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Bottlenecks, founder events, and genetic drift often result in decreased genetic diversity and increased population differentiation. These events may follow abundance declines due to natural or anthropogenic perturbations, where translocations may be an effective conservation strategy to increase population size. American black bears ( Ursus americanus) were nearly extirpated from the Central Interior Highlands, USA by 1920. In an effort to restore bears, 254 individuals were translocated from Minnesota, USA, and Manitoba, Canada, into the Ouachita and Ozark Mountains from 1958 to 1968. Using 15 microsatellites and mitochondrial haplotypes, we observed contemporary genetic diversity and differentiation between the source and supplemented populations. We inferred four genetic clusters: Source, Ouachitas, Ozarks, and a cluster in Missouri where no individuals were translocated. Coalescent models using approximate Bayesian computation identified an admixture model as having the highest posterior probability (0.942) over models where the translocation was unsuccessful or acted as a founder event. Nuclear genetic diversity was highest in the source ( AR = 9.11) and significantly lower in the translocated populations ( AR = 7.07-7.34; P = 0.004). The Missouri cluster had the lowest genetic diversity ( AR = 5.48) and served as a natural experiment showing the utility of translocations to increase genetic diversity following demographic bottlenecks. Differentiation was greater between the two admixed populations than either compared to the source, suggesting that genetic drift acted strongly over the eight generations since the translocation. The Ouachitas and Missouri were previously hypothesized to be remnant lineages. We observed a pretranslocation remnant signature in Missouri but not in the Ouachitas. [ABSTRACT FROM AUTHOR]

Harvest can affect the size and composition of wildlife populations. American black bear (Ursus americanus) populations in the Central Interior Highlands, Arkansas, USA, were nearly extirpated as a result of harvest and habitat change, but have expanded geographically and demographically since reintroduction in the late 1950s and early 1960s. Harvest levels have increased since baiting was permitted on private land in 2001; therefore, we initiated demographic analyses of 2 black bear populations to evaluate the effect of this policy change. We evaluated composition of harvest in response to baiting and used noninvasive genetic sampling in conjunction with capture-recapture methods to estimate density, survival, and population growth rate (λ) of black bear populations at locations within the Ouachita (2006-2008) and Ozark (2009-2011) national forests, Arkansas. More males were harvested than females with the use of bait. Capture probability varied annually; thus, multi-year data were valuable for capturing accurate population parameters. Density was approximately 14 bears/100 km² in the Ouachitas and approximately 26/100 km² for the Ozarks, which was greater than estimates from historical data (1989-1990). Thus, these populations maintained or exceeded previous density estimates while the use of bait was allowed on private land. However, as with any harvested population, it will be important to continue to monitor the population to be able make decisions about appropriate harvest policies going forward. [ABSTRACT FROM AUTHOR]