Geoscience Reference
In-Depth Information
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Creatures of the Night
Walking through the forest at dusk, you will
undoubtedly see mammals flying through the
forest. Nine families of bats with 75 genera are
present in the Neotropical rainforest. Of these,
five families are endemic: the funnel-eared bats,
thumbless bats, sucker-footed bats, bulldog
bats, and leaf-nosed bats. Leaf-nosed bats
include five subfamilies: the spear-nosed bats,
long-tongued bats, short-tailed bats, fruit bats,
and vampire bats. The four other families pres-
ent are sheath-tailed bats, leaf-chinned bats,
mustached and naked-backed bats, vespertilio-
nid or brown bats, and free-tailed or Mastiff bats.
Bats occupy a vast array of niches. There are
frugivores (fruit eaters), nectavores (nectar and
pollen eaters), carnivores (meat eaters), insecti-
vores (insect eaters), omnivores (generalists),
and even sangivores (blood eaters). Bats are
crucial in regulating insect populations, polli-
nating flowers, and dispersing seeds within the
Neotropics.
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Bats attain their greatest diversity in the Neo-
tropical rainforest, where they are the most
numerous and account for 39 percent of all mam-
mals in the rainforest. All Neotropical bats belong
to the suborder Microchiroptera. These bats use
sonar or echolocation. The bats emit high-fre-
quency sounds through their mouths or noses and
the returning echoes give them information about
their surroundings. They are mostly nocturnal.
Primates are another group of mammals com-
monly found in the Neotropics. Four Neotropical
families form a distinct taxonomic group called
the platyrrhines. These families consist of the
New World monkeys (Cebidae), including mar-
mosets, tamarins; squirrel and capuchin monkeys;
night monkeys and owl monkeys (Aotidae);
howler, woolly, spider, and woolly spider mon-
keys (Atelidae); and titi monkeys, sakis, and uaka-
ris (Pithecidae). Platyrrhines are different from
the catarrhine primates found in the tropical for-
ests of Asia and Africa. Platyrrhines have short
muzzles and flat, naked faces. Their nostrils are
widely set and open to the side. Their eyes face
forward, and they have short bodies, and long
hind legs (see Figure 3.6). The origin of platyr-
rhines is a matter of considerable debate. Some researchers point to a primitive rel-
ative originating in Africa, with platyrrhines evolving from this relative in the
Neotropics after South America and Africa separated. Others suggest a more
recent origin that has primates coming from Africa through Asia and North Amer-
ica to South America when the northern landmasses had more tropical environ-
ments that facilitated migrations.
Most Neotropical monkeys have long tails and spend most if not all of their
lives in trees. Many have prehensile tails (unlike their African counterparts). These
tails assist in movement and stability. Primates are the most important seed dis-
persers for canopy trees and lianas, and with continuous forest habitat, many can
travel over long distances.
Marmosets and tamarins are small primates with tufted hair, tassels, or manes
on their heads; claws instead of nails; and long nonprehensile tails. Marmosets
and tamarins feed on fruits and insects and live within the dense vegetation of the
forest canopy. Squirrel and capuchin monkeys are medium-size diurnal, arboreal
monkeys that eat fruit, leaves, insects, or small vertebrates. Squirrel monkeys do
not have prehensile tails, but capuchin monkeys do. Night or owl monkeys are
the only family of nocturnal primates in the Americas; they feed on fruits, insects,
