The Future for Wildlife
in the Missouri Breaks National Monument

Comparing Transportation Alternatives

The decision on a transportation network is one of the important factors affecting the future of wildlife in the Upper Missouri River Breaks National Monument.  Because motorized routes are known to displace big game from their preferred habitat, the transportation network within the Monument should provide access to specific destinations and all other routes should be closed and rehabilitated wherever practical. This is particularly important in light of the fact that outdoorsmen spent almost $12 million in the area of the Monument in the fall of 2003.

* calculated for year-round and seasonal motorized routes.

• The current route network is too extensive across the landscape.  Route densities are high and little core area remains for wildlife (Hartley et al 2003).  Only 200 acres or less than 1 percent of the Monument is more than 2 miles from a route.

• The BLM’s proposal provides little improvement over the current situation.

• The Friends’s proposal reduces routes on the landscape and enlarges core habitat for elk, pronghorn and bighorn sheep.  It allows 150,000 acres (30 percent) of the Monument to be greater than 2 miles from a route.

What do these numbers mean for wildlife in the Monument?

Elk:

• A respected volume on elk ecology and management states:  “Access — mainly that facilitated by roads — is perhaps the single most significant modifier of elk habitat and a factor that will remain central to elk management on public and private lands.”  (Lyon and Christensen 2002)
• Under the BLM’s proposed management plan 41 percent of the elk habitat would have road densities of 1 mile per square mile or more.  Dr. Jack Lyon, preeminent Montana wildlife biologist, found that elk habitat effectiveness is reduced 25 percent at this route density (Lyon 1983).
• BLM’s proposed plan would allow 60 percent of the area currently used by elk to have road densities greater than ½ mile per square mile despite a study done in north-central Wyoming that found that few elk used areas with route densities higher than ½ mile per square mile (Sawyer et al. 1997)
• The above bullets assume forest cover to provide habitat security.  In areas of the Monument without forest cover, the routes are a substantially larger problem for elk use of the landscape than what is stated above (Perry and Overly 1976, Morgantini and Hudson 1979, Rost and Bailey 1979, Lyon 1979). 
• Human disturbance during calving season reduces calving success rates (Phillips and Aldredge 2000).  A Colorado field study found only a 5 percent probability of elk using habitat within 0.6 miles of a road during calving season (Edge and Marcum 1991).
• Elk hunters spent approximately $1,237,500 while hunting in and around the Monument in 2003, according to the Montana Wildlife Federation. 

Pronghorn:

• Pronghorn avoid maintained roads, non-maintained dirt roads and four-wheel drive trails (Ockenfels et al. 1994).
• Under BLM’s proposed routes for the Monument, 44 both of winter range for pronghorn would have route densities higher than one mile per square mile—levels which BLM studies show will displace these animals.  (BLM 1999)
• Fencing disrupts pronghorn movement. (Van Riper and Ockenfels 1998).
• MWF data indicate that pronghorn hunters spent about $595,000 while hunting in the Breaks during the 2003 season.

Bighorn Sheep

• Research by Dr. J. E. Canfield determined that bighorn sheep are the most sensitive big game species to human disturbance (1999).
• Hunters spent approximately $55,650 hunting bighorn sheep in the Monument during the 2003 hunting season (not including license fees).

Literature Cited

Bureau of Land Management. 1999. Draft EIS for the Pinedale Anticline Oil and Gas Exploration and Development Project, Sublette County, WY.  U.S. Department of the Interior, Bureau of Land Management, Pinedale Field Office, Pinedale, WY.

Canfield, J.E., L.J. Lyon, J.M. Hillis, and M.J. Thompson. 1999. Ungulates. Pages 6.1-6.25 in Joslin, G., and H. Youmans, coords. Effects of Recreation on Rocky Mountain wildlife: A Review for Montana. Committee on Effects of Recreation on Wildlife, Montana Chapter of The Wildlife Society, MT.

Edge, W.D. and C.L. Marcum. 1991. Topography ameliorates the effects of roads and human disturbance on elk. Pages 132-137 in: Christensen, A.G., L.J. Lyon, and T.N. Lonner, Comps. Proceedings of the Elk Vulnerability Symposium. Montana State University, Bozeman, MT.

Hartley, D.A., J.L. Thomson, P. Morton, and E. Schlenker-Goodrich. 2003. Ecological effects of a transportation network on wildlife: A spatial analysis of the Upper Missouri River Breaks National Monument. The Wilderness Society, Washington, DC.

Lyon, L. J.. 1983. Road density models describing habitat effectiveness for elk. Journal of Forestry 81:592-596.

Lyon, L.J. 1979. Habitat effectiveness for elk as influenced by roads and cover. Journal of Forestry 77:658-660.

Lyon, L. J. and A. G. Christensen. 2002.  Elk and land management. Pages 557-581 in: Toweill, Dale E. and  Jack W. Thomas, Eds. North American Elk Ecology and Management.  Smithsonian Institution Press, Washington, D.C.

Morgantini, L.E. and R.J. Hudson. 1979. Human disturbance and habitat selection in elk.  Pages 132-139 in: Symposium on Elk Ecology and Management, April 3-5, 1978. Laramie, WY.

Ockenfels, Richard A., Amber Alexander, Cindy L. Dorothy Ticer, and William K. Carrel.  1994.  Home Range Movement Patterns and Habitat Selection of Pronghorn in Central Arizona. Technical Report 13. Arizona Game and Fish Department, Phoenix, AZ. 

Perry, C. and R. Overly. 1976. Impact of roads on big game distribution in portions of the Blue Mountains of Washington. Pages 62-68 in: Hieb, S.R., Ed. Proceedings of the Elk-Logging-Roads Symposium. December 16-17, 1976, Moscow, Idaho. Forest, Wildlife and Range Experiment Station, University of Idaho, Moscow, ID.

Phillips, G.E. and A.W. Alldredge. 2000. Reproductive success of elk following disturbance by humans during calving season. Journal of Wildlife Management 64(2):512-530.
Rost, G.R. and J.A. Bailey.  1979.  Distribution of mule deer and elk in relation to roads.  Journal of Wildlife Management 43(3):634-641. 

Sawyer, H. Hall, Frederick G. Lindzey, and Bert A. Jellison. 1997. Applying GIS technology to test an elk habitat effectiveness model in north-central Wyoming. Pages 176-183 in: de Vos, J., Ed. Proceedings of the 1997 Deer/Elk Workshop, Rio Rico, Arizona. Arizona Game and Fish Department, Phoenix, AZ.

Van Riper, C., and R. Ockenfels. 1998. The influence of transportation corridors on the movement of pronghorn antelope over a fragmented landscape in Northern Arizona.  International Conference on Wildlife Ecology and Transportation, 1998  pp. 241-245. 

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