Slender-billed Vulture Gyps tenuirostris Scientific name definitions

77–103 cm (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close , 2 Rasmussen, P. C., and J. C. Anderton (2012). Birds of South Asia. The Ripley Guide. Volumes 1 and 2. Second edition. National Museum of Natural History, Smithsonian Institution, Michigan State University and Lynx Edicions, Washington, DC, Michigan, MI, and Barcelona, Spain. Close ); wingspan 196–258 cm (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). Medium-sized vulture grossly similar to G. indicus but slightly larger (minimum wing length 590 mm versus 560 mm (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ) ) and with slimmer neck, thinner bill, more angular crown, darker head and neck lacking whitish down, darker dorsum and darker bill that is pale only on culmen; at close range, the head and neck  have thick creases and wrinkles not found on G. indicus, and the ear openings  are large and more prominent (3 Rasmussen, P. C., W.S Clark, S. J. Parry, and J. Schmitt (2001). Field identification of “Long-billed” vultures (Indian and Slender-billed Vultures). Oriental Bird Club Bulletin 34: 24–29. Close ). Irides dark brown, cere entirely blackish. Juvenile  like adult but with sparse pale down on hind neck (3 Rasmussen, P. C., W.S Clark, S. J. Parry, and J. Schmitt (2001). Field identification of “Long-billed” vultures (Indian and Slender-billed Vultures). Oriental Bird Club Bulletin 34: 24–29. Close ); differs from juvenile G. indicus in having darker neck skin and less down on neck (3 Rasmussen, P. C., W.S Clark, S. J. Parry, and J. Schmitt (2001). Field identification of “Long-billed” vultures (Indian and Slender-billed Vultures). Oriental Bird Club Bulletin 34: 24–29. Close ).

Until recently was considered conspecific with G. indicus, but differs on several accounts (4 Rasmussen, P.C. and Parry, S.J. (2001). The taxonomic status of the “Long-billed” Vulture Gyps indicus. Vulture News. 44: 18–21. Close , 3 Rasmussen, P. C., W.S Clark, S. J. Parry, and J. Schmitt (2001). Field identification of “Long-billed” vultures (Indian and Slender-billed Vultures). Oriental Bird Club Bulletin 34: 24–29. Close ). Has black head and narrow neck vs dark grey head and thicker, whitish-grizzled grey neck (2); dark vs pale cere, with dark vs yellow bill and claws (3); much narrower fringes on tertials and greater coverts so that contrast with primaries on folded wing much weaker (2); mottled vs clear rump (ns[1]); head apparently longer (135–145 mm vs 126–131 mm (5 Rasmussen, P. C., and J. C. Anderton (2005). Birds of South Asia. The Ripley Guide. Volumes 1 and 2. Smithsonian Institution, Washington, DC, USA and Lynx Edicions, Barcelona, Spain. Close ) ); split supported by molecular evidence (6 Johnson, J. A., H. R. L. Lerner, P. C. Rasmussen, and D. P. Mindell (2006). Systematics within Gyps vultures: a clade at risk. BMC Evolutionary Biology 6: 65. Close ). Monotypic.

Lower Himalayas, from NW India (Haryana) (2 Rasmussen, P. C., and J. C. Anderton (2012). Birds of South Asia. The Ripley Guide. Volumes 1 and 2. Second edition. National Museum of Natural History, Smithsonian Institution, Michigan State University and Lynx Edicions, Washington, DC, Michigan, MI, and Barcelona, Spain. Close ) through Nepal to Assam and N & E Myanmar; also S Laos and Cambodia; formerly more widespread in Indochina and N Malay Peninsula.

Occurs in open country and partially wooded areas in lowlands and foothills to c. 1500 m elevation; often found near villages and slaughterhouses (7 Harris, R.J. (2013). The conservation of Accipitridae vultures of Nepal: a review. J. Threatened Taxa. 5(2): 3603–3619. Close ). Frequents “vulture restaurants” in Myanmar from c. 200–1200+ m (8 Hla, H., N. M. Shwe, T. W. Htun, S. M. Zaw, S. Mahood, J. C. Eames, and J. D. Pilgrim (2011). Historical and current status of vultures in Myanmar. Bird Conservation International 21(4):376–387. Close ). Nests in trees, unlike the cliff-nesting <em>G</em>. <em>indicus</em> .

An obligate carrion-feeder, feeding on cattle and other livestock, wild ungulates and human corpses; also scavenges at rubbish dumps. May feed in large groups with <em>Gyps bengalensis</em> and Sarcogyps calvus.

Like G. indicus, makes variety of cackling, hissing and grunting sounds while feeding at carcasses.

Little published information. Breeds from Oct–Mar. Builds compact nest  of sticks 60–90 cm across, 35–50 cm deep, 7–15 m off ground in large tree  (1 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ); nests solitarily, sometimes near village. Clutch 1 egg; incubation period c. 50 days. In Cambodia, 31 nests followed from 2006–2011 produced 27 fledglings (87% successful) (9 Clements, T., Gilbert, M., Rainey, H.J., Cuthbert, R., Eames, J.C., Bunnat, P., Teak, S., Chansocheat, S. and Setha, T. (2013). Vultures in Cambodia: population, threats and conservation. Bird Conservation International. 23(1): 7-24. Close ).

