Cascade’s Frog (Rana cascadae)

photo by Walter Siegmund

Common Name: Cascade’s Frog
Scientific Name: Rana cascadae
Family: Ranidae – True Frog family
Locations: United States and possibly Canada – California, Oregon, and Washington
Size: 1.75 – 3 inches (4.4 – 7.5 cm) with females being larger than males

The Cascade’s Frog is found at high elevations in the Pacific Northwest in the Cascades Mountains, the Olympics Mountains, and the northern Sierra Nevada. They range in color from brown, copper, tan, to olive green. The frogs are a diurnal species, meaning they are active during the day. They are thought to live at least 5 years.

The frogs overwinter near their breeding sites, slow moving permanent or temporary bodies of water lacking fish. Breeding season starts from March to August, depending on location. Reproduction is pretty standard. Male frogs will call from the shallows of water to attract mates. Once the frogs pair up, the male will grasp the female around the waist. The female will then lay her eggs in masses and the male will then fertilize them. Neither parent provides any care for the eggs or tadpoles. The egg masses contain 300 to 800 eggs. The tadpoles take around 2 months after hatching to complete their metamorphism.

The International Union for the Conservation of Nature (IUCN) red list lists the Cascade’s Frog as Near Threatened. They are a candidate for the endangered species list in the United States. In California, they are listed as a species of species concern. In Oregon, they are listed as a critical species, and in Washington, they are a species of concern.

The number one reason for the decline is the introduction of non-native game fishes and American Bullfrogs (Rana catesbeiana). These fish and bullfrogs eat the frogs and tadpoles, limiting their habitat. Other reasons include drought, climate change, and pollution.

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