American Bullfrog
Search the Collections

Online Guide to the Amphibians and Reptiles of Connecticut

American Bullfrog - Rana catesbeiana


A large, bulky frog measuring up to 8 inches (20 cm) snout to vent. Its color is primarily green to dark green, generally with a white belly. The feet are large and strongly webbed. Males have larger tympanic membranes than females.



Breeding occurs from late spring to early summer. Egg masses containing many eggs are laid floating on the surface of the water. Metamorphosis takes as long as 3 years (see Klemens 1993). The larvae are large and green with little or no dark mottling on the tail.



A deep, often booming, call in middle to late summer. Commonly described as “chug-a-rum.” | Listen



Fresh water ponds, streams and rivers.



A carnivore with a wide range of suitable prey. It will eat virtually anything small enough to catch, including insects, smaller frogs, small mammals, and even small snakes.



Native to the eastern United States, now introduced nearly worldwide. It is found throughout Connecticut.






The largest frog in Connecticut. Smaller specimens are easily confused with Green Frogs. One distinguishing characteristic is the dorsolateral ridge, which is complete in Green Frogs and absent in bullfrogs.



Conant, R. and J.T. Collins. 1991. A Field Guide to Reptiles and Amphibians: Eastern/Central North America. Boston: Houghton Mifflin. 450 pp.

Klemens, M.W. 1993. Amphibians and Reptiles of Connecticut and Adjacent Regions. Hartford, CT: State Geological and Natural History Survey of Connecticut Bulletin 112. 318 pp.



Text by Gregory J. Watkins-Colwell.
Photographs © Twan Leenders. All rights reserved. Used by permission. Animals featured in photographs on this page are from Connecticut.

Audio files from The Calls of Frogs and Toads [book and CD-ROM]
Published March 2004 by Stackpole Books; 1.800.732.3669.
© 1994 Lang Elliott/NatureSound Studio
All rights reserved. Used by permission.