CRITICALLY ENDANGERED. CITES II. Like some of its congeners, has undergone serious declines from feeding on carcasses of livestock treated with veterinary drug diclofenac. Breeds in N India from Himachal Pradesh and Haryana S to Gangetic Plain and S West Bengal (possibly N Orissa), E through S Nepal and N & C Bangladesh to Assam, and in Myanmar, S Laos and Cambodia; believed extinct in Thailand and Malaysia. According to BirdLife International, it was once common throughout range, but numbers in SE Asia fell through second half of 19th century and first half of 20th century, and global population now estimated at 1500–3750 individuals. Breeding populations probably very small and restricted mainly to Cambodia, where first nests recorded only recently and surveys at “vulture restaurants” from 2004–2011 found annual totals between 26 and 51 individuals (9 Clements, T., Gilbert, M., Rainey, H.J., Cuthbert, R., Eames, J.C., Bunnat, P., Teak, S., Chansocheat, S. and Setha, T. (2013). Vultures in Cambodia: population, threats and conservation. Bird Conservation International. 23(1): 7-24. Close ), and to Myanmar, where vulture-restaurant counts in 2006 and 2007 suggested total population of c. 21 individuals (8 Hla, H., N. M. Shwe, T. W. Htun, S. M. Zaw, S. Mahood, J. C. Eames, and J. D. Pilgrim (2011). Historical and current status of vultures in Myanmar. Bird Conservation International 21(4):376–387. Close ). In SE Asia, lack of intensive agriculture and associated chemical use, and continued presence of large areas of habitat suitable for the vulture, suggest that main reason for decline in region is probably reduction in large-ungulate populations and changes in animal husbandry resulting in lack of carcasses for vultures. In India and Nepal, suffered catastrophic decline of up to 97% since mid-1990s (10 Prakash, V., Green, R. E., Pain, D. J., Ranade, S. P., Saravanan, S. and Prakash, N. (2007). Recent changes in populations of resident Gyps vultures in India. Journal of the Bombay Natural History Society. 104(2): 127-133. Close , 7 Harris, R.J. (2013). The conservation of Accipitridae vultures of Nepal: a review. J. Threatened Taxa. 5(2): 3603–3619. Close ), and recent surveys in lowland districts of Nepal recorded none at all (11 Chaudhary, A., Subedi, T. S., Giri, J. B., Baral, H. S., Chaudhary, I., Paudel, K. and Cuthbert, R. J. (2012). Population trends of critically endangered Gyps vultures in the lowlands of Nepal. Bird Conservation International. 22(3): 270-278. Close ). One seen in 2015 in Bangladesh, where no recorded since 2000 (12 Alam, A.B.M.S., Ahmed, S. and Ahammed, R. (2016). Rediscovery of the Critically Endangered Slender-billed Vulture Gyps tenuirostris in Bangladesh. BirdingASIA. 25: 69–70. Close ).

Diclofenac apparently is not used in Cambodia, and surveys in Myanmar in late 2006 and early 2007 found no firm evidence of its use there (13 Eames, J. C. (2007). Mega transect counts vultures across Myanmar. The Babbler: BirdLife in Indochina. 30. Close ); census data suggest that the Cambodian population has been stable since at least 2004 (14 Eames, J. C. (2007). Cambodian national vulture census 2007. The Babbler: BirdLife in Indochina. 33-34. Close ). In Cambodia, vultures still threatened by extremely low densities of wild ungulates and decline in number of free-ranging domestic ungulates, as well as felling of nesting trees for timber, and accidental poisoning at carcasses (laced with pesticides to kill stray dogs), a potentially serious problem. In India and Nepal, manufacture and importation of diclofenac as a veterinary drug was banned in 2006. In 2010, Bangladesh government banned production of diclofenac for use in cattle, and proposed to outlaw its distribution and sale in 2011. Although use of diclofenac in ungulate carcasses has been reduced, levels of contamination are still high in some areas. Supplemental feeding at “vulture restaurants” is a valuable attraction for ecotourists and helps focus public attention on the plight of vultures and also provides a means of censusing them. A captive-breeding programme began in 2006, when 18 individuals were caught and taken to a centre in Pinjore (Haryana), in India; by Apr 2008, 28 individuals were held at three Indian breeding centres, increasing to 35 birds in 2009 (15 Bowden, C. (2009). The Asian Gyps vulture crisis: the role of captive breeding in India to prevent total extinction. BirdingASIA. 12: 121-123. Close ); two bred in captivity for first time in 2009, and by Nov 2011 total number in breeding centres affiliated to SAVE (Saving Asia's Vultures from Extinction) was 47 (16 Bowden, C.G.R., Prakash, V., Ranade, S., Routh, A., Jakati, R.D., Cuthbert, R.J., Rahmani, A.R., Green, R.E., Prakash, N. and Parry-Jones, J. (2012). Conservation breeding for the future release of the critically endangered Asian Gyps vultures–progress of the programme in South Asia and why it is so important. Journal of the Bombay Natural History Society. 109(1–2): 43-45. Close ).