Home-range size and subadult dispersal of black bears in the Cascade Range of western Oregon

Authors

Dave Immell, Oregon Department of Fish and Wildlife, Roseburg, ORFollow
DeWaine H. Jackson, Oregon Department of Fish and Wildlife, Roseburg, ORFollow
Margaret C. Boulay, Oregon Department of Fish and Wildlife, Roseburg, ORFollow

Abstract

Knowledge of home range size and subadult dispersal activity of North American black bears is essential for understanding the complexity of how bears interact within populations and the environment. During 1993-98, we monitored 96 radiocollared black bears (Ursus americanus) in the Cascade Range of western Oregon to estimate home range and dispersal movements. Composite fixed-kernel home ranges were calculated for 37 bears. Mean home range size differed between sexes (189.7 km² for males and 33.6 km² for females); however, there was no difference between subadult and adult male or subadult and adult female mean home range size. We monitored 40 subadult bears (29 M, 11 F) for detection of dispersal activity. We did not detect any dispersal of subadult females. One subadult male dispersed as a 2 year-old, 1 dispersed as a 3 year-old and 1 as a 4-year-old. The greatest dispersal distance of any subadult was 34 km by a 2 year old male.

Recommended Citation

Immell, Dave; Jackson, DeWaine H.; and Boulay, Margaret C. (2014) "Home-range size and subadult dispersal of black bears in the Cascade Range of western Oregon," Western North American Naturalist: Vol. 74: No. 3, Article 8.
Available at: https://scholarsarchive.byu.edu/wnan/vol74/iss3/8