Observations of Feral Populations of Xenopus laevis (Pipidae) in Southern California
Xenopus laevis, a clawed frog native to Africa, is known to colonize areas outside its natural range. Extralimital populations have been reported in the United Kingdom, Ascension Island, and the United States (Wyoming, Wisconsin, Arizona, New Mexico, Utah, California, Florida, Nevada, and Colorado).
McCoid, Michael J. and Fritts, Thomas H.
"Observations of Feral Populations of Xenopus laevis (Pipidae) in Southern California,"
Bulletin of the Southern California Academy of Sciences:
Available at: http://scholar.oxy.edu/scas/vol79/iss2/6