Date of Award
Semester of Degree
Open Access Dissertation
Ph.D. in Environmental and Forest Biology
Environmental and Forest Biology
H. Brian Underwood
Steering Committee Member
Steering Committee Member
By the early 19th century, many big-game species were extirpated from much of their historic range. Implementation of harvest regulations or restrictions, habitat succession, and changes in land use practices have facilitated the return of many of these species. It is necessary, for proper management, to be able to estimate with precision or certainty, abundance and other demographic parameters as well as range expansion often with personnel and financial limitations. New advancements in analyses allow for greater extraction of information from commonly collected data.
White oak (subgenus Leucobalanus) mast production had a strong correlation with non-harvest mortality of American black bears (Ursus americanus; r = 0.89). Using white oak mast as a surrogate for hunter effort, I used a catch-effort likelihood within statistical population reconstruction (SPR) using an N- mixture multinomial model to estimate the abundance and other demographic parameters of black bears in the Mountain region of North Carolina. Abundance was estimated at 3365 (95% B.C.I. = 3165-3569) for females and 3882 (95% B.C.I. = 3696-4080) for males in 2016, with numbers continuing to increase at a rate of approximately 5% annually. SPR estimates tracked estimates from Downing population reconstruction (DPR until approximately 2008 when DPR indicated population growth to be slowing in contrast to SPR estimates. The probability of harvest ranged from 6.7-15.6% (95% B.C.I. = 6.3-16.3%) for females and 11.6-26.1% (95% B.C.I. = 11.2-26.9%) for males. Additional parameters could be estimated with the inclusion of additional data and likelihoods.
The velocity of range expansion of the Mountain and Coastal black bear populations into the Piedmont was tracked using reliable sightings, frequency and location of bear-vehicle collisions, and demographic parameters in five methods of reaction-diffusion models. The rate of expansion was approximately 4-8 km/year. Each of the five methods yielded similar velocities of range expansion, indicating the simplest method that used commonly-collected data was just as informative as more elaborate methods.
Likelihoods using other food resources availability may be necessary to modify this SPR to fit other species or bear populations in agriculturally-dominated regions, but is easily adaptable. Collecting animal- vehicle mortality locations is an inexpensive way to be estimate range expansion of elusive species.
Folta, Joseph, "The Reaction-Diffusion of Range Expansion of American Black Bears (Ursus Americanus) In North Carolina, USA" (2020). Dissertations and Theses. 183.