AMERICAN ROUGH-LEGGED HAWK 277 



where it devoured its prey on an ice cake. Another time a fine 

 roughleg pounced successfully on a cotton-tail rabbit and bore it off. 



The favorable up-currents of air on the brow of a steep hill or 

 cliff enable them to hang suspended in the air as motionless as a kite. 

 Gravitation takes the place of the kite-string, and by skillful dis- 

 position of the plane of the wings to the up-current the bird remains 

 motionless if the wind is steady. When the wind is irregular and 

 flawy, the bird swings about more or less just as a kite acts under 

 similar circumstances. When tlie wind drops for a moment the bird 

 moves with rapid wing beats. This use of the up-currents over hill 

 or cliff is a familiar habit of the roughleg, and I have frequently 

 VN-atched this habit both in Massachusetts and in Labrador. Another 

 method for securing food is also resorted to, in which the bird sits 

 on a rock or stub and watches for its prey. 



Perched, the rough-legged hawk sits very erect, preferring dead 

 trees or poles to living trees. At Ipswich I have frequently seen 

 them perched on windmills. One bird that I watched seemed to have 

 a special liking for this kind of perch, for on one occasion it visited 

 and perched on three in succession. E. A. Kitchin (1918) records the 

 following case of a bird collected from a telegraph pole by J. Hooper 

 Bowles at Tacoma, Wash., on October 20, 1917 : "The bird sat length- 

 wise of the cross-bar, on the sunny side of the pole, with wings half 

 drooping. This odd attitude was observed by Mr. Bowles for a 

 minute or more before collecting; when the hawk was brought to 

 hand, he found the wings and tail soaking wet, which probably 

 accounted for the strange position on the bar. A freshly eaten field 

 mouse, found in its stomach, may have been caught swimming across 

 one of the many cliannels of the flats, and the hawk had probably 

 been obliged to take a partial dip to secure its prey." 



Writing of this hawk. Major Bendire (1892) says that in autumn 

 in the Harney Valley, Oreg., he had "often seen a dozen or two in a 

 few hours' ride, usually standing singly on a little hillock in the open 

 prairie, or perched upon a sage busli watching for prey" — small 

 rodents and grasshoppers and occasionally rabbits. Dr. Fisher (1893) 

 says: "The rough-leg is one of the most nocturnal of our hawks, 

 and may be seen in the fading twilight watching from some low 

 perch, or beating with measured, noiseless flight, over its hunting 

 ground." Several times in January 1931 I saw a roughleg about 

 sunset enter a grove of pines, apparently to roost there for the night. 

 In so doing it disturbed a hundred or more crows that had been using 

 this grove as a roosting place, and they flew about violently cawing 

 and finally left the hawk in undisturbed possession. Crows fre- 

 quently pursue roughlegs, sometimes darting at them from above and 

 cawing loudly, but as a rule the hawk does not appear to notice them. 



