An addition to the amphibian fauna of California

Abstract

A population of salamanders of the genus Ambystoma [A. tigrinum spp.] was found at Grass Lake, Siskiyou County, in northern California [USA]. A 5 yr study has established that the salamanders are reproducing successfully and may represent a relictual population of native amphibians. The Grass Lake area has a sparse human population, which may help to explain how this secretive amphibian could have escaped notice. Attempts to determine the taxonomic position of the Grass Lake Salamander, through comparisons of body measurements and coloration with those of other western ambystomatids, were inconclusive. These comparisons suggest a close relationship with the geographically most proximate subspecies, A. tigrinum californiense Gray and A. t. melanostictum Baird. Grass Lake is near the midpoint of a gap area of approximately 800 km that separates these subspecies. Regardless of the origin of the population, it must now be listed as an established addition to the amphibian fauna of California.