American Black Bears (Ursus americanus) of the Paunsaugunt Plateau: Movements and Habitat Use

• Main Author: Dungan, Rebekah Adriana Castro
• Format: Others
• Published: BYU ScholarsArchive 2019
• Subjects: activity pattern; American black bear; home range; kernel density estimation; movements; Paunsaugunt Plateau; Ursus americanus; Life Sciences
• Online Access: https://scholarsarchive.byu.edu/etd/9100; https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=10109&context=etd

Concerns over human-bear conflict and questions about the ecology of Paunsaugunt Plateau's population of black bears (Ursus americanus) arose due to their visitation to popular recreation sites. Greater insight about bears and their habitat use provides a foundation for conflict mitigation and effective management decisions. Between 2014 and 2017, seventeen black bears (11 female, 6 male) were fitted with global positioning system (GPS) radio-collars so that we could track their locations, daily activity patterns, and ambient temperatures. By analyzing bear locations, we calculated annual and seasonal home ranges for 16 bears, including 25 den sites. Home ranges typically consisted of three dominant vegetation types, Utah juniper, ponderosa pine and Douglas fir. I used mixed effects models to better understand den site selection and found that slope (27.87 ± 2.03) was the most significant factor (p < 0.001). I also used mixed effects models to understand black bear selection of annual and seasonal home ranges. Predictor variables with the greatest effect (p < 0.001) were elevation (2419.99 ± 1.35) and aspect (138.44 ± 0.64), with coefficients of 1.128 and -1.483 respectively. Male annual home ranges (327.20 km2 ± 133.58 km2) were significantly larger (p = 0.035) than female home ranges (175.10 km2 ± 55.37 km2). However, annual home ranges for both sexes were larger than those during hyperphagia (p = 0.003) or mating (p = 0.004) seasonal home ranges, between which there was no difference (p = 0.451). Individual home ranges overlapped for most bears, consistent with their non-territorial nature. I found that bears avoided roads and lower elevations, while showing a preference for sloping terrain throughout the non-denning period. Paunsaugunt black bear home ranges are larger than any other black bear home ranges reported in literature. We determined weekly average distances and directions for all bears. For two bears, one male and one female, we determined daily averages and directions. Nine bears provided daily averages for 12 seasonal units across all four years. Activity patterns indicate the typical crepuscular pattern noted in normal bear populations that lack human habituation. Identifying areas core use areas and potential den sites is helpful to understanding black bear ecology and useful when making decisions about how to plan infrastructure and educate the public. This research indicates that Paunsaugunt black bears avoid human activity; however, we need continued research to help determine specific interactions between bears and anthropomorphic influences.