The Namdapha flying squirrel (''Biswamoyopterus biswasi'') is an

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose nu ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

Arunachal Pradesh Arunachal Pradesh (, ) is a state in Northeastern India. It was formed from the erstwhile North-East Frontier Agency (NEFA) region, and became a state on 20 February 1987. It borders the states of Assam and Nagaland to the south. It shares ...

northeast India , native_name_lang = mni , settlement_type = , image_skyline = , image_alt = , image_caption = , motto = , image_map = Northeast india.png , ...

, where it is known from a single

specimen Specimen may refer to: Science and technology * Sample (material), a limited quantity of something which is intended to be similar to and represent a larger amount * Biological specimen or biospecimen, an organic specimen held by a biorepository ...

collected in

Namdapha National Park Namdapha National Park is a large protected area in Arunachal Pradesh of Northeast India. The park was established in 1983. With more than 1,000 floral and about 1,400 faunal species, it is a biodiversity hotspot in the Eastern Himalayas. The ...

in 1981. No population estimate is available for ''B. biswasi'', but the known habitat is tall ''

Mesua ferrea ''Mesua ferrea'', the Ceylon ironwood, or cobra saffron, is a species in the family Calophyllaceae. This slow-growing tree is named after the heaviness and hardness of its timber. It is widely cultivated as an ornamental due to its graceful sh ...

'' jungles, often on hill slopes in the

catchment A drainage basin is an area of land where all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, t ...

area of

Dihing River Dihing or Burhi Dihing (Dihong = wide river ) is a large tributary, about long, of the Brahmaputra River in Upper Assam in northeastern India. The river originates at above sea level in the Eastern Himalayas (the Patkai Hills) in Arunachal P ...

(particularly on the western slope of

Patkai The Pat-kai (Pron:pʌtˌkaɪ) or Patkai Bum ( Burmese: ''Kumon Taungdan'') are a series of mountains in the Indo-Myanmar border falling in the north-eastern Indian states of Arunachal Pradesh, Nagaland and Upper Burma region of Myanmar. The ...

range) in northeastern India. It was the sole member in the genus '' Biswamoyopterus'' until the description of the

Laotian giant flying squirrel The Laotian giant flying squirrel (''Biswamoyopterus laoensis'') is an arboreal, flying squirrel endemic to Laos. It was the second described member in the genus ''Biswamoyopterus'', after being first collected in September 2012 by scientists res ...

(''Biswamoyopterus laoensis'') in 2013. In 2018, Quan Li from the Kunming Institute of Zoology at the Chinese Academy of Sciences discovered a new squirrel in the same genus while studying specimens in their collection, called the Mount Gaoligong flying squirrel (''Biswamoyopterus gaoligongensis''), based on the region it was discovered in.

Description

''Biswamoyopterus biswasi'' has reddish, grizzled fur with white above. Its crown is pale grey, its patagium is orangish and its underparts are white. The cheek teeth of ''B. biswasi'' are simple, and its

incisor Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, wher ...

s are unpigmented. Septae are multiple in

auditory bulla The tympanic part of the temporal bone is a curved plate of bone lying below the squamous part of the temporal bone, in front of the mastoid process, and surrounding the external part of the ear canal. It originates as a separate bone (tympanic ...

e and sometimes

honeycomb A honeycomb is a mass of hexagonal prismatic wax cells built by honey bees in their nests to contain their larvae and stores of honey and pollen. Beekeepers may remove the entire honeycomb to harvest honey. Honey bees consume about of honey ...

-shaped with 10 to 12 cells in it. It measures from head-to-

vent Vent or vents may refer to: Science and technology Biology *Vent, the cloaca region of an animal * Vent DNA polymerase, a thermostable DNA polymerase Geology *Hydrothermal vent, a fissure in a planet's surface from which geothermally heated wate ...

and has a long tail. The hindfoot is and the ear is . The scientific name commemorates Biswamoy Biswas, director of the

Zoological Survey of India The Zoological Survey of India (ZSI), founded on 1 July 1916 by Government of India Ministry of Environment, Forest and Climate Change, as premier Indian organisation in zoological research and studies to promote the survey, exploration and r ...

Status

The Namdapha flying squirrel is listed as critically endangered by the IUCN. It is known from a single specimen collected in 1981 in

. Its range of the Namdapha flying squirrel may be restricted to a single valley and it is threatened by poaching of animals for food from within the park, and possibly by

habitat destruction Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

. It is among the 25 "most wanted lost" species that are the focus of Global Wildlife Conservation's "Search for Lost Species" initiative. There are several later reports of sightings by tourists and local researches, but a review by scientists specialising in flying squirrels found that most—if not all—have been the result of confusion with other, more common species that occur in Namdapha National Park, especially the rather similar ''candidula'' red giant flying squirrel (''Petaurista petaurista candidula'').

References

{{Taxonbar, from=Q1482523 Biswamoyopterus Endemic fauna of India Rodents of India Environment of Arunachal Pradesh Critically endangered fauna of Asia Mammals described in 1981 Species known from a single specimen