Bat diversity in the vegetation mosaic around a lowland dipterocarp forest of Borneo

Tropical rainforests in Southeast Asia are decreasing rapidly because of conversion to agricultural lands, which in turn leads to an increase in mosaic landscapes. Little is known about the effects of these anthropogenic changes on bat fauna or feeding behaviour. To better explore anthropogenic effects on bats (Chiroptera), we investigated the diversity and feeding habits of bats in an intact lowland dipterocarp forest and surrounding areas of varying vegetation types. The total sampling effort using mist nets (32,795 m2h) resulted in the capture of 495 bats, representing 28 species. Simpson’s index of diversity was relatively high in primary forests (7.86) compared to secondary forests (3.38), orchards (3.65), and oil palm plantations (1.24). The capture rate of two frugivorous bats clearly differed among the four vegetation types, and these species were never caught in orchards or oil palm plantations. In addition, the capture rate of microchiropterans was notably lower in oil palm plantations than in the other three vegetation types. These results indicate that many bat species rarely use agricultural land for feeding, and these plant communities are not suitable for maintaining bat diversity. However, the data on the feeding habits of three megachiropterans that were frequently captured in orchards and oil palm plantations indicate that agricultural plants are their primary food sources. Orchards and oil palm plantations may be inadequate habitats for most frugivorous and insectivorous bats, but these plant communities may provide important food sources for certain species of megachiropterans.