Glaucomys volans (Linnaeus, 1758)

Fur Coloration

This species, the southern flying squirrel (Glaucomys volans), has grey-brown fur on its upper body, darker fur on its flanks, and cream-colored fur on its underside.

Body Features

It has large dark eyes, a flattened tail, and a furry membrane called a patagium that stretches between its front and rear legs, which it uses to glide through the air.

Body Size

The total length of an individual, including its tail, ranges from 21 to 26 cm (8.3 to 10.2 in), while the tail alone measures 8 to 12 cm (3.1 to 4.7 in).

Activity Pattern

Southern flying squirrels are nocturnal.

Core Diet

Their diet consists of fruits and nuts from trees including red oak, white oak, hickory, and beech; they store food, particularly acorns, to eat during winter.

Supplementary Diet

They also feed on insects, buds, mushrooms, mycorrhizal fungi, carrion, bird eggs, bird nestlings, and flowers.

Predators

Their predators include snakes, owls, hawks, raccoons, and domestic cats.

Reproductive Output

In both wild and captive populations, southern flying squirrels can produce two litters of young each year, with 2 to 7 young per litter.

Gestation Period

The gestation period lasts approximately 40 days.

Newborn Characteristics

Newborns are born furless and fully helpless.

Juvenile Development Milestones

Their ears open between 2 and 6 days old, and their fur is fully grown in by 7 days old.

Eye Development

Their eyes do not open until they reach 24 to 30 days of age.

Weaning and Independence

Mothers wean their young 65 days after birth, and young become fully independent at around 120 days of age.

Homing Ability

Southern flying squirrels have strong homing abilities, and can return to their nests if they are artificially moved distances of up to one kilometer.

Home Range Size General

Female home ranges may reach up to 40,000 m2 (430,000 sq ft), and male home ranges are typically twice this size; home ranges tend to be larger at the northern extreme of the species' range.

Home Range Estimates by Group

Average home range estimates are 2.45 hectares (6.1 acres), 9 ha (22 acres), and 16 ha (40 acres) for adult males, 1.95 ha (4.8 acres), 3.9 ha (9.6 acres), and 7.2 ha (18 acres) for adult females, and 0.61 ha (1.5 acres) for juveniles.

Home Range Overlap

Home ranges overlap significantly with one another.

Home Range Size Drivers

Near the northern limit of the species' distribution, home ranges increase in size as mast-producing trees become more dispersed.

This pattern also occurs in fragmented forests, where nesting and foraging areas are spaced widely apart.

Male Home Range Size Rationale

Male home ranges are larger than female home ranges, possibly to increase the chance of encountering potential mates.

Female Home Range Variation

Even though males have larger home ranges overall, female home ranges can increase by up to 70 percent after their offspring leave.

Nesting Site Population Effect

The number of nesting sites does not affect the total population size of southern flying squirrels, but it may influence which sex is present in an area.

Male Home Range Resources

Male home ranges contain more food resources, as they are associated with a higher-than-expected number of large red oaks and white oaks.

Female Home Range Resources

In contrast, female home ranges have lower food resources and more abundant nesting sites, which may help females avoid contact with other squirrels while raising young.

Disease Association

Human exposure to southern flying squirrels has been linked to cases of epidemic typhus in people.

Typhus spread by flying squirrels is called "sylvatic typhus."

Documented Sylvatic Typhus Cases

From 1976 to 2001, the U.S. Centers for Disease Control and Prevention documented a total of 39 sylvatic typhus cases linked to this species.

Disease Host Role

Southern flying squirrels act as hosts for the Rickettsia prowazekii bacteria.

Disease Transmission Hypothesis

It is hypothesized that transmission to humans occurs through aerosolized feces from fleas and lice that live on G. volans.

General Habitat

The southern flying squirrel inhabits eastern deciduous forests or mixed forests of North America.

Preferred Habitat Tree Species

Large hickory and beech trees are more abundant in the heavily used parts of their home ranges.

Maple, poplar, and oak trees also provide favorable habitat.

Suburban Habitat Presence

While southern flying squirrels may live in heavily wooded suburban areas, they never occur in large numbers in these regions.

Edge and Fragmented Habitat Home Range

Near the northern edge of the species' range and in fragmented forests, where mast-producing trees are more dispersed and nesting and foraging areas are widely spaced, home ranges grow larger.

Nest Types

Southern flying squirrels build nests in natural tree cavities and woodpecker holes, or construct leaf and twig nests.

Nest Usage by Season and Purpose

Leaf nests are used as refuges or resting sites, primarily during summer, while cavities are used for breeding and are used more heavily during winter.

Cavity Nest Tree Characteristics

Cavities used by southern flying squirrels are found in small snags with an average diameter at breast height of 23.27 cm (9.16 in), or in large living trees with an average diameter at breast height of 50.42 cm (19.85 in).

Cavity Nest Entrance Specifications

Cavity entrances average 4.7 cm (1.9 in) wide by 9.4 cm (3.7 in) high, and are located an average of 6.36 m (20.9 ft) above the ground.

Den Placement

Dens tend to be located on the perimeter of home ranges and positioned away from clearings.

Disturbance Crossing Preference

To cross disturbances such as plantations and logged areas, southern flying squirrels prefer to use mature forest corridors over younger ones.

Disturbance Sensitivity

This preference indicates that the species is more sensitive to forest disturbance than previously thought.