FLYING SQUIRRELS OF SOUTHEAST ASIA

INDOCHINESE FLYING SQUIRRELS

Indochinese flying squirrel

Indochinese flying squirrels (Hylopetes phayrei) are also known as Phayre's flying squirrel. They found throughout Southeast Asia, including northern and western Thailand, Laos, northern Vietnam and Myanmar. There are also small populations in Southeast China including Hainan island. They live in tropical, subtropical, and evergreen forests between 150 meters to around 3,500 meters (492 to 11483 feet) in elevation. [Source: Amanda Burrell; Olivia Helback; Nathan Nguyen, Animal Diversity Web (ADW) /=]

Indochinese flying squirrels are primarily herbivores (primarily eat plants or plants parts) but are also recognized as frugivores (eat mainly fruits), granivore (eat seeds and grain) and omnivores (eat a variety of things, including plants and animals). Animal foods include insects. Among the plant foods they eat are leaves, roots, tubers wood, bark, stems, seeds, grains, nuts and fruit. They also eat fungus and have been documented consuming cultivated fruit during the night.

Indochinese flying squirrelsare not considered endangered. On the International Union for Conservation of Nature (IUCN) Red List they are listed as Lower Risk — Least Concern Data Deficient. In CITES (Convention on International Trade in Endangered Species of Wild) they have no special status. Like many animals their habitat is being reduced by deforestation, plantation agriculture and human development. Some tribal people hunt the species to use as a good will sacrifice during marriage ceremoniess

There are 44 species of flying squirrel worldwide. The fact that most of them live in Asia has led some scientists to hypothesize that they originated there. Only two species are found in the Americas: the Northern flying squirrel and the Southern flying squirrel. Gliding has evolved independently in a variety of arboreal animals. Among mammals, these include the marsupial gliding possums of Australia, the colugos of Southeast Asia, and the scaly-tailed flying squirrels of Africa. Each group glides in a slightly different way, with their patagia being controlled by different morphological adaptations. In some marsupial gliders for example, the patagium attaches at the elbows, whereas in colugos it extends into webbed digits. The fact that all flying squirrels are “wrist gliders” with shared wrist anatomy suggests that they are all descended from a common ancestor, presumably some sort of primitive tree squirrel. Non-mammalian arboreal gliders include frogs, geckos, snakes, lizards, and even ants. [Source: Wikipedia]

Before taking off, flying squirrels bob and rotate their heads to gauge the route, and then leap into the air, spreading their patagia between cartilaginous spurs on their wrists and ankles. Small adjustments to these spurs give them some control over their speed and direction. Their flattened tails aid in steering. As their destination nears, they pull upright, prepare their padded feet to cushion the shock of impact, and ready their sharp claws to grip the bark. Gliding is an efficient way to travel but maneuverability in the air is limited. By keeping nocturnal habits, flying squirrels avoid predation by more skilled fliers, such as hawks and eagles. Owls, however, may still be a threat.

Indochinese Flying Squirrel Characteristics, Behavior and Reproduction

Indochinese flying squirrel range

Indochinese flying squirrels are very small animals. They range in weight from 113 to 180 grams (3.98 to 6.34 ounces) and have a head and body length that ranges from 17.4 to 19.7 centimeters (6.85 to 7.76 inches). Sexual Dimorphism (differences between males and females) is not present: Both sexes are roughly equal in size and look similar. Indochinese flying squirrels have a white stomach and throat with grey to dark brown or russet head and dorsal fur. The fur can have lighter tips that appear white or brown. The feet are grayish brown. The tail is flattened, but fully furred with a darker fur at the base and sides and lighter on the top. There is also a white mark behind the ears. [Source: Amanda Burrell; Olivia Helback; Nathan Nguyen, Animal Diversity Web (ADW) /=]

