Ensatina eschscholtzii

The taxonomy of this complex is controversial. Some authors would recognize from two (e.g., Frost and Hillis 1990) to as many as 11 or more species (e.g., Highton 1998), whereas others (e.g., Wake 1997, Wake and Schneider 1998, Pereira and Wake 2009, Kuchta and Wake 2016) consider evidence for evolutionary independence of segments of the complex to be inadequate or equivocal. Narrow hybrid zones have been demonstrated to exist between populations assigned to the subspecies xanthoptica and platensis, and between klauberi and eschscholtzii, and one site of sympatry with no hybridization between the latter pair has been reported (Wake et al. 1989, in D. Otte and J. A. Endler [eds.]). Broader zones of genetic admixture and reticulation between units of the complex in many areas raise questions about evolutionary independence, and borders of taxa are elusive (Crother 2017).

Large range along the coastal ranges and Sierra Nevada from southern British Columbia to northern Baja California; many stable populations; no major pervasive threats.

Southwestern British Columbia south along Coast Ranges to extreme northwestern Baja California and the Sierra San Pedro Martir, Baja California (Mahrdt et al. 1998); and along western slopes of Cascade Range and Sierra Nevada. Recently recorded east of the Cascade crest in Washington (Darda et al. 2001). Absent from Sacramento-San Joaquin valley, California. Occurs from sea level to elevations of about 8,000 ft (Stebbins 1985). See Moritz et al. (1992) for a general but up-to-date distribution map.

Represented by many and/or large occurrences throughout the range.

Habitat destruction and degradation likely are affecting a low percentage of existing populations. The nominate subspecies is probably heavily impacted by the loss of habitat as a result of the development and expansion of vineyards.