U.S. Department of Agriculture: Animal and Plant Health Inspection Service


Date of this Version

August 2006




Conflicts with American black bears (Ursus americanus) are increasing in rural and suburban areas throughout the United States. Human encroachment on bear range has increased availability of garbage, bird feeders, beehives, and other food sources. Preventing bears from attaining food from anthropogenic sources could mitigate these conflicts. We tested a new shocking mechanism that is being marketed to deter black bears from attaining food from clumped anthropogenic food sources. The Nuisance Bear Controller (NBC) has two 6-volt batteries wired to an automobile vibrator coil/condenser that emits 10,000–13,000 volts through a disk that triggers the device. Activation of the NBC only occurs when a bear or other animal contacts the disk. We tested the NBC in a rural area of central Minnesota by placing both unprotected and protected simulated bird feeders at 10 independent sites during summer and autumn 2004 and measuring the fate of each feeder. During the test period no protected feeders were robbed or destroyed by black bears, whereas 40% of unprotected feeders were robbed or destroyed (P¼0.043, one-tailed Fisher’s exact test). The NBC is an inexpensive ($200.00), portable, and adaptable system that potentially can be used in a variety of situations to deter bears from accessing concentrated food sources