Road Density as a Factor in Habitat Selection by Wolves

and Other Carnivores in the Great Lakes Region

Adrian P. Wydeven

Mammalian Ecologist/Conservation Biologist, Wisconsin Department of Natural Resources, 875 South 4th Ave., Box 220,

Park Falls, WI 54552; (715) 762-4684 x107; (fax) (715) 762-4348; wydeva@dnr.state.wi.us

David J. Mladenoff

Department of Forest Ecology and Management; University of Wisconsin Madison; 1630 Linden Drive; Madison, WI 53706

Theodore A. Sickley

Department of Forest Ecology and Management; University of Wisconsin Madison; 1630 Linden Drive; Madison, WI 53706

Bruce E. Kohn

Wisconsin Department of Natural Resources; Highway 17 S., Box 576; Rhinelander, WI 54501

R. P. Thiel

Wisconsin Department of Natural Resources; Sandhill Wildlife Area; Box 156; Babcock, WI 54413

Jennifer L. Hansen

Land Information and Computer Graphics Facility; University of Wisconsin Madison; 550 Babcock Drive, B102 Steenbach

Library; Madison , WI 53706; (608) 263-5534; (fax) (608) 262-2500; jlhanse3@facstaff.wisc.edu

Abstract

Although wolves (Canis lupus) and many other carnivores are habitat generalists, certain landscape

features can be used to predict suitable habitat. Thiel examined the concept of road density

as an important factor in the persistence of wolf populations in Wisconsin prior to the 1960s and

found a relationship with the disappearance of breeding wolf populations when average road

density exceeded 0.58 km/km 2 . Mladenoff and colleagues examined road density in the early

1990s as a factor in predicting favorable habitat of wolves colonizing Wisconsin between 1980

and 1992, and found that areas with road densities less than 0.45 km/km 2 had greater than a

50% probability of being colonized by wolf packs. Mladenoff and colleagues updated this work

in the late 1990s by examining 23 packs colonizing Wisconsin between 1993 and 1997; 78%

continued to occupy areas with road densities below 0.45 km/km 2 . In a recent examination of

radio-collared wolves in Wisconsin, a total of 60% of human-induced mortality occurred at road

densities above 0.63 km/km 2 . Although road density may become less of a factor as human

tolerance changes, and wolf populations increase, it continues to be an important factor in

habitat selection by wolves and probably other carnivores.