Our Primates In The Wild
The four species of endangered primates that we rescue and rehabilitate naturally belong in the surrounding region of south Vietnam.
Genetic studies show that gibbon ancestors diverged from the lineage leading to great apes and humans in South-East Asia about 6-9 million years ago. Gibbons are one of the most successful apes in terms of the number of species, especially in Vietnam with 7 species of gibbon from the genus Nomascus
(The Crested gibbons), including the newly described species N. annamensis
Black crested gibbon
, Nomascus concolor
Eastern black crested gibbon
- Tonkin black crested gibbon, Nomascus concolor lu
- Central Yunnan black crested gibbon, Nomascus concolor jingdongensis
- West Yunnan black crested gibbon, Nomascus concolor furvogaster
, Nomascus nasutus
Hainan black crested gibbon
- Cao Vit black crested gibbon, Nomascus nasutus nasutus
, Nomascus hainanus
Northern white-cheeked gibbon
, Nomascus leucogenys
Southern white-cheeked gibbon
, Nomascus siki
Northern buffed-cheeked gibbon
, Nomascus assamensis
, Nomascus gabriellae
In Vietnam EAST works with the most southerly species, the Golden-cheeked gibbon (Nomascus gabriellae
which are only found in South Vietnam and Cambodia. As a result of forest destruction and hunting, the wild population is estimated at less than 25,000 with the majority of the surviving population in Cambodia.
|Female golden-cheeked gibbon
||Male golden-cheeked gibbon
They live in small family groups, consisting of the parents and their offspring. Each family defends a core area of 15-80 hectares from other gibbon families, to ensure they have enough food. Although classed originally as monogamous (pairing for life) it is clear that a more flexible social structure exists with one male to two females or females conducting extra pair mating (mating with other males than her resident male).
Most mornings at sunrise the whole family sings a short duet song of 12-15 minutes to inform other gibbons of their location and social status. This song is not only unique to the species, the male and female have their own different parts to sing. The song is dominated normally by the male, but if food availability is good or many other gibbon groups are near the female will contribute more to the duet.
At birth golden-cheeked gibbons have blonde fur, but by 2 years of age this changes to black. Once they reach maturity at around 5 years of age, the females turn back to blonde whilst the males remain black with golden cheeks. Each colour change takes about one year to complete. The average life span of a golden-cheeked gibbon is 35 years.
Golden-cheeked gibbons have proved to be highly adaptable at living in disturbed secondary forest, feeding primarily on forest fruits with some leaf, flower and insects. They have evolved to feed on the tips of branches, being light in weight and able to suspensory feed.
Gibbons in the wild are very timid, although they happily co-exist with doucs, they are afraid of the tougher, noisier macaques.
Indiscriminate snares catch many macaque species that travel on the ground. For gibbons that are totally aboreal (living off the ground in the trees) they are most commonly hunted by gun or poison darts. The gibbon morning call alerts hunters of their location. When found whole families can be killed at once, as the male and young will stay near the mother, unwilling to break up the family unit.
In unprotected areas of forest in the Central Highlands of Vietnam, hunters passing by on the new highways with blow darts on their backs are a common sight. Thankfully, with strengthened law enforcement and punishment, the risks of being caught hunting gibbons have increased, creating greater protection for this endangered species, but with growing tourism the building of more highways has opened up areas previously impenetrable to hunters.
Gibbons are hunted for the pet trade, tourist attractions, traditional medicene and illegal wild meat. An analysis of information relating to our rescued gibbons at Dao Tien shows that the most common source are private restaurants and resorts, where they are held, usually in small cages for the entertainment of tourists.
|Infant gibbons as young as six months of age, illegally kept at a private tourist attraction
You can make a difference, by avoiding tourist attractions that hold these beautiful intelligent primates. Make a point of informing the owners before you leave of your objections and tell your friends to make a point of letting the owner know in the future and leave before spending a penny! Please then report the sighting to the local authorities, email@example.com
or to the ENV hotline: firstname.lastname@example.org