222 ANIMAL FORMS 
pecker (Sphyrapicus varius) is a real sapsucker, living on 
the juices of trees. A close relative of the red-headed 
woodpecker, the California woodpecker (Melanerpes formi- 
civorus), is renowned for its habit of boring holes in bark 
and inserting the acorns of the live oak. Subsequently the 
bird returns, and breaking open the acorns, devours the 
grubs which have infested them, and apparently eats the 
acorns also. 
209. Swifts, humming-birds, etc. (Macrochires).—The birds 
of this order are rapid, skilful fliers, and their wings are 
very long and pointed. The feet, on the other hand, are 
Fig. 126.—Night-hawk (Chordeiles virginianus) on nest. Photograph by H. K. Jos. 
small, relatively feeble, and adapted for perching or cling- 
ing. Accordingly, the insects upon which they feed are 
taken during flight by means of their open beaks. The 
night-hawk (Chordeiles virginianus), roosting lengthwise on 
a branch by day, at nightfall takes to the wing, and high 
in the air pursues its food after the fashion of a swallow. 
In the same haunts throughout the United States the whip- 
