Sciurus arizonensis Coues 1867
Creators: name: Wilson, Don E.
name: Thomas E. Lacher, Jr
name: Mittermeier, Russell A.
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Rodentia
Sciuridae
Sciurus
Sciurus arizonensis

description: 83. Arizona Gray Squirrel <i>Sciurus arizonensis</i> <b>French:</b> Ecureuil dArizona / <b>German:</b> Arizona-Grauhdrnchen / <b>Spanish:</b> Ardilla gris de Arizona <b>Taxonomy.</b> Sciurus arizonensis Coues, 1867, “Fort Whipple,” Yavapai County, Arizona, USA. There is disagreement on whether or not three subspecies of S. arizonensis should be recognized. Monotypic. <b>Distribution.</b> S Arizona and W New Mexico (SW USA), and NC Sonora in NW Mexico. <b>Descriptive notes.</b> Head-body mean 248-2 mm (males) and 259-1 mm (females), tail mean 245-8 mm (males) and 254-5 mm (females); weight mean 736 g (males) and 667 g (females). The Arizona Gray Squirrel has silvery gray dorsum, occasionally with faint medial brownish band and rarely suffusion of brown on haunches; prominent cream-to-white eye ring and postauricular patches are often visible. Venter is white to cream. Gray tail has grizzled appearance and is frosted with white. <b>Habitat.</b> [.ow-elevation Madrean pine (Pinus, Pinaceae) and oak (Quercus, Fagaceae) forests to higher-elevation mixed conifer forests. Riparian areas with large cottonwoods (Populus, Salicaceae) and sycamores (Platanus, Platanaceae) also have high densities of Arizona Gray Squirrels. <b>Food and Feeding.</b> The Arizona Gray Squirrel forages heavily on the ground but also regularly uses the canopy. It feeds on tree seeds, flowers, and fungi. Seeds are removed from cones of pines (Pinus), Douglas fir (Pseudotsuga menziesii), and true firs (Abies), all Pinaceae, and consumed. Acorns (Quercus) and walnuts (Juglans,Juglandaceae) are readily eaten when available. Hypogeous and epigeous fungi are also a common food. Insects are consumed opportunistically. The Arizona Gray Squirrel does occasionally scatterhoard large storable seeds in the soil. <b>Breeding.</b> The Arizona Gray Squirrel breeds in February—August during one day estrus when as many as eight males pursue females. Males possess scrotal testes from winter through summer. Testes are withdrawn into the abdominal cavity during the remaining months. Litters of 2—4 young are born in late spring or summer. Dreys and cavity nests are used to rear young that can emerge in May-September. During mild years, females may be able to produce a second litter. <b>Activity patterns.</b> Arizona Gray Squirrels are diurnal and active throughout the year. They have bimodal activity in summer with peak activity in the early morning and late afternoon; activity in winter tends to be unimodal and centered on midday heat. <b>Movements, Home range and Social organization.</b> The Arizona Gray Squirrel nests in dreys ofsticks, pine needles, and leaves in the forest canopy and in cavities in largediameter trees. Nest trees tend to be in the largest trees with the most interconnected canopies. Communal nesting is known to occur although the Arizona Gray Squirrel is best described as asocial. Male home ranges are extensive, 113 ha compared to 14 ha for females. Males maximize overlap with females, particularly during breeding. The Arizona Gray Squirrel is generally silent unless alarmed when will bark and chuck from elevated locations. <b>Status and Conservation.</b> Classified as Data Deficient on The IUCN Red List. Population trend of the Arizona Gray Squirrel is unknown. It appears to respond negatively to high levels of fire damage but positively to modest levels. Introduced Abert’s Squirrels (Sciurus aberti) appear to replace the native Arizona Gray Squirrel in parts ofits distribution. Local people hunt this large-bodied squirrel for meat and sport. <b>Bibliography.</b> Best &amp; Riedel (1995), Brown (1984), Ceballos (2014), Cudworth &amp; Koprowski (2010, 2014), Hoffmeister (1986), Thorington et al. (2012), Yensen &amp; Valdés-Alarcén (1999).
description: Published as part of <i>Don E. Wilson, Thomas E. Lacher, Jr &amp; Russell A. Mittermeier, 2016, Sciuridae, pp. 648-837 in Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona :Lynx Edicions</i> on page 745, DOI: 10.5281/zenodo.6840226