Natal dispersal and process of recruitment in a long-lived, trans-continentally migrating bird

Abstract

ABSTRACTNatal dispersal is a multi-step process. It commences when a juvenile departs from its natal site and concludes when it settles to breed for the first time. During this interim period, dispersing individuals of long-lived species undergo a wandering phase, which may span years. This phase remains one of the least studied aspects of species’ life history. We utilized a unique GPS-telemetry dataset on a slow-life history migratory bird of prey – the European honey buzzard, tracked for multiple years after fledgling. Our aim was to assess how phenology, ranging behaviour and philopatry change as individuals gain experience. Individuals exhibited variability in the age at which they first returned to their breeding range, yet all survivors settled at sites proximate to their natal nests. In subsequent returns, immatures increased the time spent within the breeding range and narrowed their ranging to smaller areas situated even closer to their natal nests. Our study unveils the complexity and protraction inherent in natal dispersal, emphasizing the importance of individual experiences and migratory improvement for successful recruitment in long-lived species.