A New Subspecies of Wood Rat (Neotoma mexicana) From Colorado

BY
ROBERT B. FINLEY, JR.

University of Kansas Publications
Museum of Natural History

Volume 5, No. 30, pp. 527-534, 2 figures in text
August 15, 1953

University of Kansas
LAWRENCE
1953

University of Kansas Publications, Museum of Natural History

Editors: E. Raymond Hall, Chairman, A. Byron Leonard, Robert W. Wilson

Volume 5, No. 30, pp. 527-534, 2 figures in text
August 15, 1953

University of Kansas
Lawrence
1953

PRINTED BY
FERD VOILAND, JR., STATE PRINTER
TOPEKA, KANSAS
1953

24-7674

A New Subspecies of Wood Rat (Neotoma mexicana) from Colorado

By
ROBERT B. FINLEY, Jr.

Field and museum studies of the wood rats of Colorado have revealed the existence of an unnamed subspecies of Neotoma mexicana in eastern Colorado south of the Arkansas River. The characters of the new subspecies are most distinctive in the northeastern part of its range near Two Buttes and Higbee. It differs in cranial characters from N. m. fallax and N. m. inopinata and averages slightly larger, but cannot be distinguished by coloration of the pelage.

This heretofore undescribed subspecies may be known as:

Neotoma mexicana scopulorum subsp. nov.

Type.—Mus. Nat. Hist., Univ. Kansas, No. 37137, old adult male, skin and skull; from 37° 47' N, 103° 28' W, three miles northwest of Higbee, 4300 feet, Otero County, Colorado; trapped 16 May 1950 by R. B. Finley, Jr., original number 500516-1.

Range.—Cañons, mesas, and foothills south of the Arkansas River, east to Two Buttes, Colorado, and south to Clayton, New Mexico. The extent of the range to the southwest in New Mexico has not been determined.

Diagnosis.—Size large for the species; interorbital constriction near middle of frontal rather than anteriorly; supraorbital ridges of frontal concave laterally; skull large, strongly arched at base of rostrum; rostrum wide; nasals wide anteriorly; upper incisors wide, light yellow; molars large, tooth-rows long; zygomatic arches wide and heavy; interparietal short, wide, and posterior margin straight or with a slight posterior median angle.

Description.—Adults in dense unworn pelage taken in February at Two Buttes Reservoir: size large for the species; tail approximately 76 per cent as long as head and body; hind feet of medium length. Pelage: moderately long, thick; tail covered with short hairs; longest vibrissae 80 mm. Color: sides near Raffia (11 E 6) (capitalized color names and designators are of Maerz and Paul, A Dictionary of Color, McGraw-Hill Book Co., New York, 1930) overlaid with black, the general effect being grayish buff (13 G 6); back darker, moderately to heavily overlaid with black; indistinct dark eye ring; underparts whitish, fur basally gray except patch of fur pure white to base almost always present on upper throat; dark line around mouth; tail bicolor, black above, whitish below; feet white to ankles.

Skull: large for the species, strongly arched at base of rostrum; rostrum heavy; zygomatic arches widely spreading, heavy, squarish; braincase moderately ridged and angular; nasals wide anteriorly, lateral margins nearly parallel or converging evenly posteriorly, tapered abruptly at posterior ends which