The Swainson's Hawk, Buteo swainsoni, is a large hawk.
Adults have long broad wings with dark flight feathers. They have a dark brown back and upper wing. There are two main colour variations:
- Light morph birds are white on the underparts and underwings; they have a grey tail with dark bars and a reddish breast. Their head is brown with a white patch on the chin.
- Dark morph birds are dark brown except for a light patch under the tail. There is a rufous variant that is lighter on the underparts with reddish bars.
Their breeding habitat is prairie and dry grasslands in western North America. They build a stick nest in a tree, shrub or on a cliff edge.
These birds are long distance migrants, wintering in Argentina.
These birds patrol open areas or scan for prey from a perch; they may also catch insects in flight. They take advantage of insects turned up by farm equipment or driven out by fire. They mainly eat small mammals, reptiles and large insects, sometimes small birds.
This bird was named after William Swainson, a British naturalist. In flight, they hold their wings in a slight dihedral; they tip back and forth slightly while soaring.
They are declining in some parts of their range due to loss of habitat.
Although the use of DDT has been banned in the United States, the Swainson's Hawk still encounters pesicide use when it migrates in the winter to Argentina. Known as the locust hawk, the hawks will eat numerous amounts of these insects and in turn ingest a high amount of toxin, which will cause thinning of egg shells.
Last updated: 07-17-2005 21:04:16
