Juvenile male: head similar to adult, but less gray and with dark streaks on crown. Back is completely streaked, heavy streaks on breast. Juvenile female: very similar to adult female. Flight: light, bouncy flight is usually not direct and purposeful—often with “twitches” or hesitation. Light underwings and generally light body coloration. Males show a row of white dots (“string of pearls”) on the trailing edges of the underwings. Fans tail when hovering.
Two subspecies occur in North America; widespread nominate sparverius is the typical migratory form. Subspecies paulus, from South Carolina to Florida, is smaller, the male with less barring on the back and fewer spots on its undersides, essentially nonmigratory.
Merlin appears darker in flight due to dark underwings, shorter tail. When perched, looks darker, more heavy-bodied, lacks the 2 moustaches. Peregrine falcon is larger, has wider wings, shorter tail, single heavy moustache. Eurasian kestrel is slightly larger, has 1 moustache, wedge-shaped tail; males have blue-gray tail and reddish wings.
Loud, ringing killy-killy-killy or klee-klee-klee used all year round. Distinctive.
Status and Distribution
Common in open areas, it ranges throughout North America, including much of Canada and into Alaska. Breeding: a cavity nester, it uses dead trees, cliffs, occasionally a dirt bank, and even a hollow giant cactus in the Southwest. It will also use man-made nestboxes placed high on trees and telephone poles. Up to 5 or 6 young per brood, depending on food availability. Migration: northern breeders follow traditional fall migration routes to wintering ranges in the southern United States and northern Mexico. Eastern populations use the coastlines more than the inland corridors, and are not reluctant to cross water. Spring migrants are only concentrated along the Great Lakes watch-sites. Winter: the majority of birds winter in the southern United States, often spaced out on every other telephone pole in agricultural areas. A small percentage winter in snow-covered states, the numbers depending on food sources.
Overall, numbers are stable. However, increases in the central United States are being offset by declines in the Northeast and the West Coast (California and Oregon). Eastern populations are thought to be affected by loss of open habitat due to 2 factors; human development and agricultural abandonment leading to reforestation, with a subsequent increase in Cooper’s hawk predation.
—From the National Geographic book Complete Birds of North America, 2006