Managing black bears
By Eric Wagner
There are two types of problem bears: habituated and conditioned.
A bear expresses habituated behavior when it has lost its fear of humans but does not gain or lose anything from being near them. A habituated bear may visit a campsite, not in search of human food specifically, but perhaps just passing through. It is not deterred by the presence of humans.
A bear expresses conditioned behavior when it has lost its fear of humans and attributes the presence of humans with a positive gain such as food. A conditioned bear may visit a campsite specifically in search of human food.
Habituated and conditioned bears are not afraid of humans and in the latter case are actually attracted to humans for food. The Arizona Game and Fish Department stated that bears demonstrating these types of behavior are generally found in areas with “marginal habitat” that are “enhanced by humans providing some type of artificial food source.”
Although a 2002 book “Bear attacks: their causes and avoidance” showed that bears generally “tend to avoid humans and developed areas,” the Arizona Game and Fish Department noted that “rapid expansion of urban areas in Arizona” forces a greater occurrence of human-black bear conflicts within the state.
The report stated that when bears are common within “human-dominated landscapes,” several undesirable effects become more common, such as “loss of pets, localized depredation on livestock, property damage, and attacks on humans,” all of which could lead to bear euthanasia.
A bear management practice that may alter the adverse behavior of habituated or conditioned bears is aversive conditioning. This can be classified as any method used to train bears to form a negative association with humans. Generally this method would be done in conjunction with the trapping and translocation of a nuisance bear.
The six most common aversive conditioning treatments involve shooting bears with rubber buckshot, rubber slugs or pepper spray, and/or scaring bears with firecrackers, other loud noises and dogs.
A questionable effectiveness
One study conducted in 2004 showed that aversive conditioning techniques used for the management of nuisance bears were not effective in stopping negative behavior. Sixty-two radio-collared black bears were captured in and around urban areas in the Lake Tahoe Basin in Nevada. Each bear was randomly placed into one of three groups that received different aversive conditioning treatments.
Bears in the first group “were hit with pepper spray, 12-gauge rubber buckshot, and a rubber slug, and exposed to cracker shells and yelling.” Bears in the second group experienced the same deterrents as group one, but were also chased by dogs. Bears in the third group, the control group, were “released in a silent manner with no physical or audible deterrents.”
The effectiveness of the different treatments was measured by the number of days it took the bears from each group to return to the area of its original capture. The study showed that almost all of the bears (92 percent) eventually returned to their original capture location. The data showed that of the total number of bears captured and released, about half (53 percent) returned within 30 days of release, and another quarter (27 percent) returned within six months.
The study revealed that “no difference between treatment groups was found for the mean number of days it took bears to return to the initial capture site.”