Factors Affecting Nest and Site Fidelity in Adirondack Barn Swallows (Hirundo rustica)

Abstract

During 1979-1983, I documented the natal and breeding dispersal of the Barn Swallow (Hirundo rustica) in the Cranberry Lake, New York, region of the Adirondacks by following the lifetime movements and breeding histories of individually marked birds. During the study, 847 birds were marked, and the movements of most were followed during the season they were marked. About 40% of the adults and 2% of the nestlings and juveniles were resighted or recaptured in two or more years. All recovered nestlings had dispersed from their natal colonies (median distance = 6.37 km). Most breeding adults remained faithful to previously used colonies, as well as to clusters within colonies, nests, and mates, when the latter were alive and available. Some individuals, however, did disperse. More females than males dispersed and usually moved farther both within and between breeding seasons. Males and, especially, females that had nested unsuccessfully with a particular mate in a particular location had a higher probability of deserting and dispersing than did successful breeders, both within and between breeding seasons. Old nests were reused at high frequencies for consecutive breeding attempts across breeding seasons. After successful first nests, breeders tended to move to secondary nests within 25 m of their first nests.