Ammospermophilus harrisii (Audubon and
Bachman, 1854)
Harris’s Antelope Squirrel
description: The dorsum is gray, suff used with reddish to
yellowish brown near the head and along the front and hind
limbs, grading to gray through the tail. A single thin white
line on each side parallels the spine. The venter is white,
extending slightly up the sides. The dorsal surface of the tail
is charcoal, and the underside is gray, resulting from a mix
of black and white hairs.
size: Both sexes—HB 229–245.8 mm (range = 216–267 mm);
T 70.9–84.6 mm (range = 67–92 mm); Mass 113–150 g.
distribution: Harris’s antelope squirrel occurs from Ari-
zona to southwestern New Mexico (USA) and adjoining So-
nora (México).geographic variation: Two subspecies are recognized.A. h. harrisii—along the east bank of the Colorado River in
Arizona (USA) and ending along the Sea of Cortez’s So-
noran coast. This form tends to be slightly darker, with
more contrast, than A. h. saxicolus.
A. h. saxicolus—eastern 60 percent of the range. This is a
paler subspecies.conservation: IUCN status—least concern. Population
trend—no information.habitat: Harris’s antelope squirrels are found in a variety
of desert habitats, and they thrive in areas with cacti and
desert shrubs.natural history: This squirrel is diurnal, active year-
round, and does not store fat. Harris’s antelope squirrels are
well adapted for climbing cacti and boulders. A. harrisii lives
in shallow inconspicuous burrows often associated with
structures such as rocks, cacti, or shrubs; the squirrels some-
times store large seeds within their burrows. A nest chamber
provisioned with bedding is found in each burrow system,
especially for pregnant females. Breeding occurs each year,
starting in December, and it can continue well into spring.
After a 30–day gestation, a single litter averaging 6.5 is most
common, but two litters may occur in mild climates. Litters
emerge at 4–5 weeks, wean by 7 weeks, and the young are
fully grown by about 217 days. Harris’s antelope squirrels are
omnivorous. They feed heavily on cactus fruits and fl esh,
consume seeds that they often store in their cheek pouches,
and will eat insects. Although these squirrels are quite con-
spicuous, densities are low and individuals are scattered
throughout most of the range. They travel a maximum ofTribe Marmotini Pocock, 1923
This tribe includes 13 genera.
Ammospermophilus Merriam, 1892
This genus contains fi ve species.