The cliff swallow is the swallow species famous for its annual return to Mission San Juan Capistrano in California. The birds’ seasonal arrival became one of the best-known migration traditions in the United States.
American cliff swallows breed across much of western and central North America and migrate south for winter, reaching parts of Brazil, Uruguay, and Argentina. Their spring return brings them to nesting areas where they build distinctive gourd-shaped mud nests, often in dense colonies beneath bridges, building eaves, and cliff overhangs.
The Mission San Juan Capistrano tradition inspired the 1940 popular song “When the Swallows Come Back to Capistrano,” written by Leon René. The birds were traditionally said to arrive around March 19, Saint Joseph’s Day, although wild migration does not follow an exact ceremonial date.
A common mistake is choosing the barn swallow, another familiar migrant. Barn swallows have deeply forked tails and are widespread around buildings, but the Capistrano legend specifically concerns cliff swallows. In recent decades, large flocks have become less dependable at the Mission, partly because development has changed nesting and feeding opportunities.