Chimney Swift (Chaetura pelagica)
It's hard to figure out how these birds ever existed without urban
areas, since they literally earn their first name by nesting and
roosting in chimneys, propping themselves against the inside surface
with short, spiny tails.
The chimney swift is normally found only east of the great plains. Small birds
at about 5 inches long, they are aloft all day long, and almost always
in groups. They migrate in large flocks and nest from Canada to the
Gulf of Mexico. Watching a flock of swifts flow funnel-like into a
chimney is a startling evening experience. The birds express
themselves with a chatter of chipping cries, one of the easiest
identifications of the species. Their only food is insects, and they are
highly beneficial.