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.