Roosts and home ranges of spotted bats (Euderma maculatum) in northern Arizona

Roosting ecology and foraging behavior of spotted bats (Euderma maculatum (J.A. Allen, 1891)) are poorly known. We captured 47 spotted bats at three locations in northern Arizona and attached radio transmitters to 16 bats to identify roosts and home ranges. We identified 14 roosts for 12 bats. Female roosts faced south; males did not select a roost aspect. Bats used a mean of 1.4 roosts during 10 days. Mean distances from capture site and nearest perennial water source to roosts were 15.1 and 5.8 km, respectively. Maximum and minimum distances from capture to roost site were 36.3 and 2.3 km, respectively. Home ranges (95% use, minimum convex polygon method) for bats averaged 297 km², which was much larger than reported for spotted bats elsewhere in their range and other insectivorous bats. Maximum flight speed was 53 km/h. Most foraging locations were in desert scrub vegetation, but bats also used woodlands and forests, perhaps seeking seasonal prey or cooler sites to reduce water stress. Maternity roosts were remote, difficult to access, and within protected areas in northern Arizona. Foraging areas and ponds used for drinking, however, included private and public lands managed for a variety of uses.