Taxonomy of the Chipmunks, Eutamias quadrivittatus and Eutamias umbrinus

by John A. White

Colorado: Moffat Co.: 11 mi. W and 11 mi. N Rangely, 6,000 ft., 3. Rio Blanco Co.: White River, 5 BS. Eagle Co.: McCoy, 2 BS. Mesa Co.: 1½ mi. S Loma, 4,600 ft., 1. Gunnison Co.: 1 mi. E Somerset, 6,100 ft., 1. Montrose Co.: 1 mi. E Naturita, 5,900 ft., 1. Dolores Co.: 1 mi. N Cahone, 6,900 ft., 1. Montezuma Co.: 1 mi. S Cortez, 5,000 ft., 1; Mesa Verde, 25 mi. SW Mancos, 7,000 ft., 2 BS.

Arizona: Navajo Co.: Keams Canyon, 80 mi. N Holbrook, 15 BS. Apache Co.: Summit, 8,000 ft., Luka Chukai Mountains, 15 mi. E Luka Chukai Navajo School, 8 BS; Wheatfield Creek, W slope Tunicha Mountains, 7,000 ft., 3 BS.

Eutamias umbrinus (J. A. Allen)

Diagnosis.—Size medium; pelage dark; sides dark; narrow cranial breadth; baculum distinguishable from that of any other species (E. palmeri excepted) by the combination of width of base more than ⅓ of length of shaft, distal ½ of shaft laterally compressed, and keel ¼ of length of tip.

Eutamias umbrinus umbrinus (J. A. Allen)

Tamias umbrinus J. A. Allen, Bull. Amer. Mus. Nat. Hist. 3:96, June, 1890.

Eutamias umbrinus, Miller and Rehn, Proc. Boston Soc. Nat. Hist. 30:45, December 27, 1901.

Type.—Male, adult, skull and skin, No. 186463 U. S. Nat. Mus., Biol. Surv. Coll.; from Blacks Fork, about 9,500 ft., Uinta Mountains, Utah; obtained on September 19, 1888, by Vernon Bailey; original No. 228.

Diagnosis.—Size medium; general tone of upper parts dark and shadowy; skull relatively small.

Description.—Color pattern: Head Pale Smoke Gray; facial stripes Fuscous Black to Snuff Brown; ear Fuscous Black; posterior margin of ear and postauricular patch grayish white; median dorsal dark stripe black with Sayal Brown along margins; lateral pair of dorsal dark stripes Sayal Brown or Fuscous Black mixed with Sayal Brown; outermost pair of dorsal dark stripes nearly absent; sides Sayal Brown mixed with Cinnamon; rump and thighs Sayal Brown mixed with Smoke Gray; antipalmar and antiplantar surfaces of feet Cinnamon-Buff; ventral surface of tail Ochraceous Tawny or Sayal Brown, with Fuscous Black around margin and Pinkish Buff around outermost edge; underparts creamy white with dark gray underfur. Skull: Large, with moderately inflated braincase and well developed zygomata. Baculum: One of the largest in the species.