Regional and Temporal Differences in the Functionality of Facultative Vertebrate Scavenger Communities

Carrion represents a nutrient-rich but ephemeral resource that plays a disproportionate role in ecosystem functioning by supporting scavenger communities and nutrient cycling. However, we lack understanding of how facultative vertebrate scavenger communities are structured across space and time. We examined the functionality of facultative vertebrate scavenger guilds on a regional and temporal scale using a dataset collected in protected areas in three geographical regions in the Netherlands (Veluwe, De Hamert Estate and KempenBroek). We assessed scavengers' functional roles-defined as species-specific contributions to carcass consumption-scavenger diversity, and carcass depletion times based on behavioural traits, feeding preferences, and carrion exploitation. Functional roles of facultative vertebrate scavengers were represented across the regions, although the occurrence of specific species was region-specific. In the Veluwe, scavenging behaviour of red fox (Vulpes vulpes) varied between consecutive years, likely driven by differences in resource availability. Across the regions, higher scavenger diversity (Shannon index) was associated with longer carrion depletion time, reflecting that slower carrion decomposition allows more facultative scavenger species to detect and utilise the carrion. Our results demonstrate that the functionality of scavenger communities is shaped by both regional and temporal factors. This highlights the importance of continuously or periodically (re)evaluating the functionality of facultative vertebrate scavenger communities across regional and temporal scales.