Geographic Distribution and Taxonomy of the Chipmunks of Wyoming

by John A. White

From E. umbrinus fremonti, the only subspecies of this species which occurs in the same area with E. amoenus in Wyoming, E. a. luteiventris differs in: Smaller size; tawny underparts; base of baculum not noticeably widened.

For comparisons with E. minimus see the account of that species.

[ Eutamias amoenus luteiventris (J. A. Allen) ]

Tamias quadrivittatus luteiventris J. A. Allen, Bull. Amer. Mus. Nat. Hist., 3:101, June, 1890.

Eutamias amoenus luteiventris, Howell, Jour. Mamm., 3:183, August 4, 1922.

Type.—Male, adult, skull and skin, No. 11991/37996 (NM); from "Chief Mountain Lake" [Waterton Lake], 3½ mi. N United States-Canadian Boundary, Alberta; obtained on August 24, 1874, by Elliot Coues; original No. 4596.

Diagnosis.—General tone of upper parts ochraceous; underparts strongly buffy; tip of baculum in adult specimens, more than 30 per cent and less than 38 per cent of length of shaft.

Description.—Color pattern: Crown Cinnamon mixed with Smoke Gray; upper two facial stripes black; submalar stripe Fuscous or Fuscous Black mixed with Ochraceous-Tawny; anterior margin of ear Ochraceous-Tawny; posterior margin of ear and postauricular patch Light Buff or buffy white; hairs inside posterior part of pinna Ochraceous-Tawny; median dorsal dark stripe black; lateral pair of dorsal dark stripes black and mixed with Tawny, frequently brownish; median pair of dorsal light stripes white tinged with Pale Smoke Gray; lateral pair of dorsal light stripes creamy white; sides Tawny or Ochraceous-Tawny; rump and thighs Dark Smoke Gray strongly mixed with Cinnamon-Buff; dorsal surface of tail Fuscous Black mixed with Clay Color; ventral surface of tail Light Ochraceous-Tawny, with Fuscous Black around margin and Clay Color around outermost edge; antipalmar and antiplantar surfaces of feet Cinnamon or Cinnamon-Buff; underparts Cinnamon-Buff or Light Ochraceous-Buff. Skull: Size medium; moderately narrowed across zygomata. Baculum: Slender; not noticeably broadened at base; tip more than 30 per cent of length of shaft.

Remarks.—Although there are no records of this subspecies from the Wind River Mountains, it probably occurs there.

The niche that this subspecies occupies is similar to that of E. m. consobrinus as shown by the fact that these two subspecies have been taken together at the same places.