Swallows and Martins
The family Hirundinidae includes 14 species found in North America.
Swallows are found worldwide, except in polar regions. They range in size from 10-23 cm. Their long, pointed wings and small bills with broad gapes are adapted for capturing insects during sustained flight. Some occasionally eat berries. Eggs 3-8, plain white or with reddish spots. The female incubates.
Martins are the largest swallows with broad, triangular wings and long forked tails. The sexes differ. Most breeding ranges do not overlap, but different species may migrate or winter together. They feed mainly on flying insects, rarely on the ground for ants and other insects. The nest is made of grass, leaves, mud, in holes, cavities, often in colonies, including bird houses with many compartments. Eggs 3-8, usually 4-5, white.
Swallows are found in North, Central and South America. They are 12-13.5 cm in size. All are glossy greenish-blue or blue above and white below. Most have a white rump or partially white rump. Tails are notched. They forage in the open, often over water. The nest is made of grass, hair, etc., in a tree hole or crevice. Some nest in loose colonies.
Northern Rough-winged Swallow
Swallows - Patuxent Bird ID Center