|Scientific Name:||Trachypithecus geei|
|Species Authority:||Khajuria, 1956|
|Taxonomic Notes:||Wangchuk et al. (2003) described a new subspecies, T. g. bhutanensis, from Bhutan in the north of the range, with T. g. geei occurring in the south, the two taxa being separated by the Main Frontal Thrust (MFT) of the Indian plate hitting into the Himalayas (Bhargava 1997). However, T. g. bhutanensis is not recognized here as a valid subspecies, as it has not been described according to ICZN rules.|
|Red List Category & Criteria:||Endangered A2c; C2a(i) ver 3.1|
|Assessor/s:||Das, J., Medhi, R. & Molur, S.|
|Reviewer/s:||Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)|
Listed as Endangered because of a serious population decline, estimated to be more than 50% over the last three generations (thirty years), inferred from observed reduction in the extent of its habitat; and because its population size is estimated to number fewer than 2,500 mature individuals, there is an observed continuing decline in the number of mature individuals, and no subpopulation contains more than 250 mature individuals.
|Range Description:||This species occurs only in Bhutan and north-eastern India (Assam). It is confined to a forest belt in western Assam between the Manas River in the east, Sankosh in the west and Brahmaputra in the south along the Indo-Bhutan border (Medhi et al. 2004). Its distribution in Bhutan is limited to the foothills of the Black Mountains (Srivastava et al. 2001). The total known range of this species in both India and Bhutan is less than 30,000 km2, and much of it is not suitable habitat (Srivastava et al. 2001). The population in India is highly fragmented, with the southern population completely separated from the northern population due to the effects of human activities.|
Native:Bhutan; India (Assam)
|Range Map:||Click here to open the map viewer and explore range.|
There is an estimated population of less than 1,500 individuals in India and around 4,000 individuals in Bhutan, with less than 2,500 mature individuals globally (J. Das pers. comm.). Demographic trends indicate a decline in the population of this species (Srivastava et al. 2001). 93% of the population is found in contiguous forest, while the remaining 7% is found in several small isolated reserves (Srivastava et al. 2001). Contrary to predictions, groups were bigger and densities higher in areas of more degraded habitat (Srivastava et al. 2001).
The population has declined by more than 30% in the last 30 years, and is expected to decline further in the near future due to various threats outlined by field biologists in both India and Bhutan (Molur et al. 2003).
|Habitat and Ecology:||This species is found in moist evergreen, dipterocarp, riverine, and moist deciduous forests, and occasionally in degraded habitats with secondary growth (Srivastava et al. 2001). This species experiences a considerable range in elevation of near sea-level in the south to above 3,000 m in the north (Wangchuk et al. 2003). One isolated population is found in the Abhaya Rubber Plantation, Nayakgaon, in the Kokrajhar district of Assam (Medhi et al. 2004). Study of this population has shown that the animals can withstand the effects of habitat change to some extent and survive in altered habitats (Medhi et al. 2004). The diet consists of young and mature leaves, ripe and unripe fruits, and seeds, with most feeding spent on young leaves (Gupta 1998, 2002). Subba (1989) and Subba and Santiapillai (1989), however, found that this species prefers fruits and buds to leaves. In forest fragments they may depend on cultivated crops such as tapioca, betel, and guava. It is diurnal and arboreal (Khajuria 1977).|
Due to habitat destruction, the populations of this species are restricted to fragmented forest pockets, especially in India (Medhi et al. 2004). Habitat destruction is the major threat to this species in India (Medhi et al. 2004). Hunting is prohibited in the Abhaya Rubber Plantation, yet electrocution from power lines and hunting by dogs are local threats, which are affecting the population (Medhi et al. 2004). A comparative analysis based on satellite images taken in 1988 and 1998 showed a 50% loss of original habitat in India for this species (Srivastava et al. 2001). Although commercial logging is banned in reserves where this species is found, illegal encroachment and woodcutting have severely affected these forest reserves (Srivastava et al. 2001). Stone quarrying and its associated noise pollution, as well as artillery firing practices in the Bamuni hills, may also have a negative effect.
