40 Sciurus aestuanshas white postauricular patches, and a reddish wash to
the body and feet.
S. a. alphonsei—northern coast of Brazil. This form has a pale
yellowish dorsum, with a grayish venter.
S. a. garbei—Espirito Santo and Bahia (Brazil). This form has
chestnut ochraceous upperparts and orange ochraceous
underparts, with a paler throat region.
S. a. georgihernandezi—northwestern portion of the range,
including Colombia.
S. a. henseli—far southern region of Brazil, and northeast
Argentina. The sides are ashy colored, and the venter is
white.
S. a. ingrami—eastern and southern coasts of Brazil. This
subspecies has an olivaceous dorsum, with a white to
buff venter.
S. a. macconnelli—mountains of southern Venezuela, Guy-
ana, and probably northern Brazil. This form is more
brownish olivaceous.
S. a. quelchii—southern Guyana and northcentral Brazil.
This form is olivaceous, with a yellow belly.
S. a. sebastiani—restricted to Sebastian Island (Brazil). This
large form has a stronger darker brown color tone than
the mainland varieties. The tail color is reddish brown,
whereas the tails of those on the mainland are gray brown.
S. a. venustus—near Mount Duida (Venezuela). This is a di-
minutive subspecies, with coloration similar to S. a.
aestuans.
conservation: IUCN status—least concern. Population
trend—no information.
habitat: S. aestuans is commonly found in tropical rainfor-
ests, swamps and wet forests, Atlantic gallery forests, sec-
ondary forests, gardens, and plantations. It can also be
found in urban parks.
natural history: This species is diurnal. Guianan squir-
rels are found in all forest levels, but most commonly in the
m ids tor y, at 5–12 m. They ma ke nes t s of leaves i n t he ca nopy
of trees. Guianan squirrels appear to be solitary. Exclusive
use of territories does not occur, and home range overlap is
considerable. The average male home range (6.5 ha) is twice
the size of that of the female (3.1 ha) in fall, and it gradually
decreases in winter after mating. Males track and sniff
females, and eventually several males chase one female
through the canopy to mate. Females are pregnant in winter
and summer, suggesting two annual mating seasons. Pri-
marily herbivorous, S. aestuans feeds predominately on
seeds and fruits of the highly diverse palms in neotropical
forests, oaks (Quercus), a variety of other trees, and up to fi ve
shrubs. Fungi are eaten in winter and spring. Guianan squir-
rels demonstrate a consistent palm nut handling behavior
for each palm species in order to obtain the protected seed
endosperm; the behavior is actually learned, beginning as a
juvenile. Guianan squirrels serve as an important seed dis-
perser by carrying and caching fruit in autumn and winter,
sometimes storing it at heights of more than 30 m. Within
forest fragments of the Atlantic forest in southeastern Bra-
zil, S. aestuans accounts for 96 percent of the seed predation
for some species. S. aestuans are probably prey for many for-
est-dwelling carnivores—such as felids, procyonids, canids,
mustelids, primates, snakes, lizards, and raptors—but docu-
mented predators are ocelots (Leopardus pardalis), margays
(Leopardus wiedii), and capuchin monkeys (Cebus). S. aestuans
has a varied vocal repertoire that includes alarm calls of
sharp “chucks” or “chatters,” soft single “chips,” and high-
pitched twanging whines. When alarmed, Guianan squir-
rels ascend a tree and chatter while running to hide, or de-
part through the canopy. S. aestuans is hunted for food in
much of its range.general references: Alvarenga and Talamoni 2006; Bor-
dignon and Monteiro-Filho 1999, 2000; Cullen et al. 2001;
Fagundes et al. 2003; Galetti 1990; Galetti et al. 1992; Grelle
2003; Müller and Vesmanis 1971; Paschoal and Galetti 1995;
Souza 2000.Sciurus alleni (Nelson, 1898)
Allen’s Squirreldescription: Allen’s squirrels have yellow brown backs
grizzled with black and gray; the head is generally darker;
and the sides are lighter. The eye ring is white to buff. The
legs are white to buff , with a dorsal grizzling of black. The
venter is white. The tail is black, sometimes suff used withSciurus aestuans. Photo courtesy Patrícia Alexandre Formozo.