Observations of the Long-toed Salamander, Ambystoma macrodactylum, in Waterton Lakes National Park, Alberta

Abstract

The ecology of the Long-Toed Salamander (Ambystoma macrodactylum) was studied in Waterton Lakes National Park, Alberta, and evidence of its presence was obtained at nine of thirteen study sites. Populations occurred throughout the park at elevations from 1280 to 1930 metres in habitat that varied from aspen parkland to subalpine forest. Salamander breeding activity occurred from early April to late June, depending on location. Development of larvae in lakes or ponds is usually completed in one season (i.e., during one summer); however, two-season development was indicated at Summit Lake (elevation 1930 m). Mark-recapture data were obtained at Linnet Lake by conducting night searches and utilizing drift fencing and pitfall traps. A Schumacher-Eschmeyer estimate of between 3274 and 4690 breeding adults (95% confidence interval) was obtained for the population. Human impacts included roadway mortality and alteration of habitat due to local contamination and/or global effects. The total count of salamander roadway mortalities near Linnet Lake in 1994 was equal to 1.4 to 2.0% of the estimated population of breeding adults. Roadway mortality also may have contributed to the unusual female biased 3:1 (464 females:155 males) sex ratio obtained for this population. Measurements of pH taken at several aquatic breeding sites indicated a decrease in pH of 1 to 2 1/2 units had occurred in the last twenty-five years; the change may pose a potential threat to salamanders. Acid precipitation may be the source of this change.