Taxonomy of the Chipmunks, Eutamias quadrivittatus and Eutamias umbrinus

by John A. White

Remarks.—Specimens from the Chuska Mountains, Zuni Mountains, and Blanco, New Mexico, are intergrades between E. q. quadrivittatus and E. q. hopiensis, but are referable to E. q. quadrivittatus.

In north-central Colorado E. umbrinus occurs in the spruce and pine forests at higher altitudes, while to the south and east of this area E. q. quadrivittatus occurs in growths of piñon in lower, semiarid areas. In the northern half of New Mexico and in south-central Colorado, E. q. quadrivittatus occurs not only in semiarid habitats but also in the moist habitats of the forests of higher altitudes. Ecologically, E. umbrinus thus replaces E. q. quadrivittatus in north-central Colorado. This ecological replacement is comparable to the ecological replacement of Thomomys bottae by T. talpoides in Utah as shown by Durrant (1952:156).

Specimens examined.—Total number, 130.

Colorado: Larimer Co.: Arkins, 1 BS. Jefferson Co.: W spur Lookout Mountain, near Golden, 1 WC. Gunnison Co.: Sapinero, 3 BS. Saguache Co.: 5 mi. N and 22 mi. W Saguache 10,000 ft., 1; 21 mi. W and 3 mi. N Saguache, 1. Fremont Co.: 18 mi. S and 7 mi. W Colorado Springs, 1; Arkansas River, "about" 26 mi. below Canon City, 15 BS. San Juan Co.: Silverton, 1 BS. Mineral Co.: 3 mi. E Creede, 1. Alamosa Co.: Sangre de Cristo Range, 24 mi. E Hooper, 2 CM. La Plata Co.: 2 mi. NE Bondad 6,100 ft., 1; Bondad, 15 mi. S Durango 6,050 ft., 1. Archuleta Co.: Chromo, 1 CM. Las Animas Co.: Trinidad, 6 BS. Baca Co.: unspecified, 1.

New Mexico: San Juan Co.: Blanco, 1 BS; Chuska Mountains, 8 BS. Rio Arriba Co.: 8 mi. N El Rito, 1; 4 mi. N El Rito, 5; Rim Rock, El Rito, 2; 2 mi. E El Rito, 7,000 ft., 1; 2 mi. SE El Rito, 1; 6 mi. E and ½ mi. S Truchas, 8,500 ft., 1; 2 mi. S and 4 mi. W Coyote, 8,100 ft., 1; unspecified, 2. Taos Co.: 3 mi. N Taos Pueblo, 5 BS; 23 mi. S and 6 mi. E Taos, 8,750 ft., 2. Union Co.: Emery Peak, 1 BS; Folsom, 3 BS; Sierra Grande, 8 BS; unspecified, 2. McKinley Co.: Bear Ridge, Zuni Mountains, 9 BS. Sandoval Co.: Bear Canyon, W foothills, Sandia Mountains, 3 BS; W foothills, near S end, Sandia Mountains, 7 BS. Santa Fe Co.: San Pedro, 7 BS. San Miguel Co.: Canadian River, 4 mi. NW Tucumcari, 1 BS. Valencia Co.: Mount Taylor, San Mateo Mountains, 10 BS.

Oklahoma: Cimarron Co.: Kenton, 1 BS.

Eutamias quadrivittatus hopiensis Merriam

Eutamias hopiensis Merriam, Proc. Biol. Soc. Washington, 18:165, June 29, 1905.

Eutamias quadrivittatus hopiensis, Howell, Jour. Mamm. 3:184, August 4, 1922.