Nestbox density is negatively associated with natal dispersal distance in Western Barn Owls ( Tyto alba )

Understanding how anthropogenic landscape modification influences dispersal dynamics is a central challenge in spatial ecology because dispersal strongly shapes population connectivity, colonization and persistence across heterogeneous environments. Artificial breeding infrastructure may alter not only the local availability of breeding sites but also the broader spatial distribution and persistence of settlement opportunities across landscapes. However, whether such anthropogenic redistribution of breeding opportunities influences the distribution of dispersal distances remains poorly understood. We examined how nestbox density influenced natal dispersal in the Western Barn Owl Tyto alba across agricultural landscapes in Israel, where one of the world's largest nestbox networks for this species has been established. Using observed natal dispersal estimates from 199 ringed individuals, we evaluated relationships between nestbox density, dispersal distance, long‐distance dispersal probability, dispersal‐distance distributions and spatial scale dependence. Generalized additive models, quantile regression, threshold‐sensitivity analyses and analyses accounting for spatial structure were used to examine dispersal responses across multiple spatial scales. Natal dispersal distance declined progressively with increasing nestbox density, with the strongest support emerging at intermediate‐to‐broad landscape extents of approximately 4–6 km surrounding natal sites. Quantile‐regression analyses demonstrated that negative density effects persisted across the dispersal distribution, but slopes did not differ among quantiles, providing no evidence for a disproportionately stronger effect towards the upper tail. Consequently, high‐density nestbox landscapes exhibited dispersal‐distance distributions shifted towards shorter distances, with fewer long‐distance movements. The same general pattern was supported by analyses accounting for broad‐scale spatial structure and natal‐box pseudoreplication, and in comparisons with realized local occupancy patterns. Our results suggest that anthropogenic redistribution of breeding infrastructure is strongly associated with shifts in the observed distribution of natal dispersal distances, particularly through reduced frequencies of long‐distance dispersal events that are expected to contribute disproportionately to large‐scale population connectivity. More broadly, the study highlights how human modification of settlement landscapes may alter dispersal patterns across biologically relevant spatial scales.