Seasonal patterns in the diet of frugivorous bats in the subtropical rainforests of Argentina

摘要

The principal goal of our research is to evaluate the dietary variation of the frugivorous bats in two contrasting subtropical rainforests in Argentina (montane rainforest in the NW with a strong seasonality and lowland rainforest in the NE with a mild seasonality). Diet was estimated on the basis of over 1000 dietary records collected along two seasonal annual cycles. Our results indicated that the dominant frugivorous bats exhibit a marked seasonality in the use of fruit resources and that some plants represent keystone resources in periods of general food scarcity. The NW bat ensemble response to fruit phenology was a strong decrease in the capture rate toward the end of the dry season. The NE bat ensemble did not show the same seasonal pattern, and we hypothesize that other variables are probably more important to determine bat abundance. Diet of bats varied in response to spatial changes in the availability of their preferred fruits. For instance, the use of Solarium, Piper, and other fruits by Sturnira bats appeared to be coupled with patterns of diversity and density of these resources.