The American bullfrog is native to much of the eastern United States. This species has successfully begun to spread west as an invasive species. It is thriving in the western United States because of its large size, high mobility, and tremendous reproductive capabilities. American bullfrogs have very generalized eating habits and often eat the same food sources as the native frog species in the western United States, causing a reduction in the overall food supply.

The relationship between the American bullfrog and native frog species in the western United States can best be characterized as .