Monkeys occupy interior forest, disturbed forest edge,
gallery forests, and dry forests. They are most diverse
and abundant in lowlands, but some occur in humid
montane forests. All are arboreal, and most species
rarely come to the ground, though some, such as the
capuchins and uakaris, occasionally do so to feed.
Taxonomically, the platyrrhines are divided into the
“typical” monkeys, placed in the family Cebidae; and
the tamarins and marmosets, sometimes called the
“squirrel- like” monkeys, in the family Callitrichidae.
Goeldi’s Monkey (discussed below), formerly placed
in its own family (Callimiconidae), is now placed in
Callitrichidae. Marmosets and tamarins are small,
and the group includes some of the world’s smallest
primates, such as the 15 cm (6 in), 85 g (3oz) Pygmy
Marmoset (discussed below). The largest Neotropical
monkeys are cebids, the biggest of which are the 9 kg
(20 lb) howlers. There are no Neotropical equivalents
of the great apes (the orangutan, gorilla, and
chimpanzees), though spider monkeys are ecologically
and anatomically similar to gibbons (small apes).
Among the more commonly seen monkeys are the
capuchins (plates 16- 4– 7), which range from Amazonia
through southern Central America. There are currently
16 species, listed in the genera Cebus and Sapajus.
Capuchins are 30– 60 cm (1– 2 ft) in length, excluding the
46 cm (18 in) prehensile tail, and weigh from 0.9 to 4 kg
(2– 9 lb). They vary from pale brown to black, and each
species has a pale face surrounded with whitish hair.
Troops, typically numbering from five to 30 or more
(depending on species), move quickly through forests
foraging for fruits, leaves, and arthropods. Some also
take birds’ eggs, baby birds, and even small mammals.
Capuchins are found in a wide variety of forest habitats,
and one is apt to encounter a capuchin group anywhere
from low tangle along the forest edge to the canopy of
interior forest. They also frequent gallery forests, dry
forests, and mangrove forests, as well as disturbed and
mature rain forest. Capuchins feed heavily on palm nuts
and thus are frequently seen among the fronds in palm
stands. They often function as seed dispersers. Capuchin
troops are noisy, and their vocalizations sometimes
attract agoutis and Collared Peccaries, which feed on
fruits dropped by the simians.
Titi monkeys (Callicebus spp.) are smaller than
capuchins. They have small faces and are thickly furred,
body color ranging from gray to black, with non-
prehensile, hairy tails. Titis are found in small groups
of two to six. Diurnal and highly active, they are very
skilled treetop jumpers. They feed on a wide variety of
fruits, buds, and various arthropods (including spiders
and millipedes), though one species, the widespread
Dusky Titi (C. moloch), feeds especially on leaves. Titis
seem to seek out thick jungle growth in which to feedPlate 16- 9. A group of Spix’s Night Monkeys (Aotus vociferans)
peering out of their shared tree cavity. Photo by Andrew
Whittaker.Plate 16- 8. Common Squirrel Monkey. Look closely, as there is
a baby on its back. Photo by Andrew Whittaker.
322 chapter 16 from monkeys to tarantulas: endless eccentricities