The role of exotic mammals in the diet of native carnivores from South America

Abstract

Abstract A better understanding of the effects of exotic species is fundamental for ecosystem management, given that biological invasions are major agents of change affecting native biodiversity worldwide. However, exotic species can also have positive effects on native communities, for instance by providing additional food sources. We reviewed dietary studies in the scientific literature published between 1980 and 2016 in order to examine the role of exotic mammals in the diets of 42 terrestrial species of the mammalian order Carnivora from South America. We recorded information about species' characteristics and analysed the ways in which they relate to exotic mammal consumption. We found 62 references in which 11 carnivores from four families were reported to consume exotic mammals. Using only dietary studies in which the frequency of occurrence of each prey item was presented, we compiled 152 cases from 56 papers. The frequency of occurrence of exotic mammals in the diet of South American carnivores reached on average 21%. The more common prey–carnivore interactions occurred with exotic lagomorphs, while exotic ungulates were less frequently consumed and were only preyed upon by pumas Puma concolor. Consumers with mainly carnivorous habits consumed exotic mammals more frequently than frugivorous or omnivorous species. The carnivore species and the location of the study area influenced the frequency of occurrence of exotic mammals in the diets described. Certain carnivores, including the puma, culpeo fox Lycalopex culpaeus, Pampas fox Lycalopex gimnocercus, lesser grison Galictis cuja and Molina's hog‐nosed skunk Conepatus chinga, consumed more exotic mammals than average, and the occurrence of exotic mammals was the highest in the diets of carnivores in the southwestern regions of South America. Exotic mammals in South America can create new food web interactions in the native carnivore community and can serve as an important food resource for some native species. This is particularly true in human‐transformed landscapes, where native prey populations have declined. Thus, it is important to consider the role of exotic mammals in the conservation of native carnivore populations.