USES OF THE WING 



105 



geon and dentist; but spears, awls, chisels, picks, hooks, crackers, 

 trowels, needles, scoops and strainers are also represented in the bird's 

 equipment. Primarily these instruments or weapons are designed to 

 secure food for the adult and to feed its young, but the bill is also of 



service in preening, 

 in gathering and 

 placing nesting ma- 

 terial or excavating 

 nesting - sites, and 

 as a weapon of at- 



FIG. 12. Recurved bill of Avocet. (Two-thirds natural size.) t f ck or Defence in 



the usually harmless 



struggles of birds. Woodpeckers use it as a drumstick. Owls rattle 

 their mandibles threateningly, and Pelicans snap theirs in loud defiance. 



With some birds, the bill is the seat of some special growth or color 

 during the breeding season. The White Pelican then wears a keel- 

 like knob on the upper mandible, and the bills of Auks, Puffins and some 

 Ducks are brightly colored or modified in form. 



Uses of the Wing. The student should observe the relation be- 

 tween the shape of a bird's wing and the character of its flight and the 

 further relation between the manner of its flight and its general habits. 



FIG. 13. Long, pointed wing and small foot of Tree Swallow, an 

 aerial bird. (Natural size.) 



Compare, for example, the wing of a Turkey Vulture with that of a 

 Quail or Partridge; one aerial, the other terrestrial in habit. Note the 

 lengthened flight-feathers and broad expanse of the Vulture's wing, 

 its comparative slowness in getting under way, its ability to soar 

 indefinitely, in short, to remain in the air with the least possible expendi- 

 ture of effort; while the rounded wing of the Quail, although incapable 

 of prolonged flight and requiring great exertion for effective use, can 

 nevertheless be employed at highest speed so quickly that the bird 

 is in full flight almost the moment 

 it leaves the ground. Continue 

 the comparison through your list 

 of birds, noting not only the power 

 but the rhythm of the wing-stroke, 

 whether it be regular or varied, 



Whether the flight be direct Or FlQ - 14 - Short, rounded wing and larg 

 j,,i , . ^ foot of Little Black Rail, a terrestrial bird 



undulating, etc. (Natural size.) 



