CLIFF SWALLOW. 
612. Petrochelidon lunifrons. 5% inches. 
Adults similar in plumage but the female slightly 
paler. Easily distinguished from the Barn Swallow by 
the square tail and light buffy forehead and rump. 
This is what is commonly called the Eave Swallow 
in the East, because of its habit of plastering its nests 
on the outside of barns or other buildings, up under 
the eaves. In the West they usually resort to cliffs 
where, sometimes, large sections of the face will be 
completely covered with the little mud flasks; often 
colonies of several thousand will build their nests to- 
gether. 
Song.—A continuous twitter, uttered while on the 
wing or at rest. 
Nest.—A flask or gourd-shaped structure of mud, 
lined with straw and feathers, attached under the 
eaves to the outside of buildings or on the faces of 
cliffs; five to seven eggs are laid; white dotted and 
spotted with reddish brown (.80 x .55). 
Range.—N. A., breeding from the Gulf to Greenland 
and Alaska; winters in the Tropics. 
