Fact sheet - Sumatran Orangutan Society

Orangutan Facts
Where are orangutans found?
Orangutans are found in Indonesia and Malaysia on the islands of Borneo and
Sumatra.
Sumatra
Borneo
How many species of orangutan are there?
There are two species of orangutan - the Sumatran orangutan (Pongo abelii) and
the Bornean orangutan (Pongo pygmaeus).
Are orangutans monkeys or apes?
Orangutans are a Great Ape along with gorillas, chimpanzees and bonobos. The
Great Apes have large brains, forward-facing eyes and gripping hands. Humans
are also Great Apes. In fact we share 96.4% of our genetic makeup with
orangutans! Apes and monkeys are
both primates. The easiest way to
distinguish between monkeys and
apes is to look for a tail. Apes don’t
have tails whereas most monkey
species do.
How long do orangutans live?
In the wild, orangutans may live up to
45 years or more. The oldest captive
orangutan was a male called “Guas” at
the Philadelphia Zoo who lived until he
was 58 years old!
What does the word ‘orangutan’ mean?
Orangutan means ‘person of the forest’. It comes from the Malay words ‘orang’
meaning people and ‘hutan’ meaning forest.
What does ‘arboreal’ mean?
Arboreal means tree-living. The orangutan is the
largest arboreal animal in the world and is well
adapted for life in the trees. The orangutan can grasp
branches with both its hands and feet and has very
mobile shoulder and hip joints. Both these features
help the orangutan to travel through the forest
canopy. Orangutans make and sleep in a new nest
every night.
How sociable are orangutans?
Unlike gorillas, chimpanzees and bonobos, orangutans
do not live in large social or family groups. They are
semi-solitary animals. Adult males are usually found
alone and adult females are usually accompanied by one or two offspring.
Do male and female orangutans look different?
There are visible differences between males and females. Adult males can reach
1.5m in height and weigh as much as 120kg. Females are much smaller. They
grow up to 1m tall and weigh about 45kg. Male orangutans develop large cheek
pads and a throat pouch when they mature. The male inflates his throat pouch
to make a loud sound called a “long call” which alerts other orangutans to his
presence and attract females.
A female orangutan with her infant
A male orangutan
What do orangutans eat?
Orangutans are mainly frugivorous (fruit eating). Ninety per cent of their diet
consists of fruit but orangutans also eat nectar, honey, bark, leaves, insects and
fungi. An orangutan’s favourite fruit is the durian. Durians are well known for
their bad smell but orangutans love them!
How long is pregnancy?
Female orangutans have their first baby at about 14-15 years old. Pregnancy
lasts for 8½ months. Young orangutans have a lot to learn to survive in the
forest and will stay with their mother until they are about 7 or 8 years old. This
period of dependency is longer than any other primate apart from humans.
Female orangutans only have one baby approximately every 8 years and will
have 3 or 4 young in their lifetime.
How endangered are orangutans?
In 1900, there were over 315,000 wild orangutans. Today, there are
approximately 60,000. That is a decrease of more than 80% in just over 100
years! Only 7,000 of these remaining orangutans live in Sumatra. The Sumatran
orangutan is classified as critically endangered and the Bornean orangutan is
classified as endangered. It is thought that the Sumatran orangutan may be the
first great ape to become extinct in the wild.
Why are orangutans endangered?
The greatest threat to orangutans is the loss of their rainforest habitat. Tropical
rainforests are being cut down for timber and the land cleared for palm oil
plantations. Orangutans have lost 80% of their habitat in the last 20 years!
Orangutans are occasionally killed or injured by plantation owners and farmers
who consider orangutans to be pests. If a female orangutan is found with an
infant, the mother may be killed and the infant sold into the illegal pet trade.
Rehabilitation centers are set up to treat and care for sick, injured or orphaned
orangutans with the ultimate aim of returning them back to the wild.
Sumatran Orangutan Society
What is the SOS doing to help orangutans?
The SOS is dedicated to the conservation and welfare of Sumatran orangutans and their
habitat. We raise awareness of the plight of this critically endangered species, and we
run several projects in Sumatra:
Tree Replanting Projects
Creating tree nurseries, planted with fruiting and hardwood seedlings, provides
sustainable livelihoods for communities surrounding critical orangutan habitat. This
means that these communities no longer need to rely on collecting wood and other
forest products from the orangutans’ habitat for an income, and they help us to replant
trees in degraded areas, restoring the orangutans’ forests.
The “Orang-U-Van”
The Orang-U-Van is a mobile education and
awareness unit which travels around Sumatra,
visiting local communities and schools. We provide
books, hold discussions and debates, show
environmental films and give presentations on
orangutans and the importance of conserving their
habitat.
School Visits
During these visits we talk to children and teachers about the plight of the orangutan,
and the current status of Sumatra’s forests. We show environmental films and offer
training in activities such as paper recycling. We have found that students are
desperate to learn more, often requesting that our team sets up a tree nursery in the
school grounds so that the children can replant the forests around their villages.
Conservation Camp
Conservation Camp inspires school children to become involved in learning about and
caring for their environment. Students are given talks on nature and wildlife, on
conservation issues and practical ways they can help the environment. This is one of
our best-loved programmes as students are not offered this kind of education at their
schools or universities.
“Orangutan Friends” Club
This club, called ‘Sahabat Orangutan’ in Indonesian, is designed to instill a sense of
pride in young Indonesians about their beautiful environment and its unique
inhabitants, especially the orangutan. We currently have over 800 members, who hold
regular meetings to discuss current environmental issues and to plan awareness-raising
activities.