Amphibians

Boreal Toad

GRTE/Dilley

Amphibians are some of the most unusual and important species found in the park. The word amphibian comes from the Greek words meaning "double life", and refers to their unusual two-stage life cycle. An amphibian begins life as an egg, laid either in water, or in some other wet environment. The larvae hatch and spend their time in water breathing through gills. They then undergo a metamorphosis into an adult form that breathes using lungs. While adults are considered terrestrial, amphibians continue to spend most of their lives near water. Unlike reptiles that have dry scaly skin, amphibians have moist, smooth, glandular skin with no scales, and they have no claws on their toes.

Amphibians are cold-blooded and cannot regulate their bodys temperature like mammals and birds. In the park, the cold annual temperatures, high elevation and dry climate limit amphibian diversity and numbers. The park is home to five species of amphibians: Columbia spotted frogs, boreal chorus frogs, western toads, western tiger salamanders and bullfrogs (introduced to the area). Northern leopard frogs are believed to be extinct in the area.

The best places to find amphibians are near rivers, streams, wetlands and lakes along the valley floor. Good places to look for spotted frogs include String Lake, Schwabacher Landing (along the Snake River) and Taggart Lake. Chorus frogs are easiest to find in late May and early June because the males are actively calling during their breeding season. Look and listen for these frogs at dusk in moist valley meadows. The boreal toad seems to be disappearing from their historic range. Sightings of these, as well as leopard frogs, should be reported to a parks visitor center.

Take some time during your visit to search for these interesting creatures. They are an important link in the food web-providing food for birds, otters and fish; and preying on insects. Finally, amphibians indicate the overall health of the ecosystem. Their dependence on water and the dual life cycle they lead makes them extremely sensitive to changes in environmental conditions.