Bird Guide: Water Birds, Game Birds, and Birds of Prey East of the Rockies

by Chester A. Reed

354. Falco rusticolus. 23 in.

Adults white, heavily barred above, and streaked below with gray and black.

Range.—Arctic regions, south in winter, rarely to northern United States.

354a. GYRFALCON (F. r. gyrfalco). Similar to the last but darker, the latter being usually more white than dusky, while this is the reverse.

354b. BLACK GYRFALCON (F. r. obsoletus). Much darker than the last, the markings tending to be buffy white spots on a grayish black ground.

PRAIRIE FALCON

355. Falco mexicanus. 18 in.

A blackish patch on the sides of the throat, similar to that of the [Duck Hawk]. Above brownish black, much paler and never with the slaty color of the Duck Hawk; below streaked or spotted with blackish brown. These falcons are fairly abundant on the western plains and prairies, and are also found in wooded mountain regions. They are strong and active and will fight fiercely if captured. They live upon small mammals, birds and occasionally, grouse. Their flight is very swift and accomplished by rapid wing beats, with occasional sailings.

Notes.—A cackle, and rapidly repeated “kee-kee-kee.” (Bendire).