Projects and Research

Oregon Spotted Frog

This species begins to breed at three years of age. Breeding occurs in February or March at lower elevations and in late May or early June at higher elevations.

Females may deposit egg masses at the same location in successive years in shallow, often temporary, pools no more than six inches deep. Eggs usually hatch within three weeks after. Tadpoles are grazers, having rough tooth rows for scraping plant surfaces and ingesting plant tissue and bacteria. 

Many factors are believed to have caused Oregon spotted frogs to decline and continue to threaten this species, including loss of habitat, non-native plant invasions, and the introduction of exotic predators such as bullfrogs. Over 95 percent of historic marsh habitat, and consequently Oregon spotted frog habitat, has been lost in the Willamette and Klamath basins.

Efforts are being made to eliminate and to prevent future introductions of bullfrogs and warm-water game fish from spotted frog habitat. Active management is also required to control non-native plant species like reed canarygrass. Protecting Oregon spotted frog populations through maintaining healthy aquatic habitats will continue to be the key objective of land managers.