FWS Focus

Overview

Characteristics
Overview

The Carolina Northern Flying Squirrel (Glaucomys sabrinus coloratus) is a small gliding mammal that is one of 25 subspecies of northern flying squirrels living in boreal coniferous and mixed coniferous/hardwood forests of the United States and Canada. The more common Southern Flying Squirrel (Glaucomys volans) also lives in the southern Appalachian Mountains but is typically found in hardwood and mixed pine-hardwood forests at lower elevations. The northern flying squirrel is distinguished from the southern flying squirrel by its larger size and the gray base of its belly hairs as opposed to a white base in the southern species. 

 

 The Carolina northern flying squirrel can trace its roots back to the last ice age. During this time, ice sheets covered much of northern North America, forcing cold-climate plants and animals further south. As temperatures warmed and ice sheets receded, those cold-climate species migrated north, and some found refuge on the high, cold peaks of the southern Appalachians. Over thousands of years, these isolated, mountain-top populations became increasingly distinct, giving rise to the Carolina northern flying squirrel, a subspecies of northern flying squirrel only found in the high-elevation areas of North Carolina, Tennessee, and southwest Virginia. 

 

Historically, Carolina northern flying squirrel habitat was dramatically altered and decfreased by industrial scale logging and subsequent forest fires in southern Appalachia around the turn of the 20th century. Today, much, though not all, of its habitat is on land dedicated to conservation (e.g. National Forests, National Park Service units), however the high-elevation forests on which the squirrel face threats that function independent of political or ownership boundaries. The balsam woolly adelgid continues to threaten Fraser fir trees, and the hemlock adelgid is now threatening Eastern and Carolina hemlocks. Beech bark disease is killing large numbers of American beech trees, an important northern hardwood species that provides nesting habitat for the Carolina northern flying squirrel. Acid precipitation and other environmental pollution continue to be a concern. Additionally, climate change climate change
Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale.

Learn more about climate change
has the potential to exacerbate these threats and add additional stressors to high-elevation forests in the Southern Appalachians. To address some of these issues, biologists are working to restore or introduce red spruce to some areas to offset the loss of conifer species.  

Scientific Name

Glaucomys sabrinus coloratus
Common Name
Carolina northern flying squirrel
FWS Category
Mammals
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Habitat

Characteristics
Habitat

The Carolina Northern Flying Squirrel is associated with high elevation red spruce and Fraser fir (spruce-fir) and mixed red spruce-northern hardwood forests of the southern Appalachian Mountains. They live in cool, wet, mature forests characterized by large trees, rotting logs, and abundant fungi, mosses, and lichens.  

Mountain

A landmass that projects conspicuously above its surroundings and is higher than a hill.

Forest

A dense growth of trees and underbrush covering a large tract.

Characteristic category

Food

Characteristics
Food

Northern flying squirrels principally feed on certain fungi and lichens, though they also eat fruits, seeds, insects, and some animal matter. One of the flying squirrel’s favorite foods is truffles, which are the fruiting bodies of mycorrhizal fungi that grow in association with the roots of plants. Conifers, such as red spruce and Fraser fir, have a high abundance of truffles and provide critical foraging habitat for the species. 

Characteristic category

Behavior

Characteristics
Behavior

The Carolina Northern Flying Squirrel is active year-round and is nocturnal, emerging from its den at dusk to forage. Dens are primarily found in cracks, crevices and cavities of live and dead trees where squirrels construct a nest made of finely shredded birch bark. Flying squirrels will also use dreys – external nests built in the branches of conifer trees. These nests are also lined with finely shredded birch bark. 

Characteristic category

Physical Characteristics

Characteristics
Size & Shape

The Carolina northern flying squirrel weighs 90-140 g (3-5 ounces) and is 260-305 mm (10-12 inches) in total body length. They have a broad flattened tail comprising 80% of their total body length, prominent eyes, and dense, silky fur. To enable gliding, they have fully furred folds of skin between their wrists and ankles (patagia) supported by slender cartilages extending from the wrist bones.  The patagia plus broad tail create the surface area needed to enable the squirrel’s characteristic gliding. 

Color & Pattern

Adults are gray with a brownish, tan, or reddish wash with a grayish white or buffy white underside.  

Characteristic category

Life Cycle

Characteristics
Reproduction

Reproduction occurs in the spring.  Females typically birth two to five young after a gestation period of around 40 days and generally have a single litter per year. Young squirrels are fully dependent on their mother’s care.  Their eyes open after about a month and nursing ends at two months, at which time young squirrels first attempt gliding.  They can live up to 8 years, but most do not live that long.   

Geography

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Timeline

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