TOP > 生物多様性センターの国際協力 > ESABII > Database > Threatened Mammal Species Database > Hoolock hoolock
Hoolock hoolock
Taxonomy (Name)
| Class | MAMMALIAIUCN | |
|---|---|---|
| Order | DIPROTODONTIAIUCN | |
| Family | HYLOBATIDAEIUCN | |
| Scientific Name | Hoolock hoolockIUCN | |
| Author | (Harlan, 1834)IUCN | |
| Synonyms | Bunopithecus hoolock ssp. hoolock (Harlan, 1834) Hylobates hoolock (Harlan, 1834)IUCN |
|
| Common Name | Western Hoolock Gibbon, Hoolock Gibbon, Western HoolockIUCN | |
| Local name | Brunei Darussalam | |
| Cambodia | ||
| China | ||
| Indonesia | ||
| Japan | ||
| Lao PDR | ||
| Malaysia | ||
| Myanmar | ||
| Mongolia | ||
| Philippines | ||
| Singapore | ||
| Republic of Korea | ||
| Thailand | ||
| Vietnam | ||
Picture
Distribution, Range
This species is found in eastern Bangladesh, northeastern India (Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, and Tripura), and northwestern Myanmar (west of the Chindwin River). It might possibly occur in China (extreme southeastern Tibet). The distribution in India is restricted to points south of the Brahmaputra and east of the Dibang (Dingba Qu) Rivers (Choudhury 2001). Animals that once were common in the plains of Arunachal Pradesh (northeasternmost India) before that habitat was cultivated for agriculture and tea are not so anymore (Islam and Feeroz 1992).
The boundary between the two species of Hoolock is the Chindwin River, which flows into the Ayerawady (Irrawady) River. At the headwaters in the north there is a hybrid zone or cline between the two species (since they are almost certainly not reproductively isolated). Das et al. (2006) reported the discovery of a population of H. leuconedys in Arunachal Pradesh, northeast India, which has traditionally been considered to be part of the range of H. hoolock.
Map
Country
| Brunei Darussalam | |
|---|---|
| Cambodia | |
| China |  |
| Indonesia | |
| Japan | |
| Lao PDR | |
| Malaysia | |
| Myanmar | |
| Mongolia | |
| Philippines | |
| Singapore | |
| Republic of Korea | |
| Thailand | |
| Vietnam |
Status
International Status
IUCN Red List Category
ENIUCN
Justification
Listed as Endangered as there is reason to believe the species has declined by at least 50% over the past 40 years (approximately three generations) due primarily to hunting and habitat loss. Over the coming 40 years, this decline is likely to reach similar proportions due to continuing habitat loss.
CITES
Appendix I
CMS
National Status
| Country | Category | Reference |
|---|---|---|
| Brunei Darussalam | ||
| Cambodia | ||
| China | E(as Hylobates hoolock) | China Red Data book of Endangered Animals(1998) （Extinct, Extirpated, Endangered, Vulnerable, Rare, Interninate） |
| Indonesia | ||
| Japan | ||
| Korea | ||
| Lao PDR | ||
| Malaysia | ||
| Mongolia | ||
| Myanmar | ||
| Philippines | ||
| Singapore | ||
| Thailand | ||
| Vietnam |
Ecology Discription
Appearance
Habitat
This species is a forest-dweller that, depending on its locale, inhabits tropical evergreen rainforests, tropical evergreen and semi-evergreen forests, tropical mixed deciduous forests, and subtropical broadleaf hill forests. It has also been noted in bamboo "brakes" and hollock (Terminalia myriocarpa) and ajhar (Largerstroemia flosreginae) plantations.
Home ranges in most populations range from 8-63 ha (Ahsan 2001; Alfred 1992; Alfred and Sati 1986, 1990; Feeroz and Islam 1992; Gittins and Tilson 1984; Islam and Feeroz 1992; Kakati 2004; Mukherjee 1986; Tilson 1979), but unusually large home ranges of 200-400 ha were reported from Tripura and Arunachal Pradesh, northeast India (Mukherjee 1982; Mukherjee et al. 1988).
Population size
There are estimated to be about 200-280 hoolocks in Bangladesh (Islam et al. 2006; Molur et al. 2005). In China, a population has been identified in Medog Nature Reserve in southeastern Tibet, just across the border from Arunachal Pradesh, but the identity of this taxon is not established and there has been no survey conducted to determine the population numbers (W. Bleisch pers. comm.).
