This study examined two different aspects of black bear (Ursus americanus) ecology in Utah. First, we determined the post-denning behaviors of female black bears in order to help management agencies protect bears from human disturbances as well as set spring hunts that minimize the taking of females with dependent young. We looked at the timing of den emergence (X = 25 March), the number of days at the den site post emergence (X = 11 days), and departure (X = 8 April) for female black bears in Utah from 2011—2013. We also analyzed the effects of cohort (lone female, female with cubs, and female with yearlings), region of Utah, year, elevation, and weather on emergence, departure, and total number of days at den. Lastly, we describe behaviors observed at the den site. We found that first emergence was significantly correlated with cohort and spring temperature. Departure date was significantly correlated with geographic region, spring temperature during emergence and departure, and temperature the spring and summer before denning. Total number of days at den was significantly correlated with cohort and last frost date from the year before. Bears spent little of the post-denning period outside of the dens (X = 9.8% of total observation time). When outside of dens, bears were often observed walking, lying down, sitting and standing. We also observed unique behaviors, including gathering nest materials, nursing, and ingesting. Dens were frequently visited by other wildlife as well. Second, we analyzed conflict between humans and black bears in Utah. The Utah Division of Wildlife Resources initiated a black bear sightings and encounters database in 2003. We upgraded this database by gathering available records and organizing them into a new database for analysis using Microsoft Access®. From 2003—2013 there were 943 records, with 499 bear-human encounters, 33 incidents, 10 attacks, 208 property damages, 187 sightings, and 6 vehicle collisions. Utah county had the highest number of events (n = 115). The majority of events took place at campsites (n = 363). Summer was the most common season for events (n = 715). Time of day was frequently not reported, but when it was, most events occurred at night (n = 173). We found no significant increase in the number of events over the last ten years. We also found no significant relationship between the number of events per year and drought data. The highest number of events involved single bears (n = 843), and over half of events had food or garbage available for the bear (n = 475).
College and Department
Life Sciences; Plant and Wildlife Sciences
BYU ScholarsArchive Citation
Miller, Julie Ann, "A Study of the American Black Bear (Ursus americanus) in Utah: An Analysis of the Post-Denning Activities and Bear-Human Conflict" (2014). All Theses and Dissertations. 4374.
American black bear, bear attacks, bear-human conflict, behaviors, camera traps, database, denning, departure, emergence, hibernation, Ursus americanus, Utah