Date of this Version
Ultrasonic devices are marketed for pest control because some manufacturers believe they possess properties aversive to animals. However, there is little evidence that ultrasound is more aversive to animals than is audible sound. In this study, we examined the efficacy of the Yard Gard ultrasonic device for deterring deer (Odocoileus virginianus) from feeding on apples. Four deer feeding stations were established at private residential properties with a history of deer damage to ornamental plants, so that control (A I and B 1) and experimental (A2 and 132) stations existed at each site. Apples were placed at each feeding station and restocked daily from mid-February to mid-March 1995. Yard Gard devices were set up at one station at each site, and we monitored daily deer activity by counting: (1) apples remaining, (2) deer tracks, and (3) deer fecal pellet groups at all feeding stations. Of the 360 total apples offered at site A while the devices were on, 175.0 (97.2%) and 179.5 (99.7%) apples were consumed at control (Al) and experimental (A2) stations, respectively. Of the 400 total apples offered at site B while the devices were on, 188 (94.0%) and 196.5 (98.3%) apples were consumed at control (B 1) and experimental (B2) stations, respectively. Apple consumption at feeding stations proved to be the only quantitative data which provided a consistent measure of deer activity. Behavioral observations made at each site revealed that several deer visited the control and experimental feeding stations while Yard Gard devices were on, Apparently, the deer were alerted by the ultrasonic emissions but were not deterred from consuming apples. In conclusion, this study produced no evidence that the Yard Gard ultrasonic device protected the area from deer activity, or preferred foods from deer damage.