hair. In both subspecies, the head is both bald and bright
red, making the animal unmistakable. The other species,
the Black Uakari (C. hosomi), found in igapo forests, is
entirely black, and the face (but not the entire head) is
bald. Uakaris (pronounced WOK- a- rees) have short,
hairy, non- prehensile tails. Groups of 10 to 30 or more
animals feed on fruits, leaves, flowers, and arthropods,
especially caterpillars. They sometimes descend to the
ground to forage on seedlings and fruits. Unfortunately,
both species of uakaris are considered endangered due
to hunting pressure and loss of forest to logging.
The sakis (Pithecia spp.; plate 1- 22) and bearded
sakis (Chiropotes spp.; plate 16- 12) resemble uakaris
in general body shape and in having long hair, but
they have dense hair on their heads and faces, and
their thick, bushy non- prehensile tails are longer than
those of uakaris. Most are brownish gray or black.
One species, the Guianan Saki (Pithecia pithecia), is
strongly sexually dimorphic, the male black with a
white face, the female gray- brown. There are, debatably,
six saki species and four bearded saki species found
in various places throughout Amazonia. Sakis, rather
like the lemurs of Madagascar, are skilled at leaping
from tree to tree, which has earned them the Spanish
name volador, or “flier.” Small groups, rarely exceeding
five animals, feed primarily on fruits and are found
mostly in well- developed rain forest. Sakis are not
nearly as uncommon as uakaris. Bearded sakis also
feed primarily on fruits but are found in larger troops,
numbering up to 25 to 30 individuals.
Spider monkeys occur from Mexico southward
through the lower Amazon. There are seven species
in the genus Ateles and two in the genus Brachyteles.
They are generally geographically separated, though
there are many areas where the ranges of two species
are parapatric (sharing a common border but not
significantly overlapping). Because there is much
variation in color within some of the species, spider
monkeys are more easily identified by range than by
appearance. The three common and wide- ranging
species are the Central American Spider Monkey (Ateles
geoffroyi), which ranges throughout Central AmericaPlate 16- 13. The White- bellied Spider Monkey of northwestern
Amazonia is now considered to be an endangered species.
Photo by Andrew Whittaker.Plate 16- 12. Brown Bearded Saki (Chiropotes chiropotes). The
red testicles of this mature male are evident in the photo.
Photo by Andrew Whittaker.
324 chapter 16 from monkeys to tarantulas: endless eccentricities