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Map of the state of Georgia (GA) and neighboring states of Alabama (AL), Florida (FL), North Carolina (NC), South Carolina (SC), and Tennessee (TN), with American black bear (Ursus americanus) distribution (green shading) and incidental, inter-population observations of bears (black triangles) between Georgia's 3 bear populations-the North Georgia Bear Population (NGP), Central Georgia Bear Population (CGP), and South Georgia Bear Population (SGP)-in Georgia, USA, 2006-2017. Bear distribution and observation data are modified and updated from Scheick et al. (2011) and Scheick and McCown (2014).
Source publication
There are 3 American black bear (Ursus americanus) populations in the state of Georgia, USA. We used multi-locus microsatellite genotypes derived from bear hair and tissue samples collected across these populations to assess levels of genetic diversity within and between populations. We used population assignment clustering to evaluate whether ther...
Contexts in source publication
Context 1
... State of Georgia, USA, contains 3 bear populations representing 2 of the southeastern American black bear subspecies ( Fig. 1; Hall 1981). The North Georgia Bear Population (NGP) and the Central Georgia Bear Population (CGP) are considered to be American black bear (Ursus americanus americanus), whereas the South Georgia Bear Population (SGP) is considered to be the Florida black bear (U. a. floridanus). Collectively, these populations comprise roughly 5,100 ...
Context 2
... other bear populations makes conservation of the CGP of special concern (Hooker et al. 2015). Although there appears to be poor connectivity between bear populations in Georgia, reports of bears in areas between the NGP and CGP, or the CGP and the SGP, are seemingly increasing (see incidental, inter-population observations, black triangles in Fig. 1), necessitating research to evaluate levels of demographic and genetic separation among the 3 Georgia bear populations. Our objectives were to use microsatellite markers to assess genetic variation within and among the NGP, CGP, and SGP, and to determine whether there was evidence of gene flow into the ...
Citations
... Identifying patterns of occupancy at a scale typical of management provides important information for managing black bear populations throughout the large, connected network of national forests in the Appalachian region. ada (Bond & Balkcom, 2014;Hooker et al., 2019;Little et al., 2017). Understanding the drivers of black bear occupancy patterns can provide insight into their ability to recover and maintain a widespread distribution. ...
Although previously close to extirpation in the southeastern United States, American black bear (Ursus americanus) abundance and distribution have increased with habitat management and harvest regulation. The north Georgia black bear population, the most abundant and widely distributed in the state, is currently being exposed to pressures from increasing anthropogenic disturbances, such as recreation and vehicle traffic. We evaluated the effects of environmental factors and anthropogenic activity on habitat use of black bears within a wildlife management area open to public recreation. We used detection/non‐detection data from camera surveys conducted at 448 locations from April to December 2023 to fit hierarchical single‐species occupancy models. Black bear detection was best explained by Julian date, its quadratic effect, and weekly human activity index. Detection increased through the spring, peaked in June, and declined throughout late summer and fall. In contrast to detection, occupancy was not affected by seasonal differences in black bear activity. Occupancy increased with increasing elevation, distance to water, and distance to high‐use recreation areas. The spatial distribution of food resources likely contributed to the observed black bear occupancy pattern related to elevation and distance to water, while human disturbance in the study area also influenced black bear occupancy. Thus, our results suggest that in a landscape open to public recreation, black bear occupancy was driven by a combination of environmental and anthropogenic factors. Identifying patterns of occupancy at a scale typical of management provides important information for managing black bear populations throughout the large, connected network of national forests in the Appalachian region.
... The central Georgia bear population (CGBP) is 1 of 3 bear populations in Georgia, USA ( Fig. 1; Georgia Department of Natural Resources 2010) and is primarily restricted to an area along the Ocmulgee River in central Georgia southeast of the city of Macon. The CGBP is considered demographically and genetically isolated (Miller 1995, Sanderlin et al. 2009, Hooker et al. 2019) and has the fewest bears of any of the bear populations in the state (89.8-111.3 males and 125.4-154.9 ...
... Other bear populations close to the CGBP are the south Georgia bear population (SGBP), located about 140 km southeast, the north Georgia bear population (NGBP), located about 175 km north, and the Apalachicola Florida bear population (AFBP), located about 207 km southwest of the CGBP. Although bears were occasionally reported in areas between these 4 populations, Hooker et al. (2019) reported that genetic diversity of the CGBP was low. Soulé and Gilpin (1991) described a wildlife corridor as a linear 2-dimensional landscape element that connects 2 or more patches of wildlife (animal) habitat that have been connected in historical time; it is meant to function as a conduit for animals. ...
... Genetic data support this conclusion. Hooker et al. (2019) reported that the degree of genetic separation (F st ) was greater between the CGBP and either the NGBP or the SGBP than between the NGBP and the SGBP, despite the far greater geographic separation of the latter, but they did document a few potential interchange events based on genetic assignment tests. A 3-year-old male bear with a microsatellite genotype consistent with bears from the AFBP was killed by a vehicle in 2015 in central Georgia, about 20 km from the CGBP, and a female with NGBP ancestry was captured in the CGBP based on population assignment clustering (Hooker et al. 2019). ...