There are no population estimates available for Myanmar. It is possible that the largest and most viable populations of western hoolock are to be found in this country, where at present almost no attention is paid to it (W. Brockelman pers. comm.). There are several thousand square kilometers of unsurveyed forest habitat in the central-west and north-west of this country, with a particular need to survey the western areas west of Chindwin/Ayerawady River. There are reports of gibbons in Rakhine Yoma Elephant Range, but there is no knowledge of the actual population level there (W. Brockelman pers. comm. 2006). The western part of Hukuang Tiger Reserve with a large area of forest (>1,000 km2) has not been surveyed, but is likely to have this species. The northern limit is just south of Hkakaraborazi National Park.
Behavior
One gibbon pair in the Borajan Reserved Forest (north-east India) was observed to habitually descend from the trees to move over scrub and short bamboo especially while trying to reach the isolated food trees inside a village. This pair was found sleeping at heights of 0 m or less in bamboo clumps (Kakati 1997). Although gibbons may be moving through, or sleeping in, bamboo forest or plantations, they cannot survive in monocultures (W. Brockleman pers. comm.). Additionally, the species has been observed in two plains forest locations (Choudhury 1991). Its preferred habitat, however, is dense evergreen and semi-evergreen forests (Choudhury 2001). It has been recorded at altitudes of up to 2,500 m in Manipur, northeast India (Choudhury 2001).
Diet
The western hoolock is a frugivorous species, with ripe fruits composing a majority of its diet (Ahsan 2001; Alfred and Sati 1986, 1994; Feeroz and Islam 1992; Islam and Feeroz 1992; Kakati 1997; Tilson 1979). A dominantly folivorous diet was reported during studies carried out in Assam's Borajan Reserved Forest, and in Tripura (Kakati 1997; Mukherjee 1986), and gibbons living in small forest fragments were observed to experience a period of almost total lack of fruit in their diet at the end of the dry season (Kakati, 2004). Low fruit availability may contribute to the relatively large home range sizes of some populations. In northeast India, the hoolock gibbon is recognized as being an important disperser of undigested seeds from large and small fruit-bearing trees (Das 2003).
Reproduction
Threat
Major Threat(s)
In Myanmar, shifting cultivation is a major threat, and so is hunting. Although logging is restricted on the western side of the Chindwin, it is still considered a threat for this species. Political and ethnic conflicts have prevented the Myanmar government to promote development and conservation activities effectively in areas of northwestern and central western Myanmar along the borders with India and Bangladesh. Thus, most conservation efforts have been concentrated within the range of H. leuconedys.
Conservation and Measurement
International
This species is listed on CITES Appendix I .IUCN
National
This species is listed on schedule I of the Indian Wildlife (Protection) Act of 1972. IUCN
Conservation law
| Country | Status | Reference |
|---|---|---|
| Brunei Darussalam | ||
| Cambodia | ||
| China | ||
| Indonesia | ||
| Japan | ||
| Korea | ||
| Lao PDR | ||
| Malaysia | ||
| Mongolia | ||
| Myanmar | Completely Protected Animals(as Hylobates hoolock) | Protection of Wildlife, Wild Plants and Conservation of Natural Areas Act 15(A), Forest Department Notification No. 583/94 |
| Philippines | ||
| Singapore | ||
| Thailand | ||
| Vietnam |
Protected Area
Overall, it is found in 30 protected areas in India (Choudhury 2001) and many others throughout its range.
Other Coservation Projects
Citation
Gittins, S. 1984. The distribution and status of the hoolock gibbon in Bangladesh. In: H. Preuschoft, D. J. Chivers, W. Y. Brockelma and N. Creel (eds), The lesser apes. Evolutionary and behavioural biology, pp. 13?15. Edinburgh University Press, Edinburgh, UK.
Gittins, S. and Tilson, R. 1984. Notes on the ecology and behaviour of the hoolock gibbon. In: H. Preuschoft, D. J. Chivers, W. Y. Brockelma and N. Creel (eds), The lesser apes. Evolutionary and behavioural biology, pp. 258-266. Edinburgh University Press, Edinburgh, UK.
