288 ANIMAL LIFE IN THE YOSEMITE 



parts of California, for even an experienced observer rarely sees, in a day's 

 walk anjnvhere in the Yosemite section, more than one or perhaps a pair 

 of the birds. 



Sixteen species of diurnal birds of prey inhabit the Yosemite region, but 

 only four of these, the Osprey, Goshawk, Ferruginous Rough-leg, and the 

 Turkey Buzzard, equal the Red-tail in size, and but one, the Golden Eagle, 

 exceeds it. (See pi. 44.) The Eagle has a golden-tinted head and neck; 

 the Osprey 's head and under surface are chiefly pure white ; the Goshawk 

 is gray-appearing in plumage and it has a long tail ; the Ferruginous 

 Rough-leg is conspicuously white beneath and has much white showing 

 at base of tail ; and the Turkey Buzzard has a bare red head, black plumage, 

 and a gray area on the under surface of each wing near the tip. Among 

 the hawks of somewhat smaller size, the Swainson has a conspicuously 

 light chin and throat, the Red-bellied, plainly black-and-white barred 

 wings and tail, and the Marsh Hawk, a white rump. None of these other 

 birds has a reddish brown tail in any plumage. 



There is much variation in the color of the under surface of the body 

 in different individuals of this species. Some have the under surface as 

 well as the back almost black, while others are nearly white below, with 

 few or no streaks or other markings. Such peculiarities are individual, 

 and cannot be correlated with sex or season. The tail in immature birds 

 is dull, much like the back in color; but all adults, regardless of 'color 

 phase,' have bright reddish brown tails. 



The Red-tail is essentially a soaring hawk. The Marsh and Sparrow 

 hawks when hunting beat along over grassland or poise hovering in the 

 air, and the bullet hawks (Cooper and Sharp-shinned hawks, and Gos- 

 hawks) usually dart after their prey in or through trees or brush ; but 

 the Red-tail proceeds in seemingly more leisurely fashion, and in the open. 

 It sails about with wings and tail widely spread (pi. 44c) and watches 

 from on high for its prey. Occasionally it may perch on a fence post 

 and watch the field near by for ground squirrels or gophers, upon which 

 it pounces with alacrity remarkable in a bird with so heavy a body. 



At times Red-tails are to be seen perched in conspicuous places on 

 branches of dead trees where they can see for considerable distances. If 

 a person comes suddenly under a bird so resting, it gets up quickly and 

 with hea"vy sweeps of its large wings rapidly gains momentum and begins 

 to glide and sail in a spiral course; it is soon able, without seeming to 

 change much the relative positions of either wings or tail, to mount high 

 into the air. 



The Red-tail is to be considered a beneficial species, as regards the 

 interests of mankind; for it lives to a large extent on ground squirrels 

 and gophers. Despite this fact, many people, having in mind the name 



