54 Sciurus granatensisS. g. sumaco—Mount Sumaco (Oriente, in eastern Ecuador).
This form is more gray, and the tail is black and buff , not
red.
S. g. tarrae—near Santander (Colombia). It is a very dark
form that is uniformly dark agouti above, with deep red
underparts.
S. g. valdiviae—Antioquia (Colombia). This is a subspecies
with a blackish yellow dorsum and a reddish orange ven-
ter; the tail is black at the base, with a reddish tip.
S. g. variabilis—near Magdalena (Colombia). It is a large-bod-
ied form that is blackish and reddish on the dorsum,
with a sharply defi ned white venter.
S. g. versicolor—northern Ecuador. It is red above and below,
with a black median stripe the length of the dorsum, and
a tail that is black at the base and the tip.
S. g. zuliae—Venezuela, near the border with Colombia. This
is a reddish form, with a very black tip on the tail.
conservation: IUCN status—least concern. Population
trend—stable.
habitat: Red-tailed squirrels inhabit many types of forests,
from sea level to montane, including secondary forests and
picnic areas and parks.
natural history: This species is diurnal. Red-tailed
squirrels are specialists on large tropical tree seeds, and
they can be heard gnawing through the thick protective
seed coats while sitting motionless on a forest perch. S.
granatensis plays a major role in the evolution and dispersal
of seeds within tropical forests. A number of other seeds,
fruits, leaves, fl owers, fungi, plant saps and exudates, and
even animal materials are eaten opportunistically. Foods
are scatter-hoarded on the ground and hidden in branch
forks or lianas in the canopy. Red-tailed squirrels can be
found fora g i ng i n mu lt iple layers of forest ca nopies t h roug h-
out the year. Most often found in the midcanopy and the
upper canopy when seeds ripen, S. granatensis is less com-
monly seen on the ground. From November to August, mat-
ing chases occur where several to many males will follow
and chase the female while grunting and snorting in an ef-
fort to gain access during a single day of estrus. Copulations
last only about 10 seconds, and males lose interest within
30 minutes after copulation. Gestation is probably about 45
days, and a litter of one to three young is born in a leaf nest
within the canopy. As many as three litters may be pro-
duced during what appears to be a prolonged breeding sea-
son. The young continue to nurse for up to two months, and
all disperse from their natal areas. Individuals live a solitary
life, although feeding aggregations may occur at seasonal
food sources. Female home ranges are relatively exclusive
and defended from other females, and they cover about 0.64
ha; male home ranges are larger, at about 1.5 ha, with con-
siderable interindividual overlap. Annual survivorship is
50–64 percent; preweaning juvenile survival is low. Maxi-
mum longevity in the wild is at least 7 years. Their major
predators are monkeys, mustelids, procyonids, felids, rap-
tors, and a multitude of snakes. S. granatensis will produce a
series of hoarse “chucks” when a larmed; however, it usua lly
remains relatively silent. Red-tailed squirrels are considered
pests throughout much of their range in places where they
come into contact with agriculture, as this species will eat a
diversity of fruit and nut crops; harvested cuts, orchards,
and the edges of pastures and urban areas harbor these
squirrels. S. granatensis is hunted as a pest and for food
throughout its range.general references: Adler et al. 1997; Carvajal and Adler
2008; Heaney and Thorington 1978; Mena-Valenzuela 1998;
Nitikman 1985.Sciurus griseus (Ord, 1818)
Western Gray Squirreldescription: Western gray squirrels have a slate to silver
gray dorsum that sometimes appears fi nely grizzled with
black, and a white to buff eye ring. The venter is white, some-
times with a faint wash of buff. The tail is colored similarly