232 HUMMINGBIRDS 
GENUS AERONAUTES. 
425. Aeronautes melanoleucus (Baird). White-throated 
Swift. 
Tail about one half as long as wing, forked, with stiffish and narrowed 
but not spiny feathers; tarsus and part of 
toes feathered; hind toe directed either 
forward or to the side, but not backward. 
Upper parts blackish; throat and breast 
and patches on wing and sides of rump white; 
sides blackish; tail without bristles. Length: 6.50-7.00, wing 5.30-5.90, 
tail 2.50-2.70. 
Remarks. — The white markings distinguish this swift from vauxii , 
whether seen from above or below. 
Distribution. — Western United States from the Pacific coast east to the 
region of the Black Hills, western Nebraska; and from Montana south to 
Lower California and Guatemala. 
Nest. — On cliffs or in caves, glued to the rocks, made of vegetable 
matter and stiff feathers, lined with bark fiber and a few feathers. Eggs : 
4 or 5, white. 
Food. — Aerial insects. 
There is one bird that needs no protective legislation for itself or 
nest. The home of the white-throated swifts is in the air around lofty 
peaks and cliffs, where they circle and wheel and dart on curved, 
cutting wings with arrow-like speed. As you stand on the crest of 
a ridge where they pass, there is a flash of black and white and a 
bullet-like whizz as one after another goes by, and you wonder that 
any living thing can move with such speed. I have seen collectors 
who were good wing shots fire till their gun barrels were hot and 
turn away with empty belts and only a single specimen of the swifts. 
As the birds seldom come to low altitudes it is not strange that they 
should be rare in collections. Their nests, placed in crevices or 
caves half way up inaccessible cliffs, have rarely been taken. 
Vernon Bailey. 
FAMILY TROCHILIDiE : HUMMINGBIRDS. 
KEY TO GENERA. ^^ 
1. Exposed culmen half as long as wing or longer. 
Calothorax, p. 242. \ y 
V. Exposed culmen less than half as long as wing'. 
S Fig. 299. 
2. Exposed culmen not more than .50; outer tail feathers 
black-barred and white-tipped in both sexes . . Atthis, p. 241. 
2'. Exposed culmen more than .50; outer tail feathers not black-barred 
and white-tipped in both sexes. 
3. Nostrils nearly or wholly naked. 
4. Tail blue black in both sexes, upper parts metallic grass green. 
Iache, p. 244. 
Fig. 298. 
4'. Tail not blue black. 
