Originally this story appeared in Highland news and is part of the Climate desk cooperation.
The first grainy clip of film shows a black bear exploding out of the trail camera frame. In another, a mule deer stops chewing wildflowers, backs away, and takes off in the opposite direction. In a third, a moose does not move at all, but remains alert.
All three animals responded to sound bites from boomboxes in the woods, part of a study looking at the effect of the sound of outdoor recreationists on wildlife. The sounds included people talking, mountain bikers running down trails – even just silent footsteps. Each clip was less than 90 seconds long.
The new study, currently being conducted in Wyoming’s Bridger-Teton National Forest, adds to mounting evidence that the mere presence of human noise, no matter how loud or quiet, fast or slow, changes animal behavior.
Don’t start feeling guilty about going for a walk just yet, though. Researchers are also trying to understand the meaning of those reactions. For some species, walkers and cyclists may be an afterthought in a forest full of natural disturbances. For others, recreationists can have an impact similar to that of terrifying predators, which invade habitats where food can be found, resulting in lower birth rates and even more deaths.
“The whole point of the study is not to vilify recreationists,” said Mark Ditmer, a research ecologist at the U.S. Forest Service’s Rocky Mountain Research Station and one of the study’s co-leaders. “It’s to understand where and when we cause the most nuisance.”
The idea that we must know and love the outdoors to protect it has been prevalent for over a century. Recreation built up a constituency that helped protect wild places. But even decades ago, there was evidence that the use of wilderness – whether formally designated or not – as a human playground caused much of the collateral damage. Paths crossed forests without rhyme or reason; used toilet paper hung from backwoods bushes. Groups like Leave No Trace began reminding people to take their trash with them, leave wildlife alone, and defecate responsibly.
Still, “non-consumptive recreation,” the weird term for enjoying the outdoors without hunting or fishing, is generally considered a net good. At best, outdoor recreation connects people to the land and sometimes inspires them to protect it — to write to legislators, attend land-use meetings, support advocacy groups, perhaps remind others to stay on trails. At worst, it seems harmless.
But recent studies show otherwise. There is one from Vail, Colorado, showing an increase in trail use by hikers and mountain bikers disturbed moose so much that the cows gave birth to fewer calves. Another from Grand Teton National Park showed that backcountry skiers frightened bighorn sheep in winter when food was scarce, with potentially deadly consequences. A 2016 review of 274 articles on how outdoor recreation affects wildlife revealed that 59 percent of interactions were negative.
But most of the research looked at the impact of random encounters with hikers, backcountry skiers and others. Few have wondered what exactly it is about humans that disturbs wildlife so much, whether it’s the way we look, the way we smell, or the sounds we make.