Such great numbers of these swallows have been seen in the far West that the name of Rocky Mountain swallows is sometimes given to them; though however rare they may have been in 1824, when DeWitt Clinton thought he "discovered" them near Lake Champlain, they are now common enough in all parts of the United States.

In the West this swallow is wholly a cliff-dweller, but it has learned to modify its home in different localities. As usually seen, it is gourd-shaped, opened at the top, built entirely of mud pellets ("bricks without straw"), softly lined with feathers and wisps of grass, and attached by the larger part to a projecting cliff or eave.

Like all the swallows, this bird lives in colonies, and the clay-colored nests beneath the eaves of barns are often so close together that a group of them resembles nothing so much as a gigantic wasp's nest. It is said that when swallows pair they are mated for life; but, then, more is said about swallows than the most tireless bird-lover could substantiate. The tradition that swallows fly low when it is going to rain may be easily credited, because the air before a storm is usually too heavy with moisture for the winged insects, upon which the swallows feed, to fly high.
End of Chapter