Date of this Version
Three bird scaring devices, ultrasonic, visual and sonic, were evaluated for repelling pigeons from inside a vacant building. After 10-30 days of treatment, none of the devices reduced the pigeon population from levels recorded in pre- and posttreatment periods. However, both the visual and sonic devices altered pigeon behavior during their 10-day treatment periods and temporarily reduced the pigeon population during the first 2 days of treatment. The ultrasonic device was completely ineffective; no change in pigeon activity was observed during a 20-day treatment period.