Twice in the same week at different events in Jackson Hole,
Bruce S. Thompson projected graphics onto a screen. Each time there were
accompanying gasps in the audience. These were not moments of shock, but rather
epiphanies that invited instant personal reflection.
Thompson, who is a professional natural sciences education
specialist who also spent 17 years as education director of the
nationally-renowned Teton Science Schools, was making vivid a phenomenon that
many outdoor-oriented people suspect, but which has been hard to put a finger
on.
The phenomenon is recreational impact on wildlife, a topic
treated by some as almost taboo.
Many people assume or claim that because they don’t actually
witness animals running away at their approach, there must not be impacts, he
said. Indeed, federal land management agencies, like the U.S. Forest Service,
have been slow to respond to the impacts of growing recreation pressure. Yet as
Thompson points out, absence of evidence doesn’t equate to absence of impact.
Right now there seems to be an awakening happening around
the realization that wildlife displacement is happening.
Thompson, who lives in Dubois, Wyoming, says his research in
to recreational impacts on wildlife was piqued by a push from commissioners in
Fremont County, Wyoming, to transform the 4,520-acre Dubois Badlands
Wilderness Study Area, stewarded by the Bureau of Land Management, into a
National Conservation Area.
Not long ago, Thompson presented what he found: that hikers
with dogs are formidable wildlife disruptors. In dog-crazy communities, of
which the Greater Yellowstone Ecosystem has an abundance, people who head out with
their domestic canines need to be aware of the impacts they cause.
A single hiker walking down a trail causes wildlife displacement of 150 feet. But a hiker with a dog on a leash results in wildlife displacement of 280 feet in one direction. When the panoramic radius on both sides of the trail is combined to create total diameter, it means dogs cause a displacement zone of 560 feet.
It’s one thing if it causes an animal to flee but then it’s
able to return after the person and dog are gone, but the disruption can become
chronic, if not permanent, when the trail receives a stream of near-constant or
heavy use. Not only does it cause the animal stress and expended energy, but it
results in the animal abandoning the prime places where it finds the best
forage and security cover, Thompson said.
Often, mountain bikers insist they are no more disruptive to
wildlife than hikers and equestrians, Thompson said. Though, there is a
problem. Bikers travel faster and cover much longer distances than hikers; they
tend not to make noise; while navigating trails, they’re more concerned about
avoiding rocks and trees than being fully attentive to their surroundings; and
the way they ride makes their presence less predictable, he explained.
If a single mountain biker is traveling twice the distance
as a hiker, then it could be argued, Thompson says, that the cyclist is having
twice the spatial impact in terms of potential wildlife disruption. And, with a
rising number of mountain bikers and local clubs pressuring the Forest Service
to let them upgrade and build new trails, the impacts are hardly benign.
“The obvious thing at stake in Greater Yellowstone, the
simple answer, is that what we have in this place is not present in those other
places,” Thompson told me. “We are confronting the old tale of dwindling
wilderness and natural systems. We’ve become a prominent symbol of the metaphor
and no one knows yet if we’ll be able to hang on to what we have [and] avoid
the mistakes those other places have made.”
No user group likes being called out. Both the Custer Gallatin
National Forest, headquartered in Bozeman, and the Bridger-Teton are presently
involved with updating their long-term management plans.
Significant scrutiny is being directed toward the Custer Gallatin
and its management of the 155,000-acre Hyalite Porcupine Buffalo Horn
Wilderness Study Area that, ecologists say, contains incredible wildlife
diversity and superior habitat in the Gallatin Mountains between Yellowstone
and Bozeman.
In 1996, conservationists sued the Forest Service for
allowing motorized recreation, mountain biking and illegal trail building to
occur in the Hyalite Porcupine Buffalo Horn, ultimately resulting in a
settlement in 2001 that forced the Custer Gallatin to assemble a travel
management plan. Illegal trespass by motorized users and mountain bikers
remains a persistent problem in the roadless Gallatin Range near Big Sky.
How much consideration are the Custer Gallatin and
Bridger-Teton giving to wildlife persistence now and in the decades to come?
What is the science telling them about the impacts of human intrusion?
“On one level, it seems completely intuitive that we’re
having impacts,” Thompson said. “But as you put the statistical information
together, it really becomes compelling. I wasn’t planning on getting involved
with this issue in my retirement, but the more I learn, it’s not something I
can persuade myself to let go of.”
Todd Wilkinson is
founder of Bozeman-based Mountain Journal (mountainjournal.org) devoted to
protecting the Greater Yellowstone Ecosystem and is a correspondent for
National Geographic. He’s also the author of “Grizzlies of Pilgrim Creek” about
famous Jackson Hole grizzly bear 399, which is available only
at mangelsen.com/grizzly.