Multi-Scale Effects Of Forest Roads On Black Bears

Scientific Disciplines
Biological Sciences - Terrestrial
University of Montana
black bear
global positioning systems gps
road density
habitat selection
Ursus americanus
traffic volume
cooperative wildlife research unit
Volume 17, No. 1-4

Multi-scale effects of forest roads on black bears
Benjamin S. Jimenez,* Montana Cooperative Wildlife Research Unit, University of Montana, 
Missoula, Montana 59812 
Michael S. Mitchell, Montana Cooperative Wildlife Research Unit, University of Montana, 
Missoula, Montana 59812
Pete Zager, Idaho Fish and Game, Lewiston, Idaho 8501
The black bear (Ursus americanus) population within the Coeur d’Alene River watershed 
of northern Idaho is exposed to high hunting and recreational pressure facilitated by a dense 
network of forest roads. Bears are hunted using bait and dogs in spring and fall, with an 
additional non-lethal summer pursuit season. To understand the effects of these roads on 
black bear behavior we used data collected from 28 adult bears fitted with Global Positioning 
Systems (GPS) collars from June 1 2007 through the fall of 2008.  We used locations 
acquired at 20 minute intervals to assess habitat selection and activity patterns of males and 
females at home range (2nd order) and within home range (3rd order) scales, both annually 
and seasonally. We tested the hypotheses that black bears 1) will show no response to road 
density in 2nd order habitat selection in areas of relatively consistent road density, 2) will 
show a functional response to roads in 3rd order habitat selection, i.e., use of habitat near 
roads will be inversely proportional to traffic volume, 3) show seasonal shifts in activity 
patterns and movement rates in proximity to roads.  Avoidance of areas containing primary 
food sources or increased activity and energy expenditure may have profound consequences 
for bears. Understanding how traffic volume and road density influences habitat selection and 
movement patterns can therefore play an important role in management of the species.