Biker appears to receive adrenaline boost during extremely close encounter.

A bear rarely goes from calm to full commitment without showing you something first. The problem is that those signals are easy to misread when your pulse jumps and the moment gets loud in your head.

Add Yahoo as a preferred source to see more of our stories on Google. Yukon Wildlife Cams on Wednesday shared footage of a black bear scent-marking a tree with a back scratch, only to have a grizzly ...