Larry L. Pater
U.S. Army Construction Eng. Res. Labs., Champaign, IL
David K. Delaney
Teryl G. Grubb
USDA Forest Service, Flagstaff, AZ
Paul Beier
Northern Arizona Univ., Flagstaff, AZ
M. Hildegard Reiser
Holloman Air Force Base, NM
The Endangered Species Act requires federal agencies to assess impacts of their activities on threatened and endangered species and to carry out programs for the conservation of listed species. In some cases activities, including military training, are curtailed because of potential impacts. There is currently no known published research on the possible impact of noise on the spotted owl. The present research addresses the question of the noise impacts of low level helicopter flights and ground activities such as chain saws and motorcycles on Mexican spotted owls (Strix occidentalis lucida). This research will characterize the effect of anthropogenic activity on breeding Mexican spotted owls by developing a dose-response threshold model that quantifies animal response relative to sound stimulus levels and approach distances. Consideration is given to the hearing range and sensitivity of the Mexican spotted owl, the sound level received at roost and nest sites, flight response of nonbreeding owls, effects on nest attentiveness of breeding females and on the rate of prey delivery by breeding males, and development of disturbance-specific management guidelines to minimize potential audio and visual impacts from helicopter and ground activities.