Biogeographical patterns and diversity in the diet of the culpeo ("Lycalopex culpaeus") in South America

Abstract

Here we describe the dietary patterns of the culpeo (or Andean fox) at a biogeographical scale. We also analyze the influence of exotic lagomorphs on its diet and explore differences between culpeo subspecies. We selected 17 mutually comparable diet studies, which include 19 independent diet assessments. Then, we extracted and standardized the values of the different diet components from these studies and calculated the relative frequency of occurrence (RF) of the ten main trophic groups that we found. Further, we calculated the Shannon-Wienner H’ trophic diversity index. The results showed that small mammals (41%), lagomorphs (21%), invertebrates (12.4%) and large herbivores (7.3%) were the most consumed groups. A factorial analysis of all trophic groups rendered four orthogonal factors that were used as response variables in relation to a set of environmental predictors. Altitude correlated with most factors (i.e. trophic groups). Exotic lagomorphs were consumed in lowlands, in higher latitudes and in regions showing high values of the human footprint index, replacing in these areas native fauna as the main prey. There were no differences in diet between the two main culpeo subspecies analysed, L.c. culpaeus and L.c. andinus. Finally, the best explanatory models (GLM) of trophic diversity selected, using the Akaike’s information criterion (AIC), showed that the most diverse diets were those composed of large herbivores, edentates, carnivorous species, birds and herptiles (i.e. amphibians and reptils), in areas of high rainfall located in protected areas. Neither latitude nor altitude seemed to have an effect on the trophic diversity of the culpeos, as they were not retained by the final models.