VU
Rufous-necked Hornbill Aceros nipalensis



Taxonomy

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.

IUCN Red List criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - A2cd+3cd+4cd

Red List history
Year Category Criteria
2020 Vulnerable A2cd+3cd+4cd
2018 Vulnerable A2cd+3cd+4cd
2016 Vulnerable A2cd+3cd+4cd
2012 Vulnerable A2cd+3cd+4cd
2008 Vulnerable A2c,d; A3c,d; A4c,d
2004 Vulnerable
2000 Vulnerable
1996 Vulnerable
1994 Vulnerable
1988 Threatened
Species attributes

Migratory status not a migrant Forest dependency high
Land-mass type continent
Average mass 2,385 g
Range

Estimate Data quality
Extent of Occurrence (breeding/resident) 1,580,000 km2 medium
Severely fragmented? no -
Population
Estimate Data quality Derivation Year of estimate
Population size 7000-10000 mature individuals medium estimated 2016
Population trend decreasing poor inferred 1996-2024
Rate of change over the past 10 years/3 generations (longer of the two periods) 30-49% - - -
Rate of change over the future 10 years/3 generations (longer of the two periods) 30-49% - - -
Rate of change over the past & future 10 years/3 generations (longer of the two periods) 30-49% - - -
Generation length 9.4 years - - -
Number of subpopulations 2-100 - - -

Population justification: Density estimates in Thailand from 3 different sites have varied between 3.69 birds/km2 (Jornburom et al. 2010) in Huai Kha Khaeng Wildlife Sanctuary to 5.5 birds/km2 in Thung Yai Naresuan Wildlife Sacutaty (Jinamoy et al. 2013) and 8.06 birds/km2 in Thung Yai Naresuan West. Density estimates in Arunachal Pradesh, north-east India were 6.9 birds/km2 in Namdapha Tiger Reserve (Naniwadekar and Datta 2013) and 6.12 birds/km2 in Eaglenest Wildlife Sanctuary (Shukla et al. 2016). Based on these population estimates, coupled with an the extent of suitable habitat remaining within the occupied range of the species estimates that the global population is 12,000-15,000 individuals (R. Naniwadekar, A. Datta and P. Lo in litt. 2016). This is equivalent to 7,900-9,900 mature individuals, rounded here to 7,000-10,000 mature individuals.

Trend justification: Across much of its range, forest has been cleared at a rapid rate. In combination with intense hunting pressure (see Datta 2009, Naniwadekar et al. 2015a, Naniwadekar et al. 2016), these processes are inferred to be driving rapid population declines, placed here in the band of 30-49% decline over three generations (28.2 years; Bird et al. 2020).


