Upper Left: California Red-Legged Frog; NPS Photo
Upper Right: Pacific Treefrog; NPS Photo
Lower: American Bullfrog; Photo Credit: John Sullivan/Ribbit Photography

These amphibious creatures are probably some of the least seen yet most heard animals in San Francisco Bay Area National Parks. Sodden areas near creeks and marshes are the best place to find most frog species. Unfortunately, similar habitats outside of parks and other protected areas are rapidly giving way to a variety of introduced changes.

Six species of frogs and toads currently call the parks home, including the non-native American bullfrog (Rana catesbeiana). The region’s most common frog is the Pacific treefrog (Pseudacris regilla), a species that calls in large, loud choruses in the late winter and spring. Foothill yellow-legged frogs (Rana boylii) were historically abundant in Pinnacles streams, but have not been seen in several decades. A re-establishment plan for this species is currently under consideration.

One of the best-studied frogs in the park is the native California red-legged frog (Rana draytonii). Red-legged frogs are a special species of concern for the parks as they have been eliminated from 70 percent of their former range, and are federally listed as a threatened species. There are still sizeable populations in Point Reyes National Seashore and Golden Gate National Recreation Area, and an effort to re-establish a population at the Bear Gulch Reservoir appears to have stabilized the population in Pinnacles National Park.