Squirrels of the World

Biswamoyopterus biswasi 89

natural history: This nocturnal species is reported to
feed on the leaves or needles of oak, cedar, and pine, and on
various fruits. It nests in tree dens and rock crevices. In Tai-
wan, a two-year survey resulted in only 14 sightings. This
and previous surveys have led to the conclusion that this
species is found throughout the Central Mountain Range of
this country, but occurs at low densities. Despite numerous
studies of B. pearsonii, little else is known about its ecology,
behavior, and population biology.

general references: Agrawal and Chakraborty 1979;

Chaimanee and Jaeger 2000; Duckworth and Molur 2008;

Lee 1998; Lunde et al. 2003; Mishra et al. 2006; Oshida 2006;

Oshida, Lin, Masuda, et al. 2000; Oshida, Lin, Yanagawa, et

al. 2002; Oshida, Shafi que, et al. 2004; Scheibe et al. 2007; A.

T. Smith and Xie 2008; Srinivasulu et al. 2004; R. W. Thor-

ington and Darrow 2000; R. W. Thorington, Pitassy, et al.

2002; Yu 2002.

Biswamoyopterus Saha, 1981

This genus contains a single species.

Biswamoyopterus biswasi Saha, 1981

Namdapha Flying Squirrel

description: This large fl ying squirrel is red, grizzled with
white, on the upperparts. The crown of the head has a patch
of pale violet gray pelage. The patagium (“wing”) is a glossy
mahogany red above. The tail beyond the interfemoral
membrane is proximally pale smoky gray, changing distally
to vinaceous rufous to russet to clove brown near the tip.
The pale smoky gray region is also washed with red. The
pelage of the muzzle is vinaceous red, changing to mahog-
any red around the eyes; there is a black line across the nasal
bridge. The body underparts are white with grayish tones.

The patagium below is washed faintly orange rufous. The

interfemoral membrane underneath has a band of pale red,

grizzled with gray and white near the margin. The under-

arm is red.

size: Sex not stated—HB 405.0 mm; TL 1010 mm.

distribution: B. biswasi is known only from the type lo-

cality: the western slope of the Patkai Range in northeast-

ern India.

geographic variation: None.

conservation: IUCN status—critically endangered. Popu-

lation trend—decreasing.

habitat: The Namdapha fl ying squirrel is reported to oc-

cupy tropical dry deciduous montane forests in riparian

zones, at elevations of 100–350 m. This species may occupy

a single valley of less than 100 km^2 in Namdapha National

Park, Tirap District, Arunachal Pradesh (northeastern In-

dia). Extensive surveys in the area have not produced

sightings.

natural history: B. biswasi is considered to be repre-

sented by extremely small populations that are probably

decreasing and susceptible to a range of threats, including

logging, agriculture, poaching for food, and extreme

weather (e.g., fl ooding). The species is thought to be crepus-

cular, but virtually no data are available on its distribution,

densities, behavior, and ecology. No specifi c conservation

measures are in place.

general references: Kumar 1998; Lee and Liao 1998;

Meijaard and Groves 2006; Molur 2008a; Molur et al. 2005;

Saha 1981.