Symphalangus syndactylus

IUCN

Alias：Symphalangus syndactylus,Siamang,Little monkey

Basic Information

Scientific classification

name：Symphalangus syndactylus
Aliases：Symphalangus syndactylus,Siamang,Little monkey
Outline：Primates
Family：G.family symmandude

Vital signs

length：70-90cm
Weight：10-16kg
lifetime：About 30 years

Feature

The largest gibbon

Details

Symphalangus syndactylus (scientific name: Symphalangus syndactylus) is called Siamang in foreign language, and has no subspecies.

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Symphalangus syndactylus is a diurnal animal that likes to live in small groups as a family unit. It is a monogamous primate, usually consisting of 5 individuals in a group, including an adult male and an adult female, and the rest are semi-adult and young gibbons, with a maximum of 3 offspring. The adult male ape serves as the leader. Gibbons have a relatively long maturity period, and their family relationships are not only stable, but also harmonious and friendly. The members of the family are generally very harmonious, caring for each other and defending together. The territory of a family group is 15 to 35 hectares.

Siamangs live in the canopy layer of the forest, resting and sleeping above the canopy. They are active during the day, starting one to two hours before dawn and dusk. They are good at using their arms to swing alternately, bending their fingers into hooks, lightly grasping branches to throw their bodies, and swinging forward in the air. They can jump more than 10 meters in one leap, and are extremely fast. They can catch flying birds in the air with one hand. When walking on the ground or vines, they raise their arms to maintain balance. When jumping in the tree, the arms are spread out to form a cross.

The main food of the siamang is fruit and leaves, and it also eats insects and flowers. In the siamang diet, fruits account for 20% to 50%, especially figs; young leaves account for about 40% to 65%. The actual proportion varies from year to year.

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The reproduction rate of Siamang monkeys is very slow, with one baby every two years. Males and females mainly mate in winter and spring. They first approach each other, and their calls become louder, longer and more melodious. After multiple attempts at contact, they become mates and mate. The gestation period of females is about 230 days. After mating and conception, they still move with the group. After 3-4 months, their abdomens bulge slightly. As the fetus grows, their abdomens gradually expand. They also become more cautious in their daily activities, but they still stay with the group until giving birth. Birth usually occurs in autumn and early winter. Each litter only produces one cub. The cub weighs about 300 grams at birth and is mostly grayish yellow. It gradually turns black or brownish black after 4-5 months of age, and turns black all over after half a year. The cubs can live on their own at the age of 2, but they still do not leave the group until they are about 6 years old and close to sexual maturity. They slowly leave the group and reach sexual maturity at the age of 8-9. They live independently and look for mates.

The main threats to Siamang monkeys are the pet trade, habitat loss, forest fragmentation, logging, road development, farmland reclamation and hydropower construction, all of which have destroyed the forests where Siamang monkeys live. About 40% of the siamang's Sumatran habitat has been destroyed; in peninsular Malaysia, lowland forests are estimated to be disappearing at a rate of 2,500 square kilometers per year. The remaining forests are also extremely fragmented.

Nine protected areas have been established to protect the siamang, including Leuser Volcano National Park in Indonesia, Krau Wildlife Sanctuary in Malaysia, and Harabala Wildlife Sanctuary in Thailand. The siamang is listed on Appendix I of the Convention on International Trade in Endangered Species (CITES), which means that international trade in the species is prohibited.

Listed on the 2008 IUCN Red List of Threatened Species, ver 3.1 - Endangered (EN).

Listed in the CITES Appendix I protected animals of the Washington Convention.

Protect wild animals and eliminate game.

Maintaining ecological balance is everyone's responsibility!

Location

Distributed in Sumatra, Malaysia and Indonesia.
Siamangs live in tropical rainforests and subtropical monsoon forests, and are arboreal. They mainly live in primary and secondary tropical rainforests, with a vertical altitude of 305-1220 meters. The area where they live is rich in fig trees, which is one of the main sources of food for them.

Form

The siamang is the largest gibbon, with a maximum height of 1 meter, a body length of 70-90 cm, arms spread to 180 cm, and a weight of 10-16 kg. The body hair is long, soft and fluffy, all black, the face is bare, there is a little white hair near the mouth, and the eyebrows are reddish brown. The ears are small, the nose is flat, and the nostrils are large. The male has a tuft of upright hair on the head, and there is also a clear tuft of black penis hair, the length of the hair is about 15 cm.
There are two other obvious characteristics that distinguish the siamang from other apes: one is that the vocal sac in the throat is bare, round and large, gray or pink, and bulges like a ball when calling; the other is that the second and third toes are webbed, so that the two toes are permanently connected together, even to the end of the joint.