
Details
Siamang
Symphalangus syndactylus
- Size
- 70–90 cm · 9–14 kg
- Diet
- Omnivore
- Activity
- Diurnal
- Sociality
- Pair
- Lifespan
- —
A large black gibbon from Sumatra and the Malay Peninsula. Its inflatable throat sac amplifies loud morning duets.

Details
Symphalangus syndactylus
A large black gibbon from Sumatra and the Malay Peninsula. Its inflatable throat sac amplifies loud morning duets.
Map: Ecoregions 2017 © RESOLVE (CC BY 4.0) · Natural Earth (PD)
Siamangs live in lowland to montane tropical rainforest, moist evergreen forest, and hill forest. Continuous high canopy is essential.
They are black with very long arms and a large throat sac. The throat sac inflates during calls and carries sound over long distances.
They are diurnal and highly arboreal, using brachiation to move between branches. Pair-based family groups defend territories with songs.
They eat fruit, young leaves, flowers, and insects. Seasonal food availability shifts the balance between fruit and leaves.
Long-term pair bonds are common, and offspring develop over several years. Fathers may help carry young.
Deforestation, fragmentation, and the pet trade threaten populations. Loud duets reinforce pair bonds and territory boundaries.