Microtus pennsylvanicus (Ord, 1815)

James H. Honacki, Kenneth E. Kinman & James W. Koeppl, 1982, Order Rodentia (Part 4), Mammal Species of the World (1 st Edition), Lawrence, Kansas, USA: Alien Press, Inc. & The Association of Systematics Collections, pp. 477-504 : 496

Microtus pennsylvanicus (Ord, 1815) . In Guthrie, A new geogr., hist., comml., grammar... Philadelphia, 2nd Amer, ed., 2:292.

REVIEWED BY: R. E. Barry, Jr. (REB); J. Ramirez-Pulido (JRP).

TYPE LOCALITY: U.S.A., Pennsylvania, "meadows below Philadelphia."

DISTRIBUTION: North America from Newfoundland to W. Alaska, north into tundra zone, south to Georgia, N. Great Plains, S. Rocky Mtns. ( U.S.A.), isolated population in N. Chihuahua ( Mexico).

COMMENT: Subgenus Microtus ; see Anderson, 1960. Includes chihuahuensis; see Bradley and Cockrum, 1968, Am. Mus. Novit., 2325:3-7. Klimkiewicz, 1970, Mammalia, 34:640-665, suggested that pennsylvanicus is conspecific with agrestis . This species requires review over its entire range and comparison with related Old and New World species (SRL). Closely related insular forms, such as breweri , provectus (here included in pennsylvanicus ), nesophilus and others may best be considered subspecies; see Chamberlain, 1954, J. Mammal., 35: 587, Fivush et al., 1975, J. Mammal., 56:272, and Wheeler, 1956, Evolution, 10: 176- 186. Hall, 1981, considered breweri and nesophilus distinct species and provectus a subspecies of pennsylvanicus , whereas Anderson, 1959:496, afforded all full specific status, without elaborating; see comments under breweri and nesophilus . Reviewed by Reich, 1981, Mamm. Species, 159:1-8. See Anderson and Hubbard, 1971, Am. Mus. Novit., 2460:1-8, for discussion of distribution.

ISIS NUMBER: 5301410008080035001.