19 
Family CAPRIMULGIDA. Goatsuckers. 
A rather small family of long-winged, short-legged, medium 
sized birds. The food is insects caught on the wing. Nocturnal 
and crepuscular. Beneficial. 
173. DUSKY POORWILL. Phalenoptilus nuttalli 
californicus. 
Rather common summer residents of the foothills and moun- 
tains. Present in the lower valleys in winter in small numbers. 
174. PACIFIC NIGHTHAWK. Chordeiles virginianus 
hesperis. 
Occasional in the eastern part of the county in the migrations. 
175. TEXAS NIGHTHAWK. Chordeiles acutipennis 
texensis. . 
Rather common summer residents of the coast region and 
foothills. 
Family MICROPODIDA. Swifts. 
Small swallow-like birds, and usually confused with swallows, 
but technically quite different. The flight is very swift. The 
food is insects caught on the wing. Beneficial. Nests are placed 
in crevices of rocks or in holes in trees; one eastern species now 
frequently places its nests in chimmeys. 
176. BLACK SWIFT. Cypseloides niger borealis. 
Rare spring migrants. 
177. VAUX SWIFT. Chetura vauxi. 
r aed common migrant. Similar to the eastern Chimney 
witt. 
178. WHITE-THROATED SWIFT. Aeronautes 
melanoleucus. 
Summer residents, common locally. Present irregularly in 
winter. Nests in steep cliffs. 
Family TROCHILIDA. Hummingbirds. 
A large family (over 400 species), exclusively American in dis- 
tribution, and mainly tropical. The smallest known birds are 
hummingbirds and the largest species are not as large as ordinary 
sparrows. The food is mostly minute insects, frequently taken 
from tubular flowers, many species add honey also. The nests 
are beautiful, warm, thick-walled, often outwardly stuccoed with 
bits of lichens. The eggs are plain white, two in a set. Some 
species are quarrelsome and all are fearless. Most species have 
a variety of notes and some have a low sweet song. 
179. BLACK-CHINNED HUMMINGBIRD. Archilochus 
alexandri. 
Common sumnier residents from the coast to the lower edge of 
the pine forests. 
180. COSTA HUMMINGBIRD. Calypte cost. 
Common summer residents. Nest preferably on hillsides. A 
few winter in the foothills at the edge of the Colorado Desert. 
