Bullfrogs (Rana catesbeiana)
The American bullfrog is native to the Eastern North America, and was initially imported for production of frog legs. It has now spread to all of the lower 48 states as well as South America, Asia and Europe. America’s largest frog species, it may weigh over a pound and measure up to 18 inches from head to toe. A female can lay up to 20,000 eggs, and the tadpoles become so large (150mm) that to the uninformed, a group of them may initially be mistaken for a school of small fish. Bullfrogs will live 7-9 years in the wild, but tadpoles require two years to mature, and they will not survive in a pond that dries up during the summer.
Tadpoles are mainly herbivorous, but adults are carnivorous, and because of their large size and indiscriminate appetite, bullfrogs can eat an impressive variety of other species, including fish, amphibians, snakes, insects, and have even been known to eat bats and baby ducks. As a result, an invasion will alter aquatic systems, and bullfrogs have been associated with declines of many Pacific Northwest amphibian populations.
Status in the Pacific Northwest: Bullfrog tadpoles require some water, so bullfrogs are found in most lowland areas west of the Cascades in WA and OR, as well as other areas across the region where moist habitats exist. In colder areas, they hibernate in mud and pond debris during the winter.
What can you do? Do not buy this species (or any other live organisms) over the internet, and do not purchase or encourage bullfrog use in home water gardens or ponds. Destroy any observed egg masses; they are easy to spot because of their large size. Once established, eradication is difficult, so restoration projects should also be designed to minimize or preclude bullfrog usage where practical.
Bullfrogs are so widespread, that reporting is not requested, but for more information, contact:
In Washington: 1-360-902-2700 (ANS Coordinator)
In Oregon: 1-866 INVADER (hotline)
In Idaho: 1-208-332-8686 (ANS Coordinator)
In Alaska: 1-877 INVASIVE (hotline)
The links provided may be outside the EPA.gov domain.