Cliff swallow

The cliff swallow can be found throughout most of North America during the breeding season. It winters in South America as far south as Argentina.

Cliff swallows nest in small to large colonies on cliff faces or manmade structures. They frequently nest underneath bridges over water bodies. They may occasionally nest alongside barn swallows (Hirundo rustica). Cliff swallows inhabit open to semi-wooded areas generally near meadows, marshes, or water.

Cliff swallows are insectivorous and feed while flying. They will feed on mosquitoes, flying ants, beetles, wasps, and other swarming insects.

The cliff swallow’s gourd-shaped nest is constructed out of mud and saliva by both the male and female. The only time swallows are usually seen on the ground is when they are collecting mud for use in their nest. It takes between 3 to 27 days for the nest to be constructed.

Between 3 to 6 eggs are laid between April and June. Both adults incubate the eggs for 12 to 14 days and the young are cared for by both parents. The young cliff swallows are usually ready for their first flight after 23 days. Cliff swallows depart their breeding area after their nestlings fledge as early as late June, although some individuals may linger in their breeding area as late as November.

Cliff swallows are considered locally common in some areas within their range and vulnerable in other areas. It is listed as a Species of Special Concern in New Jersey (not yet endangered or threatened but on its way). Because they often live in close proximity to humans and nest on manmade structures, they are sometimes considered a pest and their nests are destroyed. Destroying nests within the breeding season is illegal however.

House sparrows (Passer domesticus) are known to move into old swallow nests and even drive off adult swallows from their nests. House sparrows are a non-native invasive species which were brought into North and South America from Europe. They have caused declines in many native bird species by competing with them for resources, including nesting sites.