Deer-vehicle collisions are on the rise and are a costly side-effect of increasing deer populations and expanding transportation systems. We evaluated the efficacy of sound as a deterrent for reducing deer-vehicle collisions by observing the behavioral response of captive and free-ranging white-tailed deer (Odocoileus virginianus) to 5 pure-tone sound treatments: 0.28 kHz, 1 kHz, 8 kHz, 15 kHz, and 28 kHz. We conducted preliminary trials with semi-tame deer at the University of Georgia Captive Deer Research Facility. We exposed 8 deer in a 0.25-ha outside paddock and 5 deer in individual stalls (2.7 m x 4.8 m) to the various treatments at >70 dB Sound Pressure Level. We recorded 406 observations and determined that the behavior of captive deer did not change when presented with any of the 5 pure-tone sound treatments. We also conducted field trials at Berry College Wildlife Refuge, Georgia and gathered 319 behavioral observations of free-ranging deer relative to a moving automobile (56.45 kph). The automobile was fitted with a sound-producing device and speakers that emitted one of the pure-tone sound treatments or no sound treatment as a control. For the 1 kHz, 8 kHz, 15 kHz, and 28 kHz sound treatments, we observed no change in deer behavior relative to the control. When exposed to the 0.28 kHz treatment, deer reacted in a manner more likely to cause deer-vehicle collisions. Our results indicate that deer within 10 m of roadways did not alter their behavior in response to the pure-tone sound treatments we tested in a manner that would prevent deer-vehicle collisions. Commercially available wildlife warning whistles (aka deer whistles) are purported to emit similar consistent, continuous sounds as pure tones at various frequencies within the range of those presented in this study. Our data suggests that deer-whistles, as they are purported to operate, are likely not effective in preventing deer-vehicle collisions.

Deer-vehicle collisions are a major concern throughout much of the World, accounting for human injury and death, damage to vehicles, and immeasurable waste of deer as a wildlife resource. Throughout the planning of our research project, we reviewed the primary literature to identify strategies with the most potential to reduce deer-vehicle collisions. Our review is available online as an annotated bibliography at: http://www.forestry.uga.edu/h/ research/wildlife/devices/GADOTLiteratureReview.pdf. Our findings indicated that most states in the U.S. have attempted to minimize deer-vehicle collisions through a variety of techniques. However, most studies have not empirically examined the efficacy of such techniques and many deer-deterrent devices were not designed with an understanding of the sensory capabilities of deer. Many previous studies also were isolated in scope or were inadequately replicated to afford statistical validity. Hence, the questions regarding efficacy of many deer deterrent devices remain largely unanswered and there still exists a need for research on mitigation strategies based on the sensory abilities of deer. Until these research results become available, management efforts to minimize deer-vehicle collisions should focus on (1) implementing proper deer-herd management programs; (2) controlling roadside vegetation to minimize its attraction to deer and maximize visibility for motorists; (3) increasing motorist awareness of the danger associated with deer-vehicle collisions; (4) thoroughly monitoring deer-vehicle collision rates; and (5) encouraging communication and cooperation among governments, wildlife researchers, highway managers, motorists, and others involved in the issue of deer-vehicle collisions. We are conducting a research project designed to provide a more thorough understanding of the physiological processes driving white-tailed deer (Odocoileus virginianus) roadway behavior. Our ultimate goals are to use this knowledge to develop improved strategies designed to reduce deer-vehicle collisions.