Date of Award
Master of Science
Dr. John Bruggink
Space use is an important aspect of bear ecology that maybe influenced by infanticide risk and timber harvest. I used generalized linear mixed models (GLMM) to determine if female American black bear (Ursus americanus) space use was consistent with avoidance behavior to reduce infanticide risk in the Upper Peninsula of Michigan during the 2009–2011 and 2013–2014 breeding seasons. Females with cubs occupied core areas and home ranges of similar size and relative probability of male use to females without cubs. Additionally, females with cubs did not reduce movements during times of day when male movements were greatest. Female black bears may exhibit variation in avoidance behavior based on the occurrence of infanticide. I used GLMM to estimate black bear use of stands harvested for timber production in the Escanaba River State Forest in Michigan during May–October 2009–2011. In general, bears used stands < 100 ha more than larger stands, with some gender and seasonal differences. Bears used even-aged stands more than uneven-aged stands and stands > 6 years old more than younger stands. However, bear use did not differ between deciduous stands and coniferous stands, or among land cover types except that grass/pasture and open water were avoided. Bear use was greater in areas farther from roads. Managing the amount of black bear resources appears possible by considering the number, size, type, and rotation schedule of timber harvests in deciduous and coniferous forests. However, increased human access resulting from road creation during timber harvest activities may reduce associated benefits.
Norton, D. Cody, "Effects of Infanticide Risk and Timber Harvest on American Black Bear Space Use" (2019). All NMU Master's Theses. 609.