Reithrodontomys (Reithrodontomys) megalotis (Baird 1857)

[Reithrodon] megalotis Baird 1857, Mammalia, in: Repts. U. S. Expl. Surv., Vol. 8, 1: 451.

Type Locality: México-USA boundary region, between Janos, Chihuahua, and San Luis Springs, Grant Co., New Mexico.

Vernacular Names: Western Harvest Mouse.

Synonyms: Reithrodontomys (Reithrodontomys) alticolus Merriam 1901; Reithrodontomys (Reithrodontomys) amoles A. H. Howell 1914; Reithrodontomys (Reithrodontomys) arizonensis J. A. Allen 1895; Reithrodontomys (Reithrodontomys) aztecus J. A. Allen 1893; Reithrodontomys (Reithrodontomys) caryi A. H. Howell 1935; Reithrodontomys (Reithrodontomys) catalinae (Elliot 1904); Reithrodontomys (Reithrodontomys) cinereus Merriam 1901; Reithrodontomys (Reithrodontomys) deserti J. A. Allen 1895; Reithrodontomys (Reithrodontomys) distichlis von Bloeker 1937; Reithrodontomys (Reithrodontomys) dychei J. A. Allen 1895; Reithrodontomys (Reithrodontomys) hooperi Goodwin 1954; Reithrodontomys (Reithrodontomys) klamathensis Merriam 1899; Reithrodontomys (Reithrodontomys) limicola von Bloeker 1932; Reithrodontomys (Reithrodontomys) longicaudus (Baird 1857); Reithrodontomys (Reithrodontomys) nebrascensis J. A. Allen 1895; Reithrodontomys (Reithrodontomys) nigrescens A. H. Howell 1914; Reithrodontomys (Reithrodontomys) pallidus Rhoads 1893; Reithrodontomys (Reithrodontomys) pectoralis Hanson 1944; Reithrodontomys (Reithrodontomys) peninsulae (Elliot 1903); Reithrodontomys (Reithrodontomys) ravus Goldman 1939; Reithrodontomys (Reithrodontomys) santacruzae Pearson 1951; Reithrodontomys (Reithrodontomys) saturatus J. A. Allen and Chapman 1897; Reithrodontomys (Reithrodontomys) sestinensis J. A. Allen 1903 .

Distribution: SC British Columbia and SE Alberta, Canada; through much of W and NC USA; south to N Baja California Norte and through interior México to C Oaxaca.

Conservation: IUCN – Lower Risk (lc).

Discussion: Subgenus Reithrodontomys, megalotis species group. Formerly included R. zacatecae, which Hood et al. (1984) identified as a separate species. The substantial chromosomal variation reported (see Engstrom et al., 1981) cautions that yet other species are lumped under R. megalotis . Multivariate discrimination from R. montanus in Kansas demonstrated by Hoofer et al. (1999). Recent range expansions into NE Illinois (see Pigage and Pigage, 1994) and within N Texas (Yancey and Jones, 1997) reported; L. Choate (1997) discussed the clinal intergradation between the subspecies aztecus and megalotis on the Llano Estacado, Texas-New Mexico; southern range extension on Baja Peninsula reported by Rios and Alvarez-Castañeda (2002). See Webster and Jones (1982, Mammalian Species, 167).