Effects of landscape matrix type, patch quality and seasonality on the diet of frugivorous bats in tropical semi-deciduous forest

Abstract

Context Dry forests usually have a marked seasonality in resource availability; as a consequence, wildlife is subjected to drastic changes in food availability during the year. The presence of high-quality sites that provide food during lean periods is crucial in these habitats, especially in human-modified landscapes where resources are limited and scattered. Aims We assessed whether seasonal fluctuations in the availability of fruit resources in two contrasting landscape matrices (continuous tropical semi-deciduous forest and pasture) affect the diet diversity for frugivorous bats, and whether the presence of cenotes (freshwater-filled sinkholes) in these matrices had any effect during the rainy and dry seasons. Methods For each matrix type, two sites with a cenote and two sites with no cenote were sampled. The highest richness of chiropterochorous plants and the longer availability of fruit in the forest surrounding cenotes than in forest with no cenote helped evaluate the importance of patch quality on diet diversity. Two dry and two wet seasons were sampled to assess the effect of the season on diet diversity. Key results After four seasons, 1398 frugivorous bats belonging to seven species had been captured, with Artibeus jamaicensis being the most abundant and important seed disperser. Thirteen plant species made up the diet of the frugivorous bats, with Ficus and Solanum being the most frequent genera. Diet diversity was greater in the pasture matrix than in the continuous forest. During the dry season, diet diversity was higher at sites with a cenote in both landscape matrices, but this interaction was not statistically significant. Conclusions Frugivorous bats are flexible and capable of tracking variations in food availability at different temporal and spatial scales. The latter allows these bats to use several vegetation types during the year to complement their diet in highly seasonal forests. Implications Owing to their foraging habits and the high number and variety of seeds that bats can disperse, they create strong connections between both fragmented and continuous landscapes. Management practices that conserve the areas with arboreal vegetation are essential to the movement of bats and the seeds they disperse across fragmented landscapes that later contribute to forest regeneration.