Invasive Bullfrogs Prey on Native Species

North American Bullfrog (Rana catesbeiana)

The largest frog in North America (up to 6 inches in length and one pound in weight) with a high reproductive rate (20,000 eggs at a time).

The steep canyons and rock formations of Del Dios gorge are an ideal habitat for reptiles and amphibians. The year-round pond provides a water source for native turtles, frogs, snakes and salamanders and fractured rock is used by reptiles for cover, shelter and temperature regulation. However, the native reptiles and amphibians in the gorge are in a life-and-death struggle with the invasive North American bullfrog. The North American bullfrog is a voracious predator that consumes any animal that fits in its mouth such as snakes, worms, insects, crustaceans, frogs, lizards, tadpoles, baby turtles and eggs of fish, frogs, or salamanders.

Southern Pacific Pond Turtle (Clemmys Marmorata)

California’s only native freshwater turtle. An aquatic turtle found in ponds, streams, lakes and marshes.

Invasive species are plants and animals that are introduced to an area where they do not naturally occur and alter the ecological balance among native species. They thrive because the new habitat lacks the natural predators, diseases and resource limitations (food and shelter) that controlled their population in the native habitat. Bullfrogs and other invasive species threaten native species by preying on them and competing for food and other limited resources. Invasive species sometimes force native species into extinction, upsetting the national balance of the ecosystem. Other invasive species In Del Dios gorge include crayfish, largemouth bass and house cats.

Two-striped Garter Snake (Thamnophis hammondii)

Once a common snake in Southern California, it has been severely imapcted by invasive species. Don’t Touch! When captured, may strike, bite or exude foul-smelling musk.

Monterrey Salamander (Ensantina enschscholtzii)

Long-lived salamanders, up to 16 years of age. Lacks lungs and “breathes” through its skin. Needs moist habitat to remain hydrated.

Del Dios Gorge is part of the San Dieguito River Park’s Coast-to-Crest Trail, extending from the Pacific Ocean in Del Mar to the summit of Volcan Mountain.