American Kestrel
(Falco sparvarius)
The American Kestrel is the smallest and most common falcon in North
America. Unlike many other species of falcons, males and female kestrels have different
plumages.
Adult Male American Kestrel
Males have blue/gray upper wings coverts and the wing tips are black with white spots. The back is rufous with bars.
The lower back only is barred in adults (upper back clear), while the back is
completely barred on juveniles. The tail color is variable, but most are
reddish, with a wide sub-terminal black band. The tips of the tail is
white.
Females have barred reddish brown backs and upper
wings coverts. The wing tips are brownish without white spots. Tails
are reddish brown with brown bands. Juvenile females are similar to
adults.
As noted in the Falcon photos page,
American Kestrels are reverse size
dimorphic, meaning that the females are larger than the males. The
dimorphism is not nearly as pronounced for Kestrels as it is for some other
falcons and Accipiters.
Data below from
A Photographic Guide to North American Raptors ,
Wheeler & Clark 1995 - We highly recommend this book for anyone interested in raptors. Wheeler & Clark did not separate Male and Female data:
Length: 8-10 inches (22-27 cm)
Wingspan: 20-24 inches (52-61 cm)
Weight: 97-150 grams (3.4-5.3 oz)
Some wing and weight data that we have collected are presented below for American Kestrels
(AMKE).
AMKE un-flattened Wing Chord*
Males: mean 183.4 mm (171-191)
Females: mean 194.2 mm (177-210)
AMKE Weight (No Food in Crop)**
Males: mean 111.4 g (93-130)
Females: mean 127.4 g (108-155)
*Wing Chord is measured from from the wrist to the tip of the longest primary feather. The primary feathers have a
natural camber (bend), and can be measured flattened or un-flattened.
**Raptors store food in a crop (pouch in the throat area). Food in the crop or stomach can effect
the birds weight. We cannot know if there is food in the stomach, but we
can estimate the amount of food in the crop. We score the crop on a 0= no
food in the crop to a 3 = full crop.
Kestrels nest in cavities (cracks and crevices on
cliffs or banks and holes in trees) They do not make their own cavities,
but depend upon other birds (such as flickers or kingfishers) or natural
processes for their nesting cavities.
But you could help by building a Kestrel Nest Box:
American Kestrel Nest Box Plans
My Favorite Book on Kestrels:
The Kestrel (Eurasian Kestrel, but excellent
book). This book is rare - only one still available, but it may not last long.
American Kestrels are partially migratory. Some migrate South into Central America, while others spend the
Winter in some very cold areas in the Northern U.S. and Southern Canada.
Kestrels can be seen on migration at some very well known Raptor migration sites such as Hawk Mountain (Pa), Cape May
Point (NJ) and many other sites. They are among the first raptors to begin migration.
Click on the Raptor migration link below to learn where you can see 1000s of Kestrels during Fall Migration.
Longevity Record: 14 Years and 8 months; based upon known age
of a wild bird at
banding and subsequent band recovery (Data from Bird Banding Lab (Klimkiewicz
2008).
References for American Kestrel information:
Bent, A.C. 1937. Life Histories of North American birds of prey. U.S.
National Museum Bulletin. 167:106-121. Wash. D.C.
Call. M.W. 1978. Nesting Habitats and Surveying Techniques for Common Western
Raptors. Tech. Note TN-316. Bureau of Land Management. Denver Service
Center.
Clark, W.S. and B.K. Wheeler. 1987. A Field Guide to Hawks of
North America. The Peterson Field Guide Series. Houghton Mifflin. Boston.
Ehrlich, P.R., D.S. Dobkin and D. Wheye. 1988. The Birder's Handbook. A Field
Guide to the Natural History of North American Birds. Simon and Schuster.
New York.
Klimkiewicz, M. K. 2008. Longevity Records of North American Birds. Version
2008.1. Patuxent Wildlife Research Center. Bird Banding Laboratory. Laurel MD.
Go to Raptor Migration Page
Go to Hawk Photos page (Buteos)
Go to Falcon Photos page
Check back from time to time...
We will be adding more information in the future.
American Kestrels in Modern Falconry
Go to Bird Pictures Page
Go to Bird Watching Bliss Home
misp. American Kestral
 
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