The Large Bent-wing Bat Miniopterus schreibersii in Urban Environments: a survivor?

The Large Bent-wing Bat Miniopterus schreibersii has often been perceived as a native species thriving in our rapidly expanding urban landscape. We used a number of historical and current data sets to assess whether this perception is supported by direct evidence. Investigation of museum records revealed that it was present within inner Sydney from at least 1892. Even at this time it was utilising human structures, including the cellar of Elizabeth Bay House. An examination of both historical and current use of diurnal roosts suggests that there has been a recent possible change in the structure of populations using the Sydney metropolitan area, Australia's largest urban landscape. All roosts examined since 1995 are occupied from March to September and are vacant over the summer months. This contrasts with the only roost prior to 1995 that has been studied in any detail. Banding records indicate that a disused railway tunnel at North Sydney was occupied during most months of the year until its abandonment by bats during the 1980s. It also was known to, at times, accommodate double the maximum number of bats recorded in any roost investigated since 1995. Investigation of injury rates in urban populations provides evidence that they are indeed under stress, suffering increasing rates of injury through the winter period, unlike populations in roosts away from urban influence.