2017-11-19 20:19:36 来源:大耳朵足球投注技巧 8
New technology is putting the focus on rarely witnessed aggression between two of the fiercest predators in North America. For the last few decades, populations of cougars and bears have been on the rebound. But until recently, researchers didn’t know how these formidable predators interacted.
To improve their understanding of these potential heavyweight matches, scientists set up motion-sensitive cameras in British Columbia, where both species are increasing in number. The researchers rigged the countryside so that black bears wandering the shorelines of Vancouver Island would trigger the playing of recorded sounds of cougar growls over loudspeakers. Video cameras captured the bears’ reactions—which were not timid.