Virginia Northern Flying Squirrel Facts

The Virginia northern flying squirrel (Glaucomys sabrinus fuscus and abbreviated as VNSF) is a subspecies of northern flying squirrels (G. sabrinus) that lives in high altitudes in the Allegheny Mountains in the U.S. states of Virginia and West Virginia. In 1985, this squirrel was listed as vulnerable in the International Union for Conservation of Nature (IUCN), but after its population rebounded, was delisted in 2013.

Description

The Virginia northern flying squirrel has dense, soft fur that is brown on its back and slate gray colored on its belly. Its eyes are large, prominent, and dark. The squirrel's tail is broad and horizontally flattened, and there are membranes called patagia between the fore and hind legs that serve as "wings" when the squirrel glides from tree to tree.

Adult VNFS range in size between 10 and 12 inches, and between 4 and 6.5 ounces.

Diet

Unlike other squirrels, the Virginia northern flying squirrel usually feeds on lichen and fungi growing above and below ground instead of eating strictly nuts. It also eats certain seeds, buds, fruit, cones, insects, and other scavenged animal material.

Habit and Distribution

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By Anne Marie Helmenstine, Ph.D.

This subspecies of flying squirrel is typically found in conifer-hardwood forests or forest mosaics consisting of mature beech, yellow birch, sugar maple, hemlock, and black cherry associated with red spruce and balsam or Fraser fir. Biological studies have shown that it prefers mature growth red spruce trees at high altitudes, because of the presence of downed trees which promote the growth of fungus and lichens.

The Virginia northern flying squirrel currently exists in red spruce forests of Highland, Grant, Greenbrier, Pendleton, Pocahontas, Randolph, Tucker, Webster counties of West Virginia.

Behavior

These squirrels' large, dark eyes enable them to see in low light, so they are very active during the evenings, especially two hours after sunset and one hour before sunrise, moving among trees and on the ground. Virginia northern flying squirrels live in family groups of adults and juveniles that share ranges. Home ranges of males are approximately 133 acres.

The squirrels "fly" by launching themselves from tree branches, and spreading their limbs so the gliding membrane is exposed. They use their legs to steer and their tails to brake, and they can cover more than 150 feet in a single glide.

They may build leaf nests but often opportunistically reside in tree cavities, underground burrows, woodpecker holes, nest boxes, snags, and abandoned squirrel nests. Unlike other squirrels, Virginia northern flying squirrels remain active in the winter instead of hibernating; they are social animals and have been known to share nests with multiple males, females, and pups in their families over the winter for warmth. Their vocalizations are varied chirps.

Reproduction

The breeding season for Virginia northern flying squirrels falls between February to May and again in July. Gestation lasts 37–42 days and one or two litters of live pups are born with two to six individuals and averaging four or five. The squirrels are born from March through early July with a second season in late August to early September.

After they're born, the mothers and the newborns move to maternal nests. The young stay with their mother until they are weaned at two months and become sexually mature at 6–12 months. VNFS have a lifespan of about four years.

Threats

In 1985, the primary cause for the decrease in population was habitat destruction. In West Virginia, the decline of Appalachian red spruce forests was dramatic beginning in the 1800s. The trees were harvested to produce paper products and fine instruments (such as fiddles, guitars, and pianos). The wood was also highly valued in the ship-building industry.

"The single most important factor in the squirrels' population resurgence has been the regeneration of its forested habitat," reports the Richwood, WV, website. "While that natural regrowth has been ongoing for decades, there is considerable and growing interest by the U.S. Forest Service Monongahela National Forest and Northeastern Research Station, the state of West Virginia Division of Natural Resources, Department of Forestry and State Park Commission, The Nature Conservancy and other conservation groups, and private entities to foster large spruce restoration projects that restore the historic red spruce ecosystem of the Allegheny Highlands."

Since being declared endangered, biologists have placed and encouraged the public placement of nest boxes in 10 counties of western and southwestern Virginia.

Primary predators of the squirrel are owls, weasels, foxes, mink, hawks, raccoons, bobcats, skunks, snakes, and domestic cats and dogs.

Conservation Status

The loss of red spruce habitat by the end of the 20th century necessitated the listing of the West Virginia northern flying squirrel under the Endangered Species Act in 1985. In 1985, at the time of its Endangered Species listing, only 10 squirrels were found alive in four separate areas of its range. In the early 2000s, federal and state biologists captured more than 1,100 squirrels at over 100 sites and based on that believe that this subspecies no longer faces the threat of extinction. In 2013, the Virginia northern flying squirrels were delisted by the International Union for Conservation of Nature (IUCN) and the U.S. Fish and Wildlife Service, due to population recovery.

Sources

• Cassola, F. "Glaucomys sabrinus." The IUCN Red List of Threatened Species: e.T39553A22256914, 2016.
• Diggins, Corinne A., and W. Mark Ford. "Microhabitat Selection of the Virginia Northern Flying Squirrel (Glaucomys Sabrinus Fuscus Miller) in the Central Appalachians." BioONE 24.2 (2017): 173–90, 18. Print.
• Ford, W. M., et al. "Predictive Habitat Models Derived from Nest-Box Occupancy for the Endangered Carolina Northern Flying Squirrel in the Southern Appalachians." Endangered Species Research 27.2 (2015): 131–40. Print.
• Menzel, Jennifer M., et al. "Home Range and Habitat Use of the Vulnerable Virginia Northern Flying Squirrel Glaucomys Sabrinus Fuscus in the Central Appalachian Mountains, USA." Oryx 40.2 (2006): 204–10. Print.
• Mitchell, Donna. "Spring and Fall Diet of the Endangered West Virginia Northern Flying Squirrel (Glaucomys Sabrinus Fuscus)." BioONE 146.2 (2001): 439–43, 5. Print.
• Trapp, Stephanie E, Winston P Smith, and Elizabeth A Flaherty. "Diet and Food Availability of the Virginia Northern Flying Squirrel (Glaucomys sabrinus fuscus): Implications for Dispersal in a Fragmented Forest." Journal of Mammalogy 98.6 (2017): 1688–96. Print.
• "Virginia northern flying Squirrel (Glaucomys sabrinus fuscus)." ECOS Environmental Conservation Online System.