Natal dispersal, the movement between the birth and the frst breeding site, has been rarely studied in long-lived territorial birds with a long-lasting pre-breeding stage. Here we benefted from the longterm monitoring programs of six populations of Egyptian vultures (Neophron percnopterus) from Spain and France to study how the rearing environment determines dispersal. For 124 vultures, we recorded a median dispersal distance of 48 km (range 0–656 km). Linear models were used to assess the efect of population and individual traits on dispersal distance at two spatial scales. Dispersal distances
were inversely related to vulture density in the natal population, suggesting that birds perceive the abundance of conspecifcs as a signal of habitat quality. This was particularly true for declining
populations, so increasing levels of opportunistic philopatry seemed to arise in high density contexts as a consequence of vacancies created by human-induced adult mortality. Females dispersed further than males, but males were more sensitive to the social environment, indicating diferent dispersal tactics. Both sexes were afected by diferent individual attributes imultaneously and interactively with this social context. These results highlight that complex phenotype-by-environment interactions should be considered for advancing our understanding of dispersal dynamics in long-lived organisms.

Serrano, D., Cortés-Avizanda, A., Zuberogoitia, I., Blanco, G., Benítez, J. R., Ponchon, C., Grande, J. M., Ceballos, O., Morant, J., Arrondo, E., Zabala, J., Montelío, E., Ávila, E., González, J. L., Arroyo, B., Frías, Ó., Kobierzycki, E., Arenas, R., Tella, J. L., Donázar, J. A., 2021. Phenotypic and environmental correlates of natal dispersal in a long-lived territorial vulture. Sci. Rep. 11, 5424.| https://doi.org/10.1038/s41598-021-84811-8