Although such trends can be difficult to document with certainty, bullfrogs have been implicated in regional declines of native amphibians and fish in other countries where they have been ...

Most frogs and other amphibians hatch as fish-like larvae called tadpoles, or "pollywogs." Tadpoles exist to eat and grow. They eventually transform into froglets, a process called metamorphosis.

So in the late 1800s, when beavers were extirpated from much of the basin, the Gila chub was hurt too. Now, with added pressure from nonnative fish and bullfrog predation, habitat destruction, and ...