Justification of Red List Category
This species is classified as Critically Endangered because it has suffered an extremely rapid population decline as a result of mortality from feeding on carcasses of animals treated with the veterinary drug diclofenac.
Prakash et al. (2019) estimated the population to be c.12,000 individuals based on road transects carried out in 2015. This roughly equates to 8,000 mature individuals. It is placed in the band 5,000-15,000 mature individuals.
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 Gyps indicus and G. tenuirostris (which was only recognised as a 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) (although Tatu et al.  recorded a decline of 29.5% in Gyps indicus in Gujarat, India, during 2005-2010), 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. The frequency of reports of Indian Vulture sightings on eBird declined by c.90% during 2000-2018, further indicating a steep population decline (SoIB 2020). Surveys of breeding populations in two neighbouring Indian states during 2007-2016 found that the two populations were on different trajectories - one remained relatively stable, while the other progressively declined (McClure et al. 2021). Surveys in Pakistan found that vulture abundance declined by c.60% in the three years before the ban on veterinary diclofenac, but showed a recovery in the 2 years following the ban (Chaudhry et al. 2012)
Gyps indicus breeds in south-east Pakistan and peninsular India south of the Gangetic plain, north to Delhi, east through Madhya Pradesh, south to the Nilgiris, and occasionally further south (Collar et al. 2001). The species was first recorded in Nepal in 2011 (Subedi and DeCandido 2013). It was common until very recently, but since the mid-1990s has suffered a catastrophic decline (over 97%) throughout its range. This was first noticed in Keoladeo National Park, India (Prakash et al. 2003), where counts of feeding birds fell from 816 birds in 1985-1986 to just 25 in 1998-1999. Only tiny populations in the Ramanagaram Hills of Karnataka and Nilgiri Forest Division in Tamil Nadu are known to remain in inland southern India, and it is rare elsewhere within its former range (Prakash et al. 2007, Venkitachalam and Senthilnathan 2015, 2016). A new breeding colony appears to have developed near the India-Pakistan border in the Bikaner District, India (Chaudhry et al. 2012).
It is found in cities, towns and villages near cultivated areas, and in open and wooded areas. This species feeds almost entirely on carrion, and often associates with White-rumped Vulture G. bengalensis when scavenging at carcass dumps and slaughterhouses. It nests almost exclusively in colonies on cliffs and ruins, although in one area, where cliffs are absent, it has been reported nesting in trees. Vultures also 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, which in turn reduces the amount of food available for potentially problematic species, such as feral dogs (Prakash et al. 2012b).
By mid-2000, Gyps vultures were being found dead and dying in Pakistan and throughout India, and major declines and local extirpations were being reported (Prakash et al. 2003, 2007, Gilbert et al. 2006). The non-steroidal anti-inflammatory drug (NSAID) diclofenac, used to treat domestic livestock, has been identified as the cause of mortality, with renal failure resulting in visceral gout found in the vast majority of examined vultures (Oaks et al. 2004a, Shultz et al. 2004, Swan et al. 2006b, Gilbert et al. 2006). Vultures are exposed to diclofenac and other NSAIDs through scavenging on the carcasses of largely cattle and buffalo that have been treated with the drugs prior to death and left for scavengers to consume (as is tradition in Hindu cultures). Vultures are unable to process diclofenac and other vulture-toxic NSAIDs that then cause renal failure and death. Modelling has shown that to cause the observed rate of decline in the species just one in 760 livestock carcasses need contain diclofenac residues (Green et al. 2004), and sampling livestock carcasses in India between 2004 and 2005 showed that 10% were contaminated with diclofenac (Taggart et al. 2009). Despite awareness programmes to educate locals about the association between diclofenac and vulture mortality, a survey in Nepal indicated that the vast majority of people still do not link diclofenac use to a decline in vulture populations (Paudel 2008), potentially leading to a slower uptake of meloxicam, an alternative veterinary drug that is of low toxicity to vultures and which has been promoted as a safe alternative to diclofenac in the region (Swan et al. 2006a, Swarup et al. 2007). Recent bans of diclofenac in the region still have not eradicated its use in veterinary treatments, as it is still found in the carcasses of livestock and vultures (Cuthbert et al. 2014, 2015). This may be because the drug continues to be produced for human consumption, which is then sold on for veterinary purposes (Cuthbert et al. 2011, T. Galligan in litt. 2016); though this is not so much of a problem in Nepal and Pakistan (SAVE 2015). A second veterinary drug in use in India, ketoprofen, has also been identified to be lethal to the species, and measurements of residue levels in ungulate carcasses in India indicates that they are present in sufficient concentrations to cause vulture mortalities (Naidoo et al. 2010). Additionally, aceclofenac is a pro-drug of diclofenac, which is converted to diclofenac in cattle (Galligan et al. 2016), and is therefore as toxic to vultures as diclofenac itself. Wild vultures have also been found dead in India with visceral gout and residues of the veterinary NSAID nimesulide in their tissues (Cuthbert et al. 2016; Nambirajan et al. in prep. 2021). This combination has only been found previously for gout and diclofenac, and therefore provides a strong indication that nimesulide is also toxic to vultures (C. Bowden in litt. 2016). The availability of other NSAIDs, including ketoprofen and nimesulide, is increasing (Cuthbert et al. 2011b, Khan 2013, C. Bowden in litt. 2016). Flunixin is another NSAID that has been associated with visceral gout in vultures (Zorrilla et al. 2015), though it is not commonly in use in South Asia yet (T. Galligan in litt. 2016).
