Comparative trophic ecology of two sympatric canids in the Brazilian Pampa.

Studies on resource utilization by carnivores are essential to assess the role of the species in the ecosystem. These studies help us to understand the mechanisms that influence vertebrate community structure and the relationships between predators and prey. The aims of this study were to compare and describe the food habits of the sympatric Pampas fox (Lycalopex gymnocercus) and crab‐eating fox (Cerdocyon thous) in the Brazilian Pampa, and to evaluate the food niche overlap between them, and infer aspects of habitat preferences on the basis of their prey. For the diet analyses, 25 stomach contents of Pampas foxes and 33 of crab‐eating foxes were collected. We identified 80 prey items (49 for the Pampas fox and 63 for the crab‐eating fox) and grouped them into eight main categories. Mammals and invertebrates were the most frequent items in the diets of both canids, followed by fruits. The trophic niche breadth of the Pampas fox (Bsta = 0.56) was larger than that of the crab‐eating fox (Bsta = 0.47). The diet overlap between them was Ojk = 0.58. However, a PERMANOVA test showed that diets did not differ between species or season. Our results showed that both L. gymnocercus and C. thous had generalist diets, with a great diversity of prey, but based on similar main food items. Items that contributed the most to the diet of the Pampas fox were insects (Gryllotalpidae and Scarabaeidae) and cavies (Cavia aperea) and those that contributed the most to the diet of the crab‐eating fox were fruits of Syagrus romanzoffiana, beetles (Scarabaeidae), amphibians (Leptodactylus spp.) and cavies. This is the first study to describe and compare the food habits of these two species, occurring in sympatry in the Brazilian Pampa. Interspecific competition for food is a critical factor that determines species coexistence in carnivores. In this study we compare and describe the food habits of two sympatric foxes in southern Neotropics, the Pampas fox (Lycalopex gymnocercus) and the crab‐eating fox (Cerdocyon thous). Our results showed that both species had generalist diets, with a great diversity of prey, but based on similar main food items. The foraging strategies of these canids could be associated with the exploration of different microhabitats. This plasticity may be important for the survival of these species under the constant loss of their natural environments, persecution, and other sources of mortality. [ABSTRACT FROM AUTHOR]