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Natal dispersal, the movement between the birth and the first breeding site, has been rarely studied in long-lived territorial birds with a long-lasting pre-breeding stage. Here we benefited from the long-term 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 effect 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 conspecifics 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 different dispersal tactics. Both sexes were affected by different individual attributes simultaneously 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. [ABSTRACT FROM AUTHOR]

The monitoring of an experimental feeding station established in northern Spain allowed the evaluation of how this type of resource, predictable in space but not in time, was exploited by a guild of avian scavengers in relation to factors such as season, hour of disposal and presence of the dominant species. The presence of Egyptian Vultures Neophron percnopterus at carcasses was more likely during spring, and richness and diversity of avian scavengers was lower during the summer and when Griffon Vultures Gyps fulvus arrived earlier. The temporal unpredictability of the resource may favour exploitation by smaller and less competitive scavengers. New European regulations may present an opportunity to develop effective conservation measures to support functional scavenger assemblages. [ABSTRACT FROM AUTHOR]

Supplementary feeding stations, or “vulture restaurants”, are common conservation management tools. While a number of studies have investigated the consequences of surplus food on the population dynamics of scavengers, relatively little is known about the effects of such practices at the individual level. Within the long-term monitored breeding population of Canarian Egyptian vultures (Neophron percnopterus majorensis) we investigated individual bird’s patterns of use of a supplementary feeding station at Fuerteventura (Canary Islands), over the course of breeding (2001, 2002; 2004-2011) and non-breeding seasons (2000-2010). Our results show that during the breeding season the individual use of the supplementary feeding station was inversely related to the distance to the breeding territory, which suggests the existence of central-place foraging constraints. In addition, larger birds of poor body-condition and individuals that ultimately failed to fledge young were detected more frequently at the feeding station. During the non-breeding season, and because most breeding birds abandoned the breeding territories, the overall abundance of Egyptian vultures at the feeding station grew. Moreover, the only variable increasing the probability of presence of individuals was poor body condition so that birds with lower wing residual visited the feeding station more frequently. Supplementary feeding may benefit individuals who would otherwise have been subject to selective pressures. From our results it follows that this conservation strategy must be used with caution because it can have consequences on an individual level and thus potentially affect the viability of endangered populations. [ABSTRACT FROM AUTHOR]

Supplementary feeding stations, or “vulture restaurants”, are common conservation management tools. While a number of studies have investigated the consequences of surplus food on the population dynamics of scavengers, relatively little is known about the effects of such practices at the individual level. Within the long-term monitored breeding population of Canarian Egyptian vultures (Neophron percnopterus majorensis) we investigated individual bird’s patterns of use of a supplementary feeding station at Fuerteventura (Canary Islands), over the course of breeding (2001, 2002; 2004-2011) and non-breeding seasons (2000-2010). Our results show that during the breeding season the individual use of the supplementary feeding station was inversely related to the distance to the breeding territory, which suggests the existence of central-place foraging constraints. In addition, larger birds of poor body-condition and individuals that ultimately failed to fledge young were detected more frequently at the feeding station. During the non-breeding season, and because most breeding birds abandoned the breeding territories, the overall abundance of Egyptian vultures at the feeding station grew. Moreover, the only variable increasing the probability of presence of individuals was poor body condition so that birds with lower wing residual visited the feeding station more frequently. Supplementary feeding may benefit individuals who would otherwise have been subject to selective pressures. From our results it follows that this conservation strategy must be used with caution because it can have consequences on an individual level and thus potentially affect the viability of endangered populations. [ABSTRACT FROM AUTHOR]