Landscape variables associated with relative abundance of generalist mesopredators

Increasing densities of generalist mesopredators are a major concern in the conservation of threatened prey species. Knowledge of landscape factors influencing mesopredator abundance is therefore of essential interest to conservation managers. Identification of landscape variables to measure mesopredator abundance necessitates application over a large area. Additionally, the method should be cost effective and applicable in different settings. In our study, we used feces counts to index the relative abundance of red foxes ( Vulpes vulpes ) in a densely forested mountain range, the Black Forest in Germany. Using a negative binomial regression, we found that landscape diversity and edge density best predicted differences in feces abundance, both showing a positive correlation with feces abundance. We used these results to predict relative red fox abundance for the entire Black Forest and correlated the results with the hunting bag statistic on the municipality level averaged over 11 years. The high correlation between these two independent measures of relative abundance confirmed our results and underlined the usefulness of feces counts to measure abundance of elusive species. The model approach we employed can be used to predict abundance of a wide range of species and regions by identifying factors that influence their abundance.