Molecular ecology and conservation of caribou (rangifer tarandus) in western North America

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2012
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Abstract
As the scale and intensity of human-mediated impacts on the planet reaches unprecedented levels, there is a need for evaluating and describing the repercussions of these changes on the planet's flora and fauna. Woodland caribou are a threatened species that exemplify the challenge of protecting widespread, large species with expansive habitat requirements. Woodland caribou declines relate to habitat destruction and the consequent changes in predator-prey dynamics. Hindering conservation and management efforts is a lack of understanding the distribution of caribou diversity and the relationship of changes in habitat and environmental variables on caribou movements. Here I use a multiple methods, emphasizing molecular tools, to evaluate these knowledge gaps. First, I reconstruct the evolutionary history of caribou in Western North America, clarifying phylogeographic and broad patterns of diversity that inform delineation of conservation units. Next, I focus on west-central Alberta to evaluate landscape genetics perspectives on environmental and demographic variables that influence caribou population dynamics. Finally, I review current federal conservation policy and actions in the context of genetic variability, with a closing chapter emphasizing conservation challenges posed with ongoing climate change. Phylogenetic results demonstrate a new understanding of caribou evolution requiring the restructuring of the taxonomic identities of caribou ecotypes, a more widespread region of post-glacial "hybrid swarm," and clearer delineation of meta-populations of threatened Mountain and Boreal ecotypes. Landscape genetics show that preferred habitat and effective population size are the best predictors of genetic relationships of west-central populations, and that effective population sizes are at alarmingly low levels, emphasizing the need for management to focus on bolstering population numbers and maintaining habitat connectivity. The newly defined Designatable Units represent another version of Evolutionary Significant Units with similar limitations, particularly on the description of Boreal caribou. The proposed management recovery strategy for Boreal populations is fraught with seeming subjective criteria and emphasizes a scale of conservation unit (local population) that fails to ensure the protection of Boreal evolutionary and ecological integrity. Incorporation of the new genetic and population results detailed here offer information that can improve management and conservation objectives and promote a scientifically rigorous catalyst for policy change.
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Bibliography: p. 122-139
Some pages are in colour.
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Citation
Weckworth, B. V. (2012). Molecular ecology and conservation of caribou (rangifer tarandus) in western North America (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/4791
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