cliff swallow

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A swallow (Petrochelidon pyrrhonota) of North and South America that builds a bottle-shaped nest of mud and twigs on cliffs or under eaves.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun North American swallow that lives in colonies and builds bottle-shaped mud nests on cliffs and walls