Mount Graham Red Squirrel
Encyclopedia
The Mount Graham Red Squirrel (Tamiasciurus hudsonicus grahamensis) is an endangered subspecies of the American Red Squirrel
(Tamiasciurus hudsonicus) native to the Pinaleño Mountains
of Arizona
. It is smaller than most other subspecies of Red Squirrel, and also does not have the white-fringed tail that is common to the species. Its diet consists mainly of mixed seeds, conifer cones and air-dried fungi. It exhibits similar behavior to other squirrels in its species.
of the subspecies is rounded and its teeth are low-crowned.
zone habitats that were generally at higher elevations throughout the Pinaleño Mountains
. Recent data shows that it occurs more frequently at the ecotone zone then the other habitats. When choosing a potential nesting site, the squirrels typically pick a cool, moist
area with an abundance of food sources. Drought
, forest fires
, and insect infestation have been responsible for a decrease of the squirrel in the spruce-fir habitat.
or endangered
species status under the Endangered Species Act
in the year 1982. On May 21, 1986, the subspecies was officially recommended to become an endangered species, and on June 3, 1987, was officially listed as endangered. The Mount Graham International Observatory
was controversial when it was built in the squirrel's habitat; the observatory has been required to monitor the community near the observatory to determine if its construction is having any negative effects on the population. Habitat loss is also occurring at high levels for a variety of natural and anthropogenic reasons. In 1988, the U.S. Fish and Wildlife Service designated most of this area as a refuge, and access to the area is only granted with a special permit.
American Red Squirrel
The American Red Squirrel is one of three species of tree squirrel currently classified in the genus Tamiasciurus and known as pine squirrels...
(Tamiasciurus hudsonicus) native to the Pinaleño Mountains
Pinaleno Mountains
The Pinaleño Mountains, or the Pinal Mountains, are a remote mountain range in southeastern Arizona. They have over of vertical relief, more than any other range in the state. The mountains are surrounded by the Sonoran-Chihuahuan Desert. Subalpine forests cover the higher elevations...
of Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
. It is smaller than most other subspecies of Red Squirrel, and also does not have the white-fringed tail that is common to the species. Its diet consists mainly of mixed seeds, conifer cones and air-dried fungi. It exhibits similar behavior to other squirrels in its species.
Physical
The Mount Graham Red Squirrel is a generally tiny squirrel weighing on average around 8 ounces (226.8 g) and measuring about 8 inches (20.3 cm) in length. The subspecies also has a 6 inches (15.2 cm) tail. Unlike most other squirrels in its species, the squirrels do not have a white-fringed tail. Both females and males share similar markings and features and are typically grayish brown in color with rusty yellow or orange markings on their backside. During the winter season the squirrels ears are tufted with fur, and during the summer a black lateral line is observed on the squirrel. The skullSkull
The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...
of the subspecies is rounded and its teeth are low-crowned.
Behavior
Mount Graham Red Squirrels behave in a manner similar to most other subspecies of American Red Squirrel. They are diurnal and do not hibernate during the winter months, but instead carry out activities in the mid-day sun. Mount Graham Squirrels usually eat a diet of mixed seeds, conifer cones and air-dried fungi.Habitat
Historically, the Mount Graham Red Squirrel inhabited about 11750 acres (47.6 km²) of spruce-fir, mixed-conifer and ecotoneEcotone
An ecotone is a transition area between two biomes but different patches of the landscape, such as forest and grassland. It may be narrow or wide, and it may be local or regional...
zone habitats that were generally at higher elevations throughout the Pinaleño Mountains
Pinaleno Mountains
The Pinaleño Mountains, or the Pinal Mountains, are a remote mountain range in southeastern Arizona. They have over of vertical relief, more than any other range in the state. The mountains are surrounded by the Sonoran-Chihuahuan Desert. Subalpine forests cover the higher elevations...
. Recent data shows that it occurs more frequently at the ecotone zone then the other habitats. When choosing a potential nesting site, the squirrels typically pick a cool, moist
Moisture
Humidity is the amount of moisture the air can hold before it rains. Moisture refers to the presence of a liquid, especially water, often in trace amounts...
area with an abundance of food sources. Drought
Drought
A drought is an extended period of months or years when a region notes a deficiency in its water supply. Generally, this occurs when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region...
, forest fires
Wildfire
A wildfire is any uncontrolled fire in combustible vegetation that occurs in the countryside or a wilderness area. Other names such as brush fire, bushfire, forest fire, desert fire, grass fire, hill fire, squirrel fire, vegetation fire, veldfire, and wilkjjofire may be used to describe the same...
, and insect infestation have been responsible for a decrease of the squirrel in the spruce-fir habitat.
Conservation
The Mount Graham subspecies was believed to be extinct in the 1950s, but was "rediscovered" in the 1970s. After its rediscovery, it was suggested for threatenedThreatened species
Threatened species are any speciesg animals, plants, fungi, etc.) which are vulnerable to endangerment in the near future.The World Conservation Union is the foremost authority on threatened species, and treats threatened species not as a single category, but as a group of three categories,...
or endangered
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
species status under the Endangered Species Act
Endangered Species Act
The Endangered Species Act of 1973 is one of the dozens of United States environmental laws passed in the 1970s. Signed into law by President Richard Nixon on December 28, 1973, it was designed to protect critically imperiled species from extinction as a "consequence of economic growth and...
in the year 1982. On May 21, 1986, the subspecies was officially recommended to become an endangered species, and on June 3, 1987, was officially listed as endangered. The Mount Graham International Observatory
Mount Graham International Observatory
Mount Graham International Observatory is a division of Steward Observatory the research arm for the Department of Astronomy at The University of Arizona. It is located in southeast Arizona's Pinaleno Mountains near Mount Graham....
was controversial when it was built in the squirrel's habitat; the observatory has been required to monitor the community near the observatory to determine if its construction is having any negative effects on the population. Habitat loss is also occurring at high levels for a variety of natural and anthropogenic reasons. In 1988, the U.S. Fish and Wildlife Service designated most of this area as a refuge, and access to the area is only granted with a special permit.