Virginia Tech Bear Researchers Ensure Populations
The Cooperative Alleghany Bear Study (CABS) was initiated in 1994 as a 10-year study to ensure survival of Virginia's hunted black bear population of western Virginia. During the first six years of the study, researchers have placed radio collars on 376 of the 746 bears captured.
Michael Vaughan, Virginia Tech's internationally known wildlife sciences professor in the College of Natural Resources, works with graduate students Andrew Bridges, Daniel Lee, Colleen Olfenbuttel, and Sybille Klenzendorf to study the bear population in the Alleghany Mountains.
Sybille Klenzendorf, fisheries and wildlife Ph.D. graduate, focused part of her research on the effect of radio-collars on black bear survival in Giles, Craig, and Montgomery counties. "No study to our knowledge," says Vaughan, "has evaluated the impact of radio-collars on hunter selectivity for bears and the influence on bear survival."
Klenzendorf suspected that collared bears had a higher survival rate than non-collared bears due to hunter bias. Her research found a significant difference in the survival rate of radio-collared versus non-radio-collared females. "Bear hunters in Virginia tend not to kill female bears if they can identify the sex," explains Vaughan.
"We suspect that hunters successfully avoided harvesting radio-collared bears," continues Klenzendorf. "In hunted populations in which hunters have a goal of saving females to increase population size, those conducting radio-telemetry studies should be aware of possible bias for their survival estimates."
Daniel Lee, graduate student in fisheries and wildlife, focused his research on dispersal distance movements of sub-adult black bears in Augusta and Rockingham counties. He found that juvenile bears migrate over a span of less than one to 52 miles.
During his three-year study, Lee used ear tag transmitters to avoid potential in-grown collars. His findings show that the female population moves very slowly. The males, however, had a much greater dispersal rate. Research shows that the males tended to move along the ridge lines going northeast or southwest. Lee concluded that the further the males moved or the greater the dispersal distance traveled, the less they were harvested by hunters. Overall the dispersal distance movements were helping the bears' survival rate.
Andrew Bridges, Ph.D. candidate in fisheries and wildlife sciences, developed a morphometric-based dichotomous key that could be used in the field to correctly age one, two, and three-year old bears. Prior to the development of the key, one-year olds were frequently misidentified as two or three-year olds and vice versa.
Vaughan and his graduate students traveled to Steinkjer, Norway, to present their findings at the 14th International Conference on Bear Research and Management. Colleen Olfenbuttel, graduate student in fisheries and wildlife sciences, won Best Presentation Award at the conference for her paper on the use of ultrasonography as a non-invasive tool to detect and monitor black bear fetal development.
Lead researcher, Michael Vaughan is assistant leader of the Virginia Cooperative of Fish and Wildlife Research, USGS-BRD. He has served as vice president to the International Association for Bear Research and Management (IBA), and editor of the IBA's journal, URSUS (scientific name for bears).
