Positive effects of forest fragmentation, independent of forest amount, on bat abundance in eastern Ontario, Canada

While studies have consistently found positive effects of forest amount on bat abundance, the effects of forest fragmentation (breaking apart of forest, independent of amount) are less certain. The purpose of this study was to examine how forest amount and forest fragmentation independently affect bat abundance. I conducted acoustic bat surveys at the centres of 22 landscapes throughout eastern Ontario, where landscapes were chosen to avoid a correlation between forest amount and fragmentation (number of forest patches). I found that the effects of forest amount on bat relative abundance were mixed across species (one positive, two negative), and that forest fragmentation, independent of amount, had a positive effect on the relative abundances of three species. I suggest that the mechanism driving the positive responses to forest fragmentation is higher landscape complementation in more fragmented landscapes; that is, increased access to foraging sites from roosting sites.