Friday, September 23, 2011

Flying Squirrels

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). 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. This changes the tautness of the patagium, a furry parachute-like membrane that stretches from wrist to ankle. 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.
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. In the Pacific Northwest of North America, the Northern Spotted Owl (Strix occidentalis) is a well-known predator. Flying squirrels are nocturnal, flying at night as they are not adept in escaping birds of prey that hunt during daylight. 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.
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.
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. Gliding conserves energy.


    • Pliopetaurista kollmanni Daxner-Höck, 2004
Thorington and Hoffman (2005) recognize 15 genera of flying squirrels in two subtribes.
Tribe Pteromyini – flying squirrels
  • Subtribe Glaucomyina
    • Genus Eoglaucomys
      • Kashmir Flying Squirrel, Eoglaucomys fimbriatus
    • Genus Glaucomys – New World flying squirrels (American flying squirrels), North America
      • Southern Flying Squirrel, Glaucomys volans
      • Northern Flying Squirrel, Glaucomys sabrinus
    • Genus Hylopetes, southeast Asia
      • Particolored Flying Squirrel, Hylopetes alboniger
      • Afghan Flying Squirrel, Hylopetes baberi
      • Bartel's Flying Squirrel, Hylopetes bartelsi
      • Gray-cheeked Flying Squirrel, Hylopetes lepidus
      • Palawan Flying Squirrel, Hylopetes nigripes
      • Indochinese Flying Squirrel, Hylopetes phayrei
      • Jentink’s Flying Squirrel, Hylopetes platyurus
      • Sipora Flying Squirrel, Hylopetes sipora
      • Red-cheeked Flying Squirrel, Hylopetes spadiceus
      • Sumatran Flying Squirrel, Hylopetes winstoni
    • Genus Iomys, Malaysia and Indonesia
      • Javanese Flying Squirrel (Horsfield's Flying Squirrel), Iomys horsfieldi
      • Mentawi Flying Squirrel, Iomys sipora
    • Genus Petaurillus – pygmy flying squirrels, Borneo and Malaya
      • Lesser Pygmy Flying Squirrel, Petaurillus emiliae
      • Hose's Pygmy Flying Squirrel, Petaurillus hosei
      • Selangor Pygmy Flying Squirrel, Petaurillus kinlochii
    • Genus Petinomys, southeast Asia
      • Basilan Flying Squirrel, Petinomys crinitus
      • Travancore Flying Squirrel, Petinomys fuscocapillus
      • Whiskered Flying Squirrel, Petinomys genibarbis
      • Hagen's Flying Squirrel, Petinomys hageni
      • Siberut Flying Squirrel, Petinomys lugens
      • Mindanao Flying Squirrel, Petinomys mindanensis
      • Arrow Flying Squirrel, Petinomys sagitta
      • Temminck's Flying Squirrel, Petinomys setosus
      • Vordermann's Flying Squirrel, Petinomys vordermanni
  • Subtribe Pteromyina
    • Genus Aeretes, northeast China
      • Groove-toothed Flying Squirrel (North Chinese Flying Squirrel), Aeretes melanopterus
    • Genus Aeromys – large black flying squirrels, Thailand to Borneo
      • Black Flying Squirrel, Aeromys tephromelas
      • Thomas's Flying Squirrel, Aeromys thomasi
    • Genus Belomys, southeast Asia
      • Hairy-footed Flying Squirrel, Belomys pearsonii
    • Genus Biswamoyopterus, India
      • Namdapha Flying Squirrel, Biswamoyopterus biswasi
    • Genus Eupetaurus, Kashmir; rare
      • Woolly Flying Squirrel, Eupetaurus cinereus
    • Genus Petaurista, southeast Asia
      • Red And White Giant Flying Squirrel, Petaurista alborufus
      • Spotted Giant Flying Squirrel, Petaurista elegans
      • Hodgson's Giant Flying Squirrel, Petaurista magnificus
      • Bhutan Giant Flying Squirrel, Petaurista nobilis
      • Indian Giant Flying Squirrel, Petaurista philippensis
      • Chinese Giant Flying Squirrel, Petaurista xanthotis
      • Japanese Giant Flying Squirrel, Petaurista leucogenys
      • Red Giant Flying Squirrel, Petaurista petaurista
    • Genus Pteromys – Old World flying squirrel, Finland to Japan
      • Siberian Flying Squirrel, Pteromys volans
      • Japanese Dwarf Flying Squirrel, Pteromys momonga
    • Genus Pteromyscus, southern Thailand to Borneo
      • Smoky Flying Squirrel, Pteromyscus pulverulentus
    • Genus Trogopterus, China
      • Complex-toothed Flying Squirrel, Trogopterus xanthipes
Two new species have been recently added from northeastern Indian state of Arunachal Pradesh. These are:
  • Mechuka Giant Flying Squirrel (Petaurista mechukaensis)
  • Mishmi Hills Giant Flying Squirrel (Petaurista mishmiensis)
 The largest of the species is the woolly flying squirrel (Eupetaurus cinereus). The two species of the genus Glaucomys (Glaucomys sabrinusand Glaucomys volans) are native to North America, and the Siberian flying squirrel is native to parts of northern Europe (Pteromys volans).

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