FERRUGINOUS ROUGH-LEGGED HAWK. Archibuteo ferrugineus (Lichtenstein)

Field characters.—Size large, slightly greater than that of Red-tailed Hawk; wings broad; tail short. Upper surface of body dark brown appearing; under surface white, with small scattered streaks or bars of dark brown; base of tail in flight appearing white; legs down to bases of toes covered with feathers of a rusty or duller brown tone.

Occurrence.—Sparse winter visitant on west side of Sierra Nevada. Recorded definitely at Smith Creek, 6 miles east of Coulterville, October 17, 1919 (one specimen). Inhabits open ground.

The Ferruginous Rough-legged Hawk is, or was under original conditions, a common winter visitant to the plains of central California and to the larger open tracts in the foothill country, individuals perching in low trees and also often upon the ground. It has been called aptly the California Squirrel Hawk, in recognition of its custom of perching upon squirrel mounds in the prairie country and of preying upon the ground squirrels.

In general form the Rough-leg resembles the well-known Red-tail. It is slightly larger and its coloration is somewhat different. There is no red on the tail of the Rough-leg at any age, and the base of that member shows a considerable amount of white, easily seen when the bird is in flight. The whole under surface of the body in the Rough-leg is white with scattered small streaks of brown which, however, are not apparent at any distance. At close range, or with a specimen in hand, the lower part of the leg (tarsus) clear to the toes is seen to be covered with feathers more or less marked with brown or rusty.