| Abstract: | We documented populations of deer mice in the Kananaskis Valley, southwestern Alberta, Canada from 1979 to 1997 to determine whether these short-season populations were more, or less, variable than populations in more temperate environments. We then examined patterns of reproduction, age-specific survival, and immigration to explain variation in summer population growth. Population densities showed no multi-annual periodicity and were generally low. At maximum, numbers doubled over the breeding season, but declined over the breeding season in 4 of 16 yr. Variability in population density was low, and similar to that of Peromyscus populations in more temperate environments. No demographic parameters were related to spring population densities, and immigration rates were low when conditions for survival of nestlings and adults were favorable. Variation in summer population growth was attributed primarily to variation in nestling survival among years. |
