Primate Conservation 71In the past, bonobos were thought to be the same spe-
cies. When bonobos were recognized as a distinct species
in 1929, their common name was “pygmy chimpanzee.”
“Bonobo” replaced this term because not only does their
size range overlap with that of chimpanzees, but as we will
explore in the next chapter, this feature is not the most
characteristic difference between the two groups.
Although thought of as particularly quick and clever,
all four great apes are of equal intelligence, despite some
differences in cognitive styles. More arboreal than goril-
las but less so than orangutans, chimpanzees and bonobos
forage on the ground much of the day, knuckle-walking
like gorillas. At sunset, they return to the trees, where they
build their nests.Primate Conservation
The above survey of living primates illustrates the diver-
sity of our closest living relatives. To ensure that they will
continue to share the planet with us, primate conservation
has become an issue of vital importance. Nearly 50 percent
of the known primate species and subspecies face extinc-
tion in the next decade.^6
In Asia, the statistics are even more alarming, with more
than 70 percent of species threatened and at least 80 percent
at risk in Indonesia and Vietnam. Included among them
are all of the great apes, as well as such formerly widespread
and adaptable species as rhesus macaques. In the wild these
animals are threatened by habitat destruction caused byGorillas, found in equatorial Africa, are the largest of
the apes; an adult male can weigh over 450 pounds, with
females about half that size. Scientists distinguish between
two gorilla species: the lowland and mountain varieties.
The body is covered with a thick coat of glossy black hair,
and mature males have a silvery gray upper back. There is
a strikingly human look about the face, and like humans,
gorillas focus on things in their field of vision by directing
the eyes rather than moving the head.
Gorillas are mostly ground dwellers, but the lighter fe-
males and young may sleep in trees in carefully constructed
nests. Because of their weight, adult males spend less time
in the trees but raise and lower themselves among the tree
branches when searching for fruit. Gorillas knuckle-walk,
using all four limbs with the fingers of the hand flexed,
placing the knuckles instead of the palm of the hand on the
ground. They stand erect to reach for fruit, to see something
more easily, or to threaten perceived sources of danger with
their famous chest-beating displays. Though known for
these displays to protect the members of their troop, adult
male silverback gorillas are the gentle giants of the forest. As
vegetarians, gorillas devote a major portion of each day to
eating volumes of plant matter to sustain their massive bod-
ies. Although gorillas are gentle and tolerant, bluffing ag-
gression is an important part of their behavioral repertoire.
Chimpanzees and bonobos are two closely related
species of the same genus (Pan), pictured frequently
throughout this chapter. Bonobos are restricted in their
distribution to the rainforests of the Democratic Republic
of Congo. The common chimpanzee, by contrast, is widely
distributed in the forested portions of sub-Saharan Africa.
Chimpanzees and bonobos are probably the best known of
the apes and have long been favorites in zoos and circuses.This male orangutan was pho-
tographed along the Gohong
River on the island of Kaja,
Borneo. A resident of a pre-
serve where captive animals
are rehabituated into the wild,
the young male copied this
hunting behavior by watching
humans spear fishing along
the same river. Although so
far the orangutan has been
unable to nab a fish with his
spear tip, his intent is clear.
This rare photograph, along
with the first photograph of a
swimming orangutan, appears
in the beautiful book titled
Thinkers of the Jungle, by
Gerd Schuster, Willie Smits,
and photographer Jay Ullal.(^6) Kaplan, M. (2008, August 5). Almost half of primate species face extinc-
tion. doi:10.1038/news.2008.1013.
© Jay Ullal