Frogs and Toads

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Bullfrog

Lithobates catesbeiana
  • Ontario's largest frog at 10-15cm.
  • Green, olive or brown
  • Dorsolateral fold not present
  • Fold of skin extends from eye around the eardrum to shoulder.
  • Male has bright yellow throat and eardrum (tympanum) twice the size of the eye.
  •  Young bullfrogs have small black spots on their green backs.
  • Bullfrogs prefer the shorelines of lakes, bays, large beaver ponds, and the mouths of slow-moving rivers. Deep, permanent waterbodies are necessary because the tadpole spends the winter in the water.
  • Although active in May, male bullfrogs do not establish their shoreline territories until June or July.
  • Their deep, booming calls may be descibed by the phrase "Jug O'Rum", "Jug O'Rum", "Jug O'Rum"... At dusk they will call from a favourite location, or more often while floating at the surface of the water.
  • Males are very territorial and will defend their breeding territory with a special encounter call. If this call fails to drive away an intruder, the male will jump at the invading male, push, lock arms, kick, and try to flip him over.
  • Eggs are laid in large floating masses.
  • Tadpoles spend the winter in the water, and transform the following summer.
  • Several researchers are investigating the decline in bullfrog populations over the past fifteen years. In the past, bullfrogs have been harvested for sale of their legs to restaurants, but the causes of their widespread decline are not fully understood.
Bullfrog

Description of call: "more rummm, more rummmm"

Use this link to download the sound file if your browser does not support embedded files.

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