Justification of Red List Category
This species has suffered an extremely rapid population reduction in the recent past which is likely to continue into the near future, probably largely as a result of feeding on carcasses of animals treated with the veterinary drug diclofenac, perhaps in combination with other causes. For this reason it is classified as Critically Endangered.
Given its rarity in South-East Asia it is unlikely that more than a few hundred individuals remain there, while the total population seems unlikely to exceed 10,000 mature individuals given the patchiness of its distribution across India and the apparently catastrophic very recent declines. In light of this it is placed in the band 2,500-9,999 mature individuals. This equates to 3,750-14,999 individuals in total, here rounded to 3,500-15,000 individuals.
Cuthbert et al. (2006) calculate a decline in excess of 90% within 10 years in India. Similarly Galligan et al. (2014) reported a decline of 94% from 1992 to 2003 in India. Similar declines are expected throughout the Indian Subcontinent.
Sarcogyps calvus occurs in Pakistan (previously regular, now a rare straggler with two in Tharparker in 2002 the first record since 1980 [Nadeem et al. 2007]), Nepal (uncommon, population estimated to be 200-400 individuals [Inskipp et al. in press. 2013]), India (sparsely distributed and declining, now rare or absent from some areas, e.g. parts of Gujarat and the north-eastern states, but still fairly common in the west Himalayan foothills and reported in the Western Ghats between 2006 and 2010 [Ramesh et al. 2011]), Bangladesh (rare in the north-west), Bhutan, Myanmar (rare resident; recent records come mainly from Mount Victoria [Hla et al. 2011], with up to 11 in Shan state in 2003 - the first recent documented records in the east of the country [Bezuijen et al. 2010]), China (unrecorded in Yunnan since the late 1960s [S. Chan in litt. 2006]; possibly occurs in south-east Tibet), Thailand (near extinct in the country [P. Round in litt. 2006]), Laos (previously widespread and common, but now only occasional wanderers from the Cambodian population), Viet Nam (previously regular in central regions, but now only occasional wanderers from the Cambodian population), Cambodia (previously common, now rare and restricted to the northern and eastern plains), peninsular Malaysia (previously locally common in north, now absent), and Singapore (formerly occurred, apparently now absent) (Ferguson-Lees et al. 2001).
Historical reports indicate that it was widespread and generally abundant, but it has undergone a massive population and range decline in recent decades. Recent information indicates that in India the species started undergoing a rapid decline (41% per year) in about 1999, and declined by 91% between the early 1990s and 2003 (Cuthbert et al. 2006). Declines in the Indian Subcontinent have followed widely reported and well-researched declines in Gyps vultures owing to mortality following ingestion of the non-steroidal anti-inflammatory drug (NSAID) diclofenac, used to treat livestock, and it is hypothesised that this same drug has been responsible for the observed trends in Red-headed Vulture. Census results from Cambodia suggest that the population there has been stable since 2004 at least (Eames 2007b). Given the lack of intensive agriculture and associated chemical use in South-East Asia, and the continued presence of large areas of suitable habitat for the species, the primary reason behind its decline in the region is thought to be the demise of large ungulate populations and improvements in animal husbandry resulting in a lack of available carcasses for vultures (Clements et al. 2013). Given its rarity in South-East Asia, it is unlikely that more than a few hundred individuals remain there, while the total population seems unlikely to exceed 10,000 mature individuals given the patchiness of its distribution across India and the apparently catastrophic very recent declines.
It frequents open country usually away from human habitation, well-wooded hills and dry deciduous forest with rivers, usually below 2,500 m. Nesting has been recorded in tall trees. It occurs at lower density than Gyps vultures owing to its predominantly territorial behaviour, and movements are poorly known. Vultures play a key role in the wider landscape as providers of ecosystem services, and were previously heavily relied upon to help dispose of animal and human remains in India.
