Age, experience, and homing performance in a long-distance migrating bird, the barn swallow

Abstract Homing, the ability of animals to return to specific areas, is crucial for their survival and reproduction. It plays a fundamental role in shaping their spatial range by enabling them to maintain connections between distant critical habitats and optimize resource use. Homing performance, defined here as a combination of likelihood of return and homing time, is known to improve with repeated flights from the same starting location. However, the effect of age on this metric in adult migrant birds is still poorly investigated. I conducted an experiment to investigate whether age and experience gained from a previous homing flight along the same route influence the homing performance of adult male barn swallows Hirundo rustica. I found that the homing performance of male barn swallows increased consistently and significantly with their age. Homing performance was also significantly repeatable among individuals. Furthermore, return times from the same release location were significantly quicker on the second flight than on the first, regardless of whether the flights occurred in the same or following year. These findings suggest that, in at least one species of long-distance migratory passerine bird, homing performance improves with age and accumulated experience. To build on this knowledge, comprehensive research on the factors shaping homing performance in seasonally migratory bird species across diverse taxonomic groups is needed.