Indochinese flying squirrels are arboreal (live mainly in trees), scansorial (able to or good at climbing), glides nocturnal (active at night), motile (move around as opposed to being stationary), sedentary (remain in the same area) and have the ability to glide. During the day, it is presumed, they rest in hollow trees and come out at night to search for food. As is the case with other flying squirrels, they has a membrane that stretches between their front and hind legs that they use to glide between trees. Indochinese flying squirrels sense and communicate with vision, touch, sound and chemicals usually detected by smelling. A related species — Particolored flying squirrels — call in a high-pitched trill. /=\

The breeding season of Indochinese flying squirrels runs from April through mid June, and two or three young are born per litter. In related species such as Jentink's flying squirrel reproduction is linked to fruit production in rainforest trees, with mating occurring when fruit is abundant. Indochinese flying squirrels nests in tree cavities

Red-Cheeked Flying Squirrels

Red-cheeked flying squirrels (Hylopetes spadiceus) are found in large patch throughout Southeast Asia — in Myanmar, Thailand, Malaysia, Sumatra, northern Borneo, southern Vietnam, Laos, and Singapore. They live in primary forests, secondary forest and scrub, and cultivated areas. They are adept gliders like other flying squirrels and make their nests in hollow trees or limbs, sometimes with twigs and leaves. They have been seen at elevations of up to 1500 meters (4920 feet). [Source: Riley Fache, Animal Diversity Web (ADW) /=]

Red-cheeked flying squirrels are primarily herbivores (primarily eat plants or plants parts) but are also recognized as folivores (eat mainly leaves), frugivores (eat mainly fruits), granivores (eat seeds and grain) and omnivores (eat a variety of things, including plants and animals). They have been observed feeding mainly on flowers, fruits, and leaves. Among the other foods they eat are seeds, grains, nuts and insects. Eating adaption of this species include the loss of canines and enhancement of cusps on cheek teeth, which is characteristic of most rodents. There are no known positive effects of Red-cheeked flying squirrels on humans. /=\

red-cheeked flying squirrel

Red-cheeked flying squirrels are not endangered. The International Union for Conservation of Nature (IUCN) Red List classifies them as a species of “Least Concern”. In CITES (Convention on International Trade in Endangered Species of Wild) they have no special status. The main threats to these animals are loss of habitat due to deforestation and development by humans. They may also be hunted for meat. There are three recognized subspecies of Red-cheeked flying squirrels, based on their geographic distributions: 1) H. s. spadiceus, found in peninsular Malaysia; 2) H. s. everetti, found in Borneo; and 3) H. s. sumatrae, found in Sumatra. /=\

Red-cheeked flying squirrels are very small. They range in weight from 50 to 80 grams (1.76 to 2.82 ounces). Their average head and body length is 14.6 centimeters (5.7 inches) and their tail is 12.7 centimeters (five inches). Sexual Dimorphism (differences between males and females) is present: Males are larger than females. Red-cheeked flying squirrels have orange-brown fur with brighter red-orange cheeks and tail. Their tails resemble broad, flat arrow heads. They have a furred patagium (membrane between the forelimbs and hindlimbs used for gliding) formed by sheets of muscle. A rod of cartilage extends from the wrist and helps spread the patagium when gliding. Their big eyes are believed to provide good night vision. They have five digits on each of their hind feet and four on their fore feet.

Red-cheeked flying squirrels are arboreal (live mainly in trees), have the ability to glide, nocturnal (active at night), motile (move around as opposed to being stationary) and solitary. They communicate with vision and touch and sense using vision, touch and chemicals usually detected with smell. They tend to be very quiet use their vibrissae (whiskers) for tactile perception. The ratio of vibrissae length to head length is higher in flying squirrels than in regualr squirrels. Red-cheeked flying squirrels have been observed gliding farther than 50 meters between trees, and are even able to gain a meter in height by altering the angle and position of their patagium. /=\

Whats has been deduced about the mating systems of red-cheeked flying squirrels is based on the habits of a similar species —gray-cheeked flying squirrels (Hylopetes lepidus) — that was once considered a subspecies of red-cheeked flying squirrels. Gray-cheeked flying squirrels have a gestation period of approximately 40 days, and giver birth to between one and four young, with the average being two. They engage in year-round breeding.

