Deterrent or dinner bell? Alteration of badger activity and feeding at baited plots using ultrasonic and water jet devices

The increasing incidence of reports of damage caused by Eurasian badgers (Meles meles) in UK urban environments requires the development of effective, humane, non-lethal solutions. Ultrasonic deterrents are widely available to the public and are sold as a humane solution to the presence of unwanted animals in urban gardens. The reported failure of some ultrasonic devices may be caused by habituation of target animals to the devices and the lack of association with a negative, physical stimulus. We tested the ability of a commercially available, motion sensor-triggered ultrasonic device and a motion sensor-triggered water jet device, alone and in combination, to alter badger activity and feeding at baited plots. The ultrasonic device, whether used alone or in combination with the water jet, was associated with significantly higher badger activity at baited plots in comparison to control plots, and bait consumption was higher when the ultrasonic device was used alone. When the water jet was used alone, bait consumption was significantly reduced in comparison to control plots, but badger activity was not. There was no evidence to suggest that aversion to the ultrasonic device could be reinforced by the water jet, but some evidence to suggest that ultrasonic devices may have attracted badgers to baited plots. While the effects of the water jet on bait consumption were statistically significant, they were also very small (a 12% difference between the treatment and control fitted means). We conclude that neither device, used alone or in combination, present effective solutions to the growing problem of urban badger damage.