Namdapha Flying Squirrel

The Namdapha Flying Squirrel (Petaurista alborufus) belongs to the order Rodentia, family Sciuridae, and the genus Petaurista, which comprises the giant flying squirrels of Southeast Asia. Endemic to the eastern Himalayas, its confirmed range is confined to the Namdapha National Park in Arunachal Pradesh, India, with occasional records from adjacent Kachin State in Myanmar. It inhabits tropical moist evergreen and subtropical montane forests between 500 and 1,800 meters elevation, favoring dense canopy layers that provide ample glide corridors. The species displays a striking pelage: a dark brown to black dorsal surface, a contrasting creamy‑white ventral side, and a broad, russet‑tinged patagium that stretches from wrist to ankle, enabling glides of up to 150 meters. Large, forward‑facing eyes and a keen sense of hearing support its nocturnal lifestyle. Because it has a very limited distribution and few confirmed sightings, the IUCN classifies it as Data Deficient, highlighting the need for targeted surveys to determine its true population status and ecological requirements.

Namdapha Flying Squirrels are strictly nocturnal and spend daylight hours roosting in tree hollows or dense foliage high in the canopy. They are largely solitary, with adult males maintaining overlapping home ranges that are defended through scent marking and occasional vocalizations, while females occupy smaller, more exclusive territories centered around nesting sites. Communication consists of soft chirps, low‑frequency whistles, and a series of tail‑flicks that convey alarm or territorial intent. Their gliding ability, powered by a well‑developed patagium, allows them to move efficiently between trees, covering distances of 30‑150 meters in a single glide. Seasonal movements are minimal; however, individuals may shift to lower elevations during the monsoon to exploit fruiting trees. Territorial disputes are resolved without physical combat, relying instead on vocal displays and scent cues from urine and glandular secretions.

The Namdapha Flying Squirrel is omnivorous, with a diet dominated by seasonal fruits, nuts, and seeds from canopy trees such as Castanopsis, Quercus, and Schima species. During the fruiting season, up to 70% of its intake consists of fleshy fruits like figs (Ficus spp.) and berries, which provide essential sugars and water. In leaner months, the squirrel supplements its diet with bark, lichens, and a modest proportion of insects (primarily beetles and moth larvae) to meet protein requirements. Daily food consumption averages 150‑250 grams, equivalent to roughly 10% of body mass. Foraging occurs at night, with individuals using their sharp incisors to crack hard shells and their keen sense of smell to locate hidden food caches. They also exhibit scatter‑hoarding behavior, burying seeds in shallow soil or leaf litter to retrieve later, a strategy that aids forest regeneration.

Sexual maturity is reached at approximately 18‑24 months for both sexes. Breeding occurs once a year, typically from March to June, coinciding with the peak fruiting period of many canopy trees. After a gestation period of about 70 days, females give birth to a single offspring, occasionally twins, in a well‑lined nest constructed of leaves, twigs, and moss within a tree cavity or a dense branch fork. Neonates are altricial, blind and hairless at birth, and rely entirely on maternal care for the first six weeks. The mother nurses the young twice daily and gradually introduces solid foods such as soft fruits and insects after three weeks. Juveniles become independent at 4‑5 months, when they begin to practice gliding under maternal supervision. Parental investment is high, but post‑weaning parental care is limited, and the species does not exhibit communal rearing.

The IUCN lists the Namdapha Flying Squirrel as Data Deficient, reflecting the paucity of reliable population data. Nevertheless, habitat loss is the principal threat; extensive logging, shifting agriculture, and infrastructure development within and around Namdapha National Park have fragmented the continuous canopy required for gliding and foraging. Illegal timber extraction reduces the availability of mature trees that provide nesting hollows, while road construction increases human access and the risk of hunting, although direct hunting pressure appears low. Climate change may alter the phenology of fruiting trees, potentially disrupting the squirrel’s seasonal food supply. Current estimates suggest a declining trend, but without systematic surveys the exact population size remains unknown. Conservation actions recommended include intensified field surveys, protection of primary forest blocks, and community‑based forest management to mitigate habitat degradation.

• Can glide up to 150 meters in a single leap, covering distances comparable to a small aircraft.
• Possesses a patagium that stretches over a wing‑like surface of up to 1.2 meters when fully extended.
• Plays a crucial role in seed dispersal for several endemic tree species in the Eastern Himalayas.
• Exhibits a unique vocal repertoire that includes ultrasonic clicks used for intra‑species communication.
• Despite its limited range, it shares its habitat with several other rare mammals, making it an indicator species for forest health.