Human-black bear conflicts in Missoula, Montana

Credit: Mike O’Connell

The implication of human-wildlife conflicts are most profound when the species interacting with humans can cause property damage, or present a threat to human safety. This is the case for bears, where individuals can cause thousands of dollars’ worth of property damage, and maul or kill a person.  Human-black bear (Ursus americanus) conflicts resulting in property damage, injury or death to humans, or fear of injury or death to humans in North America have been increasing in number over the last few decades.

Credit: Rita Wolfe

This is definitely the case for Missoula, Montana, a city of approximately 65,000 people located in a valley surrounded by black bear habitat.  Missoula has a long history of human-black bear conflicts, but conflicts have been rising for the last 40 years.  This increase started in the 1970s as Missoula began its sprawl into more formerly-rural areas.  This trend was exacerbated in the late 1990s by a couple of unusually dry summers that limited the growth of natural bear foods.  One result was that Montana Fish, Wildlife & Parks fielded over 275 human-black bear interactions per year within city limits.  This was a significant jump over the 15 interactions per year reported prior to the mid-1990s.  Responding to calls and managing conflicts during these “chaotic years” put a real strain on the local Montana Fish, Wildlife & Parks personnel.

My research was developed in response to this need to reduce conflicts, and we set out to touch on some of the most important questions that were hypothesized by agency personnel, but had not been tested empirically.  We found that self-reported human behaviors have changed in a positive way over time, suggesting that education efforts within Missoula have some effect on residents (Merkle et al. 2011).  We found that fielding phone calls and conflict reports provides excellent information to predict the prevalence of conflicts, even in other urban areas.  We predicted the relative probability of a conflict based on 3 important landscape variables within an urban area: distance to forest, distance to riparian corridors, and housing density (Merkle et al. 2011).

Finally, we tested whether garbage was actually the real reason that bears ventured out of wildlands and into urban areas.  Surprisingly, we found that although bears do eat garbage when available, the presence of ripe fruits on apple trees seems to be more of an attractant than garbage.  This was even true when wildland foods were still available.  In a second analysis of the diets of black bears harvested in wildlands and bears captured in the urban area, we found almost no support that bears living near urban areas had a significant amount of garbage in their diet.  Our results suggest that management plans need to put more effort into reducing the availability of fruit to actually impact the number of conflicts (Merkle et al. 2013; Merkle et al. 2012).

Collaborators: P. R. Krausman, N. J. DeCesare, H. Robinson, P. Alaback, Wildlife Biology Program at University of Montana, Montana Fish, Wildlife & Parks