Marie-Eve André
Project
Direct and indirect effects of landscape structure on the foraging behavior of the King VultureThe spatial heterogeneity resulting from the fragmentation of forests has important effects on the process of habitat selection. In particular, the selection of feeding sites might be influenced by landscape composition and configuration, as well as by intra- and interspecific competition. This study aims at understanding direct and indirect effects of landscape structure on the foraging strategies of the King Vulture (Sarcoramphus papa), an avian scavenger of neotropical forests. To achieve this goal, carcasses were installed in the southern Yucatan Peninsula according to a paired design. The use of carcasses by KV was assessed at two spatial scales. At the local scale, two types of vegetation were considered (open and forest). At a larger scale relevant to the species (15 km radius), the relative area of cover types and their configuration in the landscape were estimated. Other variables, such as the distance to the closest road and village were included in the models. The abundance of competitor species (Turkey Vulture, Cathartes aura, and Black Vulture, Coragyps atratus) at foraging sites also allowed us to test for indirect effects of landscape structure on KV’s foraging behavior. Our results underline the importance of a high percentage and aggregation of mature forests at landscape scale in KV’s selection and use of foraging habitats. We also show that there are positive and negative relationships between KV and BV that depend on the number of BV at carcasses. Mid values of BV abundance lead to maximal abundance of KV underlining the importance of local enhancement in the detection process of food resources for KV. Very high abundances of BV resulted in the outnumbering of KV highlighting the dramatic outcome of accute competition with an invasive species. Understanding the ecological impacts of changes in landscape structure will facilitate the design of conservation strategies for this species, which provides many vital ecological services.
