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Rufous-necked Hornbill Aceros nipalensis
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This large hornbill qualifies as Vulnerable because it has a small, rapidly declining population as a result of destruction of evergreen forest and hunting (BirdLife International 2001).

Taxonomic source(s)
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.

117 cm. Large hornbill with distinctive rufous head and underparts. Males are black above with white-tipped outer primaries, white tail with black basal half, pale yellowish bill with row of vertical dark ridges on upper mandible and almost no casque, blue orbital skin and red gular skin. Female has black head, neck and underparts and slightly duller orbital skin. Juvenile is like male but bill smaller without dark ridges, tail feathers may be narrowly dark-tipped. Voice Loud barking kup or kok notes.

Distribution and population
Aceros nipalensis is currently known from Bhutan, north-east India, Myanmar, southern Yunnan and south-east Tibet, China, Thailand, Laos and Vietnam. It has declined dramatically and is now very rare across much of its historical range. It is thought to be extinct in Nepal, and to be close to extinction in Vietnam (J. C. Eames in litt. 2007); it has also disappeared from many areas in Thailand. While still widespread and fairly common in Bhutan (K. D. Bishop in litt. 2007), healthy populations elsewhere survive only in Namdapha National Park, India, Nakai-Nam Theun National Biodiversity Conservation Area, central Laos and perhaps also Huai Kha Khaeng, west Thailand, and Xishuangbanna Nature Reserve, China. Population densities in these strongholds have led some to suppose that the species is more widespread and common than field surveys suggest (Kinnaird and O'Brien 2007). It is perhaps locally common in north Myanmar, and there are recent records from West Bengal (D. Ghose in litt. 2005) and Eaglenest Wildlife Sanctuary, Arunachal Pradesh, India (Choudhury 2003, Datta 2009).

Population justification
A population estimate of 2,500-9,999 individuals has been derived from analyses of records and surveys by BirdLife International (2001). This equates to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals.

Trend justification
Across much of its range forest has been cleared at a rapid rate. In combination with intense hunting pressure these processes are suspected to have driven rapid population declines.

It inhabits mature broadleaved forests, generally between 600-1,800 m (maximum altitude 2,200 m), but locally down to 150 m. It has also been recorded in dry woodland (K. D. Bishop in litt. 2007). It nests (usually March-June) in tall, wide-girthed trees. Evidence suggests that some populations make seasonal movements between forested areas in response to variations in the abundance of fruiting trees.

Its dependence on large trees for feeding and nesting makes it especially susceptible to deforestation and habitat degradation through logging, shifting cultivation and clearance for agriculture. Furthermore, viable populations require vast tracts of forest to survive, exacerbating its susceptibility to habitat fragmentation. These problems are compounded by widespread hunting and trapping for food, and trade in pets and casques.Hunting is the primary threat to the species in Arunachal, India (Datta 2009).

Conservation Actions Underway
CITES Appendix I and II. The following protected areas support important populations: Xishuangbanna Nature Reserve, China, Thrumshing La National Park, Bhutan, Namdapha National Park, Arunachal Pradesh, India, Nakai-Nam Theun National Biodiversity Conservation Area, Laos, and Um Phang and Maewong National Parks and Huai Kha Khaeng and Thung Yai Wildlife Sanctuaries, Thailand. Field surveys were conducted in Namdapha National Park, Kamlang Wildlife Sanctuary, Jairampur Forest Division and Deomali Forest Division, Arunachal Pradesh, India, during 1996-1999 and 2002-2004 (Datta 2009).
Conservation Actions Proposed
Conduct further surveys to clarify its distribution and status. Monitor trends in selected key populations. Protect remaining extensive tracts of forest, extend existing protected areas where appropriate, and strictly control hunting in protected areas. Lobby for improved logging practices that leave patches of old growth or large trees. Design and implement hornbill conservation programmes aimed at reducing hunting levels.

BirdLife International. 2001. Threatened birds of Asia: the BirdLife International Red Data Book. BirdLife International, Cambridge, U.K.

Choudhury, A. 2003. Birds of Eaglenest Wildlife Sanctuary and Sessa Orchid Sanctuary, Arunachal Pradesh, India. Forktail 19: 1-13.

Datta, A. 2009. Observations on Rufous-necked Aceros nipalensis and Austen's Brown Anorrhinus austeni Hornbills in Arunachal Pradesh: natural history, conservation status and threats. Indian Birds 5(4): 108-117.

Kinnaird, M. F.; O'Brien, T. G. 2007. The ecology and conservation of Asian Hornbills: farmers of the forest. University of Chicago Press, Chicago, IL, USA.

Further web sources of information
Detailed species accounts from the Threatened birds of Asia: the BirdLife International Red Data Book (BirdLife International 2001).

Explore HBW Alive for further information on this species

View photos and videos and hear sounds of this species from the Internet Bird Collection

Text account compilers
Benstead, P., Bird, J., Davidson, P., Derhé, M., Mahood, S., Peet, N., Tobias, J.

Bishop, K., Eames, J.C., Ghose, D., Praveen, J.

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2016) Species factsheet: Aceros nipalensis. Downloaded from on 23/10/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from on 23/10/2016.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Additional resources for this species

ARKive species - Rufous-necked hornbill (Aceros nipalensis) 0

Key facts
Current IUCN Red List category Vulnerable
Family Bucerotidae (Hornbills)
Species name author (Hodgson, 1829)
Population size 1500-7000 mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 285,000 km2
Country endemic? No
Links to further information
- Additional Information on this species