American Bullfrog
American Bullfrog

American Bullfrog

Lithobates catesbeianus


  • Native to eastern North America
  • Can occur in lakes, ponds, wetlands, streams, irrigation ponds and ditches
  • A large robust frog reaching up to 20 cm in length and up to 800 g in weight
  • Wide flat head and smooth skin with no wrinkles, warts or spikes
  • Bullfrogs colour varies from pale green to dark olive and can have brown spots
  • Males have bright yellow throats whereas females are pale cream to white throats
  • They have large golden eyes
  • Mature males have eardrums (circular spot behind eye) twice the diameter of the eye, mature females have eardrums about the same diameter as the eye
  • Tadpoles are greenish yellow with small spots, growing up to 15 cm
  • Makes a distinct call, it’s bellow is a loud low pitch two – part drone. Want to hear the call? Click the video below.

Consequences of invasion

  • Voracious predator that eats anything that fits into its mouth, including endangered native amphibians and fish (including their eggs and larvae)
  • Can spread the chytrid fungus, which is responsible for declining amphibian populations
  • Readily outcompetes native frog populations. There is scientific evidence that when bullfrog colonies grow in wetlands it is followed by a rapid decline of native frogs
  • Tadpoles act as “ecosystem engineers”, meaning they are extremely competitive and take food and habitat away from native frogs

Integrated pest management

Don't Let it Loose

  • Do NOT purchase bullfrogs as pets
  • Never release bullfrogs into the wild
  • Do NOT transport wild bullfrogs or tadpoles from place to place, it is illegal under the Wildlife act to capture, transport, keep or sell wild animals including bullfrogs.
  • Large tadpoles can be a tempting pet or a popular addition to your backyard pond, but this has been identified as a primary way bullfrogs have been spreading through the province
  • “Build it and they will come!” If you want native frogs in your backyard pond the best thing to do is create a welcoming environment for the frogs: water, shelter and insects

Additional resources