When bat eats bat: diet and roosts of the greater broad-nosed bat (Scoteanax rueppellii) across different regions and habitats

Abstract

Roost selection and diet are fundamentally important to bats and can vary geographically and with habitat. The greater broad-nosed bat (Scoteanax rueppellii) is infrequently captured and poorly known, meaning appropriate conservation actions are difficult to determine. To assess variation across different habitats, we collected faecal samples for dietary analysis and radio-tracked individuals to identify roost trees at four different sites across New South Wales, Australia. Analysis of droppings verified beetles as the main prey in each study area except one dominated by mangroves, and confirmed for the first time carnivory in wild-caught individuals from the presence of hair from other bat species in its droppings. Very large, hollow trees were used as maternity roosts, being typically larger than neighbouring trees. Roosting habitat varied from wet sclerophyll forest in gullies to old-growth mangroves, and tree species used as roosts also varied. Colony size at maternity roosts was often 50–100 bats and fidelity to the maternity roost varied, with some being switched almost daily and others occupied for at least several days. One maternity roost was re-used 2 years later. Both the importance of beetles in the diet and roosts located in more productive landscapes suggest coastal plains and foothills may represent key habitat.