Many who hike, mountain bike, ski, and otherwise enjoy the great outdoors consider themselves stewards of it as well as users. In fact, we can thank nature-related tourism for the creation of thousands of protected areas around the planet, and research shows that it leads to habitat restoration, removal of invasive species, and decreased poaching. Sustainable nature tourism also generates revenue, political support, and direct incentives to protect wildlife and ecosystems. Some scientists even call it necessary for conservation.
But no matter how well-intentioned the hiker, our presence in nature has an impact. Whether we're causing a bear to run in the other direction, giving a slumbering marmot a good scare, or interrupting a mule deer's grazing enough times that he can't store the fat needed to make it through the winter, we put stresses on nature that weren't there in the first place.
A recent review of 274 scientific articles tried to put a number on this impact, and they came away with two fairly disturbing ones: 93 percent of the studies showed impacts on wildlife, 59 percent of them negative. It's enough to give outdoor lovers pause. We talked with Courtney Larson, a graduate student in ecology at Colorado State University and lead author on the paper, about its implications.
This study is disturbing to us outdoor enthusiasts. First off, are there any big caveats?
An important thing to understand is that we looked at whether there was an effect or not, not whether it was severe or mild, as reported by the authors of the particular study. We did no re-analysis or investigation of findings. The studies are across huge areas and variety of animals, so there is a lot of variability in the data. The possible magnitude of different effects is big, and we need to look at that next. We know effects are happening, but how bad are they? I feel [this paper] is a good start.
But we hikers and bikers, skiers, and backpackers have a bigger impact than we think.
Overall, effects of recreation on wildlife are very widespread — 93 percent of papers found at least one effect. Some surprising results were that non-motorized recreation had more frequent effect than motorized and that snow activities had more effect.
One paper found when people behave more predictably — staying on trails, not being out at night — it reduces the effect on animals.
What is the main takeaway, then, for outdoor enthusiasts?
One paper found when people behave more predictably — staying on trails, not being out at night — it reduces the effect on animals. Another big one is reducing noise while out in the wilderness. Then there are common sense things like not approaching animals, giving them space. Animals have the ability to habituate some to that human use.
What about the takeaway for other scientists?
Recreation does have some effect on wildlife, and that’s not always acknowledged. The paper identifies some areas where we need more research — in some of the less-studied taxonomy groups, for example. Also, the way we look at recreation could use more nuance, looking into questions like how much recreation is too much, what are the thresholds for affecting wildlife, and the magnitude or severity of the effects.
And for wildlife managers?
There is a real need for testing the effectiveness of management strategies. Before you put in a new trail, considering what effects might come from it and balancing that against demand for the trail.
I’m not going to make a case that it’s the most serious threat out there, but it's one that gets overlooked a lot.
Winter activities have an outsize impact according to this. Why?
First thing, it was a small sample size — it would be nice to have a few more papers about winter recreation effects. We don’t know why, but have a few speculations. For a lot of wildlife, winter is the hardest season. It is hard to find food and shelter. So, recreation during that season is an added stress during an already difficult time.
In the context of various threats to wildlife — development or climate changes, for example — where do you think recreation really ranks?
I would say bigger things like habitat loss are more of a problem. If animals don’t have habitat, it doesn’t matter if people are there or not. But this is an interesting threat to look at — we say we’ve set aside this land to conserve animals and think we’ve done our job, but if a lot of people are in there hiking and mountain biking and what not, maybe it isn’t doing the job we thought it was. I’m not going to make a case that it’s the most serious threat out there, but it's one that gets overlooked a lot.
But what about the benefits of increasing awareness and creating connections to the wild? Can they outweigh the negatives?
Part of the reason we have many protected areas is because advocates, often outdoor enthusiasts, stepped up to form them. It does pose a conflict for a lot of people, but we need to think about how we can meet the demand for outdoor recreation while leaving some areas more disturbance-free. Maybe that could be concentrating trails in certain areas and leaving other areas trail-less to meet both needs. It is tricky, because obviously we don’t have tons of protected land.
What was your motivation for doing this research?
It’s a topic I had been seeing in the literature. It seemed there wasn’t a lot of consensus out there whether recreation is a problem for wildlife or a benign use of public lands. We needed to bring the literature together on that.
What are the next steps?
I think there is a lot of space for a more nuanced understanding of the effects of different activities. How much is too much? How do we move forward, given that we know recreation is sometimes a problem.