American Kestrel

American Kestrel

The American Kestrel (Falco sparverius) is our smallest hawk.  It is really a falcon (family Falconidae).  We tend to call all hawk-like birds 'hawks' but they really are falcons, accipiters, and buteos.  Members of the falcon family here include the American Kestrel, the Merlin, the Gyrfalcon and the Peregrine Falcon.  The American Kestrel is interesting because of its size, its beautiful colouration and its ability to live near humans.  

Ten years ago the American Kestrel was a common 'hawk' around agricultural areas and human development.  Its population numbers have taken a severe hit in the last 10 years or so, so that now we have to look to find one.  When I do see one it is usually on a telephone wire or pole, watching for insects on which it feeds.  It is a small slender falcon with a beautiful patterned colourful plumage.  It often hovers over fields while searching for its prey.  When perched it will often pump its tail.

American Kestrel 

The American Kestrel is 23 cm/9 inches long and the tail appears long and is square-tipped.  The wings are slim and pointed.  The back and upper tail are a mottled chestnut colour, the breast is streaked and dotted, dark on a light cream colour.  The feet and legs are yellow.  The face is white with a bold vertical stripe before and behind the eye.  This is much bolder in the adult male.  The wings of the male are a gray blue colour; chestnut in the female.  The tail is chestnut with a dark band at the tip.  The eyes are dark.  The female is slightly larger than the male. 

The only other small hawk we have here that you might mistake for the kestrel is the merlin.  It is a little larger, and much darker in colour.  It has a shorter tail and is not so colourful overall.  It is more heavily bodied and has heavy vertical streaks on its breast.  

American Kestrel

The American Kestrel ranges over most of Canada and the US.  Most spend their winters in the southern US and Mexico.  They are permanent residents of much of South America.  On their wintering grounds they are common where they prefer open areas.  In the north migrating females arrive before the males and choose the best territories.  The males arriving later then are forced into poorer forested areas.  Here and on the rest of its summer range the breeding female is promiscuous, breeding with 2 or 3 males before settling on one mate.  They usually nest in a tree cavity on an open landscape or forest edge, where 3 to 7 white to pale pink eggs are laid.  The female incubates these eggs 29 to 30 days occasionally with a little help from the male.  Kestrels eat mainly large insects such as grasshoppers.  In the winter they eat small mammals, birds and amphibians.  

American Kestrel

The American Kestrel is the most common falcon in North America.  The vertical black lines on the face are an adaptation to cut down glare from the facial feathers.  It makes a high-pitched 'klee klee klee' call when excited.  

The American Kestrel is a very adaptable species.  It lives in many diverse conditions, from above the Arctic Circle to the tropics of Central America.  It can be found from sea level to elevations over 4500 metres (in the Andes Mountains).  It is not a long-lived species, usually living only 5 years in the wild.  

Population declines for this species have been gradual over the last many years.  Declines have been worse on the east and west coasts.  Some reasons for this have been the use of pesticides and the reforestation and development of what once were large agricultural areas.  However, we did sustain a large population increase in the 18th and 19th centuries probably due the opening up of large areas of forest for agriculture.  This would have provided ideal habitat for kestrels.  The southeastern US population has declined 82% since 1940.  Nest box programs have been started in many areas including a project promoted by the Moncton Naturalist Club.  

This falcon is an easy one to identify and will be easy to watch as it 'hawks' insects from a telephone pole near you.