Large-scale movement patterns in a social vulture are influenced by seasonality, sex, and breeding region

Abstract

Quantifying space use and segregation, as well as the extrinsic and intrinsic factors affecting them, is crucial to increase our knowledge of species-specific movement ecology and to design effective management and conservation measures. This is particularly relevant in the case of species that are highly mobile and dependent on sparse and unpredictable trophic resources, such as vultures. Here, we used the GPS-tagged data of 127 adult Griffon Vultures Gyps fulvus captured at five different breeding regions in Spain to describe the movement patterns (home-range size and fidelity, and monthly cumulative distance). We also examined how individual sex, season and breeding region determined the cumulative distance travelled and the size and overlap between consecutive monthly home-ranges. Overall, Griffon Vultures exhibited very large annual home-range sizes of 5,027 ± 2,123 km2, mean monthly cumulative distances of 1,776 ± 1,497 km, and showed a monthly home-range fidelity of 67.8 ± 25.5 %. However, individuals from northern breeding regions showed smaller home-ranges and travelled shorter monthly distances than those from southern ones. In all cases, home-ranges were larger in spring and summer than in winter and autumn. Moreover, females showed larger home-ranges and less monthly fidelity than males, indicating that the latter tended to use the similar areas throughout the year. Overall, our results indicate that both extrinsic and intrinsic factors modulate the home-range the social Griffon Vulture and that spatial segregation depend on sex and season at the individual level, without relevant differences between breeding regions in individual site fidelity.