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American Bullfrog in Onion Bottom at Merry Lea. Image by Jason Vates.

American Bullfrog
Rana catesbiana

Order: Anura
Family: Ranidae
Genus: Rana
Species: R. catesbeiana

Identifications
  • Largest frog in North America (3.5 - 6 inches in length)
  • Large tympanums (larger than the eyes in males, the same size in females)
  • Rough skin with tiny tubercles
  • Has a parietal eye (a third, but less pronounced, eye). Look for a small greyish lens between the two pronounced eyes.

Adaptations
  • Prefers still and shallow bodies of water with prolific vegetation. As humans have contributed to mass eutrophication, this vegetation has increased, and therefore bullfrogs have multiplied in areas with human settlement.
  • Carnivorous and cannibalistic, the bullfrog eats nearly any animal smaller than it. In the tadpole stage, the bullfrog eats vegetation. The cannibalistic tendencies seem counter-productive for a species, but the species has continued to survive and thrive.
  • Females lay approximately 20,000 eggs per reproductive season. Chances of survival are enhanced by the sheer number of frogs being produced from year to year.
  • During Winter, these frogs hibernate underneath mud and leaves. This allows the frog to essentially sleep through

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