Masters Theses

Date of Award

5-2021

Degree Type

Thesis

Degree Name

Master of Science

Major

Wildlife and Fisheries Science

Major Professor

Joseph D. Clark

Committee Members

Lisa I. Muller, Emma V. Willcox

Abstract

Black bears (Ursus americanus) were extirpated from the Cumberland Plateau (CP) in the late 19th to early 20th century due to habitat loss and overexploitation. After the Kentucky Department of Fish and Wildlife Resources, Tennessee Wildlife Resources Agency, and the National Park Service showed interest in reintroducing bears into Big South Fork National River and Recreation Area (BSF), Eastridge and Clark (2001) experimentally translocated black bears from the Great Smoky Mountains National Park to BSF. Since the reintroduction, this population has been monitored with capture-recapture studies using genetic identification. A current and accurate estimate of density and abundance were needed to direct future management of the population as it expands beyond the boundaries of BSF.

American black bears (Ursus americanus) were extirpated from the Cumberland Plateau in Tennessee and Kentucky in the late 19th to early 20th centuries due to habitat loss and overexploitation. After the Kentucky Department of Fish and Wildlife Resources, Tennessee Wildlife Resources Agency, and the National Park Service showed interest in reintroducing bears into Big South Fork National River and Recreation Area (BSF), Eastridge and Clark (2001) experimentally translocated 14 female black bears from the Great Smoky Mountains National Park to BSF from 1996 to 1997. In 2010–2012, a population estimate based on DNA extracted from hair samples collected at barbed wire hair traps revealed that the population expanded to 190 individuals in Tennessee and 38 in Kentucky. Based on the Tennessee estimate alone, this was an 18.3% annual increase since reintroduction. The bear population was thought to have expanded its range in the Cumberland Plateau since that estimate was conducted, so a more current estimate of bear density and abundance was needed across a wider spatial extent to direct future management of this population.

American black bears (Ursus americanus) were extirpated from the Cumberland Plateau in Tennessee and Kentucky in the late 19th to early 20th centuries due to habitat loss and overexploitation. Eastridge and Clark (2001) experimentally translocated 14 female black bears from Great Smoky Mountains National Park to Big South Fork National river and Recreation Area (BSF) from 1996 to 1997. In 2010–2012, a population estimate based on DNA extracted from hair samples collected at barbed wire hair traps revealed that the population had expanded to 190 individuals in Tennessee and 38 in Kentucky. The population was thought to have expanded its range in the Cumberland Plateau, so an updated estimate of bear density and abundance was needed across a wider spatial extent to direct future management.

I used spatially explicit capture-recapture (SECR) to estimate bear density and abundance within and surrounding BSF in northern Tennessee and southern Kentucky. Barbed-wire sampling stations (i.e., hair traps) were constructed in a 3- × 3-trap layout per cluster with 2 km between hair traps within a cluster and 16 km between cluster centers. I used DNA from hair samples obtained from hair traps to identify individual bears and establish genetic capture histories. I utilized spatial covariates to model inhomogeneous densities within the study area. Population abundance estimates across the 36,035-km2 study area were 436.2 males (95% CI = 234.1–812.5) and 450.9 females (95% CI = 295.0–689.1) for a total of 887.1 (95% CI 607.5–1,295.3) bears, excluding cubs. Average density estimates were 0.012 (95% CI = 0.007–0.023) male bears/km2 and 0.013 (95% CI = 0.008–0.020) female bears/km2, totaling 0.025 (95% CI = 0.017–0.037) bears/km2. The mean annual growth rate was 20.4% since 1998. Based on my population estimates, growth rates, and harvest reports, harvest rates in Kentucky averaged 4.2% from 2013 to 2019 ranging from 1.8% to 6.1% annually. In Tennessee, harvest rates from 2014 to 2019 averaged 12.2% ranging from 4.8% to 23.5%. Kentucky has seen greater population growth than Tennessee (31.1% and 15.0% respectively), possibly due to more restrictive harvest regulations and availability of contiguous forested federal lands.

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