Gambelia wislizenii

This species formerly was included in the genus Crotaphytus. Gambelia copeii and G. sila formerly were included in this species (see McGuire 1996). McGuire (1996) pointed out that nominal subspecies exhibit broad zones of intergradation and that dorsal pattern classes of the nominal subspecies occur sporatically throughout the range of the species; hence subspecies punctata (or punctatus) and maculosa (or maculosus) were synonymized under G. wislizenii, the species thus being monotypic.

Orange et al. (1999) examined mtDNA data for range-wide samples and identified two major clades: western (Mojave, Great Basin, and Colorado Plateau deserts) and eastern (Chihuahuan Desert). A third, more divergent lineage with unknown geographic distribution was represented by a single haplotype from southwestern Arizona. The phylogeographic breaks were consistent with a model of late Pliocene/early Pleistocene vicariance.

MtDNA data suggest that G. copeii may not warrant recognition as a distinct species (McGuire et al. 2007). Further information is needed on gene flow (or lack thereof) between G. copeii and G. wislizenii.

The geographic range extends from Oregon, southern Idaho, Utah and western Colorado south through eastern and southern California, Nevada, Arizona, New Mexico, and western Texas to northeastern Baja California and north-central mainland Mexico (including Isla Tiburon, Sonora, in the Gulf of California) (McGuire 1996, Grismer 2002, Stebbins 2003).

This lizard is represented by a very large number of occurrences that are well distributed throughout the historical range (McGuire 1996).

Major threats include habitat loss and degradation resulting from agricultural, commercial, and residential development and invasion of exotic herbaceous plants (e.g., cheatgrass) (Hammerson 1999).