194 Sundasciurus tenuissize: Female—HB 139.8 mm; T 114.8 mm; Mass 81.4 g.
Male—HB 140.7 mm; T 113.4 mm; Mass 85.2 g.
Sex not stated—HB 138.9 mm; T 114.1 mm; Mass 76.8 g.
distribution: This species can be found on the Malay Pen-
insula, Sumatra (Indonesia), the island of Borneo (divided
among Malaysia, Brunei Darussalam, and Indonesia), and
adjacent small islands.
geographic variation: Five subspecies are recognized.
S. t. tenuis—southwest Thailand and south on the Malay
Peninsula. It has a dull pelage. This form diff ers from
S. tahan by its smaller size, paler upperparts, and the
lack of a buff y suff usion on the inner thighs and ingui-
nal region.
S. t. bancarus—Banjak (= Banyak) Islands (Indonesia). The
upperparts are brown tinged with yellow. The gray un-
derparts are washed with a whitish cream buff.
S. t. modestus—Sumatra (Indonesia). The underparts are
cream gray. The dorsal surface is the typical speckled
brown of this species, but with a rufous wash on the
fl anks. The tail is the same color as the dorsal surface.
The tail tip is all black.
S. t. parvus—island of Borneo (divided among Malaysia, Bru-
nei Darussalam, and Indonesia). The underparts are
tinged buff. Otherwise the coloration is similar to S. t.
tenuis.
S. t. procerus—Bunguran Island (Indonesia). This form is
similar to S. t. tenuis, but smaller.conservation: IUCN status—least concern. Population
trend—decreasing.habitat: S. tenuis occurs in tall and secondary forests
throughout the lowlands and hills of the island of Borneo,
except for most of Sabah (Malaysia) and northern and south-
eastern East Kalimantan (Indonesia). It was recorded at an
elevation of 1650 m, but most records are from lower eleva-
tions. It appears to be replaced ecologically by S. jentinki in
the mountain ranges in the northern and central parts of the
island of Borneo.Sundasciurus tenuis. Photo courtesy Norman Lim.