Welcome to the Cliff Swallow Project

Among the most highly social land birds in the world, cliff swallows inhabit large colonies, historically constructing their characteristic gourd-shaped mud nests beneath cliff ledges across western North America. Colonies can host up to 6000 nests, although some birds nest as solitary pairs or in smaller groups. In recent years, they've adapted to new nesting environments, including creating colonies beneath building eaves and bridges and expanding their range into previously unoccupied regions of eastern North America.

We began our field study of cliff swallows in western Nebraska in 1982. Our study area is home to around 300 cliff swallow colonies of varying sizes each summer and encompasses what is likely the densest population of this species on the continent. These birds exhibit remarkable adaptations to a colonial lifestyle, prompting our investigation into the reasons behind their group living and the implications of colony size variation. Through our research, we aim to address fundamental questions in animal behavior and evolutionary ecology.