Distribution of long-toed salamanders and introduced trout in high- and low-elevation wetlands in southwestern Alberta, Canada

Abstract

Several species of trout have been introduced into most wetlands within the mountain and foothill regions of southwestern Alberta, Canada. In this study, we used standard survey methods to evaluate the distribution of long-toed salamander (Ambystoma macrodactylum) larvae relative to introduced trout within 27 low-elevation wetlands and 30 high-elevation wetlands in Waterton Lakes National Park and the adjacent Castle Special Management Area. Results provided indirect evidence of salamander displacement by trout. At high elevations, salamander larvae were not detected in any of the sites that contained trout. The complete allotopy between trout and long-toed salamanders within high-elevation sites supports previous studies completed within the core of this species' range, further documenting the widespread negative impacts of introduced trout on native amphibians in upper basins. Similarly, salamander larvae were present in each of the low-elevation wetlands that lacked trout; they co-occurred in only 4 of 27 low-elevation wetlands. Allotopy within lower elevation sites is particularly important from a conservation perspective because, relative to populations in high-elevation wetlands, these populations tend to contain individuals with rapid growth and high dispersal rates.