Space Use in Cinereous Vultures (Aegypius monachus): The Role of Artificial Feeding

The factors affecting vultures’ space use can be complex, but food availability is often considered the primary determinant. However, when vultures’ food resources become highly predictable, their role in movement ecology has been little studied. Conservation planning for endangered vulture species requires a comprehensive understanding of space use. In this study, we quantified several metrics that may affect the space use of Cinereous Vultures (Aegypius monachus), a central-place forager isolated in the southeastern Balkans, which had access to substantial artificially provided food (33 tons per year) during the study period (2004–2009). Metrics examined for putative influence on ranging behavior included season, age, sex, breeding status, and artificially provided food quantity. Home range and core area sizes were larger during the breeding season and smaller during the non-breeding season. Although age, sex, and breeding status did not affect space use, we found strong evidence that artificially provided food predictability can shape the movement ecology of Cinereous Vultures. Annual home range size, core area, and seasonal overlap of the spatial parameters did not vary greatly over the years, suggesting repeatability in the species’ ranging behavior. Highly predictable artificially provided food can modify the movement ecology of necrophagous species. Yet, providing safe food is essential to preserve this endangered vulture. We suggest that feeding programs be gradually diversified to simulate natural carrion availability by using multiple small feeding sites and supplementing them unpredictably with small amounts of food.