Callosciurus erythraeus 137in lowland dipterocarp forests. In a lowland dipterocarp for-
est in the Krau Wildlife Reserve (Pahang, Malaysia), C. cani-
ceps was captured only 8 percent as frequently as C. notatus
(4 individuals versus 53 individuals live trapped, respec-
tively). In China, it also occurs in dipterocarp forests with
thick brushy vegetation. It may be found at elevations of up
to 2500 m, but it is more common at lower elevations.
natural history: In the Ulu Gombak Forest Reserve (Se-
langor, Malaysia), this squirrel is most active from 4 to
6 p.m., but it is also active in the morning. It is usually seen
at heights between 0 and 10 m, less frequently at 10–15 m,
and infrequently at greater heights or on the ground. One
study notes that it feeds on 13 species of plants—on fruits
(45%), leaves (21%), bark (17%), and fl owers (10%)—with “oth-
ers” comprising the rest of its diet. Elsewhere, insects are
reported to be included in the diet. The home ranges of in-
dividuals overlap, both between and within sexes, with
those of the males averaging 2.4–2.6 ha, and those of the fe-
males, 1.2–1.5 ha. The gray-bellied squirrel seems to respond
diff erently to various kinds of predators. It reacts to terres-
trial predators with a repeated staccato bark, which causes
other conspecifi cs to climb upward and remain silent; it re-
sponds to a n aer ia l predator w it h a low-f requenc y ba rk i f t he
predator is d ist a nt a nd a “rat t le” ca l l i f it is close; a nd it reac t s
to snakes with a “squeak” call that attracts other squirrels to
join in mobbing the snake. Other gray-bellied squirrels re-
spond to the “rattle” call by stopping any movement, and
they join in the vocalizing if the aerial predator is near
them. When a female comes into estrous, she attracts six to
eight males and mates with four to six of them in a six-hour
period. After mating with the female, a male gives a barking
vocalization, like the antipredator call, for 12–35 minutes,
during which time the female and the other males do not
move. In the Ulu Gombak Forest Reserve, pregnant females
have been trapped in most months of the year, and litter size
is one to fi ve, with a mean of 2.2 (n = 14). The nest is spheri-
cal, with a poorly defi ned lateral entrance. It has an outer
wall of small twigs or coarse leaves, which is lined with
shredded fi brous material. The nest is usually in the upper
branches of a small tree or bush, but one was found on the
ground at the foot of a bamboo clump, among leaf litter.general references: Abdullah et al. 2001; Lundahl and
Olsson 2002; Moore and Tate 1965; Saiful et al. 2001; Tamura
1993; Tamura and Yong 1993.Callosciurus erythraeus (Pallas, 1779)
Pallas’s Squirreldescription: This is an exceedingly variable squirrel that
is generally recognizable by the combination of the reddish
coloration of the venter and the olive brown coloration of
the dorsum. C. erythraeus has been divided into several spe-
cies by some taxonomists.size: Female—HB 217.4 mm (n = 142); T 216.6 mm (n = 10);
Mass 375.1 g (n = 343).
Male—HB 227.0 mm (n = 15); T 205.3 mm (n = 15); Mass
359.2 g (n = 371).
Sex not stated—HB 209.3 mm (n = 52); T 176.9 mm (n = 46);
Mass 286.5 g (n = 2).distribution: This species is found west of the Irrawaddy
River in Bhutan, India, Myanmar, and Tibet, as well as east
of the Irrawaddy River in Myanmar, southern China, Laos,
Cambodia, Vietnam, Thailand, peninsular Malaysia, and Tai-
wan. Pallas’s squirrel has been introduced to Argentina, the
Neth erlands, Belgium, France, Italy, Hong Kong (China), and
Japan. In 1935, 40 squirrels were introduced from Taiwan toCallosciurus caniceps bimaculatus. Photo courtesy Nick Baker,
http://www.ecologyasia.com.