Individual traits such as body mass can serve as early warning signals of changes in the fitness prospects of animal populations facing environmental impacts. Here, taking advantage of a 19?year monitoring, the question how individual, population and environmental factors modulate long?term changes in the body mass of Canarian Egyptian vultures was addressed. Individual vulture body mass increased when primary productivity was highly variable, but decreased in years with a high abundance of...

To predict the threat of biological invasions to native species, it is critical to understand how increasing abundance of invasive alien species affects native populations and communities. The form of this relationship across taxa and ecosystems is unknown, but is expected to depend strongly on the trophic position. Using a global metaanalysis based on empirical studies, the authors assessed the shape, direction, and strength of native responses to increasing invader abundance.

Large avian scavengers are among the most vulnerable vertebrates, and many of their populations have declined severely in recent decades. To help mitigate this marked reduction in abundance, supplementary feeding stations (SFS) have been created worldwide, often without consideration of the scientific evidence supporting the suitability of the practice. In this review, the role of SFS is examined.

Understanding how density dependence modifies demographic parameters in long-lived vertebrates is a challenge for ecologists. A number of studies have highlighted the importance of habitat heterogeneity in density dependence in territorial species, but less information exists on demographic processes in colonial species. In this study, long-term data from a recovering population of Cinereous Vultures in southern Spain were used to evaluate environmental and population parameters influencing...