Symphalangus syndactylus | Siamang
Good spot: Japanese Village, Bukit Tinggi, Pahang state, Malaysia
Taxonomy & Occurrence
Symphalangus syndactylus is a monotypic species (no subspecies). It is found in Indonesia (Barisan Mountains of west-central Sumatra), Malaysia (mountains of the Malay Peninsula south of the Perak River), and a small area of southern peninsular Thailand.
* Thomas Geissmann suggests that the Sumatran and Malaysian populations are different subspecies, but I have yet to find his publication so, I'll wait on that and for now follow .
IUCN Conservation Status
The Siamang is special. Besides being the largest of gibbons (Hoolock, Hylobates, Nomascus, Symphalangus), both males and females also have a large throat pouch. They can inflate this pouch to the size of their head, allowing them to sing loud, resonating duets. Two digits on each foot are partially joined by a membrane - hence their scientific name syndactylus, from the Ancient Greek.
© Andie Ang
West Sumatra, Indonesia
 Mittermeier R.A., Rylands A.B. & Wilson D.E., 2013.Handbook of the Mammals of the World: Primates. Vol. 3. Lynx Edicons: Barcelona.
 O'Brien T.G., Kinnaird M.F., Nurcahyo A., Iqbal A. and Rusmanto M., 2004. Abundance and distribution of sympatric gibbons in a threatened Sumatran rain forest. International Journal of Primatology 25: 267-284.
Illustration: Wells, Lyn. 2008. In Francis, Charles. A Guide to the Mammals of Southeast Asia. Princeton: Princeton Univerty Press.
Page Last Updated: 31 August 2018
Seeing this Species
The loudest of gibbons, the Siamang can be heard from kilometers away. Both Agile Gibbon and White-handed Gibbon are found together with Siamang throughout most of its range in Peninsular Malaysia and Sumatra, Indonesia.
Botanical Garden of Japanese Village, Bukit Tinggi, Pahang state, Malaysia
The Botanical Garden is a nature park situated within the Japanese Village of Berjaya Hills at Bukit Tinggi. About five minutes away from Colmar Tropicale by car or shuttle bus, the garden straddles four acres of highland rainforest - only the jungle floor was cleared of its original vegetation to make way for show plants. The 1km cemented trail meanders through the garden in a loop, beginning with a sharp descent from the Ryo Zan Tei Japanese Restaurant at the entrance, then passing through neat clumps of flowers (!!), herbs and ferns spread between the footpaths and trees.
Probability of Success: Pretty high? Several people have posted about sighting Siamang here.
Fraser's Hill, Pahang, Malaysia
Please see the page for Pale-thighed Surili
I spent a morning here in March 2014 but did not see Siamang. Instead, I saw the Pale-thighed Surili two times!
Bukit Barisan Selatan National Park, Sumatra, Indonesia
Population density appears very high here, with one group for every 2.23 sq km, and an average group size of 3.9, for a population estimate of 22,390 individuals in this 3,568 sq km national park . Siamang and Agile Gibbon densities are negatively correlated, with Agile Gibbon more abundant in mid-elevation forests and Siamang most abundant in lowland and submontane forests.
Together with Gunung Leuser and Kerinci Seblat national parks, Bukit Barisan Seletan forms a World Heritage Site called the Tropical Rainforest Heritage of Sumatra.
Overlapping species: Mitred Leaf Monkey, Agile Gibbon