Biswamoyopterus biswasi Saha, 1981:333

Namdapha flying squirrel, Biswas' flying squirrel (proposed)



Taxonomy & Nomenclature

Synonym/s: Biswamoyopterus laoensis Sanamxay et al., 2013


Conservation Status

Missing, but possibly conspecific with one or both of its congeners (Li et al., 2020). As such, it would have taxonomic priority and thus be taxonomically rediscovered.

Last record: 1981

IUCN RedList status: Critically Endangered


The Namdapha flying squirrel (Biswamoyopterus biswasi) is only known from a single specimen collected in Namdapha National Park, Arunachal Pradesh in 1981 (Saha, 1981). No other specimens have been confirmed as being observed in the wild, however, possible sightings by a birdwatcher from Switzerland have been reported:

"This species is restricted to type locality only in the adjacent slopes of a particular valley and the EoO is less than 100 sq km. It was believed there were no recent sightings until three specimens were seen at Deban and one at Haldibari on 23 and 24 December 2002 by a Swiss birdwatcher in Namdapha (Ritschard, 2003)." (Molur et al. 2005:431)



Namdapha National Park, Arunachal Pradesh, India


Biology & Ecology




Only known from the holotype. 



A photograph of this specimen may be seen here:



Original scientific description:

Saha, S. S. (1981). A New Genus and a New Species of Flying Squirrel (Mammalia: Rodentia: Sciuridae) from Northeastern India. Zoological Survey of India 4(3): 331-336.


Other references:

Alfred, J.R.B., Sinha, N. K. and Chakraborty, S. (2002). Checklist of Mammals of India. Published by Director, Zool. Surv. India, Kolkata. Rec. zool. Surv. India, Occ. Paper. 199: 1-289.

Chatterjee, P., Dam, D., Tripathy, B. and Chandra, K. (2020). Status, distribution and research gaps of rodents (Mammalia: Rodentia) in North-Eastern States of India. Travaux du Muséum National d’Histoire Naturelle “Grigore Antipa” 63(2): 261-277.

Corbet, G. B. and Hill, J. E. (1992). Mammals of the Indo-Malayan Region: a Systematic Review. Oxford University Press, Oxford, UK.

Holmes, Branden. (2021). What's Lost and What Remains: The Sixth Extinction in 100 Accounts (eBook). Self published.

Li G, Lwin YH, Yang B, Qin T, Phothisath P, Maung K-W, Quan R-C, Li S (2020). Taxonomic revision and phylogenetic position of the flying squirrel genus Biswamoyopterus (Mammalia, Rodentia, Sciuridae, Pteromyini) on the northern Indo-China peninsula. ZooKeys 939: 65-85.

Li, Qui, Li, Xue-You, Jackson, Stephen M., Li, Fei, Jiang, Ming, Zhao, Wei, Song, Wen-Yu and Jiang, Xue-Long. (2019). Discovery and description of a mysterious Asian flying squirrel (Rodentia, Sciuridae, Biswamoyopterus) from Mount Gaoligong, southwest China. Zookeys 864: 147-160. Full paper:

Mishra, C., A. Datta and M.D. Madhusudhan. (2004). The high altitude wildlife of western Arunachal Pradesh: a survey report. DERC Technical report No. 8.

Molur, S. (2008). Biswamoyopterus biswasi. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.1. ( Downloaded on 01 October 2011.

Pradhan, M. S. and Talmale, S. S. 2009. List of valid Rodent taxa (Class: Mammalia, Order: Rodentia) from Indian Subcontinent region including Myanmar. Published by the Director, Zool. Surv. India, Kolkata. Rec. zool. Surv. India, Kolkata. 297: 1-239.

Pradhan, M. S. and Talmale, S. S. 2011. A Checklist of valid Indian Rodent Taxa (Mammalia: Rodentia). Published by Zoological Survey of India (Online version: Updated till May, 2011.). 12 pp.

Ritschard, M. (2003). RFI Namdapha Flying Squirrel. Email message submitted to from locustella, dated Tuesday, August 12, 2003, 2:26PM.

Sanamxay, Daosavanh et al. (2013). Rediscovery of Biswamoyopterus (Mammalia: Rodentia: Sciuridae: Pteromyini) in Asia, with the description of a new species from Lao PDR. Zootaxa 3686 (4): 471-481. [Abstract]

Sanjay Molur, C. Srinivasulu, Bhargavi Srinivasulu, Sally Walker, P.O. Nameer and Latha Ravikumar. (2005). Status of South Asian Non-volant Small Mammals: Conservation Assessment and Management Plan (C.A.M.P.) Workshop Report. Zoo Outreach Organisation / CBSG-South Asia, Coimbatore, India, 618pp.

Srinivasulu, C., Chakraborty, S. and Pradhan, M. S. (2004). Checklist of sciurids (Mammalia: Rodentia: Sciuridae) of South Asia. Zoos’ Print Journal 19(2): 1351-1360.

Talukdar, N.R., Choudhury, P., Barbhuiya, R. A., Ahmad, F., Daolagupu, D. and Baishya, J. B. (2021). Mammals of northeastern India: an updated checklist. Journal of Threatened Taxa 13(4): 18059-18098. doi:

Wilson, D.E. and Reeder, D. M. (eds.). 2005. Mammal Species of the World: A Taxonomic and Geographic Reference- Third Edition Johns Hopkins University Press, Baltimore, MD. 2: 1-2141.


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