Landscape Ecology and Population Genetics of Minnesota's Bats

Bats in North America are facing an unprecedented variety of threats, including habitat loss, wind energy development, and white nose syndrome. However, the habitat where people most commonly encounter bats, the city, is among the least researched, in spite of its increasing importance on the landscape. Additionally, little work has been performed on the population genetics and recent evolutionary history of one of the most common bats in North America, Myotis lucifugus. My dissertation research elaborated on these research gaps. Chapter 1 explored the role the degree to which land cover influences the activity by 7 species of bats in the Twin Cities metropolitan area of Minnesota. I found that species differ dramatically in the scale and land cover variables to which they respond. In Chapter 2, I used population genetic techniques to study the degree to which female little brown bats (M. lucifugus) display philopatry to their natal roosts, and to discover the frequency with which they move to new colonies. I found that, contrary to assumptions based on banding studies, female M. lucifugus frequently move to new summer colonies, and that females from multiple hibernating populations co-occur in summer colonies. These findings have important implications for the spread of white-nose syndrome. Finally, in Chapter 3 I used phylogenetic and environmental niche modeling methods to explore the role which Pleistocene glacial refugia played in the evolution of lineages within the M. lucifugus/thysanodes/evotis species complex, with particular emphasis on M. l. lucifugus. The genetic pattern within M. l. lucifugus is generally concordant with isolation in a single large refugium in the southeastern United States. Niche models for the broader range of M. lucifugus suggest isolation in several western and Beringian refugia, suggesting that this could have been a source of some of the genetic diversity within that species complex.