982 ANIMAL LIFE IN THE YO SEMITE 



Occurrence. — Kesident at lower altitudes on west slope of Sierra Nevada and passes 

 in migration east of mountains. Observed at Snelling and reported from Smith Creek 

 east of Coulterville. Noted in Yosemite Valley by us, May 16, 1919, and by Mr. Joseph 

 Mailliard (1918, p. 18), September 26, 1917. Seen during fall months near Walker 

 Lake and Williams Butte. Frequents vicinity of meadows and marshes. 



The Marsh Hawk is to be looked for over large open pasture lands and 

 marshes where it hunts, in its own special manner, for the small animals 

 which live in the short vegetation. Over such territory it floats about 

 with an appearance of laziness or indifference, slowly flapping its long 

 wings a few times and then sailing. It often skims low over the meadows, 

 but it never mounts high in the air to circle or soar like the Red-tailed 

 Hawk. When on the wing the bird's white 'rump' patch gives an effect 

 of its tail being disconnected from the body. The whole demeanor of 

 the bird, totally unlike that of the active ' ' bullet hawks ' ' or speedy falcons, 

 is one of deliberation. 



In mid-September of 1915, near Williams Butte, we saw five Marsh 

 Hawks harrying over a small meadow in search of grasshoppers. On 

 another occasion one was seen perched on a post beside an alfalfa field. 

 Meadow Mice, too, are kno^vn to constitute a staple article in the diet of 

 this hawk. 



Sharp-shinned Hawk. Accipiter velox (Wilson) 



Field characters. — In size, between Eobin and Pigeon; spread wings rounded in 

 outline; tail narrow and nearly square-ended. (See pi. 44/.) Upper surface dark 

 bluish gray in adults, brown in immatures; under surface mixed reddish brown and 

 white, cross-barred in adults, streaked in immatures; tail barred w^ith blackish brown 

 above and grayish white below. Flight rapid and direct; not often seen to circle, and 

 never to poise on beating wings. Earely utters any kind of notes. 



Occurrence. — Fairly common on west flank of the Sierras. Eecorded in summer in 

 Transition and Canadian zones, in winter only below the level of heavy snow. Frequents 

 woods and bottom-land thickets. 



Against the broad-winged soaring hawks and the sharp-winged falcons 

 the bird lover in the Sierras holds no brief, for these birds prey chiefly 

 on rodents and insects and only on rare occasions attack song birds. But 

 against the long-tailed, round-winged 'bullet hawks' he must make com- 

 plaint, for these species are the unremitting enemies of other birds. Of 

 the three species of bullet hawks in the Yosemite region, the Sharp-shinned 

 Hawk is the smallest in size and probably the most important single enemy 

 of the smaller song birds. 



By reason of its relatively short, rounded wings and long tail this 

 hawk is able to pursue small birds into such retreats as dense trees and 

 bushes. It is thus often to be seen dashing into or through a thicket in 

 pursuit of some one songster it has marked down, while consternation 

 reigns among all the feathered creatures in the vicinity. 



