Swainson's Hawk

Photo by Bob Gress

 

Common Name: Swainson's Hawk

 Scientific Name: Buteo swainsonii

Measurements:

Length: 17 - 22 inches
Wingspread: 47 - 54 inches
Weight: 1.3 - 2.7 pounds

 

Comments: These gregarious hawks can often be found feeding and migrating in flocks that may total more than a thousand birds. There are no recognized subspecies of Swainson’s hawks, but they can be light, rufous or dark morph birds. On lighter colored birds a dark brown bib can be seen between a lighter colored chin and belly. When seen in flight the leading edge of the wing is light, and the flight feathers are dark. Juveniles have a streaked plumage.

Distribution: Swainson’s hawks breed from southwestern Canada through central and western United States to the northern parts of Mexico. A large majority of the birds winter in the pampas of Argentina. For the birds that breed in Canada and winter in Argentina that means traveling over 6,000 miles, a trip that may take nearly 2 months to complete. Populations have been reduced since the early 1900s due to loss of habitat and declining prey populations as a direct result of pesticide application to insects in agricultural crops.

Food: Non-breeding birds eat mostly large insects. Grasshoppers seem to be a favorite. They are often seen foraging in fields where farm machinery disturbs their prey. During the breeding season Swainson’s hawks eat a more typical hawk diet of rodents, rabbits, ground squirrels, birds and reptiles.