Predicting the Ecological and Social Suitability of Black Bear Habitat in Michigan's Lower Peninsula

Abstract

Abstract Black bear (Ursus americanus) populations in Michigan’s Northern Lower Peninsula (NLP) are observed to be increasing and expanding their geographic extent, as indicated by trends in bear nuisance reports, harvest reports, and sightings. I modeled bear habitat selection in the NLP using observed telemetry locations and 12 environmental variables. I used bear telemetry locations from 20 males and 35 females that were collected by the Michigan Department of Natural Resources throughout the NLP from 1992 to 2000. I chose Bayesian discrete choice hierarchical models to model bear selection of grid cells at three different spatial resolutions – 3 km, 2 km, and 1 km. I used separate models for males and females because of their different habitat requirements and behavior. The male 3km model and female 2km model best fit the data and were used to identify existing suitable habitat in the NLP and also used to predict the suitability of areas in the entire Lower Peninsula for potential bear range expansion. The results of applying the models illustrate a paucity of suitable bear habitat in the Southern Lower Peninsula (SLP). However, the results also indicate the potential for wildlife management agencies to develop a bear habitat network in the LP. In addition, I integrated survey information from the Social Carrying Capacity (SCC) project with the GIS-based habitat prediction models to illuminate the relationships between human behavior and attitudes regarding bears and suitable bear habitat in Michigan’s Lower Peninsula. This analysis was conducted within two bear-density regions identified by researchers at Michigan’s Department of Natural Resources (Zone B and Zone C) where bear populations and human development have recently been expanding. Overall, the variables I chose to evaluate describe respondent demography as well as attitudes toward bear presence and bear-management policies. Using these variables, I identified potential conflict regions as places with more intolerant people and x suitable bear habitat. The results indicated no significant relationship between variables that represented attitudes towards bears and bear management policies with suitable bear habitat. However, the conflict region maps indicated that Zone C had approximately more than twice as much area where potential bear/human conflict can occur than in Zone B. Furthermore, there is no denying that the landscape is considerably different between the two zones and thus residents in Zone C may respond more unpredictably than residents in Zone B to current methods the MDNR employs to handle nuisance bears. The results from this research will enable the Michigan Department of Natural Resources to refine their future bear harvest strategies and develop regionally specific bear management plans.