Country/territory distribution
Country/Territory Presence Origin Resident Breeding visitor Non-breeding visitor Passage migrant
Bhutan extant native yes
China (mainland) extant native yes
India extant native yes
Laos extant native yes
Myanmar extant native yes
Nepal extinct native yes
Thailand extant native yes
Vietnam extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Bhutan Deothang / Narphang / Samdrup Jongkhar
Bhutan Jigme Singye Wangchuk National Park
Bhutan Kamji
Bhutan Khaling / Neoli Wildlife Sanctuary
Bhutan Kori La
Bhutan Phipsoo Wildlife Sanctuary
Bhutan Royal Manas National Park
Bhutan Samtse
Bhutan Sarpang-Gelephu foothills
Bhutan Thrumsing La National Park
Bhutan Toorsa Strict Nature Reserve
China (mainland) Lhakhang
China (mainland) Nabanhe Nature Reserve
China (mainland) Xishuangbanna
China (mainland) Yarlung Zangbo Daxiagu Nature Reserve
India Ango or Anko Hills
India Barail Range forests
India Behali Reserve Forest
India Bunning Wildlife Sanctuary
India Buxa Tiger Reserve (National Park)
India Chaglagaum - Denning
India Chayang Tajo - Khenewa - Lada
India Chirang Reserve Forest
India Dailong Rongku Forest
India Dhansiri Reserve Forest
India Dichu Reserve Forest
India Eaglenest Wildlife Sanctuary
India East and North Karbi Anglong Wildlife Sanctuaries
India Fakim Wildlife Sanctuary and Saramati area
India Fambong Lho Wildlife Sanctuary - Himalayan Zoological Park - Ratey Chu Reserve Forest
India Intaki National Park
India Itanagar Wildlife Sanctuary
India Jatinga
India Jiri - Makru Wildlife Sanctuary
India Kailam Wildlife Sanctuary
India Kamlang Wildlife Sanctuary and Reserve Forest
India Kane Wildlife Sanctuary
India Koloriang - Sarli - Damin area
India Langting-Mupa Reserve Forest
India Lava - Neora Valley National Park
India Lowland forests of South Sikkim (Melli-Baguwa-Kitam, Jorethang-Namchi, Sombarey)
India Maenam Wildlife Sanctuary - Tendong Reserve Forest
India Magu Thingbu
India Mahananda Wildlife Sanctuary
India Manabum and Tengapani Reserve Forests
India Manas National Park
India Mandla Phudung
India Mechuka - Tato
India Mehao Wildlife Sanctuary
India Monigong - Jorgging - Tuting
India Mouling National Park
India Mount Paona
India Mount Zanibu
India Mount Ziphu
India Nacho - Limeking - Taksing - Majha
India Nafra - Lada area
India Namdapha National Park
India Nameri National Park
India Namsangmukh - Borduria
India Nongkhyllem and adjacent areas
India Norpuh Reserve Forests
India Pakhui or Pakke Wildlife Sanctuary
India Pangolakha Wildlife Sanctuary - Zuluk - Bedang Tso - Natula Complex
India Papum Reserve Forest
India Ripu Reserve Forest
India Saipung
India Satoi Range
India Sessa Orchid Sanctuary
India Shergaon - Tenzinggang - Kalaktang
India Shiroi Community Forest
India Sonai-Rupai Wildlife Sanctuary
India Subansiri
India Taley Valley Wildlife Sanctuary
India Thorangtlang Wildlife Sanctuary
India Upper Dihing (East) Complex
India Upper Dihing (West) Complex
India Walong
India Yardi - Rabe Supse Wildlife Sanctuary
Laos Nakai-Nam Theun
Laos Phou Dendin
Laos Phou Loeuy
Myanmar Hkakaborazi
Myanmar Hponkanrazi
Myanmar Hukaung Valley
Myanmar Kyauk Pan Taung
Myanmar Nat-yekan
Myanmar Ngwe Taung
Thailand Huai Kha Khaeng
Thailand Mae Wong
Thailand Thung Yai - Naresuan
Thailand Umphang
Vietnam Che Tao
Vietnam Pu Mat

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Moist Lowland major resident
Forest Subtropical/Tropical Moist Montane major resident
Altitude 300 - 2400 m Occasional altitudinal limits 150 - 2900 m

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Shifting agriculture Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Species disturbance, Ecosystem degradation, Ecosystem conversion
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Majority (50-90%) Rapid Declines Medium Impact: 7
Stresses
Species mortality
Biological resource use Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Minority (<50%) Rapid Declines Medium Impact: 6
Stresses
Ecosystem degradation
Residential & commercial development Commercial & industrial areas Timing Scope Severity Impact
Future Minority (<50%) Unknown Unknown
Stresses
Ecosystem degradation, Ecosystem conversion
Residential & commercial development Housing & urban areas Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Ecosystem degradation, Ecosystem conversion

Utilisation
Purpose Scale
Food - human subsistence, national
Other household goods subsistence, national
Pets/display animals, horticulture subsistence, national

Recommended citation
BirdLife International (2024) Species factsheet: Rufous-necked Hornbill Aceros nipalensis. Downloaded from https://datazone.birdlife.org/species/factsheet/rufous-necked-hornbill-aceros-nipalensis on 23/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 23/12/2024.