Other possible contributory factors are changes in human consumption and processing of dead livestock (which have occurred in response to the collapse in vulture numbers), unintentional poisoning from consumption of poisoned baits intended for feral dogs or wild carnivores, electrocution or collision with energy infrastructure, disturbance from rock climbers at cliff nesting sites (Botha et al. 2017), drought (Hall et al. 2012) and mining activity (Chhangani 2004).
Conservation Actions Underway
CITES Appendix II, CMS Appendices 1 & 2, Raptors MOU Category 1. It has been reported from many protected areas across its range. In 2006 the Indian government passed a bill banning the manufacture and importation of diclofenac as a veterinary drug, and in 2008 further legislation was passed banning the manufacture, sale, distribution or use of veterinary diclofenac. Similar laws are now in place in Nepal, Pakistan and Bangladesh. 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). These bans have led to a reduction of diclofenac within ungulate carcasses (the principal food source for vultures) in India (Cuthbert et al. 2011a ) and a study of 11 administrative districts in Nepal found diclofenac use dropped by 90% since 2006 following the introduction of measures to reduce its use (Anon 2008). However, levels of diclofenac contamination still remain high and human forms of the drug are still sold for veterinary use (Cuthbert et al. 2011a,b). In response to the misuse of human diclofenac, the Government of India banned the manufacture of all diclofenac products in vial sizes larger than 3 ml (the single dose for humans) in 2015, and this is predicted to make the drug too expensive and too complicated to use on large-bodied animals and thereby stop its misuse in livestock (T. Galligan in litt. 2016). 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. 2006a, Swarup et al. 2007); though three additional drugs, aceclofenac, nimesulide and ketoprofen, are known to be toxic to vultures, and approximately another 10 drugs need to be tested (Galligan 2013, Cuthbert et al. 2016).
The Report of the International South Asian Vulture Recovery Plan Workshop in 2004 gave a comprehensive list of recommendations including establishing a minimum of three captive breeding centres each capable of holding 25 pairs (Bombay Natural History Society 2004) - ultimately at least 150 pairs of the three species should be held in captivity to ensure sufficient birds are available to re-establish wild colonies in the future (Lindsay 2008). Captive breeding efforts are ongoing - by 2015 the Indian breeding centres were fledging 60 juveniles per year of all three resident Gyps vultures combined (V. Prakash pers. comm.; Bowden in litt. 2016), and there are currently over 600 individuals in captivity at three captive breeding centres in India (SAVE 2021).
