Rana cascadae
Cascades frog

This species lives in the Cascade mountain range in a band from Washington south to the Oregon-California border, with additional populations scattered populations in the mountains of Northern California (AmphibiaWeb 2001).

Lives in streams and ponds in the mountains and coniferous forests 800-2740m. During warm and moist periods, it stays in water and surrounding vegetation. In winter, it hibernates in the soil under the lake bottom (AmphibiaWeb 2001).

Adult males are usually 50-60mm and females between 50-75mm long. Olive brown in color with a dark strip from the tip of the snout to the forelimbs. Its back and legs are usually covered with dark spots. It has a light, honey-colored underside, and a bright yellow groin with dark mottling. The toes are not fully webbed and have dorsalateral folds. The male has a swollen and darkened thumb base (Stebbins 1985).

The tadpole has a relatively long tail (Northern Prarie Wildlife Research Center 2001).

Diurnal and basks on water-covered rocks. Moves slowly, and often allows close approach. When it senses danger, it tries to swim fast, rather than hiding on the bottom.

The mating call is a low pitched grating, chuckling sound with 4-5 notes per second. A series of rapid clucks or double clucks, each lasting about 0.5 seconds. It calls from either above or below the water (Stebbins 1985).

Aquatic and semiaquatic insectivore (California Wildlife Habitat Relationships System 2001).

While still common in some areas of suitable habitat in the northern half of its range, there are been substantial declines in populations of R. cascadae in California and Oregon. Likely causes of the decline in California are habitat loss and predation by non-native trout, exacerbated by drought. Effort to suppress fires and cattle grazing in Lassen Volvanic National Park has led to shrub and tree overgrowth of open meadows , filling up the aquatic habitats in which many of the frogs breed. Trout have been introduced into a number of mountain lakes and eat tadpoles.

These reasons may not explain the substantial decline of this species in Oregon. There is some evidence that increased ultraviolet radiation exposure due to depletion of atmospheric ozone may be another important factor in extinction (AmphibiaWeb 2001).