Siamang gibbon

Symphalangus syndactylus

IUCN Status: Endangered

Siamang gibbons are the largest of the gibbon species, a group of ‘lesser’ apes found in Asia. Siamang gibbons have black shaggy fur and very long arms, which they use for swinging from branch to branch. They have large throat pouches which inflate to allow them to vocalise and sing.

Siamang gibbon

Symphalangus syndactylus

IUCN Status: Endangered

Siamang gibbons are the largest of the gibbon species, a group of ‘lesser’ apes found in Asia. Siamang gibbons have black shaggy fur and very long arms, which they use for swinging from branch to branch. They have large throat pouches which inflate to allow them to vocalise and sing.

General Information

Where do they live? (Natural habitat)

Siamang gibbons are found in mountain and lowland forests on the island of Sumatra, in Malaysia and in small parts of Thailand. They prefer to spend time in the trees rather than on the forest floor.

How long do they live?

Siamang gibbons can live up to 40 years in zoos, and between 25-40 years in the wild.

What do they eat?

Their diet is mostly made up of leaves and fruit, but they also eat insects and flowers.

Group name

Family

Zoo location

Orangutan Rainforest

Closest related species / sister species

The closest relatives of siamang gibbons are the species belonging to the three other genera of gibbons: hoolock gibbons, Nomascus gibbons and Hylobates.

Animal class

Mammalia

Animal order

Primates

Fun facts

Communication

Gibbons call and sing to establish their territory and to reinforce family or mating bonds. Siamang gibbon calls are louder than those of other gibbons.

All thumbs

Siamangs are the only gibbons with both opposable thumbs and opposable toes.

Gardeners of the Rainforest

Siamangs have an important role in their forest habitat. When they eat the fruit of one tree, they spread seeds through their poo, leading to more trees growing elsewhere, and a healthier tree population.

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Family Life

Siamang gibbons live in small groups of 3 to 6 individuals – a monogamous (having only one mate) mating pair and their offspring who have yet to leave the family. When an infant is born, it clings to its mother for around 8 months. At 6-8 years old, the siamang will leave their family group to find a mate and start a new family.

Baby name

Infant

Gestation (pregnancy) period

7-8 months

Number of young at birth

Usually 1, occasionally twin births do occur.

Weight at birth

Approximately 500 grams

Age at maturity

Approximately 8 to 9 years

Size male adult

Up to 90 cm tall and approximately 12 kg

Size female adult

Up to 90 cm tall and approximately 10 kg

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Conservation

Endangered

The siamang gibbon is classified as Endangered by the International Union for Conservation of Nature

Current population estimate

Approximately 22,000 individuals

Threats

The biggest threats to siamang gibbons are habitat loss (mainly due deforestation for the palm oil industry) and the illegal pet trade.

What is Dublin Zoo doing?

In 2019, Dublin Zoo began providing support to the Supayang Gibbon Conservation Centre in Sumatra which is run by an organisation called Kalaweit. Kalaweit’s objective is the protection of gibbons in their habitats. The Supayang Gibbon Conservation Centre houses rescued siamang gibbons along with other species of gibbons and bears. The centre provides care for these animals and when possible releases them back into the wild. Kalaweit also manages and patrols the Supayang Reserve which borders the centre and is home to wild siamang.
Dublin Zoo participates in the European Endangered Species Programme (EEP) for siamang gibbons.

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Siamang Gibbon Conservation

See what Dublin Zoo is doing to help Siamang gibbons in the wild
Find out more

Most asked questions

  • How do siamangs make their call so loud?

    Siamangs have a special throat sac that inflates to allow their call to be heard from kilometres away.

  • What do siamangs eat?

    Their diet is mostly made up of leaves and fruit, but they also eat insects and flowers.

  • What does siamang use its long arms for?

    Siamangs use their long arms for swinging through the trees (brachiating) and for balance when walking on two legs.

  • What is the main mode of movement for a siamang?

    Siamangs can generally be found swinging through the trees, but they can walk when on the ground.

  • Where do siamangs live?

    Siamang gibbons are found in mountain and lowland forests on the island of Sumatra, in Malaysia and in small parts of Thailand.

  • What do gibbons eat?

    The majority of their diet consists of leaves, the rest is made up of fruit, which varies seasonally.

  • Are gibbons monkeys?

    No, gibbons are lesser apes. You can tell they are not monkeys because they don’t have a tail. Most monkeys have a tail.

  • Why do gibbons make calls and howling noises?

    Gibbons call and sing to establish their territory and to reinforce family or mating bonds. Siamang gibbon calls are louder than those of other gibbons.

  • Are gibbons endangered?

    Siamang gibbons are classified as Endangered due to habitat loss (mainly due to deforestation for the palm oil industry) and the illegal pet trade. Other species of gibbons are also classified as Endangered or Critically Endangered.

  • Do gibbons have tails?

    No, gibbons are lesser apes which mean they have no tails. Monkeys have tails, while apes do not.

  • How many species of gibbons are there?

    There are 19 species of gibbon in 4 genera.

  • What are baby gibbons called?

    Baby gibbons are called infants.

  • How long do siamang gibbons live?

    Siamang gibbons can live up to 40 years in zoos, and between 25-40 years in the wild.

  • Why are gibbons endangered?

    The biggest threats to siamang gibbons are habitat loss (mainly due deforestation for the palm oil industry) and the illegal pet trade.

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