Introduction | Habitat | Behaviour | Development
orangutans are, together with bonobos, chimpanzees and gorillas, members
of the biological family Hominidae or great apes, to which also
humans belong. These four great apes are considered to be the closest
relatives to humans, showing resemblance in genetic characteristics (97%
similar) as well as cognitive capacities and behaviour.
Orangutans are the most solitary and arboreal
of the great apes. They spend a large amount of their time alone and
in the trees. Orangutans
are actually the largest tree living mammals in the world and the only
red ape. Furthermore orangutans are the only great ape species living in
South East Asia.
While all the other great ape species are found in Africa, orangutans
are only found in the tropical rainforests on the islands of Borneo and
Sumatra, in the countries of Indonesia and Malaysia.
In the Ponginae subfamily of the great apes,
only two species still exist, both belonging to the genus Pongo. These
orangutan species are both characterized by their long arms and reddish
fur. They are distinguished as their deviation in habitat (two islands)
suggests: Pongo abelii in Sumatra and the Pongo
pygmaeus in Borneo.
The phenotypic differences between the two geographically separated species
are apparent. The Sumatran orangutans are thinner and have paler
red coats than their Bornean relatives. Hair and face are longer, with
the face diamond shaped instead of square like as in the Bornean
species. Adult males of both species have prominent cheekpads, called
flanges. In the Sumatran orangutans these flanges are covered with fine,
white hair and point more towards the front, whereas in the Bornean orangs
the cheekpads are more horizontally stretched, markedly larger, and
covered with short bristly hair. The throatpouches of the Bornean males
are larger as well and are more pendulous.
Except for these phenotypic differences,
the two species can also be distinguished genetically and behave differently
as well. Sumatran orangutans
for example are more social and hardly come to the ground, as
opposed to their Bornean relatives which are more solitary and regularly
to the ground. Sumatran orangutans furthermore seem to have a longer
What’s in the
The name Pongo was used by Linnaeus in 1760,
who laid the foundations for the modern system of taxonomy. The name
comes from a 16th century
account by Andrew Battell (an English sailor held prisoner by the Portuguese
in Angola), in which the name Pongo was given to refer to an anthropoid
monster, of which it is now believed, a gorilla was meant. Precise descriptions
of species remained quite unclear until the end of the 18th century.
It was in 1799, that Lacépède, a French naturalist, used
the word Pongo to refer to the genus of which the orangutan belongs to.
Another name for orangutan, primarily used
by local people is Maias or Mawas, which has its origins in the Malaysian
language. It is however
unclear to what these words refer to: only to orangutans, or all apes
in general. The word orangutan also has its
origins in the Malaysian language. Here the meaning is a lot more obvious
can be easily derived from
the words "orang" and "hutan" which literally mean
'man of the forest'.