FERRUGINOUS ROUGHLEG 291 



chance to approach the bird than a man on foot. A bird standing 

 on the ground on a smooth, level jDrairie can sometimes be secured 

 by driving an automobile at it at high speed; the surprised hawk 

 must rise slowly, and the man with a gun is almost under it before 

 the hawk can get away. When launching into the air off a perch 

 or when rising from the ground, this big heavy hawk flaps heavily 

 and awkwardly; but when well under way it soars gracefully and 

 easily, mounting in great circles far up into the sky. I once saw 

 nine of these great hawks in the air at one time, soaring majestically 

 at varjdng heights over a burnt prairie near Quill Lake, Saskatche- 

 wan; these birds were probably hunting in true Buteo style. It is 

 often more active in its hunting motions, beating over the open 

 country a few feet above the ground, much after the manner of the 

 American roughleg, but flying more swiftly and ready to pounce on 

 any unlucky mammal it may surprise. Again it may stand patiently 

 above the burrow of a prairie dog or ground squirrel, waiting to 

 seize the unsuspecting animal if it shows its head. 



In its behavior toward other bird species it seems to be a peaceful 

 and harmless neighbor, except in the few cases where it needs food 

 for its tender young. Magpies often build their nests in the same 

 tree with it, and other birds seem to have very little fear of it. But 

 it can defend its young with spirit, if necessary, as evidenced by 

 Mr. Cameron's (1914) account of one that attacked a great horned 

 owl and drove it away from the vicinity of its nest. 



Voice. — The alarm notes heard when the nest is disturbed are 

 recorded in my notes as a loud kree-a^ or ke-a-ah^ or again as a harsh 

 ka^h^ kaah, like one of the notes of the herring gull. 



Field 771 arks. — The adult in the light phase is easily recognized 

 from below by its practically white tail, unmarked by bars, and by 

 its nearly all white under parts, broken only by the dark V formed 

 by the brown tibiae converging to a point where the feet come 

 together under the tail. As seen from above the head is whiter than 

 most hawks, the back and shoulders more rufous, the tail whitish, 

 and there is a light area in the widely extended primaries. This last 

 character apj^ears in all plumages. In immature plumages the under 

 parts and tail are whiter than in other hawks. In the dark phase 

 the plain light-colored tail and the light space in the primaries are 

 distinctive. 



Winter. — The ferruginous roughleg withdraws largely from the 

 northern portions of its range in autumn to spend the wiiiter in the 

 milder portions of the United States. A young bird banded at 

 Rosebud, Alberta, on July 7, 1930, was shot at Trinidad, Colo., on 

 September 26, 1930; and another, banded at the same place the next 

 day, was killed at Seagraves, Tex., on December 9, 1930. This hawk 



