The American Kestrel is a small, familiar falcon of open country, with a wide distribution across North America. It is one of our smallest hawks, with pronounced plumage differences between males and females. Immature kestrels are unique among North American birds of prey in having different male and female plumages. The kestrel is often seen perched atop power poles or hydro lines. It is a graceful flier, and commonly hovers in one spot, examining the ground below for insect or rodent prey. When perched, it commonly bobs its tail up and down.
Both sexes are quite colorful. The male has slate blue wings, a reddish-brown back sparsely barred with black, a white face marked with a heavy black bar below the eye and another behind the cheek, white to buffy orange (mostly in adult male) underparts sparsely marked with black spots and a reddish-brown tail with a wide black subterminal band. The female has reddish-brown wings, barred with black like her back, and a reddish-brown tail banded with black. Her pale underparts are streaked with brown. Both birds are slightly larger than robins or about the size of a jay.
SIZE
The American Kestrel is the smallest North American falcon and one of the smallest hawks on the continent. Females are slightly larger than males. Lengths average 10 inches (25 centimeters) for females and nine inches (24 centimeters) for males. Wingspans average 22 inches (57 centimeters) for females and 21 inches (55 centimeters) for males. Weights average 0.3 pounds (120 grams) for females and 0.2 pounds (111 grams) for males.
MORPHS
There are no morphs. The female and male differ in plumage and are easily told apart. Albinism is rare.
SPECIFIC DESCRIPTION
Adult Male - Perched
- small falcon usually found in open country
- when perched bobs its tail up and down
- two well-defined dark facial stripes or mustache marks and white cheeks
- blue-gray crown with rufous patch
- buffy to rufous breast and reddish-brown back with some dark barring on lower parts
- various sized black spots, mainly on flanks and middle areas of underbody
- blue-gray on upper wings
- reddish-brown tail with wide dark band near white tip
Adult Female - Perched
- similar to male but upperparts dark reddish-brown, evenly barred or blotched with black
- dull blue-gray crown with rufous patch
- underparts buffy, streaked with reddish brown
- reddish-brown tail with many narrow dark bands; the subterminal, or last band, usually wider
Immature Male - Perched
- similar to adult male but with heavier barring on back, white breast streaked with black, and black shaft streaks on crown patch
Immature Female - Perched
-similar to adult female but with final dark bar on tail no wider than any other bar. This may be difficult to see in the field.
SIMILAR SPECIES
The American Kestrel could be confused with three other hawks. The Merlin is also a small falcon but both sexes have narrow pale bands on a dark tail and lacks the light spots on the trailing edge of the male kestrel's underwing. The female kestrel is much rustier in color than a Merlin. The Black-shouldered Kite also frequents open country but is whitish with large black patches at the bend of the underwing. The Peregrine Falcon is a much larger falcon. The adult Peregrine is slate blue-gray with no rufous on the head or back. Its chest is white or light buffy, with a barred belly and a dark tail with non-contrasting pale thin bands. The immature Peregrine Falcon is heavily streaked below, has darker underwings and a darker tail. It lacks any hint of rust or rufous.
OTHER NAMES
The American Kestrel was formerly known as "Sparrow Hawk." It has also been called the "Desert Sparrow Hawk", "Eastern Sparrow Hawk", "Little Kestrel", "Little Sparrow Hawk", and "wind hover" which is a common folk name for the related Eurasian Kestrel (Falco tinnunculus).
ETYMOLOGY
The scientific name Falco sparverius translates into "sickle" (Latin = falx) and "pertaining to a sparrow" (Latin = sparverius). The "sickle" refers to this species' typically falcon-shaped wings, beak, and talons. The "sparrow" reference is to the bird's former common name, "Sparrow Hawk. "
MYTHOLOGY
Although no mythology has been recorded, the American Kestrel was probably kept as a pet by some Indian tribes including the Paiutes. American Kestrel remains have often been discovered in the sacred burial bundles of Plains Indians.
VOICE
The American Kestrel has three basic vocalizations - the "klee" or "killy", the "whine", and the "chitter." The "klee" or "killy" is usually delivered as a rapid series - "killy, killy, killy, killy" when the kestrel is upset or excited. It is used at the apex of the dive display, during fights with other kestrels, and after unsuccessful hunting attempts.
The "whine" may last as long as one to two minutes and may be single or treble. The more intense the situation, the more likely the "whine" will move toward the treble extreme. "Whines" are given during courtship feeding and copulation. The treble whine is heard from breeding females and fledged hungry young.
The "chitter" is the most frequent vocalization in male - female interactions. Its volume and duration depends upon the stress or excitement of the situation. It is associated with friendly approaches and bodily contact between the sexes during breeding season. Occasionally a "chitter" follows a "whine."
Calling occurs throughout the day. Nestlings at two weeks can produce all three vocalizations. Female kestrels tend to have slightly lower pitched and harsher voices than males.