In natural areas like state parks where there are high concentrations of humans, it’s not uncommon for grizzly bears to become accustomed to people—and to seek out the food they carry. And while the majority of grizzlies simply scavenge leftovers after hikers have vacated a campsite, every once in a while they become aggressive. 

Until recently, the options for a bear who had killed or injured a human were pretty limited—they were either euthanized or relocated to a zoo. But several European countries and Canada have started developing bear rehab centers as an alternative option. According to National Geographic, the rehab centers take in orphaned cubs and problem bears, teaching them to avoid humans before releasing them back into the wild. 

Though the rehab programs are relatively new, their success rates are high. Since 2007, the Northern Lights Wildlife Society in British Columbia has released 18 orphaned cubs back into the wild, and only two have gotten into trouble with humans. Additionally, the survival and reproduction rates of released grizzlies are comparable to those of fully wild bears. 

The rehab centers have found that they don’t need to scare grizzlies in order to make them wary of humans. In the past, the National Park Service has used rubber bullets as an aversion technique to make grizzlies stay away from people. To some degree, the rehab programs do attempt to foster wariness in the bears—for instance, veterinarians, whose needles cause the bears minor pain, are some of the only humans the grizzlies ever meet. But instead of relying on “aversive conditioning," the rehab centers are more interested in providing them with the “bear” necessities—that is, introducing them to wild foods and giving them a chance to build up their size and strength in order to increase their chances of survival in the wild. 

[h/t National Geographic]