Classification and Range
American kestrels are classified in the genus Falco of the family Falconidae. There are 16 subspecies of American kestrels currently recognized throughout North and South America. The American kestrel is our most abundant North American falcon. It is found throughout North America south of the tree line. Northern populations migrate south in the winter as far as Central America and the Caribbean.
American kestrels inhabit a wide range of habitats, from deserts to forest edges, but they prefer more open country.
American kestrels are the smallest falcons in North America, and next to the Seychelles kestrels (Falco araea), are the smallest kestrels in the world. Their long, tapered wings give them the telltale characteristics of a falcon. This is one of the few raptors in North America where the males and females can be distinguished by their plumage. Both males and females have rusty-colored heads with a gray fringe. Males have reddish-brown backs, blue-gray wings and a reddish-brown tail. Females have reddish-brown wings and banded tails. The female's breast is beige and heavily streaked with brown. Females are considerably larger than males, averaging 9 to 11 inches (23-28 cm). Males average 8 to 10 inches (20-25 cm). Females have wingspans up to 2 feet (60 cm). American kestrels weigh between 3.5 and 5.5 ounces (100-155 gr).
A banded American kestrel lived 11.5 years in the wild. The maximum recorded age in captivity is about 17 years.
I In the wild: During summer months, American kestrels feed primarily in the early morning and evening hours on large insects such as grasshoppers. They also hunt small rodents and birds. During the winter, they hunt throughout daylight hours, preying primarily upon small birds and rodents.
At the zoo: Quail, mice and insects.
American kestrels are solitary birds throughout most of the year. During the mating season, however, males and females pair up and establish territories which they both defend. American kestrels chiefly nest in old tree cavities, but hollows in buildings and holes in cut banks of streams and rock faces as well as nest boxes, are also used. A clutch of four to six buff-colored eggs are laid at two- or three-day intervals. Eggs are incubated for about 30 days by the female.
Chicks are fed bits of prey brought to the nest by the male. After about 20 days, chicks are eating whole prey. About 30 days after hatching, they are ready to leave the nest, although parents and their young remain together for a period of time thereafter. When alarmed, kestrels utter a high-pitched cry of excitement, alarm or irritation which can be described as klee-klee-klee or killy-killy-killy.
A kestrel's flight is buoyant, rapid and graceful. These birds are frequently observed in both urban and rural areas, and when hunting they seek high perches such as trees or utility lines from which they search the ground for prey. If something of interest is spotted, the kestrel may hover over the spot where the prey was spotted.
Many birds can hover, but few can maintain this tiring mode of flight as long as the kestrel. The lightweight kestrel accomplishes this amazing feat by rapidly beating its powerful wings, and at the same time fanning out its tail feathers to provide lift from the wind.
Whether from a perch or from the air, once prey is spotted, the kestrel's attack is quick and decisive. Partially folding its wings, it swoops to the ground, captures its prey with its sharp talons and returns to its perch to eat.
Location at the Zoo
American kestrels can be seen at the zoo's Raptor Center. However, other birds that can be viewed at the Raptor Center include the bald eagle, gyrfalcon, Harris's hawk, turkey vulture as well as great horned, spectacled and barred owls. Woodland Park Zoo's Eagle Release Program has rehabilitated and released back into the wild more than 80 eagles, plus other raptor species.
American kestrels are not endangered and are one of the most common New World raptors. Despite the overall health of American kestrel populations throughout the New World, some populations, including those in Florida, Texas, Arkansas and some northeastern states, are decreasing due to habitat alteration. Installing nesting boxes and protecting vital habitat required by these raptors will help to stabilize these populations.
Many raptor species are in danger. Human-caused changes in land use are escalating, and this affects the habitats and migratory corridors required by some raptors for survival. Vast forests are removed for timber and other paper products, and industrial emissions pollute water and air resources.
Critical shoreline and riparian zone habitats are rapidly converted by expanding human communities and agricultural needs. Illegal shooting and trapping are also lowering raptor numbers. It's only a matter of time until more raptor species may face extinction, unless we protect their habitats.
Humans need raptors. Here are only a few of the benefits raptors provide:
- Raptors help keep animal populations in balance.
- Raptors consume many animals that humans consider as pests, including mice, rats and destructive species of insects. This helps to control disease and damage to crops.
- As top predators of their food chain, raptors are an indicator species of the overall health of the ecosystem in which they live.
- Of equal importance, witnessing wild raptors enriches each of our lives. Imagine what life would be like if we could no longer hear the haunting evening call of the owl.
How You Can Help!
Efforts to save threatened and endangered raptors require cooperation and support at international, national, regional and individual levels. You can help in this cause. Join and become active in Woodland Park Zoo and other conservation organizations. Recycle forest products. Eliminate or reduce pesticide use. Support breeding programs for endangered birds of prey at zoos and other animal care organizations. Let your elected representatives know your views about the conservation of migratory birds and their wild habitats.
Contact Woodland Park Zoo at email@example.com to find out how you can support conservation efforts at the zoo. Discover more about raptors by contacting the Peregrine Fund at their Web site www.peregrinefund.org. Learn other ways you can help conserve wildlife and the habitats they require for survival by visiting our How You Can Help page.
Sources and Suggested Reading
Johnsgard, Paul A. 1990. Hawks, Eagles, and Falcons of North America. Smithsonian Institution, Washington, DC. 403 p.
Weidensaul, Scott. 1996. Raptors: The Birds of Prey. Lyons and Burford, Publishers, New York, NY. 382 p.
Burnie, David. 1988. Bird (Eyewitness Books). Alfred A. Knopf, Inc., New York, NY. 64 p
Zoobooks. 1986. Birds of Prey. Wildlife Education, Ltd., San Diego, CA. 16 p.