Temminck's Flying Squirrels

red-cheeked flying squirrel range

Temminck’s flying squirrels (Petinomys setosus) live throughout much of Southeast Asia — in northwestern and southern Thailand, northern and eastern Myanmar, Sumatra, the northern third of Borneo, southern peninsular Malaysia, and Laos. They are relatively adaptable and survive in a variety of habitats including wet tropical rainforests and dry deciduous and monsoonal forests. They prefer primary forests but have also been observed in partially cut forests and areas in around fruit and rubber plantations.[Source: Ward Chapman; Ashley Contreras; Kathryn DeWilde; Tyler Mohrmann; Dana Sheets-Nichols, Animal Diversity Web (ADW) /=]

Temminck’s flying squirrels are primarily, frugivores (eat mainly fruits) but are also regarded as herbivores (primarily eat plants or plants parts) and granivores (eats seeds and grain). Among the plant foods they eat are seeds, grains, nuts and fruit. On the International Union for Conservation of Nature (IUCN) Red List Temminck’s flying squirrels are listed as Vulnerable. In CITES (Convention on International Trade in Endangered Species of Wild) they have no special status. Their average lifespan in the wild is estimated to be 3.3 years.

Temminck’s flying squirrels are very small. Their average weight is 42.4 grams (1.49 ounces) and their average length is 11.6 centimeters (4.57 inches). They have a mix of of black and brown fur on their back side and off-white, cream-colored fur on their underside. The tail is flat and is similar colored as their back fur and patches of white at the base and tip. Temminck’s flying squirrels are distinguished by the presence of black rings that encircle the eyes and connect to the nose via a black streak.

Little is known about the behavior of Temminck’s flying squirrels. They are arboreal (live mainly in trees), have the ability to glide, nocturnal (active at night) and are motile (move around as opposed to being stationary) One study found that a specimen from this species preferred isolated habitats away from human settlements and activities. They sense using touch and chemicals usually detected with smell. Average litter size is likely one to two offspring.

Indian Giant Flying Squirrels

range of the giant Indian flying squirrel

Indian giant flying squirrels(Petaurista philippensis) are widely distributed across Asia — in South Asia, mainland of Southeast Asia, and central and southern China. In South Asia they have a fragmented distribution in Sri Lanka and India, primarily concentrated in the Himalayan Mountains and northeast regions north of Bombay and Rajastan. In Southeast Asia they are found in Thailand, Vietnam, Myanmar, Cambodia and Laos but not Malaysia or Indonesia. In China, Indian giant flying squirrels have been has recorded in Yunnan, Hainan Island, Sichuan, and Shaanxi. They can also be found on Taiwan.[Source: Brandi Ringgenberg, Animal Diversity Web (ADW) /=]

Indian giant flying squirrels make their homes in tree cavities and occupy the tree canopy. They live in deciduous and evergreen forests of South Asia, hardwood forests of Taiwan, and patches of forests on Hainan Island. In Southeast Asia they can be found in tropical rainforests and subtropical rainforests from 0 to 500 meters in elevation. temperate broad leafed forests from 500 to 1,800 meters, and temperate mixed forests from 1,800 to 2,500 meters. They are often sighted on the edges of forests, or within plantations among their primary food source, fig trees.

Indian giant flying squirrels may their numbers limited in certain areas but overall they are endangered. The International Union for Conservation of Nature (IUCN) Red List classifies them as a species of “Least Concern”. In CITES (Convention on International Trade in Endangered Species of Wild) they have no special status. They are regarded as crop pests in some places and most negatively impacted by habitat loss but appear to adapt fairly well to environments that have been affected by humans. Among the known predators are domestic cats, owls, arboreal snakes, raccoon dogs, martens and fishers and black crested gibbons. The latter have been observed reaching into flying squirrel nests, pulling out juveniles and swinging them by the tail against trees and rocks to kill them. When the squirrel is dead, its carcass is eaten and shared by the gibbon with its offspring.

