INVASIVE PLANTS & INSECTS

Bullfrogs

WHAT ARE BULLFROGS AND WHERE DID THEY COME FROM?

Bullfrogs are a non-native frog species that have been introduced to BC where they displace native frogs. They are established in BC and their range is spreading across the Lower Mainland and on Vancouver Island.

They are originally from the eastern part of North America and were introduced to BC by frog farmers that harvest them for frog legs. Since their introduction in the early twentieth century, they have spread both on their own and with help from humans. Bullfrogs are most active in the summer during the breeding season (June and July).

WHY BULLFROGS ARE A PROBLEM
  • Bullfrogs displace native frogs like the Red-legged Frog and Pacific Chorus Frog
  • they eat anything that will fit into their mouths including insects, birds, small mammals and including smaller frogs (even smaller Bullfrogs)
  • the last 2 years of hot summers has lead to more abundant, active and noticeable populations across the Lower Mainland
  • their breeding success is high–each female can lay between 10,000–20,000 eggs
  • once established in a wetland of notable size, they are extremely difficult to eradicate
HOW TO IDENTIFY BULLFROGS
  • very large, robust frog, up to 20 cm long (not including their legs)
  • green or brown with a grey belly and large golden eyes
  • males have bright yellow throats during mating season while females have paler cream or white throats
  • very large ear drums
  • nocturnal
  • active season (mid-April–mid-October)
  • breeding calls are loud and intense
  • they rarely leave the water and are often seen floating underneath the surface of the water with only their eyes visible
  • Bullfrog tadpoles are up to 15 cm long and very dark green (almost black). They spend up to two years in the tadpole stage (most other frog species only spend a few months as tadpoles)
WHAT YOU CAN DO ABOUT BULLFROGS
  • if you find new Bullfrog colonies report them to the Provincial Wildlife database
  • do not transport Bullfrogs from one pond to another
  • do not catch tadpoles to keep for pets. Bullfrogs are considered wildlife in BC, and it is illegal under the Wildlife Act to capture, transport, keep or sell them
  • find out more about Bullfrogs and the BC Frogwatch Program

Contact

Tiffany Bentley
Parks Planning Assistant

604-921-2913

Email

×