Résumé
Abstract This study aimed to link the plants consumed by Cavia magna and their availability in the environment, (Ilha dos Marinheiros) determining its food preference. In the environment, 96 species were recorded. Twenty-four plant species were identified in the fecal samples. There wasn't significant difference in the composition of plant species among seasons, although the variation was significant between the island's northern and southern areas concerning the fecal samples. Mantel test's results supported that the availability of vegetation has significant influence on the species consumed. Being that the most consumed species (present on the feces) were distant to their distribution areas, we propose that C. magna of Ilha dos Marinheiros actively search and select items to eat, showing food preference for some species.