Effects of Tornado Disturbance on Bat Communities in Southern Illinois

摘要

On 6 May 2003, a tornado severely damaged 284 ha of Mermet Lake State Forest and Wildlife Area in southern Illinois. We used mist nets and Anabat ultrasonic detectors to determine if community composition and habitat use of bats differed between the tornado-disturbed forest and surrounding undisturbed forest during the summers of 2004 and 2005. Ten species of bats (118 individuals) were caught using mist nets on sites in undisturbed forest; 4 species (I I individuals) were mist-netted on disturbed sites (chi(2) = 34.24, df = 1, P < 0.0001). The Anabat system documented six species on both habitat types with no difference in the number of bat passes detected acoustically. We suspect that apparent differences in mist-net data reflect the greater ability of bats on the disturbed sites to avoid nets. Telemetry data and field observations confirmed bats used disturbed and undisturbed areas for roosting and foraging. Unless precluded by higher fire danger, we suggest that tornado-disturbed areas remain non-salvaged because they provide additional roosting and foraging habitat for many bat species.