160 THE UNIVERSITY OF THE STATE OF NEW YORK 



Marsh hawk Nu HM7 



The marsh hawk finds its food of mice by sailing back and 

 forth over the meadows (sailing not soaring). The sixth pri- 

 maries have apparently been molted and are being replaced. 

 Black tern Nu TfB9 



Compare with the preceding, noting the long wings. 



c Soaring 



Accomplished by holding the wings and tail at such an angle 

 that without any apparent movement, the bird is able to take 

 advantage of air currents and sail in large circles, rising higher 

 and higher. For this method of flight, a large broad wing and 

 fanlike tail are necessary. 



Bald eagle Nu EB 



The eagle and all the broad winged hawks (Buteos) spend 

 much time soaring high over head watching the ground for prey. 

 Note the breadth of wing and the fanlike tail. 



Young bald eagle Nu EBl 



Compare with the preceding. 



Young bald eagle Nu EB52 



The wings of the eagle are so heavy that for many weeks after 

 they are full grown the young bird is unable to hold them up. 



Turkey vulture Nu VuT4 



Note the great expanse of wing. 



Turkey vultures Nu VuT8 



These birds are just getting under way when they are at some 

 disadvantage because of their large wings. The "buzzards" soar 

 for hours at a time with apparently no effort. 



d Darting 



Accomplished by suddenly increasing the wing strokes over 

 normal flight and is used by birds in pursuing flying insects, 

 other birds, or in escaping enemies. The shorter the wing the 

 more rapidly it can be moved and in birds that must gain sud- 

 den momentum from a stationary position we find the shortest 

 wings, as in members of the grouse family. In birds that have 

 longer wings and must take flight suddenly, the effect of a 

 shorter wing that can be moved much more rapidly is brought 

 about by spreading the primary feathers. 



