FEEDING AND POTENTIAL SEED DISPERSION BY BATS AT VALE DO TABOCAS FARM, A CLOUD FOREST ENCLAVE IN THE BRAZILIAN CAATINGA

Bats: feeding and potential seed dispersal in a rainforest enclave in Caatinga

Abstract

This study investigated the feeding patterns of fruit bats in a fragment of cloud forest enclave located in the Brazilian semiarid Caatinga and evaluated the role of bat species as potential seed dispersers. Bats were captured with mist nets during six nights each month between April 2015 and March 2016, and fecal samples were collected for content analysis. The physical integrity of the seeds was also confirmed by observing broken and intact seeds. A total of 703 bat specimens belonging to the family Phyllostomidae, including nine genera and 12 species, were captured during the fieldwork. At least 50 species of fruit-bearing plants that can be used by bats were identified, which together fruited for 12 months. Among the fruit bats, 512 fecal samples were found, of which 466 contained fruits, 44 contained insects, and two contained pollen grains. An analysis of fecal samples indicated a predominance of fruits with endozoochorous seeds (80%) in the bats' diet, which explored at least 31 different items, primarily from pioneer plants such as Ficus, Cecropia, and Solanum, even when other food sources were available. There was significant variation among bat species in the consumption of different items, except for the three Artibeus species, which had similar diets. Only 23 of the 243 (approximately 10%) fecal samples analyzed here contained damaged seeds; only one broken seed was found in each sample. The consumption of fruits from diverse plant species, the production of mixed seed rain, the release of intact seeds, and the predominance of fruits with endozoochorous seeds in the bats' diet reflect the importance of the frugivorous guild for the reproduction of diverse plant species. The concentration of the diet on fruits of pioneer plants weighing less than 5 g, whose small seeds are ingested together with the pulp, reinforces their role in the restoration of degraded areas and, in turn, in the regeneration of cloud forest enclaves found in the Brazilian semiarid region.