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Home -> Kingdom Animalia -> Phylum Chordata -> Subphylum Vertebrata -> Class Aves -> Order Falconiformes -> Family Falconidae -> Subfamily Falconinae -> Species Falco sparverius

Falco sparverius
American kestrel

2010/09/12 02:59:24.569 GMT-4

By Kathryn McCollough

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Aves
Order: Falconiformes
Family: Falconidae
Subfamily: Falconinae
Genus: Falco
Species: Falco sparverius

Geographic Range

The American kestrel permanently inhabits (without seasonal migration) North and South America from near the tree-line in Alaska and Canada and south to Tierra del Fuego. The bird can also be found in the West Indies, the Juan Fernandez Islands and Chile. It is largely absent from heavily forested areas, including Amazonia.

Biogeographic Regions:
nearctic (native ); neotropical (native ).


The American kestrel nests in tree cavities, woodpecker holes, crevices of buildings, holes in banks, nest boxes or, rarely, old nests of other birds. The American kestrel is highly adaptable behaviorly and lives just about everywhere, as long as there is some open ground for hunting and conspicuous places on which to perch (e.g., telephone wires).

Physical Description

117 g (average)
(4.12 oz)
[External Source: AnAge]

male: 103g to 120g

female: 126g to 166g

Generally, the American kestrel is 19 - 21 cm in length with an average wingspan of 50 - 60 cm.

Excepting the Seychelles kestrel, the American kestral is the smallest species in the genus Falco. There is a strong selection for sexual dichromatism, with males being brightly and rufously colored and females having a more even tone.

Some key physical features:
endothermic ; bilateral symmetry .


Time to hatching
29 days (average)
[External Source: AnAge]

Age at sexual or reproductive maturity (female)
365 days (average)
[External Source: AnAge]

Age at sexual or reproductive maturity (male)
365 days (average)
[External Source: AnAge]

For up to six weeks before egg laying, females are promiscuous, mating with two or three males. Once a female settles with one mate, the pair mate frequently until egg laying. Three to seven eggs are laid (usually 4 or 5) over a period of 2 or 3 days. Eggs are white, cream or pale pink with an average size of 35 x 29 mm. Laying dates vary with geographical location:

Chile: September - October

Trinidad: May

Curacao: January

Florida: mid-March - early June

Central USA: mid-April - early June

Canada: late May - mid-June

The female does most of the incubation, but males have been known to occasionally sit. Both sexes have brooding patches. Incubation lasts 29 - 30 days and hatched chicks are non-competitive. Once chicks have hatched, females beg food from males. The female, in turn, feeds the young for the first 20 days. After that period, chicks beg for food from males and feed themselves. After 30 days, chicks leave the nest. The family remains as a unit for some time. The survival rate of chicks is about 50% under natural conditions, but it is usually higher under better conditions (e.g., human-provided nesting boxes).

Key reproductive features:
iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous .


The American kestrel is, for the most part, not a social bird. During the mating season, males and females pair up and have joint territories. Presumably, the pair or the male defends the territory. The function of the territory may not be so much to ensure mating as to maintain a pair bond during the nesting season when the male is needed to help rear offspring.

Key behaviors:
flies; motile .

Food Habits

In the summer, American kestrels hunt in the early morning and evening, eating large insects (mainly grasshoppers). During winter, they hunt throughout daylight hours and eat small mammals (mice and sparrow-sized birds), sandpiper chicks, lizards, scorpions and amphibians.

Economic Importance for Humans: Positive

The American kestrel plays a prominent part in controlling creatures that humans usually consider a nuisance (mice, insects, etc.).

Conservation Status

IUCN Red List: [link]:
Least Concern.

US Migratory Bird Act: [link]:

US Federal List: [link]:
No special status.

CITES: [link]:
Appendix II.

State of Michigan List: [link]:
No special status.

The availability of nesting places (tree-cavities) may be the chief density limiting factor in breeding populations of American kestrels. This density can be increased by the installation of nesting boxes. However, whether or not additional nesting boxes are introduced, the bird is common.

Other Comments

The common name "sparrow-hawk" is a misnomer because the diet of Falco sparvarius is not even close to being exclusively made up of sparrows. Its other common name, "American kestrel," is more appropriate.

For More Information


Kathryn McCollough (author), University of Michigan.


Amadon, Dean and Leslie Brown, EAGLES, HAWKS AND FALCONS OF THE WORLD, McGraw-Hill Book Company, 1968, v 1 & 2, pp. 85, 771-776.

Cade, Tom J., THE FALCONS OF THE WORLD, Cornell University Press, Ithaca NY, 1982, pp. 152-160.

Sprunt, Alexander, jr. D. Sc., NORTH AMERICAN BIRDS OF PREY, Bonanza Books, NY MCMLV, pp. 158-161.

2010/09/12 02:59:25.470 GMT-4

To cite this page: McCollough, K. 2001. "Falco sparverius" (On-line), Animal Diversity Web. Accessed September 13, 2010 at

Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

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