Indian Giant Flying Squirrel Characteristics and Diet

Indian giant flying squirrels weigh up to 1.65 kilograms (3.63 pounds). Their average length is one meters (3.28 feet). Sexual Dimorphism (differences between males and females) is not present: Both sexes are roughly equal in size and look similar. Males generally weigh about 1.260 kilograms while females weigh around 1.33 grams. There is little difference between skulls of Indian giant flying squirrels males and females. [Source: Brandi Ringgenberg, Animal Diversity Web (ADW) /=]

Indian giant flying squirrels have a patagium (membrane between the forelimbs and hindlimbs used for gliding) similar to one in northern flying squirrels, used to glide from tree to tree. They prefer short gliding distances as longer ones require broader, unobstructed landing platforms, which are not always available in the dense forest. A wide range of fur color have been observed depending on the location. Mostly they have dark maroon to black back with white tips, with a lighter brown to white underside.

Indian giant flying squirrels are primarily herbivores (primarily eat plants or plants parts) but are also regarded as folivores (eat mainly leaves). Among the plant foods they eat are leaves, wood, bark, stems, fruit, flowers, sap or other plant fluids and lichens. They prefer fruits and leaves of ficus trees and, unlike many other flying squirrels, they don’t eat insects or other animal matter. Ficus fruits are an easily accessible source of energy rich in calcium, minerals, low in fat content, and possibly a source of animal protein as wasps implant their larvae in them. Indian giant flying squirrels prefer mature leaves to immature ones. More mature leaves are consumed in February and December, when ficus trees produce less fruit. Feeding is more common along the edge of the forest, where sunlight generates greater leaf production. The diet of Indian giant flying squirrels found on plantations get two thirds of their food from ficus and jackfruit trees. They are also good at exploiting food resources in disturbed areas where logging has occured. Their ability to consume leaf material, bark, sap at disturbed sites has helped Indian giant flying squirrels thrive even places with habitat disturbances. /=\

Indian Giant Flying Squirrel Behavior

Indian giant flying squirrels are arboreal (live mainly in trees), have the ability to glide, nocturnal (active at night), crepuscular (active at dawn and dusk), motile (move around as opposed to being stationary). They are generally solitary, leaving their nests shortly after dusk and returning before dawn. On average, they spend nine to 13 hours out in the open, increasing their duration when nights get longer in the winter months. They are most active around dawn and dusk. However, their activity patterns vary according to the month. During the winter to early spring, they become less active around near midnight, resting more often and feasting on mature leaves. From spring to early summer they are active throughout the night. [Source: Brandi Ringgenberg, Animal Diversity Web (ADW) /=]

The average home range for adult male Indian giant flying squirrels is four hectares and 2.2 hectares for adult females. Depending on food availability and the number of receptive femalesresent, a male's home range may increase. Smaller gliders have an energetic advantage over larger gliders with heavier bodies but larger gliders are more energy efficient as they tend to land and leap less often. Folivores, such as Indian giant flying squirrels, also require a smaller home range, when compared to fruit-eating smaller flying squirrels due to the availability of more leaves than fruit. This also means they have to glide less frequently. Daily range distances average 255 to 640 meters for adults; less in the summer when higher quality food resources are easier to access. Different individuals are affected by different environmental factors. Some travel less with increased rainfall; others travel less when mature leaves are more plentiful. Lactating females tend to have a larger range than non-lactating females as they need more energy of milk production. /=\

