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Glaucomys volanssouthern flying squirrel

By David L. Fox and Michael Mulheisen

Geographic Range

Glaucomys volans is found in southeastern Canada, the eastern United States, and south as far as Mexico and Honduras.

Habitat

Southern flying squirrels are found in woodlands. They seem to prefer seed-producing hardwoods, particularly maple, beech, hickory, oak, and poplar. They are also found in mixed conifer/deciduous forests.

Physical Description

Flying squirrels are easily distinguished by the "gliding membrane", a flap of loose skin that extends from wrist to ankle. The loose skin along the side of the body is supported by cartilaginous spurs on the wrists and ankles. The soft fur on the back and tail is grey with varying amounts of grey tinge; the belly is white. The tail is dorso-ventrally flattened. The eyes are very large, probably related to the nocturnal habits and the visual requirements of gliding. Total length is 21.1 to 25.7 cm and tail length is 7.9 to 12 cm.

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    46 to 85 g
    1.62 to 3.00 oz
  • Average mass
    65.38 g
    2.30 oz
  • Range length
    21.2 to 25.7 cm
    8.35 to 10.12 in
  • Average basal metabolic rate
    0.414 W
    AnAge

Reproduction

Little is known about the mating system in southern flying squirrels. Males and females do not associate much beyond breeding.

Not much is known about mating in southern flying squirrels.

Females are polyestrous and typically mate twice per year. Births thus have two peaks, from February to May and from July to September. There is, however, some geographic variation in the timing of births. (In Michigan, they court and breed in winter and early spring.) The gestation period is 40 days. Litters can range from one to six young, though two or three is most common. The young are weaned at 65 days (an unusually long time for an animal this small) and are independent at 120 days. Maturity is usually attained at twelve months, though ages as young as nine months have been reported.

  • Breeding interval
    Southern flying squirrels breed twice each year.
  • Breeding season
    Breeding occurs from January to April and from June to August.
  • Range number of offspring
    1 to 6
  • Average number of offspring
    2-3
  • Average number of offspring
    4
    AnAge
  • Average gestation period
    40 days
  • Average gestation period
    40 days
    AnAge
  • Average birth mass
    3.35 g
    0.12 oz
    AnAge
  • Average time to independence
    120 days
  • Range age at sexual or reproductive maturity (female)
    9 (low) months
  • Average age at sexual or reproductive maturity (female)
    12 months
  • Average age at sexual or reproductive maturity (male)
    12 months

Young flying squirrels are born naked and helpless in their mother's nest. Their ears open at 2 to 6 days old, they develop some fur by 7 days old, and their eyes open by their 24th or 30th day of life. Females care for their young in the nest and nurse them for 65 days, which is an unusually long time for an animal of this size. The young become independent by 4 months old unless they are born later in the summer, in which case they usually overwinter as a family.

Lifespan / Longevity

Southern flying squirrels in the wild can live to 5 or 6 years old. In captivity they have been known to live up to 10 years. Most flying squirrels probably die in their first year of life.

Behavior

Activity is primarily nocturnal. Flying squirrels are often seen in pairs, and can be gregarious. During winter, groups of 10 to 20 individuals are sometimes found in dens in hollow trees. Females have been reported to be territorial and to defend nest sites during the mating season. Flying squirrels live in hollow trees, deserted woodpecker holes, and in buildings and bird boxes. Nests are made of soft materials like shredded bark, dry leaves, moss, feathers and fur.

Flying squirrels are not true fliers but gliders. They leap from high vantages and spread the arms and legs, stretching the loose skin of the body into an efficient sail. As they approach a landing, they raise the tail to change the course of the glide upwards and extend the limbs to use the skin as a parachute. Upon landing, they quickly move to the other side of the tree to avoid predators that may have detected and followed them during the glide. They are agile in the air, avoiding obstacles like trees and even making 90 turns. From a height of 18 meters they can glide about 50 meters; maximum glide is about 80 meters.

Home Range

Home ranges in both sexes range in size from about .5 to about 1.5 hectares. Male ranges overlap; female ranges do not overlap with each other or those of males.

Communication and Perception

Southern flying squirrels have very large eyes in order to see well in low light. They have keen senses of smell, touch, vision, and hearing. They probably communicate about reproductive condition through chemical cues. Vibrissae on the cheeks, chin, and ankles help them in navigating at night. They are relatively quiet but may use some vocalizations in social communication.

Food Habits

Southern flying squirrels are omnivores and eat a wide range of foods, including nuts, acorns, seeds, berries, fruit, moths, junebugs, leaf buds, bark, eggs and young birds, young mice, insects carrion, and fungus. They are especially fond of hickory nuts and acorns; one sure sign of the presence of this species is piles of gnawed hickory nuts at the base of large hickory trees. They will store food for winter use.

  • Animal Foods
  • birds
  • eggs
  • carrion
  • insects
  • Plant Foods
  • leaves
  • wood, bark, or stems
  • seeds, grains, and nuts
  • fruit
  • Other Foods
  • fungus

Predation

Flying squirrels avoid predators by being nocturnal and by being fast and agile in the trees and during their glides. They are alert for predators constantly. The most successful predators on flying squirrels are able to fly, such as hawks and owls, or can climb well, such as domestic cats, bobcats, weasels, raccoons, and climbing snakes.

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Flying squirrels consume large numbers of the fruiting bodies of subterranean fungi, dispersing the spores in their feces. The mycelia of these fungi form close associations with the roots of many species of trees and are believed to be essential for tree growth and maintenance. They also disperse the seeds of hardwood trees.

  • Ecosystem Impact
  • disperses seeds

Economic Importance for Humans

Economic Importance for Humans: Positive

Flying squirrels play important ecosystem roles in hardwood forests. They are also sometimes kept as pets.

Economic Importance for Humans: Negative

Flying squirrels are sometimes pests when they make nests in houses.

Conservation Status

Some subspecies in Central America are rare and may be endangered.

Other Comments

Southern flying squirrels are often the most common squirrel in hardwood woodlands and suburban areas. Because they are nocturnal and seldom seen, most people don't recognize that they live with flying squirrels.

Contributors

David L. Fox (author), University of Michigan-Ann Arbor, Michael Mulheisen (author), University of Michigan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

arboreal

Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carrion

flesh of dead animals.

chemical

uses smells or other chemicals to communicate

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

hibernation

the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.

internal fertilization

fertilization takes place within the female's body

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

omnivore

an animal that mainly eats all kinds of things, including plants and animals

pet trade

the business of buying and selling animals for people to keep in their homes as pets.

polygynous

having more than one female as a mate at one time

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

solitary

lives alone

stores or caches food

places a food item in a special place to be eaten later. Also called "hoarding"

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

Baker, R. H. 1983. Michigan Mammals. Michigan State University Press.

Forsyth, A., 1985. Mammals of the Canadian Wild. Camden House Publishing Ltd.: Camden East, Ontario, 351 pp.

Nowak, R. N., 1991. Walker's Mammals of the World. The Johns Hopkins University Press: Baltimore, MD, 1629 pp.

"Animal Life Histories Database" (On-line).

Ruff, S., D. Wilson. 1999. The Smithsonian Book of North American Mammals. Washington [D.C.]: Smithsonian Institution Press in association with the American Society of Mammalogists.

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