Wildlife officials in California are worried about a strange ailment that appears to strip young bears of their fear of humans—and also is causing fatal brain inflammation. Cases have been turning up in the state since at least 2014, including four in the last year, reports CBS Sacramento. As an example, the Sacramento Bee cites this popular video from 2019 in which a bear cub ventures up to a snowboarder. The video may evoke laughs, but the behavior is anything but normal for a bear. Sure enough, when the same animal was caught soon afterward, it was found to have brain inflammation. In this case, the bear didn't have to be put down, but the animal requires veterinary care to this day and likely will never be released back into the wild. So far, scientists have discovered five new viruses in the sick bears, though it's not clear whether the viruses are to blame.
"We started seeing something strange, I believe it was about five years ago," an exec with the nonprofit BEAR League tells CBS. For example, a bear walked into a school, then into a classroom full of children. "He sat in the back just like a puppy dog," says Ann Bryant. "That was not normal. That bear should have been terrified to go into a building with a lot of people." Generally, afflicted bears just seem off—often with a tilted head or a zoned-out look. Wildlife officials say the ailment doesn't appear to make the "neurologically dull" animals more aggressive toward humans, though they're wary if close encounters continue to increase, per KRCR. There's also the possibility of a potentially harmful virus jumping to humans, though the chances of that happening appear to be low, per the Bee. Cases also have turned up in Nevada. (Read more bears stories.)