Predicting the Spatial Distribution of Human-Black Bear Interactions Across an Urban Area

Scientific Disciplines
Biological Sciences - Terrestrial
missoula, montana
University of Montana
Montana Fish Wildlife Parks
American black bear
Spatial probability incidents
bear interactions
human black bear interactions
spatial distribution
urban areas
Volume 16, No. 4

Predicting the spatial distribution of human-black bear 
interactions across an urban area

Jerod A. Merkle,* and Paul R. Krausman, Boone and Crockett Program in Wildlife Conservation, 
and Wildlife Biology, University of Montana, Missoula, Montana 59812
James J. Jonkel, Montana Fish, Wildlife and Parks, Missoula, Montana 59804
Nick J. DeCesare, Wildlife Biology Program, University of Montana, Missoula, Montana 59812
Human (Homo sapiens)-black bear (Ursus americanus) interactions are increasing 
throughout North America.  Information that assists managers in developing methods to 
reduce conflicts is lacking. We used human-bear incident data, i.e., phone complaints and 
conflicts, collected in Missoula, Montana, by Montana Fish, Wildlife and Parks from 2003-
2008 to describe the attractants and human impacts of incidents, and develop a model 
that predicts the spatial probability of incidents.  We combined the locations of black bear 
sightings (n
 = 307), other incidents, e.g., bear seen feeding on garbage (n = 549), and sites 
where proactive management actions were carried out (n = 108), and compared them to 
5000 random locations using logistic regression. Based on literature, we used distance to 
forested patches, distance to water, and housing density as variables in our model. Garbage 
(38%), fruit trees (10%), and bird feeders (7%) were the most common attractants at incident 
sites, and some incidents resulted in threats to human safety (9%) and property damage 
(7%). All variables were significant in the predictive model, and the model performed well 
at discriminating the relative spatial probability of incidents (rs = 0.782; P < 0.01). The 
probability of incidents increased when residents lived close to forested patches, close to 
water, and in intermediate housing densities (~ 6.6 houses/ha). Our results suggest that 
spatial patterns in human-black bear interactions are predictable and these patterns can be 
used to understand the potential for conflict in developing areas and to identify areas where 
preventative management is necessary.