What are they?Bullfrogs are the largest frog species in North America. They are found in a variety of freshwater habitats, including ponds, marshes, streams, rivers, canals, reservoirs, ditches, shallow wetlands, and storm water ponds. Bullfrogs compete with, and prey on, a wide range of native species, and can affect significantly native ecosystems such as wetlands.
Are they here yet?Yes. Bullfrogs are found throughout the lowlands of Washington.
Why should I care?
Bullfrogs are predators that eat practically anything they can catch. They can swallow tree frogs, other amphibians and reptiles such as the western pond turtle, minnows, small birds, and young snakes. Introduced bullfrogs have been blamed for native species declines in much of North America.
What should I do if I find one?
How can we stop them?
Prevent the spread of bullfrogs by not purchasing or sharing bullfrogs at any life stage (from eggs to adults). Do not release unwanted pet frogs to the wild. Bullfrogs are classified as a Prohibited Aquatic Animal Species in Washington, meaning they may not be possessed, purchased, sold, propagated, transported, or released into state waters (Revised Code of Washington 77.12.020, Washington Administrative Code 220-12-090). For more information on management methods, see http://wdfw.wa.gov/living/frogs.html#managing. In Washington, bullfrogs only may be caught or killed by angling, hand dip netting, spearing (gigging), or with bow and arrow (Washington Administrative Code 232-12-619).
What are their characteristics?
- Egg masses are black on top and white underneath. They start as a round,
basketball-size mass that flattens over time.
- Tadpoles are dark green with black dots, orange or bronze eyes, and opaque yellow underbellies, and are up to 6 inches long.
- Juveniles are green to brown with small black spots, orange or bronze eyes, and a fold of skin from the eye around the eardrum.
- Adults are 7-8 inches, with large, exposed eardrums the size of their eyes, and are green, tan, or dark brown with dark spots and gold eyes.
How do I distinguish them from native species?
Native green and bronze frogs have two parallel lines of raised glandular skin between the back and sides; the bullfrog does not have these features.
Where can I get more information?
- Washington Department of Fish and Wildlife: Bullfrogs
- U.S. Department of Agriculture, Animal and Plant Health Inspection Service
- U.S. Department of Agriculture, National Agricultural Library