Tiger Salamanders and Climate Change

In a study funded by the Environmental Protection Agency, researchers modeled the effects of global climate change on plants, animals, intensity of weather events, fire frequencies, ecological processes, and the local economy for Rocky Mountain National Park and its gateway community Estes Park in an effort to predict changes expected to occur over the next few decades. Some of the results from the study suggested that tundra and tundra-dependent animals were likely to virtually disappear, fires were likely to become more frequent, visitors would likely have a longer season to enjoy snow-free activities, but snow-dependent activities would become less available, and traffic would likely increase.

One group of animals they did not examine was salamanders. A recent research project in Yellowstone National Park demonstrated that tiger salamander populations responded in a measurable way during a warmer, past climate period. A team of scientists led by Elizabeth Hadly from Stanford University looked at a 3,000 year fossil accumulation of tiger salamanders and determined that when climatic conditions were warmer than now, adult tiger salamanders were larger than paedomorphic salamanders. Paedomorphic tiger salamanders become sexually mature but continue to live in the water and retain larval characteristics due to environmental conditions as compared to adult salamanders that metamorphose, losing larval characteristics, and become terrestrial (land dwellers). Under environmental current conditions, paedomorphic salamanders tend to occur more frequently at high altitudes and cold environments. They also tend to be larger than terrestrial adult salamanders in the same area.

The Yellowstone study suggests that Rocky Mountain National Park staff and visitors may start seeing fewer paedomorphic and more, larger terrestrial adult tiger salamanders as conditions continue to warm two to five degrees centigrade as predicted in the region of the park based on the two most widely accepted climate models. What this would mean to tiger salamander population numbers, which are currently thought to be stable, or to populations of other park amphibians known to be less well off is still unclear.

If you'd like to look for a paedomorphic tiger salamander in Rocky Mountain National Park, visit Lily Lake in the southern part of the park. It is right beside Colorado Highway 7, and has easy parking as well as a handicapped accessible trail around the lake. Paedomorphic tiger salamanders are frequently observed along the shallow margins of the lake.