Correction of Locality Records for the Endangered Arroyo Toad (Anaxyrus californicus) from the Desert Region of Southern California

Abstract/Summary

The development of an effective recovery plan for an endangered species requires knowledge of that species distribution and spatial arrangements within preferred habitat. Although the best available information of a species distribution is used to develop a plan, it is often lacking in regard to its actual geographical extent. The arroyo toad (Anaxyrus californicus) occurs in coastal drainages from Monterey County, California, south into northwestern Baja California, Mexico. Through field reconnaissance and the study of museum specimens, we determined that the four reported populations of the arroyo toad in the Sonoran Desert region of Riverside, San Diego, and Imperial counties, California are in error. Two additional sites in the Sonoran Desert are discussed regarding the possibility that the species occurs there. We recommend the continued study of arroyo toad populations in order to establish a better understanding of their distribution and the boundaries of their geographical range.