SAVE (Saving Asia's Vultures from Extinction) has developed the concept of Vulture Safe Zones; areas (with a minimum of 100 km radius, equating to 30,000 km2) around important vulture breeding colonies, where education and advocacy efforts are focused on eliminating the use of diclofenac and other vulture-toxic drugs (Galligan 2013, Mukherjee et al. 2014). Conservation activities include: meeting key groups (e.g. pharmacists, veterinarians and livestock owners); engaging government officials (e.g. drug control, livestock services and forest departments) at tehsil, district and state levels; engaging with the public (e.g. festival programmes, media coverage and signage); diclofenac-free district declaration; community-run formal or informal Vulture Safe Feeding Sites (i.e., vulture [Jatayu] restaurants); vulture-related income generation for villages at nesting or feeding sites; diclofenac-meloxicam exchanges; husbandry and veterinary training camps; and national and international ecotourism to feeding sites and conservation breeding sites (T. Galligan in litt. 2016). There are currently 12 provisional Vulture Safe Zones being established in India, Nepal, Pakistan and Bangladesh (Mukherjee et al. 2014). These areas will provide a safe environment into which birds bred in captivity can be released (Bowden et al. 2012). Diversionary feeding has been shown to reduce (but not eliminate) vulture mortality from diclofenac poisoning, and uncertainty over the movements of Asian Gyps vultures makes the effectiveness of measures such as these uncertain (Pain et al. 2008). Satellite tagging has been employed on Asian Gyps vultures to improve understanding of their movements and range use so as to aid the development of conservation strategies for the genus (Ellis 2004).
The species is covered by a Multi-species Action Plan (MsAP) for the conservation of African-Eurasian vultures (Botha et al. 2017). An updated 5-year (2020-2025) action plan has been produced for vulture conservation in India (MoEFCC 2020), and a 4-year (2015-2019) action plan was was written for Nepal but has not been updated (DNPWC 2015). In 2012 the governments of India, Pakistan, Nepal and Bangladesh adopted a number of priority actions for the conservation of vultures, proposed by SAVE. These include banning large multi-dose vials of human diclofenac, testing other NSAIDs for toxicity to vultures and expanding the Vulture Safe Zones initiative (Galligan 2013). In 2014, SAVE produced A Blueprint for the recovery of South Asia’s Critically Endangered Gyps vultures that presents key conservation actions for the region and timelines for each action (SAVE 2014).
Conservation Actions Proposed
Identify the location and number of remaining individuals. Measure the frequency of diclofenac treated carcasses available to vultures. Support the ban on the veterinary use of diclofenac, and attempt to implement a ban on other vulture-toxic NSAIDs. Support species management or restoration, as needed. Monitor remaining populations. Support captive breeding efforts at a number of separate centres. Manage genetic stock in the captive-bred population (Bowden et al. 2012). Promote the immediate adoption of meloxicam as an alternative to diclofenac. Test other non-steroidal anti-inflammatory drugs (NSAIDs) to identify additional safe alternative drugs to diclofenac and also other toxic ones. Three drugs, aceclofenac, ketoprofen and nimesulide, are thought to be toxic to vultures (Cuthbert et al. 2015), and approximately another 10 drugs need to be tested (Galligan 2013). Fully implement restrictions in the size of diclofenac vials sold for human use to make them less practical to use for veterinary purposes and take action against companies that fail to comply with the diclofenac ban (Cuthbert et al. 2011). Attempt to estimate the potential value, in terms of ecosystem services, provided by wild vultures. Protect nesting areas. Maintain and promote Vulture Safe Zones, including trans-boundary efforts. Within VSZs, promote livestock management training and provide free veterinary camps.These and multiple other Conservation Actions were proposed as part of SAVE (2014) and SAVE (2015) for all Asian vultures. A comprehensive list of conservation actions proposed can be found in Botha et al. (2017).
92 cm. Typical Gyps vulture. Robust, strong features giving eagle-like bearing. Perched adults have pale-yellowish bill and cere; pale eyerings; large white neck-ruff; and buff back and upperwing coverts. The stout blackish neck has pale down. Juveniles have dark bill with pale culmen; pinkish head and neck covered in pale down and dingy heavily streaked underparts. In flight thighs are heavily feathered and concolourous with the rest of the underparts. Similar spp. Told from the allopatric and distinctive Slender-billed Vulture G. tenuirostris by robust build, clean plumage, pale bill (in adults) and downy head and neck (juveniles).
Text account compilers
Bohra, D.L., Bowden, C., Cuthbert, R., Galligan, T., Gilbert, M., Khan, A.A., Khan, M., Prakash, V., Rahmani, A., Riseborough, R., Venkatachalam, R., Benstead, P., Wheatley, H., Taylor, J., Bird, J., Crosby, M., Butchart, S., Calvert, R., Westrip, J.R.S. & Symes, A.
BirdLife International (2022) Species factsheet: Gyps indicus. Downloaded from http://www.birdlife.org on 18/08/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 18/08/2022.