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Thea V. Kristensen

Publications and source records attributed to Thea V. Kristensen.

2 recordsLinked to original sources

Modelling potential areas of human-wildlife conflict using community-based data: A case study of black bears (Ursus americanus) in Massachusetts

Human-wildlife conflict has intensified with the continued expansion of human populations into natural habitats. American black bears ( Ursus americanus ) are increasingly coming into contact with people, particularly as bears return to areas where they were previously extirpated. Citizen science offers a promising tool for predicting where such conflicts might occur by providing large-scale data on human-wildlife interactions. We used citizen science observations to model areas of overlap between humans and bears in Massachusetts. Additionally, we created a distribution model by integrating designed research data with citizen science data. Through simulations, we evaluated how to best augment citizen science with designed research data to enhance species distribution modeling. Our model showed high sensitivity in detecting areas where humans and bears overlap, with high housing density and proximity to roads predicting overlap. The inclusion of designed research data improved accuracy of distribution in less-populated areas, although some bias remained. When simulating behavioral differences between urban and forest-dwelling bears, strategic designed research data helped detect elusive forest bears, which are less likely to be observed by people. Overall, incorporating citizen science into conflict models can lead to better predictions of where interactions will occur and therefore will be a helpful tool for developing management strategies as human-wildlife conflict increases.

Massachusetts↗

Influence of drift and admixture on population structure of American black bears ( Ursus americanus ) in the Central Interior Highlands, USA, 50 years after translocation

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 (A R = 9.11) and significantly lower in the translocated populations (A R = 7.07-7.34; P = 0.004). The Missouri cluster had the lowest genetic diversity (A R = 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.

Molecular Ecology↗