Cliff Swallow

The Cliff Swallow, Hirundo pyrrhonota (sometimes Petrochelidon pyrrhonota), is a member of the passerine bird family Hirundinidae, the swallows and martins.

It breeds in North America and Mexico, and is migratory, wintering in southern South America. This species is a very rare vagrant to western Europe.

These birds average 5 inches long with a tiny bill. The adult has an iridiscent blue back and crown, brown wings and tail, and buff rump. The nape and forehead are white. The underparts are white except for a red face. The tail is square-ended.

Young birds are essentially brown above and whitish below, except for the buff rump and dark face.

The only confusion species is the closely related Cave Swallow, which is richer in colour and has a cinnamon rump and forehead.

Cliff Swallows breed in large colonies. They build conical mud nests and lay 3-6 eggs. The natural nest sites are on cliffs, preferably beneath overhangs, but as with the Eurasian House Martin, man-made structures are now the principal locations for breeding.

This species has always been plentiful in the west of North America, where there are many natural sites, but the abundance in the east has varied.

European settlement provided many new nest sites on buildings, but the population declined in the late nineteenth and early twentieth centuries as the supply of unpainted barns declined. There has been a subsequent revival as dams and bridges have provided suitable sites.

Like all swallows and martins, Cliff Swallows subsist primarily on a diet of insects which are caught in flight.

Reference

Swallows and Martins of the World by Turner and Rose, ISBN 0-7470-3202-5