Swainson's Hawk

Adult Swainson's Hawk (Buteo swainsoni ), light morph

The Swainson's Hawk (Buteo swainsoni ) is a representative of Real buzzards ( genus Buteo ) from the Accipitridae family ( Accipitridae ). It is found in western North America.

Description

The Swainson's Hawk has an average body length of 53 centimeters and a wingspan of 132 centimeters. It can be distinguished from each other based on the Buzzard long, narrow and pointed wings ending.

In gliding over plains and the prairie, the wings are installed and the tumbling flight reminiscent of vultures.

Its plumage is extremely variable. It lacks in contrast to the red-tailed hawk, the bright spots on the screen springs and the ceilings of the primaries. The beak is less powerful, the cere is yellow. The upper wing surface is uniformly brown to dark brown, the wing-coverts have pale bright end seams. The bottom and upper tail-coverts are bright, as is the always white throat patch. In Flight bright transverse bands can be seen on the big feathers ( secondaries, primaries and tail feathers ).

The iris is bright with young birds, adult birds at dark.

We can distinguish three prairie buzzard morphs ( color types).

Light morph

The underside of the wings of the dark morph has a pale, dirty - whitish color, contrasting with the dark cross bands of the United plumage. They have a distinct, brown bib, which is clearly distinct from the rest of white underside. The flanks have an incomplete, thin, light brown cross bands. The pants ' ( feathered lower leg) are white and not ties.

Young birds of this morph have a dark beard Streif which settles from the bright throat and a bright eye over strips of the beak root to the back of the head. The sides have big, the belly smaller dark spots.

Intermediaries morphs

The coloring of the intermediate morphs ( intermediate type ) is between the light and dark morphs and includes a brownish type with a. In this light brown underparts, including the pants is uniformly dark quergebändert ( cuckoo, ').

Dark morph

The dark morph of the prairie buzzard is dark brown with white under tail-coverts. The bright transverse bands on the wing underside stand out less strongly on the otherwise dark underside. The darkest individuals of this morph have a solid color bottom.

Voice

Outside the breeding season of the Swainson's Hawk is little ruffreudig. The call is a shrill " kiarrrrrrr ", which sounds weaker than the similar call of Rotschwanzbussards.

Dissemination

The Swainson's Hawk comes in a wide strip from the hinterland to the west coast of the United States prior to approximately the middle of the Great Plains. In the north of its range extends into the southwestern Canada, south to northern Mexico.

Hiking

The Swainson's Hawk is a partial migrant, the train takes place in large flocks. The largest part of the winter in South America, rare Florida and the Central Valley in California.