Siamang
They are a black-furred gibbon native to the forests of Indonesia, Malaysia and Thailand. It is the largest of the gibbons and can be twice the size of other gibbons. Two features distinguish the siamang from other gibbons. The first is that two digits on each foot--the second and third toes--are partially joined by a membrane. The second is the large gular sac (found in males and females), which is a throat pouch which can be inflated to the size of the siamang's head, allowing it to make loud, resonating calls or songs.
Habitat
They inhabit the forest remnants of Sumatra Island and the Malay Peninsula, and is widely distributed from lowland forest to mountain forest—even rainforest—and can be found at altitudes up to 3800m. The siamang lives in groups of up to six individuals (four individuals on average) with an average home range of 23 hectares. On the mp to the right the siamang species's habitat is in green.
Diet
They eat various parts of plants. They eat at least 160 species of plants, from vines to woody plants. Its major food is figs. They tend to eat ripe rather than unique fruit and young rather than old leaves. It eats flowers and a few animals, mainly insects. When they eat large flowers, they only consume the petals,but it eats all the parts of small flowers, with the small fruit collected in its hand before being consumed. When it eats big or hard seeds or seeds with sharp edges. It peels out the fruit flesh and throws away the seed.
Breeding
They are one of the primates that tend to mate with one partner for their entire lives. Generally they have just one baby at a time, although twins do happen. They are pregnant for about 8 months and will generally breed only every 2-3 years.
Population
They are classed as vulnerable on the IUCN Red List and they are decreasing. In a study on this species in Bukit Barisan Selatan National Park, Sumatra, calculated an average group density of one group for every 2.23 km2, with an average group size of 3.9, and a population estimate of 22,390 individuals. Healthy populations persist at the southern limit of its range in Bukit Barisan Selatan National Park, and these populations should survive over the long-term if the park maintains its present forest area, and if illegal hunting and habitat degradation are stopped. While some populations of this species appear secure today, its future is uncertain and will depend on vastly improved conservation efforts, especially in Sumatra's remaining parks and protected areas. Population densities for this species range from 2.4 to 24.6 individuals/km2.
Threats
This species is threatened by forest conversion and opportunistic collection for pet trade on Sumatra, where both of these threats extend to populations in national parks and protection forests. Between 1995 and 2000, almost 40% of the habitat for this species on Sumatra was damaged or destroyed by logging, road development (barrier and hunting) and conversion to agriculture or plantations . Legal logging seems to be accelerating in Sumatra. Forests, where they remain, are extremely fragmented. Coffee plantations present an increasing threat. The siamang is one of the most heavily traded gibbon species for illegal pet trade.
Conservation
This species is protected protected throughout its range, both by local laws as well as internationally through its listing on CITES Appendix I. It is known to occur in at least nine protected areas: Bukit Barisan National Park, Gunung Leuser National Park, Way Kambas National Park, West Langkat R (Indonesia); Fraser's Hill R, Gunong Besout Forest Reserve, Krau Wildlife Reserve, Ulu Gombak Wildlife Reserve (Malaysia); Hala Bala Wildlife Sanctuary (Thailand). There is a large worldwide captive population, in 96 collections.