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Margalida A.,Bearded Vulture Study and Protection Group | Margalida A.,University of Bern | Benitez J.R.,Linea de Geodiversidad y Biodiversidad | Sanchez-Zapata J.A.,University Miguel Hernández | And 3 more authors.
Ibis | Year: 2012

Between 2000 and 2009 we studied the diet and breeding success of Egyptian Vultures Neophron percnopterus in southern Spain. Wild species accounted for 74.9% of prey items (n=1071) with a predominance of mammals (62.3%), followed by birds (20.8%) and reptiles (13.1%). Spatially, the diet was highly varied and not restricted to carcasses of livestock; wild Rabbits Oryctolagus cuniculus accounted for 54% of the overall remains. The spatial variability may reflect regional and local disparity in the availability of main prey. The temporal relationship between variation in trophic diversity and Vulture nesting productivity (both values showing a long-term decrease) might suggest a causal link between variation in diet and reproductive output. We hypothesize that high turnover rates could explain productivity variation as a consequence of the recruitment of less experienced individuals to the breeding population. This could in turn generate covariation between diet and reproductive output. © 2011 The Authors. Ibis © 2011 British Ornithologists' Union.

Sanz-Aguilar A.,CSIC - Doñana Biological Station | Sanz-Aguilar A.,CSIC - Mediterranean Institute for Advanced Studies | Sanchez-Zapata J.A.,University Miguel Hernández | Carrete M.,Pablo De Olavide University | And 4 more authors.
Biological Conservation | Year: 2015

Large body-sized avian scavengers, including the Egyptian vulture (Neophron percnopterus), are globally threatened due to human-related mortality so guidelines quantifying the efficacy of different management approaches are urgently needed. We used 14. years of territory and individual-based data on a small and geographically isolated Spanish population to estimate survival, recruitment and breeding success. We then forecasted their population viability under current vital rates and under management scenarios that mitigated the main sources of non-natural mortality at breeding grounds (fatalities from wind farms and illegal poisoning). Mean breeding success was 0.68 (SD. = 0.17) under current conditions. Annual probabilities of survival were 0.72 (SE. = 0.06) for fledglings and 2. yr old non-breeders, 0.73 (SE. = 0.04) for non-breeders older than 2. yrs old and 0.93 (SE. = 0.04) for breeders. Probabilities of recruitment were 0 for birds aged 1-4, 0.10 (SE. = 0.06) for birds aged 5 and 0.19 (SE. = 0.09) for older birds. Population viability analyses estimated an annual decline of 3-4% of the breeding population under current conditions. Our results indicate that only by combining different management actions in the breeding area, especially by removing the most important causes of human-related mortality (poisoning and collisions on wind farms), will the population grow and persist in the long term. Reinforcement with captive breeding may also have positive effects but only in combination with the reduction in causes of non-natural mortality. These results, although obtained for a focal species, may be applicable to other endangered populations of long-lived avian scavengers inhabiting southern Europe. © 2015 Elsevier Ltd.

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