American Kestrel

Falco sparverius

• Content: Ned Harris
• Photo: Ned Harris

American Kestrels are year round residents at Sabino Canyon.

American Kestrels are our smallest (9 inches long with a wingspan of 22 inches) and most common North American falcon. They are identified by reddish brown back and tail plus two dark mustache marks on the face. Kestrels are sexually dimorphic; the males and females look different. The males (photograph on right) have blue-grey upper wing coverts that show both in flight and when perched. The male’s tail is rufous with a broad black subterminal band. The female’s tail is rufous with several narrow dark brown bands.

Kestrels fly with weak, shallow wingbeats. Their flight is light and buoyant and readily distinguished from that of its cousin the Merlin which has a more direct flight. Kestrels habitually bob their tail upon landing which is another way to distinguish them from Merlins. They are often seen on roadside wires or fence posts.

Kestrels hunt within a small range, mainly for insects, reptiles, small birds and mammals. They hunt from a perch and also by hovering and dropping straight down on their prey. The author has observed prey as large as a Desert Spiny Lizard being brought to the nest site by the male.

Kestrels are cavity nesters and compete with other birds for these nest sites. The author has observed a pair of American Kestrels nesting in an old Gila Woodpecker nest cavity in a saguaro. Typically there are 4 or 5 eggs. Both sexes incubate the eggs for 29 or 30 days. Youngsters fledge in 30 days and are independent in about 51 days. They are generally monogamous, seeking a new mate only if their original partner is lost.

This photograph, of a pair of American Kestrels, was taken in May 2008 on Tucson’s east side. American Kestrels are year round residents at Sabino Canyon.