Indian giant flying squirrels sense and communicate with vision, touch, sound and chemicals usually detected by smelling. Their large eyes in relation to body size implies they highly have developed vision and night vision.. Similar flying squirrels also have good hearing. Other flying squirrel species have vibrissae on their chin, cheeks, and ankles that help them sense and navigate at night. Many species of flying squirrel communicate with auditory, visual, and chemical cues, especially during the breeding season, but not much is known about these. /=\

Indian Giant Flying Squirrel Mating, Reproduction and Offspring

range of the giant Indian flying squirrel

Little is known about the mating system of Indian giant flying squirrels but it is thought that are polygynous (males have more than one female as a mate at one time) or polygynandrous (promiscuous, with both males and females having multiple partners) based on the location and home range size of the males. Indian giant flying squirrels engage in seasonal breeding and have two breeding seasons a year: during February to March and July to August. The number of offspring ranges from one to two, with the average number being one. The average gestation period is 46 days. The average weaning age is three months and the age in which they become independent ranging from 95 to 185 days. [Source: Brandi Ringgenberg, Animal Diversity Web (ADW) /=]

During the mating season, the male may alter his diet and activities to cope with reproduction, by spending more time finding a mate and less time eating. Breeding lasts for two weeks, females mate with an average of three to five males.

Young are precocial. This means they are relatively well-developed when born. Parental care is provided by females. Young are born within the tree cavity the squirrel occupies and they are only raised by their biological mother. At birth, Indian giant flying squirrels weigh approximately 56 grams compared to 1.65 kilograms for adults.

Red Giant Flying Squirrel

Red giant flying squirrels (Petaurista petaurista) are also known as common giant flying squirrels and giant flying squirrels. Among the largest tree-dwelling squirrels, they range across South Asia, Southeast Asia, Indonesia and China from the eastern border regions of Afghanistan to Java, and from Kashmir, Taiwan, and southern China to Sri Lanka. Its greatest numbers are found in the forest regions of Pakistan. [Source: Sarah Newlin and James Bradshaw, Animal Diversity Web (ADW) /=]

The diet of red giant flying squirrels consists primarily of pine cones, tree buds, leaves, young branches, and, when in season, various fruits and nuts. In captivity, they eat raisins and nuts and refuse shrubs and other leafy substances. Red giant flying squirrels make their nests in the tree cavities of densely forested areas in forests. Their average lifespan in captivity is 16 years. The two main predators of red giant flying squirrels are the charsa marten and the bengal cat, which are able to surprise the squirrel while it sleeps.

Within their geographic range red giant flying squirrels are quite common.The International Union for Conservation of Nature (IUCN) Red List classifies them as a species of “Least Concern”. However, the cutting and burning of forest regions have significantly reduced the size of their habitats. They are sometimes hunted. Their pelt have been seen for sale in markets in Murree and Rawalpindi.

Spotted Giant Flying Squirrels

spotted giant flying squirrels

Spotted giant flying squirrels (Petaurista elegans) are also known as lesser giant flying squirrels. Their range extends from Nepal in the west into Southeast Asia and the Malay Peninsula, as far east as Vietnam. Their range in the south includes the islands of Sumatra, Java and Borneo, as well as a few smaller surrounding islands. The lifespan of spotted giant flying squirrels is not known, but members of a related species, red giant flying squirrels, have lived up to 16 years in captivity. [Source: Eva Ryckman, Animal Diversity Web (ADW) /=]

Spotted giant flying squirrels are found in temperate and tropical forests. They are usually encountered in trees 15-20 meters above ground and are more common at higher altitudes — 3,000 to 4,000 meters (9,842 to 13,124 feet). The most often observed at lower elevations in the spring, possibly because there is more food there and less at higher altitudes during that time of year.

Giant flying squirrels were once fairly abundant within their range and they are still are not considered endangered. The International Union for Conservation of Nature (IUCN) Red List classifies them as a species of “Least Concern”. In CITES (Convention on International Trade in Endangered Species of Wild) they have no special status. However, human degradation of their habitat, especially of tall trees necessary for nesting sites, and hunting pressures have had a negative impact on their numbers and breeding success. Likely natural predator include owls and civets.

