Arboreal Gibbons Harmed by Deforestation
Asian Small Primates Lose Habitat and Food as Rainforests Disappear
Sep 4, 2008
The gibbon family includes anywhere from 9 to 15 species, depending on which reference is used. Twelve species are listed by the IUCN as vulnerable, threatened or endangered. Some of the confusion as to which are truly separate species may be cleared up with further study of these lesser primates. But what is clear is that there is pressure on all gibbon species from human encroachment.
While gibbons are found in China, Laos, Vietnam, Cambodia, Thailand, India, Myanmar (Burma), Malaysia and Indonesia, in most of these countries they are only found in small numbers.
The Gibbon Species and Their IUCN Status
Critically Endangered:
- Javan Gibbons (Hylobates moloch)
- Eastern Black-crested gibbons (Nomascus nasutus)
Endangered:
- Hoolock Gibbons (Bunopithecus hoolock, also known as Hylobates hoolock)
- Black Gibbons (Nomascus concolor ) This species is divided into two subspecies-Tonkin black-crested (Nomascus concolor concolor) and the Laotian black-crested gibbon (Nomascus concolor lu) by some taxonomists but others suggest they may be subpopulations instead
Vulnerable:
- Buff or Yellow-cheeked gibbons (Nomascus gabriellae)
- Capped or Crowned Gibbon (Hylobates pileatus)
- Dwarf or Kloss’ Gibbon (Hylobates klossi)
Lower Risk but near threatened:
- Agile Gibbon (Hylobates agilis) This species is comprised of 3 subspecies- the Mountain agile gibbon(agilis),the lowland agile gibbon (unko) and Bornean agile or Bornean white-bearded gibbon (albibarbis)
- Common or White-handed gibbon (Hylobates lar) with five subspecies Malaysian (lar), Central (entelloides), Carpenter’s (carpenteri), Yunnan (yunnanensis) which may be extinct in China and Sumatran (vestitus)
- Bornean or Muller’s Gibbon (Hylobates muelleri)
- Siamang (Symphalangus syndactylus)
Data Deficient:
- The white-cheeked gibbon (Nomascus leucogenys), however, one of its subspecies, the northern white-cheeked (leucogynes) is suspected to be nearly extinct in much of its range. The southern subspecies (siki) is less studied and its status is yet to be determined
Threats to Gibbons and Siamang
Gibbons and siamang are largely arboreal, spending little time on the ground. Since they travel through the trees, deforestation and habitat fragmentation is one of the main threats they face. The fruits, flowers, seeds and bark of local trees also provide the majority of their food. These are supplemented with insects, spiders, birds and bird eggs, most of which are found in the rainforest trees.
Gibbons live in small family groups, so finding mates when offspring are old enough to leave the family requires traveling to a new territory. Gibbons isolated in a rainforest fragment may never mate, reducing an already limited gene pool.
Gibbons are hunted in some of their range with poachers taking animals both for the traditional medicine trade and as food. The pet trade takes a toll on gibbons as well. If a female is killed, her young are taken to sell to the public. In some cases the female is killed simply to get the baby more easily.
The Future for Gibbons and Siamang
The Asian rainforest habitat is being systematically fragmented, largely due to the needs of the growing human population in the area. In order for gibbons to survive, efforts must focus on finding ways for local people to thrive without further loss of this critical habitat.
As part of that effort, educating those people about the gibbons and the value of their habitat, both locally and globally, will be necessary. Without the involvement of the people of the area, the push to save the gibbon is unlikely to succeed.
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