American cliff swallows behavior

American cliff swallows are very social. Large flocks forage together in flight throughout the day; birds have been timed at up to almost 30 mph. In cool and cloudy weather, the swallow gives a “squeak” call to announce the discovery of an insect swarm.This call attracts other birds to the food source.

The birds preen their feathers and sunbathe together at their daytime perches on wires, small twigs and rooftops, and they roost together at night, clinging to reeds and tall grasses. To protect their young against enemies, such as American kestrels, black-billed magpies, bull snakes and rats, the cliff swallows build sheltered nests in large colonies. Central nests are sought after, because the nests at the edges of a colony are more vulnerable to attack. But there is not always safety in numbers: very large, conspicuous colonies attract predators. Cliff swallows usually give alarm calls and surround the predator in a loose group to drive it off.