Can intra-specific variation in carnivore home-range size be explained using remote-sensing estimates of environmental productivity?

Carnivore home-range sizes vary profoundly between populations within a species. One commonly cited reason for this is variation in prey population density and environmental productivity. However, obtaining reliable measures of prey density in the field is both time and effort consuming. Therefore, a methodology that enabled scientists and managers to extrapolate home-range sizes across areas would be a valuable tool. So far, the potentials of different remote-sensing indices to represent environmental productivity have been poorly evaluated in this context. In this study, we have evaluated the utility of a readily available remote-sensing index, the Fraction of Photosynthetically Active Radiation absorbed by vegetation canopies (FPAR), to explain interpopulation variation in home-range size for 12 carnivore species. In multiple regression models, evaluated by the Bayesian Information Criterion (BIC), we found that the FPAR index added predictive power to the models for eight of the species. The explanatory power varied between 16% and 71% for the different species. We suggest that using remote-sensing indices such as FPAR to predict area specific home-range sizes for carnivores could potentially be a powerful tool, but that the methodology needs to be further developed in order to add more explanatory power for some species.