During our public outreach this summer on travel-management changes proposed for the Boggy-Glade area of the San Juan National Forest, theres been much discussion regarding the effects of motorized travel on wildlife and hunting. U.S. Forest Service and Colorado Parks and Wildlife (formerly Colorado Division of Wildlife CDOW) biologists have spoken with many members of the public about how responsible travel management, combined with innovative habitat improvement work, can benefit both wildlife and the hunting experience.
Snow and seasonal conditions affect how deer and elk use the landscape. In summer most herds are found high up in the mountains of the Dolores Ranger District, but in winter, they must migrate to lower elevations, primarily Disappointment Valley and Dry Creek Basin, as well as private and federal lands west of the Dolores River Canyon.
The Boggy-Glade area offers great transitional habitat for deer and elk in fall during this annual migration thats also why its a good place to go hunting. When they get there, if the forage and habitat is good, they stay, and hunters have a good season. But if theres not enough to eat or there are too many disturbances, such as high levels of motorized traffic, deer and elk will leave public lands sooner and congregate on adjacent private lands. There they can cause agricultural crop damage and are not accessible to hunters using public lands. The state paid approximately $250,000 annually between 2007 and 2009 to farmers in Montezuma, Dolores and San Miguel counties (CDOW 2009).
Scientific studies conducted in the western United States have looked at elk and their habitat needs and have established that; 1) elk seek habitat that offers cover and forage (Thomas, J.W., and D.E. Towell. 1982. Elk of North America, ecology and management. Harrisburg, PA: Stackpole Books.), and 2) their usage of that preferred habitat is limited when it is bisected by roads open to vehicles (Leege 1984, Lyon 1984, Lyon et al. 1985, Roloff 1998, Lyon and Christensen 2002, Wertz et al. 2004). Put simply, the more open motorized routes in an area, the lower the quality of the wildlife habitat and less desirable it is for elk and deer to utilize or stay in that area.
Although the Boggy-Glade area of the National Forest offers good habitat, motorized disturbance is currently an issue, especially during big-game hunting seasons, beginning in late August with archery through end of the rifle season in mid November. During these times, roads and trails that normally receive minimal motorized use are used extensively. In response to this increased pressure, herds become extremely wary and sensitive to perceived dangers. This often results in the dispersion of big game and the use of critical energy reserves for these animals.
Open areas of forest, meadows and canyons between roads are very important in allowing the herds to distance themselves from noise and intrusions so they can feel secure enough to stay. Studies show that unrestricted motorized use can cause enough disturbances to big game that animals will abandon important forage areas (Naylor L.M. et al., Behavioral Responses of North American Elk to Recreational Activity. 2008, Journal of Wildlife Management.)
But we can have both motorized access and high-quality wildlife habitat. It is well documented that providing large enough security areas between open roads reduces elk vulnerability and increases hunting opportunities. Studies recommend that natural areas offering forage and hiding cover should be larger than 250 acres and at least one-quarter mile from any open road (Thomas, J.W., and D.E. Towell. 1982. Elk of North America, ecology and management. Harrisburg, PA: Stackpole Books.). This is the scenario described in Modified Alternative B of the Boggy-Glade Travel Management Plan.
In addition to responsible motorized travel management, habitat improvement projects that increase fall and winter forage will give big game an added incentive to depend upon public lands for sustenance. Offering reasonable options for motorized access with sufficient quality and quantity of wildlife habitat between road corridors will benefit wildlife and the hunters who seek them.
Ivan Messinger is a U.S. Forest Service wildlife biologist working out of the Dolores Public Lands Office.