They occasionally eat berries and seeds. Flocks perch in long rows on branches and wires. When they nest, they usually produce 2 broods. Male and female build nest in 7 to 14 days on buildings, occasionally caves, culverts and under bridges. Swallows nest in colonies, yearlings from a first clutch often aid in feeding nestlings.
Breeders tend to return to same colony.
Males help incubate eggs. They winter from lesser Antilles, Puerto Rico and Panama. Chipper Woods Bird Observatory Nova Scotia Museum of Natural History Department of Ecology and Evolutionary Biology, Cornell University Special Thanks to Volunteer Erin Buchanan for helping create this page.