Search

Many aspects of the spatial ecology of the cinereous vulture (Aegypius monachus) are still unknown. The Iberian population is thought to be predominantly sedentary, but the spatial patterns of young individuals have been barely studied. The aim of this study was to provide a comprehensive understanding of the juvenile dispersal of the Iberian cinereous vultures. To this end, we GPS-tagged 41 Cinereous Vultures and tracked their movements during the period 2002–2021, from the end of parental care to the beginning of reproductive age. We examined the influence of age, season and sex on movement metrics (accumulated distances, distances to nest and home range sizes). During the juvenile dispersal period, cinereous vultures travelled over large areas of the Iberian Peninsula and southern Europe. Despite the high individual variability, we found a negative age-related trend in all movement metrics: the younger individuals (<1 year old) often performed farther movements and occupied larger areas, stabilising their movements during immature (1–3 years) and subadult (4 years) phases. On the other hand, season influenced the accumulated distance within all age classes; warm months positively influenced flight effort. Finally, females flew farther and occupied larger areas than males, consistently within age classes. This study did not take into account many factors which may explain part of the high variability observed: landscape, supplementary feeding sites, dumps, colony size, interspecific interactions, stochastic events, etc. Further studies are needed to investigate the influence of these factors on the dispersal of the species in more detail, but this work provides the first approach to the juvenile dispersal of the cinereous vulture in Iberia.

Although the western Mediterranean population of the Cinereous Vulture Aegypius monachus is considered to be mainly resident, a small but increasing number of individuals migrate between western Europe and western Sahel. We used GPS tracking on two juvenile vultures from Spain to reveal their migration routes and their wintering areas in Senegal.

Large scavengers are strongly dependent on environmental conditions and carrion distribution and abundance, so season and breeding-related factors may influence the spatial ecology of species such as the Cinereous Vulture (Aegypius monachus), the largest European raptor. Iberia holds one of the biggest populations worldwide, but some aspects of the spatial ecology of the species in this region remain unknown. In this study, 17 adult Cinereous Vultures were GPS-tracked in order to study their spatial ecology during the adult phase. The average monthly home ranges (95% Kernel Density Estimation, KDE) and core areas (50% KDE) were 6543 ± 19,935 km2 and 1174 ± 4004 km2, respectively. The average monthly home range fidelity ranged between 50 and 73%. Differences in movement-related variables between the seasonal periods (incubation, chick-rearing and non-breeding) were found. During the chick-rearing period, the monthly accumulated distance was higher than during the other periods: 3316 ± 1108 (chick-rearing) vs. 1621 ± 622 (incubation) vs. 1726 ± 1159 km per month (non-breeding). Additionally, large home range sizes were more frequent during the chick-rearing period. There are two likely causes for these seasonal differences. Firstly, chick-rearing entails a higher energetic expenditure by the parental individuals in foraging activities, so larger movements and foraging areas are expected during this period. Secondly, the flight is favoured during spring and summer due to environmental conditions. Matching chick-rearing and warm months is a great evolutionary advantage for soaring-gliding raptors, as it allows them to cover larger areas with low energy expenditure. Furthermore, six individuals tagged as nestlings highlights the philopatric behaviour of the species: vultures settle their breeding areas 54 ± 51 km from their natal nest (range = 9–138 km).