CONICET | Buscador de Institutos y Recursos Humanos

South American caviomorph rodents occur in a broad range of ecosystems, display a great diversity of habits, and the greatest morphological and ecological disparity among rodents, and, as primary consumers, they constitute the food of a large number of predators. We reviewed 127 studies which included 249 diets of mammalian carnivores from South America, to investigate the importance of caviomorphs as their prey, and patterns of predation on them. We also present a case study to evaluate the importance of two caviomorph species in the structure of a raptor assemblage. Results indicate that consumption of caviomorphs is a common event for carnivores; they were present in 76% of the diet samples. At a biogeographical scale, the probability of consumption of caviomorphs increases with increasing predator body weight, decreasing species richness in predator diets, and decreasing longitude. Several carnivore species exhibited local trophic specialization toward some caviomoph species, which can explain the negative relationship between FO of caviomorphs in predators diets and dietary richness. We found an east-west longitudinal gradient in FO of caviomorphs in diets, which could be related to a gradient of biodiversity and availability of prey (different from caviomorphs) for predators. Sociality does not prevent predation when compared with predation on solitary species, and diurnal social species were more predated than nocturnal. There were not overlap between activity time of both predator and prey for diurnal caviomorphs, enhancing the importance of these prey to carnivores. Our case study shows that both, Ctenomys haigi and Microcavia australis, were important prey for the entire assemblage of raptors and were responsible for the formation of a trophic guild based on their consumption.

enviar mensaje