108 THE FEET 



In short^ailed birds like Murres, the feet, when extended backward, 

 act as rudders in flight. It may be added that all the Water-birds, the 

 Gallinae, Columbae and Raptores, carry the feet extended backward in 

 flight, while all the Passeres, or Perching Birds, carry them drawn up 

 forward. In the intermediate groups (Cuckoos, Trogons, Wood- 

 peckers, Swifts, Hummingbirds and Parrots) the manner in which the 



FIG. 19. Toes of Ruffed Grouse. Naked in summer, fringed in winter to serve as 

 snowshoes. Illustrating seasonal adaptation in structure. 



feet are held in flight does not appear to be definitely known, though 

 it seems probable that they are drawn up as in the Passeres. (See Town- 

 send, "A Labrador Spring," pp. 180-205.) 



The longer-winged diving birds, like Cormorants and Water-Tur- 

 keys, use only the feet to propel them when under water; Grebes and 

 Loons also use the feet for a similar purpose, and to a lesser extent 

 the wings. 



The relation between the two organs of locomotion, wings and feet, 

 should be observed, when it will be found 

 that when the former are greatly developed the 

 feet are correspondingly small (e. g. Man-o'- 

 war-bird; Swallows), while when the feet are 

 large the wings are proportionately short and 

 weak (e. g. the Rails and Gallinules). 



In securing food, feet are of service in 

 scratching (e. g. Gallinse; Fox Sparrows), while in 

 predaceous birds long, recurved talons and grasp- 

 ing power reach their maximum among birds. 



Parrots use the foot as a hand, and many 

 birds employ it to gather and place nesting 

 material. With gallinaceous birds, particularly 

 __ those that have spurs, the foot is a weapon. In 



FIG. 20. Foot of Osprey; Herons and Goatsuckers, the middle-toe has a 

 to show large, apposed lateral terminal comb or pectination the func- 



claws and spicules on under ... - , . , . -. 



surface of toes. tion of which is unknown. 



