American Kestrel, Falco sparverius

Kingdom:  Animalia

Phylum:  Chordata

Class:  Aves

Order:  Falconiformes

Family:  Falconidae

Genus:  Falco

Species:  sparverius

Status

Occasionally referred to as the sparrow hawk (since they periodically eat sparrows), the American kestrel is the smallest and most common falcon in North America.  U.S. Fish and Wildlife Service Status: Not Listed.  International Union for the Conservation of Nature Status: Least Concern.

Description

It is one of the few raptors that are sexually dimorphic, meaning males and females have different coloring or appearances.  The back of the female’s wings and tail are rusty brown with fine dark barring.  The male’s wings are blue gray and the tail is rust-colored with a wide dark band and a white tip.  Both sexes have two dark mustache marks, called a malar stripe and markings on the back of the head, called ocelli.

 Habitat and Range

The American kestrel permanently inhabits North and South America.  Kestrels prefer open country, mountains, moorlands or grasslands.  In addition to requiring open space for hunting, American Kestrels seem to need perches to hunt from and some sort of cavity for nesting (either natural or man-made).

Diet

In the summer, American kestrels hunt in the early morning and evening, eating large insects and small mammals.  During winter, they hunt throughout daylight hours and eat small mammals, sparrow-sized birds, and lizards that may be active at various periods of the day.

Reproduction

They start courtship around April after the male establishes a nesting territory.  They are commonly found nesting in woodpecker holes, crevices in cliffs, or man-made nest boxes, usually 20 feet above the ground with an easterly exposure.  The female does most of the incubation, but males have been known to occasionally sit.  Incubation lasts 29 – 30 days.  After the chicks hatch it is another 30 days before they fledge.

Behavior

Their active flight is light and buoyant, and they are the only North American falcon species to hunt by hovering.  Hovering is achieved by matching flight speed to the wind speed and flying direct into the wind, cancelling motion.  Thus kestrels are sometimes called the Windhover Hawk.  Sometimes they chase birds in direct rapid flight, but usually they hunt from a perch.  Kestrels that are not permanent residents migrate south or to lower elevations in small groups during September and October.  They will follow mountain ranges where thermal activity and wind currents enable them to drift south without too much effort.  Some do winter in Nevada.

Wow!

  • Kestrels are sexually dimorphic.
  • Both sexes have brooding patches, patches of featherless, highly-vascularized skin used to warm eggs while brooding.
  • Life span: In wild 8-10 years, In captivity 10-13 years
  • Kestrels that are found in the northern range, above latitude 45 degrees north, migrate.  While kestrels south of 35 degrees north are mostly year-round residents.
  • Kestrels are the most common falcon species in North America.