Comparative Roosting Ecology of Cynopterus (Chiroptera: Pteropodidae) Fruit Bats in Peninsular Malaysia 1

Although the use of modified roosts has been reported in more than 20 species of bats in the tropics, comparative studies of the roosting ecology of congeneric tent‐roosting species are notably lacking. In the Paleotropics, this unique behavior has been described in two species belonging to the genus, Cynopterus : C. sphinx and C. brachyotis . However, it is not known whether tent roosting is an essential component of their roosting ecology, or whether the behavior is found in other members of the genus. In this study we characterize the roosting ecology of four sympatric species of Cynopterus in peninsular Malaysia and use these data to address two main questions. (1) Do all four species use modified roosts and, in those that do, is tent‐roosting obligate or opportunistic? (2) Do species pairs overlap in roost preferences and roosting habitat and, if so, is there evidence for interspecific interactions in relation to these resources? We radio‐tracked bats at two floristically distinct sites and located a total of 249 roosts. Interspecific roost niche overlap was minimal at both sites and we found no evidence for interspecific competition for roost resources at the local level. Species differences in roosting ecology were defined primarily by spatial separation of roosting habitats and secondarily by within‐habitat differences in roost selection. Importantly, we found that although periodic use of modified roosts was a characteristic shared by all four species, most roosts were unmodified, indicating that tent roosting is a facultative behavior in Malaysian Cynopterus .