Agile Gibbon (Hylobates agilis)

Interesting :

The body shape and color of agile gibbon is similar to that of lar gibbon. Both male and female will not change their colors. For example, if it is born with black in color, it will have black color for the whole life. Both sexes can be black or white. Agile gibbon does not have white marking spot circled around its face. Some of agile gibbon may have faded white marking spot and white eyebrows.

Habitat :

It is found in Southern part of Thailand, Malaysia, Sumatra, and Borneo. HABITAT AND ECOLOGY This species occurs at highest densities in dipterocarp-dominated forests, but their known habitat ranges from swamp and lowland forests to hill, submontane, and montane forests (O'Brien et al. 2004; Yanuar 2009). Additionally, populations in Bukit Barisan Selatan National Park in Sumatra do not seem to avoid forest edges near human habitations (O'Brien et al. 2004), a behavior that has also been observed in the Batang Toru Forest Complex, North Sumatra, Indonesia (Nowak pers. obs.). While they prefer undisturbed primary forest, some studies from Sumatra indicate that they can also be found in previously disturbed regenerating forest (Sultan et al. 2009; Lee et al. 2015). In southern Sumatra, populations were found up to 1,400 meters (O'Brien et al. 2004). These arboreal and diurnal primates are primarily frugivorous (preferring fruits high in sugar, such as figs), but they will consume flowers, immature leaves, and insects as well (Gittins 1979, 1982). An average home range size of 29 ha has been determined in a study at Sungai Dal (Gunung Bubu Forest Reserve) on the Malayan peninsula (Gittins 1979, 1982; Gittins and Raemaekers 1980), whereas a study from within and in areas surrounding Kerinci-Seblat National Park, Sumatra, Indonesia has documented average home ranges of 22.5 ha in forest fragments and 24.7 ha in more continuous forested areas (Yanuar and Chivers 2010). Within the submontane forests of the Batang Toru Forest Complex, agile gibbons have been documented to have home ranges over 50 ha (Nowak pers. obs.). Wild gibbons from the genus Hylobates are known to have relatively slow life histories, including a late age at first reproduction (8-12 years) and long interbirth interval (2.2-3.8 years) (Palombit, 1995; Reichard and Barelli, 2008; O’Brien and Kinnaird 2011). Recent work by O’Brien and Kinnaird (2011) has also shown that agile gibbons in Bukit Barisan Selatan National Park have extremely low birth (0.22-0.28 infants female-1 yr-1) and infant to juvenile survival rates (33.3%), which they suggest is related to increased resource competition with larger and more abundant sympatric species (e.g. siamangs).

Food :

It eats fruits, treetops, bird eggs, and insects.

Behavior :

It likes to swing from branch to branch. It stays on high trees all day. In order to drink water, it uses back finger to touch on water and suck on it. It likes staying in sunlight during early morning on the trees. During daytime or afternoon, where the weather is extremely hot, it will move down from the trees to avoid sunlight. When it is frightened, it swings quickly from branch to branch. The important enemies of black gibbon are hawks and pythons.

Current Status :

Agile gibbons are protected throughout their range by local laws, whereas all international commercial trade is prohibited through its listing on CITES Appendix I. The extent to which national or international laws actually protect the species is uncertain. The species occurs in a number of protected areas, including Berbak National Park, Bukit Barisan Selatan National Park, Bukit Tiga Puluh National Park, Kerinci Seblat National Park, Sembilang National Park, and Way Kambas National Park in Indonesia; Belum, Selama, and Ulu Mudah Wildlife Reserves in Malaysia; and Bang Lang National Park, Budo-Sungai Padi National Park, Hala Bala Wildlife Sanctuary, and Namtok Sipo National Park in Thailand. Unfortunately, many of these are merely gazetted or proposed, and as such, their actual protected status is uncertain. Moreover, many of the Sumatran reserves are in montane regions where the species occurs only at low densities. In Bukit Barisan Selatan National Park in southwestern Sumatra, as with other national parks in Sumatra that house agile gibbons, populations are presently secure and healthy, but their continued survival depends on the Indonesian government’s ability to stop the ongoing and illegal deforestation of its protected forest areas (O'Brien et al. 2004). Ultimately, the key to conserving this species relies on the ability of local governments to uphold their national laws and regulations. Increasing monitoring capacity, improving law enforcement, stopping illegal logging, curbing legal logging and forest conversion, implementing forest restoration projects, stopping road construction, confronting human-animal conflict, and enhancing connectivity across fragmented landscapes are all key conservation actions that are urgently required.


CLASS : Mammalia

ORDER : Primates

FAMILY : Hylobatidae

GENUS : Hylobates

SPECIES : Agile Gibbon (Hylobates agilis)

Conservation status : Endangered

Age :

It can live up to 30 years.

Reproductive :

It is mature and ready for mating at the age of 7 – 8 years. Gestation period is around 8 months. One litter contains only one young. Young black gibbon weans when it is 4 – 7 months and stays with its mother until it is 2 years old. Then, it will separate and live on its own.

Reference :

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Point of view :

Update : 11 April 2017