SCIURIDA—SCIURUS ABERTI. 
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OS 
a | 
SCIURUS ABERTI Woodh. 
Abert’s Squirrel, 
Sciurus dorsalis WOODHOUSE, Proc. Acad, Nat. Sci. Phila. vi, 1852, 110 (not S. dorsalis of Gray). 
Sciurus aberti WOODHOUSE, Proc. Acad. Nat. Sci. Phila. vi, 1852, 220; Sitgreaves’s Expl. Colorado and 
Zuni Rivers, 1853, 53, Mam. pl. vi—AupuBon & BacuMan, Quad. N. Am. iii, 1854, 262, pl. 
cliii, fig. 1.—Batrp, Mam. N. Am. 1857, 267.—ALLEN, Proc. Bost. Soc. Nat. Hist. xvi, 1864, 
287.—CouEs, Am. Nat. i, 1867, 355.—Cours & Yarrow, Wheele1’s Survs. and Expl. West of 
100th Merid. v, Zo6]. 1876, 115. 
Sciurus alberti GRay, Ann. and Mag. Nat. Hist. 3d. ser. xx, 1867, 417 (lege aberti). 
Sciurus castanotus BairD, Proc. Acad. Nat. Sci. Phila. vii, 1855, 332 (typ. error for castanonotus). 
Sciurus castanonotus BarrD, Mam. N. Am. 1857, 266; U.S. and Mex. Bound. Surv. ii, pt. ii, 1859, 35, pl. v. 
Speciric cuars.—Length of body 11 inches; of tail-vertebrae 8; of tail 
to end of hairs 12. Above, plumbeous-gray, with generally a more or less broad 
dorsal area of reddish-brown ; beneath, pure white; sides of the body with a 
distinct, generally conspicuous, black line, separating the white of the under 
parts from the gray of the upper parts. Runs into melanistic phases, in which 
the color varies from brownish-fuscous to uniform black throughout. Tail 
centrally black above, broadly edged with white, wholly white below. Ears 
very large; in winter, with long pointed ear-tufts, an inch to an inch and a 
half in length. The ears are larger in this species than in any other Ameri- 
can species of the genus. 
The brownish area on the back varies in color from yellowish-brown to 
strong reddish-brown or bright chestnut, and in extent from a short narrow 
stripe along the middle of the back, one to three inches in length, to a broad 
band extending the whole length of the body, which sometimes widens so as 
to cover the whole back from the nape to the tail. It is occasionally almost 
wholly obsolete, and, when confined to a narrow stripe, is much paler than 
when of larger extent. Some specimens have a chestnut spot at the posterior 
base of the ear, which sometimes involves the basal half of the ear-tuft; 
most of the specimens are without the chestnut ear-patch. Nearly half of 
the specimens are also wholly without ear-tufts. This is apparently a sea- 
sonal feature, but may be to some extent individual. Of specimens obtained 
the same day at the same locality, some have well-developed ear-tufts, while 
others are wholly without them. The majority of the specimens taken in 
summer show no trace of ear-tufts. 
There are four specimens from Colorado City, Colo., which present a 
melanistic phase of coloration,* varying from pale yellowish-brown to black. 
*Dr. Coues informs me that the black Abert’s Squirrels are the prevailing style in portions of 
Colorado. The collection made by Mrs. M. A. Maxwell in the vicinity of Boulder contains several 
examples of this phase, which, Dr. Coues was assured by this lady, is much more commonly found there 
than the normal one. 
