CR
Slender-billed Vulture Gyps tenuirostris



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.
Rasmussen, P. C.; Parry, S. J. 2001. The taxonomic status of the "Long-billed" Vulture Gyps indicus. Vulture News 44: 18-21.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
A2ace+4ace A2ace+4ace A2ace+4ace; D1

Red List history
Year Category Criteria
2021 Critically Endangered A2ace+4ace
2016 Critically Endangered A2ce+4ce
2015 Critically Endangered A2ce+4ce
2013 Critically Endangered A2ce+4ce
2012 Critically Endangered A2ce+4ce
2010 Critically Endangered A2c,e; A4c,e
2009 Critically Endangered A2c,e; A4c,e
2008 Critically Endangered
2004 Critically Endangered
2002 Critically Endangered
2000 Not Recognised
1994 Not Recognised
1988 Not Recognised
Species attributes

Migratory status not a migrant Forest dependency Low
Land mass type Land-mass type - continent
Average mass -
Distribution

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 2,130,000 medium
Number of locations -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 730-870 medium estimated 2015
Population trend Decreasing medium estimated -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) - - -
Decline (10 years/3 generation past and future) 95-99 - - -
Number of subpopulations - - -
Percentage in largest subpopulation - - -
Generation length (yrs) 12.03 - - -

Population justification: Considerable confusion over the taxonomy and identification of Gyps vultures has occurred, making it difficult to be sure of the population size. In 2015, the population was estimated to be c.1,000 individuals in India (Prakash et al. 2019; MoEFCC 2020), 47 individuals in Cambodia (Sum & Loveridge 2016), fewer than 50 individuals in Nepal (DNPWC 2015), and a single breeding pair in Bangladesh (MoEF 2016). Very little is known about the size of the population in Myanmar, however counts made at vulture restaurants during 2003-2006 suggest a population of c.21 individuals (Hla et al. 2010). The total population is therefore thought to be c.1,100-1,300 individuals, roughly equating to 730-870 mature individuals.

