THE FROGS AND TOADS OF MOUNT RAINIER NATIONAL PARK

The study of amphibians and reptiles (herpetofauna) in National Parks has been largely limited to inventories or checklists. A few scattered works have been done on taxonomic problems, or with political species (i.e. species that are popular, scary, or of economic significance). Regetably, our knowledge of most of these animals remains at this level. We know where they occur but little else. The knowledge of the Mount Rainier National Park herpetofauna lacks quality detailed research even at this level. Detailed accurate observations of park amphibians and reptiles by qualified visitors and employees can be a tremendous aid in filling this void in the knowledge of the park's natural history. A familiarity of all the faunal forms of the park can also be an aid in understanding ecosystems, and educating and assisting visitors.

The following is a description of five components of Mount Rainier National Park, the frogs and toads. This is not an identification guide, but rather a note of the animals general locations and habitat in the park, an interesting characteristic or two, and an attempt to allude to their position in the ecosystem.

The most evolutionarily primitive in the Tailed Frog (Accaphus trueii). The male has a structure resembling a tail that is used as a copulatory organ. This is the only frog in the world with this organ. Three other members of the family found in New Zealand all lack the tail. The frog is only found from southwest British Columbia to northern California, west of the Cascades. In Mount Rainier National Park, look for it up to nearly 6000' in or along fast moving streams. It often sits on logs or rocks near the spray of waterfalls. The Talied Frog tadpoles have a unique large suckerlike mouth for attaching themselves to rocks in fast-moving streams. When threatened the tadpoles release their hold and are swept away in the rushing water where they attach themselves to a new rock.

The only "true toad" in the park is the Northwestern Toad (Bufo boreas). It is common below 6000' in a variety of habitats, sometimes far from permanent water. This toad gets quite large, nearly five inches from snout to vent, tends to walk rather than hop. The call of the Northwestern Toad during early spring breeding sounds like the peeping of a baby chick. The "true toads" in the family Bufonidae have chunky bodies and are warty and have parotid glands.

These glands and warts secrete a distasteful mild poison that serves to predators, however some animals eat toads with no effect. Dried toads may have been used in the past in Indian rituals. The skins contain bufontinine, a strong hallucinogen that produces strong and adverse affects in humans.

The small greenish tree frog found in Mount Rainier National Park is the Pacific Treefrog (Hyla regilla). This frog has been seen in the park up to about 4500', but is more common at lower elevations. Tree frogs climb limbs and twigs or nearly vertical surfaces with adhesive toe pads. Many, including this species, are capable of rapidly changing skin color if moved from one background to another. The color changes may also function in thermoregulation, the darker colors allowing the frog to warm, the lighter colors allowing it to reflect more radiant energy and stay cooler. During spring breeding the Pacific Treefrog commonly calls from shrubs or plants near the ground beside streams. The call is a loud two syllable kreck-ek of rising inflection.

Two additional frogs are found in the park, the Red-legged Frog (Rana aurora), and the Cascade Frog (Rana cascadae). Both are in the family Ranidae, the group of frogs the biologists call the "true frogs," based on their smooth skin and webbed hind feet. These frogs also have skin folds along each side of their backs. They are similar in appearance and habitat and a review of species characteristics is helpful in identification. The Red-legged Frog is less abundant, tends to be found at lower elevations, and strays further from water in damp woods. The Cascades Frog is the mountain frog and is the most abundant frog in the park, occurring in lakes, pools, and streams up to approximately 6500'.

Calls of the raniid frogs consist of chuckles, grinds, growls, trills, grunts, and clucks, and recent research has discovered a rather complex system of communication. In many similar species the call is the only positive distinguishing characteristic. The Red-legged and Cascades frogs have calls of three to five seconds duration that sound similar and are easily missed.

Jim W. Grace