| Flying squirrel Temporal range: Early Oligocene - Recent |
|
|---|---|
| Northern flying squirrel (Glaucomys sabrinus) | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Rodentia |
| Family: | Sciuridae |
| Subfamily: | Sciurinae |
| Tribe: | Pteromyini Brandt, 1855 |
| Genera | |
|
Aeretes |
|
Flying squirrels, scientifically known as Pteromyini or Petauristini, are a tribe of 44 species of squirrels (family Sciuridae).
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Flying squirrels are not capable of powered flight like birds or bats; instead, they glide between trees. They are capable of obtaining lift within the course of these flights, with flights recorded to 90 meters (295 ft).[2][3] The direction and speed of the animal in midair is varied by changing the positions of its two arms and legs, largely controlled by small cartilaginous wrist bones.[4] This changes the tautness of the patagium, a furry parachute-like membrane that stretches from wrist to ankle.[4] It has a fluffy tail that stabilizes in flight. The tail acts as an adjunct airfoil, working as an air brake before landing on a tree trunk.[5]
The colugos, Petauridae, and Anomaluridae are gliding mammals, which are similar to flying squirrels, because of convergent evolution. A few mammals can glide through the trees, but they do not actually fly (like birds and bats). They have a membrane of skin on either side of their body.
The largest of the species is the woolly flying squirrel (Eupetaurus cinereus). The two species of the genus Glaucomys (Glaucomys sabrinus and Glaucomys volans) are native to North America, and the Siberian flying squirrel is native to parts of northern Europe (Pteromys volans).
Thorington and Hoffman (2005) recognize 15 genera of flying squirrels in two subtribes.
Tribe Pteromyini – flying squirrels
Two new species have been recently added from the northeastern Indian state of Arunachal Pradesh.[6][7] These are:
Though their life expectancy in the wild is six years, flying squirrels may live fifteen years in captivity. This is due to these creatures being important prey animals. Predation mortality rates in sub-adults are high. Predators include arboreal snakes, raccoons, nocturnal owls, martens, fishers, coyotes, and the domestic cat.[2] In the Pacific Northwest of North America, the Northern Spotted Owl (Strix occidentalis) is a well-known predator. Flying squirrels are nocturnal,[8] flying at night as they are not adept in escaping birds of prey that hunt during daylight.[2] Flying squirrels eat according to how hungry they are and what type of environment they are in. They eat whatever types of food they can find in their environment; if desperate they will eat anything. Southern Flying Squirrels eat seeds, insects, gastropods such as slugs and snails, spiders, tree shrubs, flowers, fungi and tree sap.
The mating season is between February to March. When young are born, the female squirrels live with them in maternal nest sites; they nurture and protect them until they leave the nest. The males do not participate in nurturing their offspring.[9]
At birth, they are mostly hairless,apart from their whiskers, and most of their senses are not present. The internal organs are visible through the skin, and their sex can be signified. By week 5 of their life, they are almost fully furred and developed. At that point, they can respond to their environment and start to develop a mind of their own. Through the upcoming weeks of their lives, they practice leaping and gliding. After two and a half months, their gliding skills are perfected, they are ready to leave their nest and are capable of independent survival.[10]
Flying squirrels can easily forage for food in the night, given their highly developed sense of smell, where they harvest fruits, nuts, fungi, and bird eggs.[2][11] Gliding conserves energy.[3]