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Merrill, Nathaniel

Wildlife and Fisheries Biology Program

2005

M.S.

Black bears (Ursus americanus) inhabited most of the land area that is now Vermont before colonization by Europeans. Following widespread deforestation for agriculture, the bear population was reduced to refugial populations in the more mountainous regions of the state. Since the late 1800' s Vermont has gradually reforested, and the bear population has rebounded, however human population growth and residential sprawl are beginning to reduce bear habitat again. Little is known about the genetic structure of the population, but radio-telemetry studies have indicated that human development and highways can influence black bear movement patterns. If highways are potential barriers to gene flow, they could create isolated subpopulations within the state, which would have implications for population management. In this study, mtDNA control-region sequence data from a statewide sample of 128 black bears were analyzed to investigate the genetic structure of the population. Results of an AMOVA analysis, pairwise FST, and estimation of migration rates suggest that there is significant genetic structure in the Vermont bear population. A model of population subdivision utilizing all the large highways within the state, creating 9 subpopulations, resulted in a