Molur et al. (2003) list the following threats for this species: “Crop plantations, grazing, harvesting non-woody vegetation for firewood and charcoal production, selective logging, timber collection, human settlement, deforestation, fragmentation, trade, killed by domestic dogs, habitat loss, high juvenile mortality, inbreeding, and local trade in live animals as pets and in road shows. Trade is insignificant.” Due to road construction and other human activities (settlements), the northern and southern populations are completely separated and this has led to loss of suitable habitats and fragmentation (J. Das pers. comm.). There are potential threats to the population in the near future in India due to mustard cultivation and other human activities, and therefore the population is also expected to decline (J. Das pers. comm.).
This species is a Schedule I species in the Wildlife Protection Act (1972) (Medhi et al. 2004). It is also listed on CITES Appendix I (Molur et al. 2003). The Chakrashila Wildlife Sanctuary is the only protected habitat for this species in India (Medhi et al. 2004). However, Srivastava et al. (2001) reports that the species is also found in Ripu, Chirrang, and Manas Forest Reserves. Yet these reserves are unstable, and the complete protection of Manas National Park is needed (Srivastava et al. 2001). By upgrading the protection and status of this species, it is believed that isolated populations can be linked through corridors that will prevent genetic fragmentation (Srivastava et al. 2001). A long-term study is needed to assess the actual impact of habitat alteration on the species over long periods of time (Medhi et al. 2004). Medhi et al. (2004) suggest the following actions to protect the population of this species in Nayakgaon: insulation or diversion of electric lines, motivate villagers to restrain their dogs, planting of trees to develop a corridor between the Nayakgaon population and the Chakrashila population, a long term study of behavior and ecology, and regular monitoring of the population.
In Bhutan this species is found in Black Mountains National Park (Srivastava et al. 2001), Pipsu Wildlife Sanctuary, Royal Manas National Park and Trumshingla National Park (Molur et al. 2003).
Molur et al. (2003) list the following research actions needed for the conservation of this species: taxonomy, survey studies, limiting factor research, and habitat fragmentation. The following management actions are needed: habitat management, wild population management, monitoring, public education, and Population and Habitat Viability Assessment.
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Gee, E. 1961. The distribution and feeding habits of the golden langur, Presbytis geei Gee (Khajuria, 1956). Journal of the Bombay Natural History Society 58: 1–12.
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Gupta, A. K. 1998. Conservation of golden langur (Trachypithecus geei) in Tripura, northeast India. University of Antananarivo, Madagascar.
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Khajuria, H. 1955. A new langur (primates: Colobidae) from Goalpara District, Assam. Annals and Magazine of Natural History 9(12): 86–88.
Khajuria, H. 1977. Ecological observations on the Golden Langur, Presbytis geei Khajuria with remarks on its conservation. In: M. R. N. Prasad and T. C. Anand Kumar (eds), Use of Non-human Primates in Biomedical Research, pp. 52-61. Indian National Science Academy, New Delhi, India.
Medhi, R., Chetry, D., Bhattacharjee, P. C. and Patiri, B. N. 2004. Status of Trachypithecus geei in a rubber plantation in Western Assam, India. International Journal of Primatology 25(6): 1331-1337.
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.
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Srivastava, A., Biswas, J., Das, J. and Bujarbarua, P. 2001. Status and distribution of golden langurs (Trachypithecus geei) in Assam, India. American Journal of Primatology 55(1): 15-23.
Subba, P. B. 1989. The status and conservation of the Golden Langur (Presbytis geei Khajuria, 1956) in the Manas National Park, Bhutan. Tiger Paper 16(4): 16–18.
Subba, P. B. and Santiapillai, C. 1989. Golden Langur in the Royal Manas National Park of Bhutan. Primate Conservation 10: 31-32.
Wangchuk, T. 1995. A census and the biogeography of golden langurs (Presbytis geei) in Bhutan. Asian Primates 5(3-4): 26.
Wangchuk, T., Inouye, D. W. and Hare, M. P. 2003. A new subspecies of Golden Langur (Trachypithecus geei) from Bhutan. Folia Primatologica 74(2): 104-108.
|Citation:||Das, J., Medhi, R. & Molur, S. 2008. Trachypithecus geei. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 14 March 2014.|
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