36 Microsciurus santanderensisconservation: IUCN status—data defi cient. Population
trend—no information.
habitat: This species is found in marshlands and montane
forests within its restricted range.
natural history: M. santanderensis is diurnal. Once con-
sidered a subspecies of Sciurus pucheranii, this dwarf squirrel
is poorly known. It is reported from forests, at elevations of
100–1000 m and 2700–3800 m.general references:Alberico and Rojas-Dias 2002; Alberico et al. 2000; Eisen-
berg 1989; Leonard et al. 2009.Rheithrosciurus Gray, 1867
This genus contains a single species.
Rheithrosciurus macrotis (Gray, 1856)
Tufted Ground Squirrel
description: Tufted ground squirrels have a distinctive
longitudinal groove on their incisors. The dorsum is brown
with a slightly grizzled reddish tone. The shoulders and
front limbs are sometimes more grizzled with a grayish
wash. The hips, hind limbs, and base of the tail are a reddish
bay. A white to buff to yellow stripe runs longitudinally
along the fl ank, sometimes in tandem with a dark brownish
stripe. The ears are large, with exaggerated red to dark
brown tufts. The venter is pale gray to buff. The tail is griz-
zled charcoal heavily frosted with white.
size: Both sexes—HB 335–352 mm; T 299–342 mm; Mass
1170–1280 g.distribution: This species is found on the island of Bor-
neo (divided among Malaysia, Brunei Darussalam, and
Indonesia).geographic variation: None.conservation: IUCN status—vulnerable. Population
trend—decreasing, totally protected in Sarawak (Malaysia).habitat: Tufted ground squirrels are only recorded from
lowland primary forest, where they are found on hillsides,
at elevations less than 1100 m; however, survey eff orts in
other habitat types have not focused on this species. On oc-
casion it can be seen in orchards and secondary forests.Rheithrosciurus macrotis. Photo courtesy Wildlife Conserva-
tion Society–Malaysia Program.