Trend justification: This species declined across South-East Asia during the 20th century probably as a result of the collapse of wild ungulate populations and, to some degree, persecution. Survey results indicate that declines throughout the Indian Subcontinent probably began in the 1990s and were extremely rapid, resulting in an overall population decline of this species and G. indicus (which were only recognised as separate species in 2001) of greater than 97% over a 10-15 year period (Prakash et al. 2007), equating to 99% over three generations (36.09 years [Bird et al. 2020]). The combined population appeared to be relatively stable from 2003-2011 (Prakash et al. 2012), but declined again during 2011-2015, with a mean rate of decline from 2000-2015 of c.11% per year (Prakash et al. 2019), equating to 98.5% over three generations. In Nepal the species was formerly fairly common and widespread, but during 2002-2011 it declined by 18.7% per year (Chaudhary et al. 2012), equating to >99% over three generations, although there has since been a partial recovery (Galligan et al. 2020; Bhusal et al. 2019). It is now extremely rare in the east of Nepal and local and uncommon in the centre and west (Inskipp et al. 2016). The population in Cambodia, which until recently had remained remained relatively stable (with a steady increase during 2004-2013), declined from 68 to 37 individuals during 2013-2016 (Loveridge et al. 2019), equating to a decline of >99% over three generations.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Bangladesh N Extant Yes
Cambodia N Extant Yes
India N Extant Yes
Laos N Extant Yes
Malaysia N Extinct Yes
Myanmar N Extant Yes
Nepal N Extant Yes
Thailand N Extinct Yes
Vietnam N Possibly Extinct Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Myanmar Nam San Valley
Laos Xe Khampho / Xe Pian
Laos Xe Kong Plains
Laos Siphandon
Cambodia Chhep
Cambodia Lomphat
Cambodia Upper Srepok Catchment
Cambodia Mondulkiri - Kratie Lowlands
Myanmar Kamaing
Cambodia Western Siem Pang
India Dibang Reserve Forest and adjacent areas
India Amchang Hills
India Dhansiri Reserve Forest
India Dibru - Saikhowa Complex
India East and North Karbi Anglong Wildlife Sanctuaries
India Gibbon (Hollongapar) Sanctuary
India Innerline, Katakal and Barak Reserve Forests
India Jamjing and Sengajan
India Kuarbari Dalani
India Laokhowa and Burhachapori Sanctuaries
India Lumding - Marat Longri
India Majuli
India Manas National Park
India Nameri National Park
India Orang National Park
India Pabho Reserve Forest
India Pabitora Wildlife Sanctuary
India Pani-Dihing Bird Sanctuary
India Ripu and Chirang Reserve Forests
India Sibsagar Tanks
India Son Beel
India Sonai-Rupai Wildlife Sanctuary
India Subansiri
India Tamaranga - Dalani - Bhairab Complex
India Upper Dihing (East) Complex
India Urpod Beel
India Gobind Sagar and Naina Devi Wildlife Sanctuaries
India Sarah Valley, Lower Dharamshala
India Kalesar Wildlife Sanctuary
India Ramnagar Wildlife Sanctuary
India Nokrek National Park
India Nongkhyllem and adjacent areas
India Harike Lake Bird Sanctuary
India Fambong Lho Wildlife Sanctuary - Himalayan Zoological Park - Ratey Chu Reserve Forest
India Lowland forests of South Sikkim (Melli-Baguwa-Kitam, Jorethang-Namchi, Sombarey)
India Corbett Tiger Reserve
India Rajaji National Park
India Sonanadi Wildlife Sanctuary
India Buxa Tiger Reserve (National Park)
India Mahananda Wildlife Sanctuary
Nepal Nawalparasi forests
Nepal Rampur valley
India The Chapories of Lohit Reserve
India Pong Dam Lake Wildlife Sanctuary
India Asan Barrage
India Dudhwa National Park
India Bherjan-Borajan-Podumoni Wildlife Sanctuary
India Bordoloni - Sampora
India Chakrashila Complex
India Deepor Beel Bird Sanctuary
India Dum Duma, Dangori and Kumsong Reserve Forests
India Jhanjimukh - Kokilamukh
India Kaziranga National Park
India Tirap - Burhidihing
India Upper Dihing (West) Complex
India Lumding Reserve Forest
Laos Xe Khampho
Laos Xe Pian
Nepal Jagdishpur Reservoir
Nepal Phulchoki Mountain forests
Nepal Annapurna Conservation Area
Nepal Barandabhar forests and wetlands
Nepal Bardia National Park
Nepal Chitwan National Park
Nepal Dang Deukhuri foothill forests and west Rapti wetlands
Nepal Dharan forests
Nepal Farmlands in Lumbini area
Nepal Ghodaghodi Lake
Nepal Koshi Tappu Wildlife Reserve and Koshi Barrage
Nepal Mai Valley forests
Nepal Parsa Wildlife Reserve
Nepal Sukla Phanta Wildlife Reserve
Myanmar Indawgyi Lake Wildlife Sanctuary and surroundings
Myanmar Hukaung Valley extension
Myanmar Lwoilin/Ginga Mountain
India Sareswar Beel
India Marat Longri Wildlife Sanctuary
India Maguri and Motapung Beels
India Manas Reserve Forest
India Innerline (West) and Katakhal Reserve Forests
India Dadara-Pasariya-Singimari
India Chirang Reserve Forest
India Ripu Reserve Forest
India Simbalbara National Park
India Pilibhit Tiger Reserve
India Kamlang Wildlife Sanctuary and Reserve Forest
India Amangarh Reserve Forest
India Innerline (East) and Barak Reserve Forests
India Namdapha National Park
India Pawalgarh Conservation Reserve
India Naina Devi Himalayan Bird Conservation Reserve
India Nandhour Wildlife Sanctuary

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Artificial/Terrestrial Urban Areas suitable resident
Forest Subtropical/Tropical Dry suitable resident
Grassland Subtropical/Tropical Dry suitable resident
Savanna Dry suitable resident
Shrubland Subtropical/Tropical Dry suitable resident
Altitude 0 - 2000 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Stresses
Species mortality
Biological resource use Hunting & trapping terrestrial animals - Unintentional effects (species is not the target) Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Species mortality, Other
Biological resource use Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Stresses
Ecosystem degradation, Reduced reproductive success
Energy production & mining Renewable energy Timing Scope Severity Impact
Ongoing Majority (50-90%) Unknown Unknown
Stresses
Species mortality
Natural system modifications Other ecosystem modifications Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation
Other options Other threat Timing Scope Severity Impact
Ongoing Majority (50-90%) Very Rapid Declines High Impact: 8
Stresses
Species mortality
Pollution Agricultural & forestry effluents - Herbicides and pesticides Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Stresses
Species mortality
Transportation & service corridors Utility & service lines Timing Scope Severity Impact
Ongoing Majority (50-90%) Unknown Unknown
Stresses
Species mortality

Utilisation
Purpose Primary form used Life stage used Source Scale Level Timing
Pets/display animals, horticulture - - International Non-trivial Recent

Recommended citation
BirdLife International (2022) Species factsheet: Gyps tenuirostris. Downloaded from http://www.birdlife.org on 27/06/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 27/06/2022.