In their recent appeal of revisions to the Sawtooth National Forest's travel plan for the Minidoka, Fairfield and Ketchum ranger districts, conservationists repeatedly discuss the impacts off-road recreation has on wildlife.
To back up these resource concerns, which their appeal indicates is primarily focused on the south Idaho Minidoka Ranger District, the Idaho chapter of The Wilderness Society and Idaho Conservation League point to a study conducted from 2002-2004 by U.S. Forest Service researcher Michael Wisdom and others.
The researchers considered the cumulative impacts of off-road recreation—both motorized and non-motorized—on elk and mule deer during an in-depth study at the Starkey Experimental Forest and Range, a joint wildlife research facility located in northeast Oregon's Blue Mountains. The facility is run by the Oregon Department of Fish and Wildlife and the Forest Service.
A wide variety of habitats are contained within the fenced-in 28,000-acre enclosure occupied by deer and elk. The facility is equipped to evaluate real-time and landscape-level responses of elk and deer to human activities under controlled experimentation.
The researchers sent recreationists into the facility at various times of the day on all-terrain vehicles (ATVs), by horseback, on mountain bikes and by foot to evaluate the separate responses deer and elk have when presented with pressure from each of these activities. The study period also included times without any human use.
The researchers concluded that ATVs had the greatest impacts on elk movements. The next highest impact to elk came from mountain bikers, while hikers and horseback riders showed the least impact.
"Movement rates of elk...were higher during the five-day treatments of mountain bike and ATV activity," the report states.
The report seems less conclusive about the various impacts the different uses have on mule deer. Interestingly, it says that movement rates increased slightly during periods of all four off-road activities, except ATV riding. The researchers theorize that deer may resort to more "fine-scale" changes in habitat use when facing these activities.
"It is possible that deer may respond to an off-road activity by seeking dense cover, rather than running from the activity," the report states.
The report goes on to say that this response may lead to reduced foraging opportunities for deer and a resulting deficiency in putting on fat reserves prior to winter.
