Bats in rural landscapes: a significant but largely unknown faunal component

Bats—a prominent component of the mammal fauna There are 90 taxa of bats currently known from Australia, which together make up more than 25% of the native mammal fauna (Duncan et al. 1999). These species belong to seven families: the Pteropodidae (flying-foxes, fruit-bats and blossom-bats), Megadermatidae (Ghost Bat), Rhinolophidae (horseshoe bats), Hipposideridae (leaf-nosed bats), Emballonuridae (sheathtail bats), Molossidae (freetail bats) and Vespertilionidae (vespertilionid bats). Bats occur in substantial numbers throughout all environments in Australia, from the tropics to the arid deserts, and in most areas constitute a large part of the local mammalian fauna. They are important contributors to a range of ecosystem processes, including seed dispersal, pollination, and predation of invertebrates. However, other than the flying foxes, which are large and visible in their diurnal roost sites, most species of bats are poorly known and rarely encountered. This is particularly true in temperate environments of southern Australia, where the dominant group of bats are the vespertilionids. These species are all small (4-25 g body weight), nocturnal in activity, and roost during the day in locations seldom seen by most people. They have two main habitat requirements: suitable areas in The Northern Plains of Victoria, like other agricultural regions of southern Australia, has experienced extensive loss and fragmentation of its native woodlands. Thirteen species of insectivorous bats occur in the area. All are dependent on remnant native vegetation for roosting and foraging. To investigate how these species are distributed throughout the landscape, we sampled 195 sites in remnants of varying size and form. Bats were widespread throughout all remnant types, with at least some activity at every site. In addition to the larger blocks, foraging occurred around individual trees in paddocks, but not in open farmland devoid of trees. Two species were studied intensively to investigate how they used the fragmented landscape. Gould's Wattled Bats (Chalinolobus gouldii) roosted predominantly in very large live trees in Barmah State Forest, an extensive floodplain woodland, while foraging up to 11 km away in remnants in farmland. There were differences in the behaviour of males and females of the Lesser Long-eared Bat (Nyctophilus geoffroyi). Most males roosted and foraged in relatively small woodland areas in farmland. In contrast, females moved considerably further with most roosting in Barmah S.F. and foraging up to 12 km distant in farmland remnants. Different types of roost were selected by males and females, and during the breeding and non-breeding …