Population Dynamics and Movements of Problem Black Bears in Great Smoky Mountains National Park
Date of Award
Master of Science
Wildlife and Fisheries Science
Michael R. Pelton
Boyd L. Dearden, James L. Schmidhammer
From 10 July 1967 to 6 December 1989, 341 black bears (Ursus americanus) in Great Smoky Mountains National Park were captured and relocated 570 times. Capture, release, and recovery locations of relocated bears were plotted on topographic maps using the Universal Transverse Mercator grid system. Objectives of this study were to delineate the sex and age structure of problem black bears and to determine factors contributing to the success of black bear relocations.
Excluding cubs and dependent yearlings, mean ages at initial capture of male and female bears were 3.9 and 4.6 years, respectively. Males comprised 619% of all captured bears, and 54.7%, 72.9%, and 58.0% of cubs, subadults, and adults respectively. The higher percentage of males was likely due to their larger home ranges and wide dispersal patters of the subadult age class. Only 18 of 504 tagged research bears (3.6%) were subsequently captured for creating problems; this suggests that problem bears comprise a small percentage of the overall bear population.
Seasonal distribution of captures of problem bears coincided with public visitation in Great Smoky Mountains National Park. Most captures of problem bears were in summer (75.1%) and were associated with areas of high public visitation. A significant interaction (P=0.25) existed between the sex, age class, and season in which bears initially were captured. Seasonal differences in home range use and activities by different sex and age classes of bears were probably responsible for this interaction.
The number of problem bear relocations each year ranged from 4 to 80. The number of individual problem bears captured each year ranged from 2 to 63 and may indicate fluctuations in the bear population. Changes in National Park Service policies regarding bears, advances in capture techniques, and financial and personal constraints also were partly responsible for yearly trends in captures of problem bears.
Most relocated bears (55.6%) were never recovered, and 32.4% were recaptured due to persistent nuisance behavior. Recaptured bears (X̄=4.1 years) were significantly older (P=0.0052) than those not recaptured (X̄=3.0 years). Only 14.3% of bears relocated distances greater than 64 km were recaptured. Mean time elapsed between release and recapture was 297 days; males and females averaged 225 and 399 days, respectively. Bears with previous relocation experience were recaptured more frequently in fewer days than those relocated for the first time. Several bears returned distances near or exceeding 100 km, overcoming significant natural and artificial barriers such as lakes, rivers, major highways and human developments.
At least 63 bears in this study (18.5%) were killed. Most bear mortality was due to legal harvest, however, no relocated bears were reported as part of the legal bear harvest in Tennessee. The percentage of males and females killed were 19.7% and 17.3%, respectively. Mean time from relocation to recovery was 253 days. Forty bears were killed the same year they were relocated. Bears were recovered a mean of 43.3 km from their release site and 84.5 km from their capture site.
The success of black bear relocations can be enhanced by designing a definitive relocation strategy based on the sex and age of bears, season captured, relocation distance, release area, and previous experience. Relocations, however, are not practical for all problem bears, and some bears probably should be destroyed. Relocations should be used in combination with other methods to reduce nuisance behavior of bears, and the availability of human food and garbage.
Stiver, William Henry, "Population Dynamics and Movements of Problem Black Bears in Great Smoky Mountains National Park. " Master's Thesis, University of Tennessee, 1991.