American Bullfrog

Rana catesbeiana

Bullfrog by Alison Sheehey © 2000

Bullfrog by Alison Sheehey © 2000

Native distribution - Eastern & central United States. This nocturnal frog is the largest in North American and has been introduced as a human food source worldwide. The bullfrog was first introduced to California in 1895 for its meaty legs and to augment the declining native red-legged frog, whose populations were already suffered from overharvesting. Today, this invasive species can be found in nearly every pond, lake, and slow-moving stream below 2500 m in California. The bullfrog is responsible for the disappearance of many native species of frog and fish throughout the world. Bullfrog prey includes earthworms, insects, small snakes, turtles, birds, and mammals. In California spadefoot toads, red-legged and yellow-legged frogs, young western pond turtles as well as native fish and even waterfowl chicks fall prey to this carnivorous frog. Eradication efforts are being attempted in Europe and elsewhere although pressures from hunting groups continue to make this a commercial species.

Tadpoles: 10.2 - 17.1 cm. Color olive-green, larval stage for up to two years.

Adults: 9 - 20 cm long and up to 0.5 kg. Yellowish-green above with dark green splotches. Belly cream to yellow sometimes with gray mottling. Large external eardrum. Rear feet webbed. Juvenile splotches smaller. In breeding season male's throat is yellow, female's is white.

Deep jug 'o rum call. Does not say bud why zer ;-) Juveniles scream a deep peep when startled.

Breeding: In California from May to late August in still or slow-moving water with aquatic vegetation.

Mostly aquatic but will venture our on warm nights in search of insects. Find them under street lights near water.

Kern Introduced Species: plant list with a short introduction to exotic species    Kern Naturalized Animal Checklist    

Bullfrog    Virginia Opossum    Fox Squirrel    ROCK PIGEON    Spotted Dove    Ringed Turtle Dove    Eurasian Collared Dove    Rose-ringed Parakeet    European Starling    House Sparrow    Hodgepodge of introduced Species

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page updated 17-Jan-2008