Geographic Distribution and Taxonomy of the Chipmunks of Wyoming

by John A. White

Tamias quadrivittatus b. var. pallidus J. A. Allen, Proc. Boston Soc. Nat. Hist. 16:289, 1874.

Eutamias minimus pallidus, Howell, Jour. Mamm. 3:183, August 4, 1922.

Lectotype.—Skull and skin, No. 11656/38311 (NM); from Camp Thorne, near Glendive, Dawson County, Montana; obtained on July 18, 1873, by J. A. Allen; original No. 200.

Diagnosis.—Size large; over-all tone of upper parts pale grayish brown; baculum large.

Description.—Color pattern: Crown Pale Smoke Gray mixed with Clay Color; facial stripes Fuscous Black mixed with Clay Color; anterior margin of ear and hairs inside posterior part of pinna Pale Pinkish Buff; posterior margin of ear and postauricular patch grayish white; median dorsal dark stripe black with Clay Color along margins; other dorsal dark stripes Fuscous mixed with Clay Color; median pair of dorsal light stripes Pale Smoke Gray; lateral pair of dorsal light stripes creamy white; sides Cinnamon-Buff; rump and thighs Smoke Gray mixed with Pale Buff; dorsal surface of tail Fuscous Black slightly mixed with Warm Buff; ventral surface of tail Pinkish Cinnamon or Pinkish Buff, with Fuscous Black along margin and Warm Buff along outermost edge; antipalmar and antiplantar surfaces of feet Pinkish Buff, Warm Buff or Pale Yellow-Orange; underparts white with dark underfur. Skull and Baculum: Large but of same proportions as in other subspecies of E. minimus.

Comparisons.—From E. m. silvaticus, the subspecies from the Black Hills, E. m. pallidus differs in: Paler; underside of tail paler; sides paler.

From E. m. confinis, the subspecies from the Big Horn Mountains, E. m. pallidus differs in: Over-all tone of upper parts paler; sides paler; underside of tail paler.

From E. m. operarius, the subspecies from the mountains in south-central Wyoming, E. m. pallidus differs in: Over-all tone of upper parts paler; sides paler; underside of tail paler.

For comparisons with E. m. minimus and E. m. consobrinus, see the accounts of those subspecies.

Remarks.—Specimens from near Buffalo, Johnson Co., are intergrades between E. m. pallidus and E. m. confinis and are referable to E. m. confinis. Specimens from near Sundance (not in Bear Lodge Mountains), Crook Co., are intergrades between E. m. pallidus and E. m. silvaticus (Howell 1929:55). Specimens from the Laramie Range in Converse Co. are intergrades between E. m. pallidus and E. m. operarius, and referable to E. m. operarius. Specimens from near Greybull, Big Horn Co., are intergrades between E. m. pallidus and E. m. minimus and are referable to E. m. pallidus. These specimens show no intergradation with E. m. confinis which occurs but a short distance to the east in the Big Horn Mountains. Intergradation between E. m. pallidus and E. m. minimus probably exists in northeastern Natrona Co. and southwestern Johnson Co.