| Human-wildlife conflicts are increasing worldwide as more wildlife species, including black bears (Ursus americanus), become conditioned to human food. Non-lethal means of dealing with "nuisance" wildlife are urgently needed, but it is difficult to develop proactive solutions without first understanding the problem. Nuisance black bears were studied in Sequoia and Yosemite National Parks to determine how nuisance behavior originates, what methods may be used to eliminate its occurrence, and when and where it nuisance behavior is most likely to occur.; First, we tested the hypothesis that food-conditioned foraging behavior (foraging on human food in developed areas) is learned socially, through vertical transmission from sows to cubs. Nine wild sows produced a total of 20 cubs, with 18 (90%) of the cubs remaining wild by the end of their second year. By contrast, 23 food-conditioned sows produced a total of 79 cubs, with only 35 (44%) of the cubs remaining wild by the end of their second year. The main predictor of the cubs' outcome was whether the cubs were raised in developed areas, more than whether the sow was food-conditioned.; Next, the effectiveness of aversive conditioning, in reducing conflict through behavioral modification was tested. We used projectiles with varying impact intensities to evaluate their effectiveness. Together, these forms of aversive conditioning were successful in getting 16 of 25 bears with moderate exposure to human food to abandon unwanted behaviors, while two bears required annual treatments. Of the eleven bears that had the greatest exposure to human food, aversive conditioning was only successful in getting one bear to abandon unwanted behaviors.; Finally, we studied the seasonal movement patterns of black bears in relation to preferred natural foods. We used GPS collars to collect location data on wild, adult female bears during summer and fall. The results indicated that there was a relationship between the inter-annual variability in the availability of high-quality natural foods and the seasonal ranging behavior of black bears. There also appeared to be a relationship between when the bears shift their range to exploit alternate foods and the occurrence of human-bear incidents. |
