Small Mammal Movements and Fire History: Testing the Long-Term Effects of the 1988 Huckleberry Mountain Fire
Fires are an important ecological force shaping biological communities in western North America. Fires change landscapes in ways which influence the relative abundance and activities of the organisms occurring in those habitats. Preliminary results from previous work suggest the stage of fire succession may influence individual movements on the landscape. As part of a long-term study of the 1988 Yellowstone fires along the John D. Rockefeller, Jr. Memorial Parkway, we set out to examine these patterns in more detail to (1) test whether the two dominant small mammal species were moving different distances based upon the stage of succession in a particular habitat, and (2) determine the role of habitat complexity, resource types, and species abundance in driving these patterns. Using movement distances from capture-recapture data and fluorescent powder tracking of individuals we compared movement distances and habitat usage between mid-succession and late-succession trapping grids for red-backed voles (Myodes gapperi) and deer mice (Peromyscus maniculatus). The results suggest deer mice, some of the first colonizers to burned habitat, are moving farther than red-backed voles, and move farther in burned habitats than in unburned habitats. Red-backed voles exhibit slightly, but not significantly, longer movements in burned habitats. Powder tracking results suggest habitat complexity, in particular the quantity of coarse woody debris, may partially explain the differences in movement patterns by burn history. These results are important for understanding the long-lasting impacts of fire history on population and community patterns.