Presented by Shayne R. Halter, University of New Mexico, Department of Biology. Hummingbirds use energy at extremely high rates, especially during migrations. To survive these long trips, they must maintain adequate amounts of body fat for fuel. Shayne Halter’s research investigates how four species of hummingbirds balance their energy levels, as they transit the arid landscapes of the American southwest. He combines measurements from feathers, body fat, and metabolism, to map migration and energy budgets, to determine how hummingbirds adjust for energy shortfalls. His emphasis is on how hummingbirds use nocturnal torpor to conserve fat during migrations. This research will help us assess hummingbird health and develop conservation measures, as climate and land-use change make food resources less predictable in the southwest.