Microtus californicus Peale 1848

Microtus californicus Peale 1848, Mammalia, in: Repts. U. S. Expl. Surv., Vol. 8: 46.

Type Locality: USA, California, Santa Clara Co., vicinity of San Francisco Bay, San Francisquito Creek near Palo Alto (as fixed by Kellogg, 1918:5).

Vernacular Names: California Vole.

Synonyms: Microtus aequivocatus Osgood 1928; Microtus aestuarinus Kellogg 1918; Microtus constrictus Bailey 1900; Microtus edax (Le Conte 1853); Microtus eximius Kellogg 1918; Microtus grinnelli Huey 1931; Microtus halophilus Von Bloeker 1937; Microtus hyperuthrus Elliot 1903; Microtus kernensis Kellogg 1918; Microtus mariposae Kellogg 1918; Microtus mohavensis Kellogg 1918; Microtus neglectus Kellogg 1918; Microtus paludicola Hatfield 1935; Microtus perplexabilis Grinnell 1926; Microtus sanctidiegi Kellogg 1918; Microtus sanpabloensis Thaeler 1961; Microtus scirpensis Bailey 1900; Microtus stephensi Von Bloeker 1932; Microtus trowbridgii (Baird 1857); Microtus vallicola Bailey 1898 .

Distribution: Oak woodlands and grasslands of Pacific coast, from SW Oregon through California, USA, to N Baja California Norte, México.

Conservation: U.S. ESA – Endangered; IUCN – Vulnerable as M. c. mohavensis and M. c. scirpensis, Data Deficient as M. c. stephensi, Lower Risk (nt) as M. c. vallicola, otherwise Lower Risk (lc).

Discussion: Broadly affiliated with other North American Microtus, but evidence for nearest specific relative contradictory (compare assessments of Anderson, 1959; Conroy and Cook, 2000 a; Hooper and Hart, 1962; Moore and Janecek, 1990). Zagorodnyuk (1990) acknowledged enigmatic phyletic stature as sole member of californicus species group, subgenus Mynomes . Geographic races delineated by Kellogg (1918); Gill (1980) recorded instances of sterility in hybrids between M. c. californicus and M. c. stephensi .