Mt. Graham red squirrels (Tamiasciurus hudsonicus grahamensis) are a native species to Southeastern Arizona, and are only found in the Pinaleño Mountains of Graham County. The Mt. Graham red squirrel was actually thought to be extinct in the 1950’s until they were rediscovered two decades later.  On June 3, 1987, the Mt. Graham red squirrel was listed as endangered under the Endangered Species Act.

The Mt. Graham red squirrel is a distinct sub-species from the North American red squirrels that range from the coasts of Alaska down to the Rocky Mountains. It is distinguished by a smaller body and more narrow head than other red squirrels but maintains the brownish-red sides and white belly that characterize squirrels in its species.

The Mt. Graham red squirrels are most active during the day and spend their time foraging for seeds of coniferous trees. However, their diet also consists of insects, mushrooms, bird eggs, nestlings and various other items. Both genders are highly territorial and will aggressively defend their “middens” from other squirrels. Like other members of its species, Mt. Graham red squirrels do not hibernate during the winter but will venture out into the cold only in mid-day when it is warmest.

The forest habitat of the Mt Graham red squirrel has been impacted by wildfire, and disease reducing the available food resources and cover from predators.  This has led to a reduction in their wild population. In addition, an introduced squirrel species (Abert’s Squirrel) is now outcompeting Mt. Graham red squirrels for these limited food resources.

At the Phoenix Zoo

The Phoenix Zoo’s Conservation Center currently maintains a population of Mt. Graham red squirrels which are housed in a temperature regulated building.  Because the temperatures in Phoenix are much higher than on Mt. Graham the building is maintained at 65 to 72Fº degrees throughout the year.

To help natural populations, the Phoenix Zoo is working with U.S. Fish and Wildlife to develop a pilot breeding program, focusing on establishing a sustainable method to breed and release Mt. Graham red squirrel back to the wild.   Over the next several years we will be working to develop breeding management protocols and general husbandry guidelines designed to produce animals that can survive reintroduction.  We are hopeful that through the conservation efforts of the Phoenix Zoo and other partners, the Mt. Graham red squirrel will be present in its natural habitat for years to come.