Bureau of Reclamation Lower Colorado Region Banner
Reclamation Home              Regional Offices              Newsroom              Library              Projects & Facilities
Phoenix Area Office

Native Aquatic Species of the Gila River Basin
in Arizona and New Mexico

Nonnative Aquatic Species Profiles


Bullfrog.  Credit: Gina Mikel.  Found: http://www.scientificillustrator.com/illustration/amphibians/bullfrog_watercolor.html
American Bullfrog (Rana catesbeiana)

The bullfrog is one of the largest, most geographically widespread, and highly aquatic species of frog (up to 8 inches snout-vent length) in North America, but it is not native west of the Rocky Mountains. The bullfrog is olive-green to brown in color with faint bands on the hind legs. The tympanum is large, the chin is usually mottled, and it lacks a dorsolateral fold that is characteristic of leopard frogs.

In Arizona, bullfrogs are found in deep and calm waters of rivers, lakes, streams, ditches, and stock tanks at low- to high-elevations in Lower Colorado River Desertscrub through Petran Montane Conifer Forest biotic communities. They are capable of traveling several miles overland (Brennan and Holycross 2006), a habit that thwarts eradication efforts at locations where they impact native leopard frogs (FWS 2005), salamanders (FWS 2002), garter snakes (Rosen and Schwalbe 1995), and fishes (Mueller et al. 2006) via predation. Bullfrogs will eat anything that moves and can fit into their mouths, and organisms such as crayfish, insects, clams, fish, turtles, and small mammals have been found in their stomachs (Clarkson and deVos 1986).

Work Cited:

Brennan, T.C., and A.T. Holycross. 2006. A field guide to amphibians and reptiles in Arizona. Arizona Game and Fish Department, Phoenix.

Clarkson, R.W., and J.C. deVos, Jr. 1986. The bullfrog, Rana catesbeiana Shaw, in the lower Colorado River, Arizona-California. Journal of Herpetology 20:42-49.

U.S. Fish and Wildlife Service (FWS). 2002. Sonora tiger salamander recovery plan. U.S. Fish and Wildlife Service, Phoenix, Arizona.

U.S. Fish and Wildlife Service (FWS). 2005. Draft Chiricahua leopard frog (Rana chiricahuensis) recovery plan. U.S. Fish and Wildlife Service, Albuquerque, New Mexico.

Rosen, P.C., and C.R. Schwalbe. 1995. Bullfrogs: introduced predators in southwestern wetlands. Pages 452-454 in E.T. LaRoe, G.S. Farris, C.E. Puckett, P.D. Doran, and M.J. Mac, editors. Our living resources: a report to the nation on the distribution, abundance, and health of U.S. plants, animals, and ecosystems. U.S. Department of Interior, National Biological Service, Washington, DC.


Last Reviewed:
June 25, 2009

Webmaster:
Joseph J. Billerbeck - jbillerbeck@usbr.gov