<P> Yellowstone is home for four species of amphibians . Glacial activity and current cool and dry conditions are likely responsible for their relatively low numbers in Yellowstone . </P> <P> Although no Yellowstone reptile or amphibian species are currently listed as threatened or endangered, several--including the boreal toad--are thought to be declining in the West . Surveys and monitoring are underway to try to determine if amphibian populations are declining in Yellowstone National Park . In 2014, a population of plains spadefoot toad was found in the park . More common species include the boreal chorus frog, columbian spotted frog, and the blotched tiger salamander . </P> <P> Cool, dry conditions limit Yellowstone's reptiles to six species and population numbers for these species are not known . Known reptile species in the park: prairie rattlesnake (Crotalus viridis viridis), bullsnake (Pituophis catenifer sayi), valley garter snake (Thamnophis sirtalis fitchi), wandering garter snake (Thamnophis elegans vagrans), rubber boa (Charina bottae), sagebrush lizard (Sceloporus graciosus graciosus). </P> <P> In 1991 park staff began cooperating with researchers from Idaho State University to sample additional park habitats for reptiles and amphibians . This led to establishment of long - term monitoring sites in the park . The relatively undisturbed nature of the park and the baseline data may prove useful in testing hypotheses concerning the apparent declines of several species of toads and frogs in the western United States . Reptile and amphibian population declines may be caused by such factors as drought, pollution, disease, predation, habitat loss and fragmentation, introduced fish and other non-native species . </P>

What animals do you see at yellowstone national park