Hawks Aloft, Inc.
Conservation, Avian Research, and Education
PO Box 10028 - Albuquerque, NM 87184 - (505) 828-9455

 

American Kestrel (Falco sparverius)

Field Marks:

-  length: 12 in. wingspan: 22 in.

-  vertical black malar stripes under the eyes and rusty-red base coloration on back feathers

-  sexually dimorphic in plumage

-  males have bluish gray patches on the wings, solid rusty tail, and black chest spots

-  females have black banding on wings and tail, and vertical brown chest streaks

-  also called a sparrow hawk

Breeding Range:

American Kestrels breed in all parts of the United States, most of Canada, and the northern half of Central America. 

Wintering Range:

Kestrels winter in the southern half of their breeding range and throughout Central America.  Kestrels in the northern latitudes migrate, while southern residents typically remain on their territories year-round.  Migration is in response to photoperiod and food availability, rather than temperature change. 

Habitat Preferences:

They live in a wide variety of habitats, with open or semi-open areas.  They seek trees or man-made structures large enough to contain suitable nesting cavities.  American Kestrels nest in meadows, grasslands, deserts, parkland, agricultural fields, and urban or suburban areas regardless of dominant vegetation.  The availability of a nest cavity is the most important factor in nest site selection.  They readily take to artificial nest boxes in a habitat devoid of natural cavities. 

Nesting:

Kestrels are typically monogamous, but extra-parental assistance or extra-pair copulations are not unusual.  The coloration of the male seems to be a factor in mate selection.  Kestrels nest in tree cavities with openings approximately 3 inches in diameter.  The clutch size is typically 4-5 eggs, with one egg laid every other day.  Incubation typically lasts for 30 days.  The young fledge 28-31 days after hatching, and remain with their parents for 12-14 days after fledging.   

Feeding:

Kestrels primarily feed on insects and small rodents.  A high percentage of small birds are also taken.  They also occasionally feed on reptiles.  In urban areas, they often hunt at bird feeders.  Small prey is eaten on the ground, while larger prey is taken to a tree or post perch. 

Conservation Status:

American Kestrels are the most abundant North American falcon, and there are estimated to be as many as 1.2 million pairs.  Populations are increasing in North America in response to increased habitat and the creation of artificial cavities.  Although American Kestrels are not listed as threatened or endangered, they are protected under the Migratory Bird Treaty Act.