GIBBONS

SIAMANG GIBBON SINGS

The different species of Gibbons are easily to recognize when you compare them with other species of monkey and apes. However, they evolved from the common ancestor two million years ago.

There are nine species of Gibbons of which eight are more or less the same size. They only differ in colour. Although some species are different but they do not share the same space.  The one species, the Siamang, is larger. It lives in the areas as two other species of the gibbons – the Lar and the Agile gibbons.

LAR GIBBON

The gibbons have all the same characteristics of all apes; long arms; long, slender legs and feet; no tails and their bodies are covered in dense, long hairs. The skin of their faces is dark and has no hairs. They move more upright than monkeys and have less distinct muzzle. 

Gibbons swing from branches to branches by their long, strong arms in an alarming speed. They almost fly through trees and are capable of getting hold of supports which could as much as 15m apart. Their quick movements seem as if they barely tough them. One advantage is that their fingers are very long and their use them as a hook. They can be so quick that they able to run along a slim branch on their hang legs only.

The most remarkable feature of gibbons is their “song”. It echoes round their forest mostly at dawn and can be heard 2-3 km away.

WAY OF LIFE

Gibbons are active in the morning and afternoon. They rest during the hottest time of the day and sleep at night. They built a nest onto branches with twigs and leaves. They live in family groups with one male, female and up to four offsprings. Scientists discovered they mate for life.  Only the Kloss gibbon’s male lives a slightly separate life. He either falls behind the female and her offspring or travels at the side of them. One of the most distinguished and important contact between each others is grooming.

Each family has its own territory. It will live in it and defend it if necessary. There are usually two to four families in a group have a territory of about 1 sqkm of forest. In their territories the smaller gibbons cover 1 to 1.5km a day. The larger species Siamang only travel half as much.

Most of their time is spent feeding and travelling through the branches looking for food. Like the Orang-utan they do prefer ripe fruit and testing it with pressing with their thumb and index finger like human. In each territory there are a variety of trees producing fruit at different times of the year.  They also eat leaves and small amount of insects and spiders which provides them with protein. They pick the fruit with one hand but hang on branches with the other. Since each group has its territory and do not overlap there is no danger of food shortage or compete with each other. Only the Siamang shares territories with smaller gibbons because it eats mostly leaves and therefore it has not to travel all the time.

FAMILY LIFE

Gibbons only mate every two to three years and the female gives birth to one baby. It has a gestation period of seven to eight months. The youngster clings to the mother’s chest for some time while she swings from tree to tree looking for food.  In the first year she watches it all the time and suckling it. The baby is weaned at the beginning of the second year. In the third year the baby will move about by itself but still within the group.

The young gibbons is fully grown at six years but still stays another two year before it moves out of the group and look for a mate and start its own family.

LAR GIBBON FEMALE 
WITH BABY

GIBBONS’ SONG

All gibbons sing and it is a very important part of their social life. They could sing either every day or every five days but it is usually performed at dawn. The length of the song also varies from ten minutes or up to two hours. It usually starts with racing around in the branches, pulling off  leaves and making a familiar racket.

The songs have several purposes. They are used to tell the neighbours it is their territory and also a bonding between male and female. The female does likewise and warns other females and groups of their territory.

DANGER OF EXTINCTION

All Asian apes are in great danger of extinction. Previously the threat came from hunters. They mostly shot the adults to catch the babies and selling them as pets or to zoos. In a great number of cases the babies died before they reach their destiny. When this outlook was changed and the hunters became more or less conservationists the danger is now deforestation.

Cutting down continuously the rainforest affect mostly the Orang Utan but only at the moment.  Eventually it will also have an impact on smaller species like the gibbons. It had been noticed that since these animals are driven into smaller areas the adults are becoming more aggressive to each others and the reproduction dropped.

How much more is mankind willing to destroy its world? When will mankind get to its senses and say enough is enough.

MULLER'S GIBBON