The disappearance of vultures from Asia is linked to a suite of factors: notably the demise of wild ungulates (Clements et al. 2013), the intensification of agriculture, increased sophistication of waste disposal techniques, direct persecution and disease. However, rapid declines since the turn of the 21st century are believed to have been driven by the pharmaceutical NSAID diclofenac used to treat livestock, which has proven highly toxic to vultures, causing mortality from renal failure that results in visceral gout (Cuthbert et al. 2006). A recent study found that Red-headed Vulture population declines in India had slowed and were possibly increasing following a ban on diclofenac, which suggests that the species is also adversely affected by the drug (Galligan et al. 2014). It seems plausible that this species previously had less exposure to the toxin owing to competitive exclusion from carcasses by Gyps spp. vultures (Cuthbert et al. 2006). Surveys in Myanmar in late 2006 and early 2007 found no evidence that diclofenac was being used in livestock (Eames 2007a) and it is not in use in Cambodia (Mahood in litt. 2012). In Cambodia at least it experiences some incidental mortality through the widespread use of poisons to catch fish or waterbirds at trapeangs (waterholes).
Conservation Actions Underway
CITES Appendix II. CMS Appendix II. It has been reported from many protected areas across its range. The governments of India, Nepal and Pakistan passed legislation in 2006 banning the manufacture and importation of diclofenac as a veterinary drug, with India passing further legislation in 2008 banning the manufacture, sale, distribution or use of veterinary diclofenac. A letter from the Drug Controller General of India in 2008 warned more than 70 drugs firms not to sell the veterinary form of diclofenac, and to mark human diclofenac containers 'not for veterinary use' (BirdLife International 2008). In October 2010, the government of Bangladesh banned the production of diclofenac for use in cattle, and the distribution and sale of the drug were due to be outlawed during the first half of 2011 (M.M.H. Khan in litt. 2010). While these bans have been introduced and have led to a reduction of diclofenac within ungulate carcasses (the principal food source for vultures in South Asia) levels of diclofenac contamination still remain high and human forms of the drug are still sold for veterinary use (Cuthbert et al. 2011a,b). Efforts to replace diclofenac with a suitable alternative are on-going and are showing signs of success with evidence for a decrease in diclofenac and an increase in the safe alternative (Cuthbert et al. 2011c). An alternative drug, meloxicam, which is out of patent and manufactured in Asia has been tested on Gyps vultures with no ill-effects (Swan et al. 2006, Swarup et al. 2007). Awareness-raising work has been carried out in Nepal to highlight the use of alternatives to diclofenac (Subedi 2013).
Monitoring of vultures has been conducted in a number of protected areas in India, and monitoring of vulture populations combined with supplementary feeding is underway in the northern and eastern plains of Cambodia. There are currently seven vulture restaurants in Cambodia, which are run by The Cambodia Vulture Conservation Project, a partnership between the Royal Cambodian Government and national and international NGOs (e.g. Masphal and Vorsak 2007, H. Rainey in litt. 2008). Advocacy to reduce the use of poisons and poisoned bait to catch fish and waterfowl has succeeded in reducing the number of vultures being poisoned accidentally (S. Mahood in litt. 2012). A five-year captive breeding and reintroduction scheme to be run by the Zoological Park Association and Kasetsart University was due to begin in 2007 in Uthai Thani, Thailand (Anon 2007), but captive breeding efforts are not as advanced as they are for Critically Endangered Gyps vultures and these are urgently needed. Surveys utilising vulture restaurants were carried out in Myanmar in late 2006 and early 2007, accompanied by research into the locations of nesting colonies, causes of vulture deaths and potential that diclofenac was being used in livestock (Eames 2007a). Further research on the causes of decline in this species was being proposed in 2011 (R. Cuthbert in litt. 2011).
76-86 cm. Medium-sized bulky vulture. Mainly black except for bare red head, neck and legs; also white thigh-patches and ruff. Juveniles have paler more mottled plumage. Similar spp. No real confusion species within its range.
Text account compilers
Benstead, P., Bird, J., Butchart, S., Symes, A., Taylor, J., Allinson, T & Ashpole, J
Chan, S., Chunkino, G., Cuthbert, R., Eames, J.C., Htin Hla, T., Khan, M., Rainey, H., Round, P. & Mahood, S.
BirdLife International (2017) Species factsheet: Sarcogyps calvus. Downloaded from http://www.birdlife.org on 23/09/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 23/09/2017.