The American Kestrel
By Kim DiPasquale

American KestrelAmerican Kestrel.
Photo by Kim DiPasquale.
The American Kestrel, falco sparvarius, is North America’s smallest and most colorful falcon. With males being more colorful and smaller than females, it is also one of the most sexually dimorphic raptors. Kestrels are common in North America and can be found in cities, in farmland and in open country. They prefer relatively open, lightly wooded areas wherever prey is abundant and there are places to perch and watch and wait. They are commonly seen at Bolsa Chica perching and hunting on the North side of the pocket marsh which is adjacent to the trees and open grasslands on the upper mesa. It is fairly common year round but there is an influx of additional birds from September to March. Its diet includes mice and other small mammals, reptiles, large insects, and smaller songbirds. They nest in cavities in trees and lay 3-7 eggs. The call is a shrill, rapid killy-killy-killy-killy, or klee-klee-klee.

These birds average 9-11 inches with a 21-23 inch wingspan. They have narrow, pointed wings and a long, rusty barred tail with a black tip. The larger female has a rusty-colored back with dark barring, and streaked underparts. The male displays blue-gray shoulders, wings and crown, and spotted underparts. Both sexes have double black stripes on a white face. A similar species, the Merlin, is also found at Bolsa Chica. The Merlin is about the same size but stockier and with a more powerful flight pattern. The Merlin is darker in overall color with a heavily streaked breast and shows a white stripe over the eye.