Animal Fact Sheet
GREAT GIBBON SIAMANG
Class: Mammalia
Order: Primate
Family: Hylobatide
Genus: Hylobates
Species: syndactuylus
Credit: Kim Bowes
Description:
The great gibbon siamang (or siamang) is the largest of the gibbons. The
siamang has a thick black fur coat, no tail, and enlarged throat sac that is
used as a sound box to amplify its voice. Siamangs also have opposable
thumbs.
Size:
The head-body length of the siamang is between 29 and 35 inches, with the
arm length 2.3-2.6 times its body length.
Life Span:
Siamangs live 25-30 years in the wild, while in captivity they can live 30
years.
Diet:
In the wild: leaves, fruit, insects, birds, bird eggs, small vertebrates
At the Zoo: fruits and vegetables, mealworms, crickets, high fiber biscuits
Geographic
Range:
The siamang lives mainly in Sumatra, in Indonesia.
Habitat:
They are found in the tropical rainforests and tropical deciduous forests, in
the middle canopy.
Reproduction:
Every 2-3 years, after a gestation period of 230-235 days (7 months) a female
gives birth to one young, but twins do occur. The offspring clings to its
mother’s belly constantly for the first 3-4 months of its life. The offspring
receives a high level of parental care from both the mother and the father.
The siamang reaches maturity in about 6-7 years.
Special
Adaptations:
The siamang hooks branches instead of grasping branches with its hands. It
sleeps sitting upright on a branch high in the canopy, with its arms folded
and its head between its knees, instead of making a nest somewhere. The
siamang sings very loudly in the morning, being heard up to three miles
away. It is the only primate to walk erect on two legs (besides humans).
Behavior:
The siamang is a monogamous animal, with researchers not sure if they
“remarry” after a mate dies. They are very territorial, with both the male and
female marking their territory vocally by singing a duet. They are bipedal on
the ground, with a hand-over-hand swinging motion in the trees
(brachiation). They move less and slower than most gibbons, which means
that they have smaller territories. Their most important social activity is
grooming.
Related
Species:
There are nine other gibbon species (lesser apes), including the whitecheeked gibbon.
Where am I in
the Zoo:
Siamangs are found in an outdoor exhibit in Wild Asia on your way to the
orangutan building.