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Amphibians of Washington


American bullfrog
(Lithobates catesbeianus)

 

What they look like

  • Largest frog in North America; 17-25cm with legs
  • Light to dark green or brown with or without spots
  • Eyes are golden in color and larger than their tympanums (eardrums)
  • Have a fold of skin on each side from their eye down along their sides
  • Legs have thick black stripes on their legs and have very large webbed feet

Where they live

  • They are an introduced species in Washington State, originally found only to the east of the Rocky Mountains
  • Currently found in many low elevation areas in Washington
  • Live in lakes, ponds and wetlands, generally in the water or on the shoreline

Breeding

  • Breeding season is spring and summer
  • Females can lay up to 25,000 eggs in one mass
  • Eggs can hatch within 5 days but takes the tadpoles two years to complete metamorphosis

Cool Biology Facts

  • Can jump 3-6 feet! (1-2 meters)
  • Have been introduced worldwide and have caused problems in many areas due to competition with local species.
  • Males are territorial and will get in physical fights to defend their territory.
  • Many restaurants in the US have bullfrogs on the menu and there are actual bullfrog farms to supply them!
  • Have no natural enemies due to the toxicity of secretions from their paratoid glands.
  • Are often carriers of the chytrid fungus that has been one of the major reasons for many frog species declines; however they are generally resistant to the devastating effects of the fungus.

Photo

Distribution Map

Threats

Their population is increasing and in many areas efforts are being made to eradicate them.