NPS Photo by Sally King

Abert’s Squirrel (Sciurus aberti)

Abert’s squirrel can be found in ponderosa pine forests across the four corners region of Arizona, New Mexico, Utah, and Colorado.  In 1941, the Arizona Game and Fish Department successfully introduced Abert's squirrel as a game species from northern Arizona into the Santa Catalina Mountains.  By 1959, Abert’s squirrel had spread into the Rincon Mountains of the park. Now this squirrel is the most common tree squirrel in the Rincons, outcompeting the native Arizona gray squirrels, whose numbers are declining.

NPS

Arizona Gray Squirrel (Sciurus arizonensis)

The Arizona gray squirrel is a native species.  Their number has declined since 1959 when Abert’s squirrels arrived in the Rincon Mountains from their introduction site in the nearby Santa Catalina Mountains.  Arizona gray squirrels prefer forests of large trees such as ponderosa pine, oak, and walnut.  However, in the Rincon Mountains, they are now only found in areas with large oak trees.

NPS

Harris’s Antelope Squirrel (Ammospermophilus harrisii)

Harris’s antelope squirrels are commonly seen by visitors.  They are distinguished by the prominent stripe along their side.  They are active during the daytime and can be seen foraging during some of the hottest summer days.  When their body temperatures get too warm, they dash into their burrows or a shady location to sprawl on their stomachs and cool off.  

NPS

Rock Squirrel (Spermophilus variegates)

Rock squirrels prefer rocky areas in high mountains to the desert floor.  They are one of the most commonly seen mammals at Saguaro National Park.  Though similar in appearance to the Arizona gray squirrel, rock squirrels are larger and live in burrows, not trees.  Rock squirrels live well near humans and are considered pests because they feed on crops and often make their burrows under houses.

NPS photo by Jim Creager

Round-tailed Ground Squirrel  (Spermophilus tereticaudus)

Round-tailed ground squirrels are abundant in desert regions of Saguaro National Park.  They prefer flat, open areas with sandy soils where they can dig burrows.  They are very social squirrels and live in colonies similar to prairie dogs.  Young males leave the colony, while young females remain in the colonies to which they were born.

NPS/Saguaro National Park

Cliff Chipmunk (Tamius dorsalis)

Cliff chipmunks are very abundant in the upper elevations of the Rincon Mountains and in lower elevations in large riparian corridors. Cliff chipmunks differ from Harris’s antelope ground squirrel in the lack of a stripe along the body and the presence of a stripe on their face.