Too Much is Bad: Increasing Numbers of Livestock and Conspecifics Reduce Body Mass in an Avian Scavenger

Individual traits such as body mass can serve early warning signals of changes in the fitness prospects animal populations facing environmental impacts. Here, taking advantage a 19-yr monitoring, we assessed how individual, population, and factors modulate long-term Canarian Egyptian vultures. vulture increased when primary productivity was highly variable, but decreased years with high abundance livestock. We hypothesized that carcasses wild animals, natural food resource be essential for avian scavengers, could more abundant periods weather instability depleted livestock numbers lead to overgrazing. In addition, increasing population also negatively affect suggesting density-dependent competition food. Interestingly, relative strength availability on changed age territorial status, pattern presumably shaped by differences competitive abilities and/or age-dependent knowledge foraging skills. Our study supports individual plastic may extremely reliable tools better understand response secondary consumers current future human-induced changes.