| I examined basic anuran biology, and responses to habitat disturbance and predators, in Alberta, concentrating on the province's boreal mixedwood ecoregion. Using landscape data for a 504 km2 area, I found that loss of small wetlands increased the distance between remaining water bodies, potentially exceeding the movement capabilities of most wood frogs (Rana sylvatica). Using movement cost maps derived from slope, habitat, and moisture data, I found that most upland portions of the study area were potentially appropriate for wood frog use and travel.;I used fish and anuran abundance estimates from 12 lakes over five years to examine relationships between these groups. Severe fish winterkills were often followed by large anuran recruitment events; young-of-the-year wood frog abundance was related most strongly to changes in abundance of small-bodied fish species, whereas toad (western, Bufo boreas, and Canadian, B. hemiophrys) abundance was related to changes in populations of large-bodied fish species. I ran whole-pond experiments over 2 years to examine interactions between anuran larvae and small-bodied fish species. Wood frog larval activity and survival to metamorphosis were dramatically reduced in the presence of fathead minnow (Pimephales promelas) and brook stickleback (Culaea inconstans); western toad larvae were unaffected by fish presence.;Growth rates, longevity, and size at age of anurans often vary across latitude. Using skeletochronology, I examined these parameters for Canadian toads at four sites in three ecoregions across an 850 km latitudinal gradient from Brooks to Fort McMurray, Alberta. I also examined variation in age and size structure across three sites at a local scale. Growth rate, adjusted for length of active season, was higher at the two northern sites. Growth rates were similar at three boreal sites that were within 10 km of each other, but size structure of toad populations at these sites varied. Longevity varied from seven to 12 years across sites.;Results of my research on the ecology of northern anuran populations can be used in conservation efforts focused on these species in western Canada. |