Spotted Giant Flying Squirrel Characteristics and Diet

Spotted giant flying squirrels are about the size of a cat. They range in weight from 1.14 to 1.36 kilograms (2.5 to 3 pounds) and have a head and body length that ranges from 30.5 to 58.5 centimeters (12 to 23inches). Their brush-like tail can exceed the length of their body and range from 35.6 to 63.5 centimeters (14 to 25inches) in length. Sexual Dimorphism (differences between males and females) is not present: Both sexes are roughly equal in size and look similar. [Source: Eva Ryckman, Animal Diversity Web (ADW) /=]

Eva Ryckman wrote in Animal Diversity Web: All Petaurista have a furry membrane between their ankles and wrists that is supported by a cartilaginous rod that assists in gliding. Six mammae are located on their abdominal region. Their general coloration is dark on top and light on the underside. There is significant geographic variation in the species, and some authorities recognize multiple subspecies. Variants involve coloration of the back (brown to black), spotting on the back (unspotted to spotted, with spotted individuals varying in the extent of spotting), presence of reddish rump patch and/or a black line running the length of their backs, and the coloration of limbs and tail (black, brown or orange). The presence of intermediates connecting these forms supports recognizing all within a single, variable species. /=\

Spotted giant flying squirrels are primarily omnivores (eat a variety of things, including plants and animals). Animal foods include eggs, insects, larvae and terrestrial non-insect arthropods. Among the plant foods they eat are leaves seeds, grains, soft fruit, nuts, leaves and shoots. Spotted giant flying squirrels sense and communicate with vision, touch, sound and chemicals usually detected by smelling. Flying squirrels tend to be quiet animals. Because they are nocturnal they may rely on auditory and chemical cues and have especially keen night vision.

Spotted Giant Flying Squirrel Behavior and Reproduction

spotted giant flying squirrels range

Spotted giant flying squirrels are arboreal (live mainly in trees), have the ability to glide, nocturnal (active at night), motile (move around as opposed to being stationary) and social (associates with others of its species; forms social groups). They spend the day in tree cavities. Little is known about their social behavior but their close relative, red giant flying squirrels, occur in groups of a mated pair and their offspring. The extent of the home range of spotted giant flying squirrels is not known but a related species, the Japanese giant flying squirrel, occupies home ranges of 0.46 to 5.16 hectares in area. Home ranges of individuals overlap. [Source: Eva Ryckman, Animal Diversity Web (ADW) /=]

According to Animal Diversity Web: Species of Petaurista share a method of gliding. By jumping and extending their extremities as far as possible they create a parachute with which they may glide long distances. They can control the direction of their gliding by the tension in the membrane, as well as by using their tail as a rudder. When the squirrel approaches its destination it increase the angle of its membrane relative to direction of movement. This results in a short upward glide and reduction in speed, allowing a comfortable landing. Though their membrane may be good for gliding, it makes climbing more difficult, and individuals limit their activities to the night hours when predation is not as high. /=\

The mating systems of spotted giant flying squirrels have not been studied. Studies of their close relative, red giant flying squirrels, suggested that mated pairs remain together throughout the year. Spotted giant flying squirrels are known to produce litters of one or two offspring. In Nepal, lactating females were collected in October. Because mated pairs may remain together throughout the year this suggests that both males and females have parental roles.

Image Sources: Wikimedia Commons

Text Sources: Animal Diversity Web animaldiversity.org ; National Geographic, Live Science, Natural History magazine, David Attenborough books, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Discover magazine, The New Yorker, Time, Reuters, Associated Press, AFP, Lonely Planet Guides, Wikipedia, The Guardian, Top Secret Animal Attack Files website and various books and other publications.

Last updated April 2025