Ecological and evolutionary consequences of mammalian flight

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The evolution of flight was a key innovation leading to three diverse groups: insects, birds, and bats. With over 1100 species worldwide, bats are an extremely successful group of mammals. My students and I test hypotheses regarding the costs and benefits of flight, and their influence on bat ecology, morphology, behaviour, life history, and diversity. We use field and laboratory observations and experiments at sites in western and northern Canada. In the North, bats must adjust their feeding, roosting and reproductive behaviours to cope with short, cold growing seasons and short nights. How do nocturnal animals deal with no night and squeeze reproduction into a short season? In the prairies, bats hibernate in crevices along river valleys, yet periodically switch roosts. Is roost switching due to changing weather conditions? How will the hibernation behaviours of prairie bats influence the spread of white-nose-syndrome, a disease killing millions of hibernating bats in Eastern North America and rapidly moving west? What is the basic biology of migratory bats? How far do they travel, what routes do they use, and is migration behaviour learned from mother to offspring? What are the consequences of fatalities at wind turbines for these species? Do populations of bats adapt to local habitats and if so, how does flight influence diversification? To address these fundamental and applied questions, we use small radio-transmitters to track the movements, and feeding and roosting decisions of individual bats in their natural habitats. Microphones record the echolocation calls of flying bats, enabling us to measure their abundance and diversity, and determine the relationship to habitat type. We measure the metabolic rates of bats under different environmental conditions to determine the costs and benefits of using torpor and selecting roost microclimates. We also use molecular (DNA) techniques to assess the genetic differences of populations in different habitats, and the relatedness of migratory bats in different areas. Our goal is to understand how flight influenced the evolution of bat diversity, and influences their susceptibility to novel disturbances such as white-nose-syndrome, wind energy facilities, and habitat change.