Livestock prevalence in the Egyptian vulture diet during European sanitary restrictions on carcass disposal

Abstract

Food is a primary factor driving animal population dynamics. Low quality food (e.g. poisoned carrion) has caused large declines of Asian and African vulture populations pushing some species to the brink of extinction. Although Europe emerges as a stronghold for the guild, European vultures face potential food shortages due to sanitary restrictions banning the disposal of livestock carcasses in the field after the Bovine Spongiform Encephalopathy (BSE). Determining the diet of European vultures and in particular the role livestock plays in it is needed for preserving these species and their scavenging role in food webs. We analysed the diet composition of 13 nests of the endangered Egyptian vulture (Neophron percnopterus) in a species stronghold in Europe (NW Spain), during the period of BSE restrictions (2007, 2009 and 2010). We identified 312 remains from 25 species, mainly mammals (70.8%), birds (17.0%) and fishes (7.7%). Livestock dominated the Egyptian vulture diet, comprising 23.9% of total items (11.8% of sheep-goat, 7.0% of bovine). Differences in diet composition among nests responded to habitat characteristics determining the availability of some food items (e.g. water for fishes). Our findings support a major role of livestock in the Egyptian vulture diet, suggesting a lack of compliance with sanitary restrictions banning the disposal of livestock carcasses in the field, with potential to affect vulture conservation and their scavenging function in ecosystems.