THE BIRDS 223 
poorwill (Antrostomus vociferus) occurs, sleeping by day, 
but active at night. Neither of these birds constructs nests, 
but lays its streaked and mottled eggs directly on the 
ground. The chimney-swifts (Chetwra pelagica), swallow- 
like in general form and habits, but very unlike the swallows 
Fig. 127,Anna hummers (one day old), showing short bill and small size of body, 
Compare with last joint of little finger. 
in structure, frequent hollow trees or unused chimneys, to 
which they attach their shallow nests. The nearly related 
humming-birds are chiefly natives of tropical America, only 
a few species extending into the United States. Of these 
the little, brilliantly colored, and pugnacious ruby throat 
(Trochilus colubris) is the most widely distributed. Its 
nest, like that of other hummers, is composed of moss and 
lichens bound together with cobweb and lined with down. 
210. Perching birds (Passeres).—The remaining birds, 
over six thousand in all, belong to one order, the Passeres 
or perchers. They are characterized by great activity, 
interesting habits, frequently by exquisite powers of song, 
and in addition to several other structural arrangements 
have the feet adapted for perching. Their nesting habits 
