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  • UC Riverside
  • College of Natural and Agricultural Sciences

John J. Crayon (Jack)

M.S., Ecology and Evolutionary Biology
B.S., Wildlife and Fisheries Biology, U.C. Davis, 1997
Advisors: John Lovich and John Rotenberry

I am interested in the issues surrounding the intersection of three fields: conservation biology, herpetology, and invasion biology. Introduced species such as the bullfrog (Rana catesbeiana) and African clawed frog (Xenopus laevis) offer exceptional opportunities for elucidating issues in life history theory, especially given the plasticity of their reproductive responses in the novel habitats of invaded areas. Their impacts on California's herpetofauna, and the mitigation of such impacts, although less tightly tied to theoretical questions, are equally compelling issues to me.

For my thesis, I am completing a study of habitat use by western toads (Bufo boreas) in Death Valley National Park.


Crayon, J. 2002. Xenopus laevis. In Lannoo, M.J. (Ed.), Status and Conservation of U.S. Amphibians. Volume 2: Species Acounts. University of California Press, Berkeley, CA.

"The Impacts of African Clawed Frog (Xenopus laevis) Introductions in California". January 27, 2000. Oral presentation at the Annual Meeting of the Western Section of the Wildlife Society, Riverside, CA.

Crayon, J.J. 1999. Habitat use by western toads (Bufo boreas) in the Darwin Falls Wash. Unpublished report to the Resource Management Division, Death Valley National Park, National Park Service.

Crayon, J.J. 1998. Rana catesbeiana. Diet. Herpetological Review 29(4):232.

Crayon, J.J., and R.L. Hothem. 1998. Xenopus laevis. Predation. Herpetological Review 29(3):165-166.

Crayon, J.J., 1996. The African Clawed Frog (Xenopus laevis) on Edwards AFB: implications for wildlife. Unpublished Report to the Environmental Management Directorate, Edwards Air Force Base, California.