Ammospermophilus harrisii
| Harris's Antelope Squirrel
(Ammospermophilus harrisii) | |
|---|---|
| Range | |
 | |
| Taxonomic classification | |
| Order: | Rodentia |
| Suborder: | Sciuromorpha |
| Family: | Sciuridae |
| Subfamily: | Xerinae |
| Tribe: | Marmotini |
| Genus: | Ammospermophilus |
| Binomial details | |
| Ammospermophilus harrisii (Audubon & Bachman, 1854) | |
| Other resources | |
| Full taxonomic details at MDD | |
The Harris's Antelope Squirrel (Ammospermophilus harrisii) is a ground squirrel found in the Sonoran and Chihuahuan deserts of southwestern United States and northwestern Mexico. It prefers desert habitats composed of shrubs, small trees, and cactus.
Desription
From Best et al. (1990): "Ammospermophilus harrisii is medium in size. The tail is medium to short and the ears are small. The dorsum in winter pelage is pale brown to grizzly black and paler in summer; there is one whitish stripe along each side of the body. ...The eyes are of moderate size and placed midway between the point of the nose and the root of the ear; a white ring encircles the eye, giving it a spectacled appearance (Neal, 1964)."
Museum specimens
Holotype: USNM 59869. Ammospermophilus harrisii saxicolus. Adult female. Tinajas Altas, Gila Mountains, Yuma County, Arizona. Collected 17 February 1894. 
Holotype: USNM 59869. Ammospermophilus harrisii saxicolus. Adult female. Tinajas Altas, Gila Mountains, Yuma County, Arizona. Collected 17 February 1894. 
Holotype: USNM 59869. Ammospermophilus harrisii saxicolus. Adult female. Tinajas Altas, Gila Mountains, Yuma County, Arizona. Collected 17 February 1894.
External measurements
Length measurements are in millimeters (mm) and weight measurements are in grams (g), unless stated otherwise. If available, the sample size (n=) is provided. If a range is not provided and n= is not given, then the listed measurement represents an average.
| Part of range | Reference | Total length | Tail length | Hindfoot length | Ear length | Mass |
|---|---|---|---|---|---|---|
| Arizona | Hoffmeister (1986) | 216–267 (n=64) | 67–92 (n=64) | 35–46 (n=64) | 10–16 (n=64) | |
| Mexico (Sonora) | Hoffmeister (1986) | 225–250 (n=13) | 74–85 (n=13) | 37–44 (n=13) | 12–15 (n=13) |
Skull
From Best et al. (1990): "The skull is wide postorbitally, the bullae are inflated, and the braincase is relatively flattened, with a gentle slope from the highest point posteriorly to the lambdoidal crest. The masseteric tubercle is small and directly below the infraorbital foramen, and the outer edge of the infraorbital foramen is inclined slightly ventromedially. The interorbital foramen always is present and large (Hoffmeister, 1986). ...The teeth are rather small and the lower incisors slightly curved. The incisors are yellowish."
Holotype: USNM 59869. Ammospermophilus harrisii saxicolus. Adult female. Tinajas Altas, Gila Mountains, Yuma County, Arizona. Collected 17 February 1894. Dorsal view of the skull. 
Holotype: USNM 59869. Ammospermophilus harrisii saxicolus. Adult female. Tinajas Altas, Gila Mountains, Yuma County, Arizona. Collected 17 February 1894. Lateral view of the skull. 
Holotype: USNM 59869. Ammospermophilus harrisii saxicolus. Adult female. Tinajas Altas, Gila Mountains, Yuma County, Arizona. Collected 17 February 1894. Ventral view of the skull. 
Holotype: USNM 59869. Ammospermophilus harrisii saxicolus. Adult female. Tinajas Altas, Gila Mountains, Yuma County, Arizona. Collected 17 February 1894. Dorsal view of the mandible. 
Holotype: USNM 59869. Ammospermophilus harrisii saxicolus. Adult female. Tinajas Altas, Gila Mountains, Yuma County, Arizona. Collected 17 February 1894. Lateral view of the mandible.
Similar species
The range of the Harris's Antelope Squirrel (Ammospermophilus harrisii) does not overlap with that of any other species of Ammospermophilus. The Colorado River appears to be a major biogeographic barrier for this species, separating it from the White-tailed Antelope Squirrel (Ammospermophilus leucurus) to the north and west.
From Best et al. (1990): "Ammospermophilus harrisii differs from other similar-sized ground squirrels by its grayish dorsum and tail and by the presence of one white stripe along both sides of the body from shoulder to rump (Caire, 1978). It is distinguished from other members of the genus by the mixed black and white undersurface of the tail; other Ammospermophilus have a white undersurface of the tail (Hall, 1981). A. harrisii is distinguished from A. leucurus by pelage color (usually darker and grayer), and especially by the banding pattern on the undersurface of the tail (salt and pepper gray compared to white surrounded by one black band in A. l. leucurus). Cranially, the two are similar, but A. harrisii has slightly larger auditory bullae (Hafner, 1981)."
Harris's Antelope Squirrel (Ammospermophilus harrisii) photographed by Steve Huckabone in Yavapai County, Arizona. -
White-tailed Antelope Squirrel (Ammospermophilus leucurus) photographed by lonnyholmes in Clark County, Nevada.
References
Best TL, Titus AS, Caesar K, Lewis CL. 1990. Ammospermophilus harrisii. Mammalian Species (366): 1-7.
Caire W. 1978. The distribution and zoogeography of the mammals of Sonora, Mexico. Unpublished Ph.D. dissertation, The University of New Mexico, Albuquerque, 613 pp.
Findley JS, Harris AH, Wilson DE, Jones C. 1975. Mammals of New Mexico. Albuquerque (NM, USA): University of New Mexico Press.
Hafner DJ. 1981. Evolution and historical zoogeography of antelope ground squirrels, genus Ammospermophilus (Rodentia: Sciuridae). Unpublished Ph.D. dissertation, The University of New Mexico, Albuquerque, 225 pp.
Hoffmeister DF. 1986. Mammals of Arizona. Tucson (AZ, USA): University of Arizona Press.
Neal BJ. 1964. Comparative biology of two southwestern ground squirrels Citellus harrisii and C. tereticaudus. Unpublished Ph.D. dissert., The University of Arizona, Tucson, 125 pp.