Groves, C. 1967. Geographic variation in the hoolock or white-browed gibbon (Hylobates hoolock Harlan 1834). Folia Primatologica 7: 276-283.
Groves, C. P. 2001. Primate taxonomy. Smithsonian Institution Press, Washington, DC, USA.
Gupta, A. K. 2005. Conservation of hoolock gibbon (Bunopithecus hoolock) in Northeast India. A final report of Wildlife Institute of India and United States Fish and Wildlife Services collaborative project (No. 98210-2-G153). Wildlife Institute of India and United States Fish and Wildlife Services.
Haimoff, E. H., Gittins, S. P., Whitten, A. J. and Chivers, D. J. 1984. A phylogeny and classification of gibbons based on morphology and ethology. In: H. Preuschoft,D. J. Chivers, W. Y. Brockelman and N. Creel (eds), The lesser apes. Evolutionary and behavioural biology, pp. 614-632. Edinburgh University Press, Edinburgh, UK.
Islam, M. and Feeroz, M. 1992. Ecology of hoolock gibbon of Bangladesh. Primates 33(4): 451-464.
Islam, M., Feeroz, M., Muzaffar, S., Kabir, M. and Begum, S. 2006. Conservation of the hoolock gibbons (Hoolock hoolock) of Bangladesh: Population estimates, habitat suitability and management options. United States Fish and Wildlife Service.
Kakati, K. 1997. Food selection and ranging in hoolock gibbon (Hylobates hoolock Harlan 1834) in Borajan Reserved Forest. MSc Thesis, Saurashtra University.
Kakati, K. 1999. The singing apes: The world of the hoolock gibbons in the Borajan reserve forest in Assam is dying, thanks to illegal tree-felling. Frontline - India's National Magazine 16(3): 65-70.
Kakati, K. 2004. Impact on forest fragmentation on the hoolock gibbon in Assam, India. Ph.D. Thesis, University of Cambridge.
Molur, S., Brandon-Jones, D., Dittus, W., Eudey, A., Kumar, A., Singh, M., Feeroz, M. M., Chalise, M., Priya, P. and Walker, S. 2003. Status of South Asian Primates: Conservation Assessment and Managment Plan Report. Workshop Report, 2003. Zoo Outreach Organization/CBSG-South Asia, Coimbatore, India.
Molur, S., Walker, S., Islam, A., Miller, P., Srinivasulu, C., Nameer, P., Daniel, B. and Ravikumar, L. 2005. Conservation of western hoolock gibbon (Hoolock hoolock hoolock) in India and Bangladesh. Comibatore, India.
Mootnick, A. and Groves, C. 2005. A new generic name for the hoolock gibbon (Hylobatidae). International Journal of Primatology 26(4): 971-976.
Mukherjee, R. 1982. Survey of non-human primates of Tripura, India. Journal of the Zoological Society of India 34(1-2): 70-81.
Mukherjee, R. 1986. The ecology of the hoolock gibbon, H. hoolock, in Tripura, India. In: J. G. Else and P. C. Lee (eds), Primate ecology and conservation, Cambridge, UK and London, UK.
Mukherjee, R., Chaudhuri, S. and Murmu, A. 1988. Hoolock gibbons in Arunachal Pradesh, northeast India: Lohit District. Primate Conservation 9: 121-123.
Mukherjee, R., Chaudhuri, S. and Murmu, A. 1992. Status and conservation problems of hoolock gibbon (Hylobates hoolock) in some of its range of distribution in north-eastern India. Primate Report 34: 133-138.
Osterberg, P. 2006. Habitat requirements and the effects of forest fragmentation on the western hoolock gibbon (Hoolock hoolock hoolock) in Lawachara National Park. M.Sc. Thesis, Oxford Brookes University.
Srivastava, A. and Mohnot, S. M. 2001. Distribution, conservation status and priorities for primates in Northeast India. ENVIS Bulletin: Wildlife and Protected Areas 1(1): 102-108.
Tilson, R. 1979. On the behaviour of the hoolock gibbons (Hylobates hoolock) during different seasons in Assam, India. Journal of the Bombay Natural History Society 76(1): 1-16.
Walker, S. 2005. Highlights of the population and habitat viability assessment for western hoolock gibbon (Bunopithecus hoolock hoolock) held in Bangladesh. Zoo's Print Magazine 20(4): 2-4.