Habitat fragmentation and loss contribute to isolation of wildlife populations and increased extinction risks for various species, including many large carnivores. We studied a small and isolated population of American black bears ( Ursus americanus ) that is of conservation concern in central Georgia, USA (i.e., central Georgia bear population [CGBP]). Our goal was to evaluate the potential for demographic and genetic interchange from neighboring bear populations to the CGBP. To evaluate resource selection and movement potential, we used 35,487 global positioning system locations collected every 20 minutes from 2012 to 2014 from 33 male bears in the CGBP. We then developed a step selection function model based on conditional logistic regression. Male bears chose steps that avoided crops, roads, and human developments and were closer to forests and woody wetlands than expected based on availability. We used a geographic information system to simulate 300 bear movement paths from nearby bear populations in northern Florida, northern Georgia, and southern Georgia to estimate the potential for immigration to the CGBP. Only 4 simulated movement paths from the nearby populations intersected the CGBP. The creation of a hypothetical 1‐km‐wide corridor between the southern Georgia population and the CGBP produced only minor improvements in interchange. Our findings suggest that demographic connectivity between the CGBP and surrounding bear populations may be limited, and coupled with previous works showing genetic isolation in the CGBP, that creation of corridors may have only marginal effects on restoring gene flow, at least in the near term. Management actions such as translocation and the establishment of stepping stone populations may be needed to increase the genetic diversity and demographic stability of bears in the CGBP. © 2021 The Wildlife Society.
... geographically and genetically isolated of these populations is the CGP, which was separated from the NGP and SGP by >150 km (Hooker et al. 2019). Grahl (1985) reported a population estimate of 64 black bears for the CGP, whereas Sanderlin (2009) derived annual and seasonal estimates ranging from 106 to 213 bears. ...
... We used 10 microsatellite markers (G1A, G10L, G10M, CXX20, MU59, G10X, CXX110, D1A, G10U, and D123) and a ZFX-ZFY sex marker to produce reliable individual identifications. Genetic variability was low in our study area (Hooker et al. 2019), so the laboratory combined standard protocols for re-analysis of mismatching markers in pairs of similar genotypes (Paetkau 2003, Kendall et al. 2009) with the practice of extending genotypes in question with 2 additional markers (REN145P07 and G10H) to resolve potential genotyping errors. ...
... We excluded these small fragments in the peripheral agricultural lands from the state-space because although bears might have used these small patches, we felt it was safe to assume that the density of activity centers within them was close to zero. If bears were able to establish home ranges in small forest fragments in intensive agricultural landscapes, it seems likely that the population would have expanded its range, and that there would be gene flow with other populations in Georgia, which was not the case (Hooker et al. 2019). Additionally, Gray et al. (2016) noted that none of 41 female bears radio-marked in our study population denned farther than 1 km outside the boundaries of our state-space. ...
The Central Georgia Bear Population (CGP) is the least abundant and most isolated of Georgia's 3 American black bear (Ursus americanus) populations. Beginning in 2011, changes to regulations governing harvest of the CGP resulted in an increase in female bear harvest, creating concern that future harvest could be an important influence on population viability. Hence, our objective was to assess viability of the CGP under various levels of female mortality. During 2012–2016, we used barbed‐wire hair snares to collect bear hair samples from within the range of the CGP in Georgia, USA. We used microsatellite genotyping to identify individual bears and created robust‐design, spatial detection histories for all female bears detected. We fit open population spatial capture‐recapture (SCR) models to the detection histories in a Bayesian framework. We used the Widely Applicable Information Criterion (WAIC) to rank models that varied with respect to sources of variation in detection probability, survival, and per capita recruitment, and used the model with the lowest WAIC to forecast dynamics of the CGP 50 years into the future under various levels of female mortality. We assessed the 50‐year extinction probability under a continuation of mortality levels documented during 2012–2016, and under incremental increases in female mortality above this baseline. The top model included density‐dependent per capita recruitment, annual variation in detection probability, and a trap‐level behavioral response. Abundance increased from 106 (95% CI = 86–132) females in 2012 to 136 (95% CI = 113–161) females in 2013 and remained relatively stable thereafter. Annual female survival was 0.75 (95% CI = 0.69–0.82) and did not vary among years. The per capita recruitment rate decreased over time as density increased, and was 0.49 (95% CI = 0.33–0.66) during the first time interval and 0.29 (95% CI = 0.20–0.38) during the final time interval. Annual growth rate () was 1.28 (95% CI = 1.07–1.52) between 2012 and 2013 but decreased throughout the study, ending at 1.04 (95% CI = 0.93–1.17). Forecasts indicated continuation of the female mortality levels experienced from 2012–2016 were sustainable over 50 years, with the estimated extinction risk being <0.001%. Increasing annual harvest by 5 females introduced a negligible increase in the 50‐year probability of extinction, but harvesting an additional 10 females/year caused extinction risk to rise to 1.15%. We recommend that harvest regulations are structured such that mortality rates remain at current levels or do not increase by more than an annual average of 5 females above levels observed during our study. Furthermore, we recommend that managers continue to monitor the population so that harvest regulations and population models can be refined over time. © 2020 The Wildlife Society. We found that increasing annual harvest by 5 females in a black bear population introduced a negligible increase in the 50‐year probability of extinction, but harvesting an additional 10 females/year caused extinction risk to rise to 1.15%. We recommend that harvest regulations be structured such that mortality rates remain at current levels or do not increase by more than an annual average of 5 females above levels observed during our study.