Diet of four small mammal species from Atlantic forest patches in South Brazil

Abstract

In this study we analyse the diet composition of small mammals of western Paraná state, southern Brazil. Species studied were mostly unknown on feeding habits. Animals were sampled during the faunal survey carried out in October 1998 when implementing the Salto Caxias dam. The diet composition, based on gut contents, seems to be mostly opportunistic and generalist for the three marsupials, Micoureus paraguayanus, Caluromys lanatus, and Monodelphis sorex, and for the rodent, Akodon paranaensis, studied. Caeca of the four small mammal species had in general a small quantity of insects when compared with other digestive tract portions. However, when volume consumed was evaluated, Arthropoda was the most important item for three species of them. Inversely, fruits were important for C. lanatus. The estimated amount of plant material (seeds and other plant structures) had a higher importance for C. lanatus, mainly for caecum samples, however these items were also found in the other mammal species samples but in lower proportions. The high proportion of intact seeds on both, digestive tract and caecum, when compared with predated seeds, is noticeable, suggesting that the species are seed dispersal. Monodelphis sorex seems to have a more insectivorous diet, as it is a small cursorial mammal, although there was also evidence for frugivory or carnivory. Akodon paranaensis was insectivorous-omnivorous, although fruits and vertebrate prey were also consumed, indicating also and opportunistic diet. Caluromys lanatus is classifi ed as a more frugivorous species, besides the consumption of vertebrate prey. Insectivorous habit seems to be frequent in neotropical small mammals, with consumption of vertebrates or fruits being only opportunistic. The insectivory (except for C. lanatus) and opportunistic habit appear to dominate among the small mammal species studied.

Key words: Micoureus paraguayanus, Caluromys lanatus, Monodelphis sorex, Akodon paranaensis, food habits.