I don't know how general that is but I remember reading a book about something that happened maybe in the 1950s, 1960s Soviet Union. Geologists explored a remote area, and they were ambushed by a human-killing bear. He hid in the bushes next to the path they took to get water, the sound of the bottles the person sent to get water carried told the bear someone was coming. They lost several people. If only I could remember the title... the main story line was about the bear, the background story for why they were there was that they followed stories of hallucinations and found mercury, a valuable resource at the time (today I'd be more scared of the mercury than the bear).