Date of Award
Master of Science
Wildlife and Fisheries Science
Michael R. Pelton
Frank van Manen, Joe Clark, Arnold M. Saxton
Since the establishment of Great Smoky Mountains National Park (GSMNP) in 1934, interactions between black bears (Ursus americanus) and visitors have been a regular occurrence. Prior to 1990, capture and relocation was the primary management alternative for nuisance bears in GSMNP. Since 1990, wildlife biologists in GSMNP have used capture and on-site release as an aversive conditioning technique for nuisance black bears. This technique involves capturing and immobilizing bears that frequent developed areas, collecting biological data, and releasing the bears back into the same area. The premise of this technique is to reinforce the natural fear of humans and thereby reduce the likelihood of return. Although capture and on-site release seems to have had some success in deterring nuisance bears from developed areas of GSMNP, it has not been tested quantitatively.
I evaluated capture and on-site release as a management technique for nuisance black bears in GSMNP. The objectives of Part 1 of my study were to identify correlates of success for on-site releases, estimate survival, and evaluate movements in relation to the release sites of nuisance black bears.
During 1997 and 1998, I captured and released 28 bears (16 males, 12 females) a total of 30 times. Bears were released in picnic areas (n=14), backcountry campsites or shelters (n=10), campgrounds (n=2), parking lots (n=1), and roadsides (n=1). Nine of the 28 bears (32%) were relocated to different areas as a result of continued nuisance activity.
I defined the overall success rate of on-site releases as the total number of bears that were not relocated within the same year divided by the total number of bears released on-site. Between 1990-1998, 63 bears (44 males, 13 females, and 11 females with young) were released on-site in front country areas of GSMNP a total of 85 times with an overall success rate of 74%.
I used data from 1990-1998 to identify the key factors that contribute to the success of on-site releases in front country areas of GSMNP. I developed multiple variable logistic regression models based on 6 different success definitions to identify correlates of success. Success definitions were defined by post release observations or management actions at the release site within the same year and in successive years. My analysis identified sex, family group size, capture area type, time of nuisance activity, and population abundance as important variables in determining success of on-site releases. The results indicated that success of on-site releases may be increased by frequent night-time monitoring of campgrounds and picnic areas to detect and capture nuisance bears when they are night active and coordinating the frequency and effort of monitoring based on the estimated population increase or decrease from the previous year. Managers in GSMNP can use these models to predict and compare the relative probability of management success for various scenarios.
During 1997-1998, I radio-collared and monitored 23 bears (12 males, 11 females) to estimate survival of bears released on-site. I estimated survival using the Kaplan-Meier staggered entry procedure. Survival during the entire study period for all bears was 0.71 (95% CI=0.50-0.93). Survival for males and females during the study was 0.50(95% CI=0.24-0.76) and 1.00 (95% CI=0.76-1.00), respectively. Although survival functions between the sexes did not differ (P=0.22), overall survival rates were different (P<0.001). Legal hunting was the only cause of mortality during the study.
I used compositional analysis to determine bear movements in relation to their release sites. I used telemetry data from 14 bears (9 males, 5 females) to calculate home ranges and created distance zones of 1, 2, 3, 4, 5, and >5 km around each release site. The distance zone >5 km from the release site had the highest proportional composition for home range area and the number of locations within each zone. However, bear use between the distance zones did not differ suggesting that bears were neither avoiding nor attracted to the area of the release sites. Thus, on-site releases did not displace bears from the area near the release sites.
The results from my study indicated that capture and release on-site is a viable management alternative to relocation and better meets the objective for bears management in GSMNP. Capture and release on-site requires biologists to take a proactive approach to managing nuisance bears and allows bears to remain in GSMNP as a continued resource.
Rehabilitation and release of orphaned bears into the wild offers a management alternative for black bear managers. The objective of Part II of my study was to estimate survival of orphaned bears that were rehabilitated and released into the Great Smoky Mountains. Between October 1997 and June 1998, I released 11 rehabilitated orphan bears (6 males, 5 females) into the Smoky Mountains. I documented no mortality during the study period. I estimated survival using the Kaplan-Meier staggered entry procedure and back dated release dates to determine survival of bears by post release days. Because the fate of 2 bears in the study was unknown, I performed 2 analyses to estimate minimum and maximum survival. Survival up to 180 days post release ranged from 0.77 (90% CI=0.34-1.00) to 1.00(90% CI=0.76-1.00). The results indicated that short-term survival (up to 180 days) of rehabilitated orphan bears is possible may be a viable alternative to managers for dealing with orphan bears.
Clark, Jay Edwin, "Capture and On-Site Release of Nuisance Black Bears and Survival of Orphaned Black Bears Released in The Great Smoky Mountains. " Master's Thesis, University of Tennessee, 1999.