Slender-billed Vulture(Gyps tenuirostris)
At 80-95 cm, in length, this mid-sized vulture is about the same size as its sister species, the Indian vulture. This vulture is mostly grey with a pale rump and grey under tail coverts. The thighs have whitish down. The neck is long, bare, skinny and black. The black head is angular and narrow with the dark bill appearing narrow midway. The ear opening is prominent and exposed.
The juvenile resembles adult, but it has browner neck-ruff. The upperwing-coverts are duller and browner with indistinct streaks. Underparts and underwing-coverts are duller and browner. The bird becomes gradually paler with age.
Habitat
The slender-billed vulture is found in India from the Gangetic plain north, west to Himachal Pradesh, south potentially as far as northern Odisha, and east through Assam. It is also found in north and central Bangladesh, southern Nepal, Burma and Cambodia. The Slender-billed Vulture frequents open country and partly wooded areas in lowlands, and sometimes slopes up to 1500 metres of elevation. The Range for this species on the map is the blue colour.
Diet
The Slender-billed Vulture is a scavenger. It feeds mostly from carcasses of various dead animals such as cattle, wild ungulates and human corpses in India. It often feeds at rubbish dumps and near slaughterhouses where it can get debris.
Breeding
There is little information about the breeding behaviour of this vulture. It nests in large, bulky stick nest in large tree or on rocky ledge. Both adults share all the nesting duties. Aerial displays with flight in tandem are probably performed above the nesting-site. The breeding season occurs between October and March. The Slender-billed Vulture may be loosely colonial (up to 10 pairs), but it is more often solitary nester. Both adults build a large, bulky stick nest with shallow cup. It is placed in large tree, between 7 and 15 metres above the ground, or on rock ledge or building. The female lays a single white egg with some pale reddish flecks and blotches. The incubation lasts about 50 days, shared by both parents. The chick is regularly fed by the adults at nest, and for some weeks more after fledging.
Population
According to the IUCN Red List, they are classed as Critically Endangered(CR). Considerable confusion over the taxonomy and identification of Gyps vultures has occurred, making it difficult to be sure of the population size. It is considered likely to number 1,000-2,499 mature individuals, equating to 1,500-3,750 individuals in total. 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. Since the mid-1990s, declines have been noted in three species of Gyps vulture across the Indian Subcontinent, including this species. These declines are driven by high adult mortality as a result of residues of the anti-inflammatory drug diclofenac used to treat domestic livestock. An extremely rapid decline is estimated to have occurred over the last three generations.
Threats
By mid-2000, Gyps vultures were being found dead and dying in Nepal, Pakistan, and throughout India, and major declines and local extirpations were being reported. The anti-inflammatory drug diclofenac, used to treat domestic livestock, has been identified as the cause of mortality. Vultures are exposed to diclofenac (and other Non-Steroidal Anti-Inflammatory Drugs) through scavenging on the carcasses of largely cattle and buffalo that had been treated prior to death (often as part of palliative care) and left for scavengers to consume (as is tradition in Hindu cultures). Vultures are unable to process diclofenac and other vulture-toxic NSAIDs that therefore cause renal failure and death. Modelling has shown that to cause the observed rate of decline in Gyps vultures, just one in 760 livestock carcasses need contain diclofenac residues and sampling carcasses of livestock in India between 2004 and 2005 showed that 10% were contaminated with diclofenac. 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, potentially leading to a slower uptake of a vulture safe alternative drug (meloxicam). Also, despite bans and the wide availability of meloxicam, diclofenac is still widely found in carcasses and vultures. This is largely because pharmaceutical companies (mostly from India) continued to manufacture large vials of diclofenac for human use, which are distributed, sold and used for veterinary purposes. Other veterinary drugs (ketoprofen, flunixin, nimesulide, aceclofenac and fenbendazole) have also recently been identified to be potentially lethal to vulture species. Other likely potential contributory factors to declines in this species are changes in human consumption and processing of dead livestock, reduced food availability, avian malaria, destruction of nesting trees, direct persecution, poisoning of carcasses and pesticide use but these are probably of minor significance. In South-East Asia, the near-total disappearance of the species pre-dated the present crisis, and probably results from the collapse of large wild mammal populations and improved management of deceased livestock leading to scarcity of available food, but persecution and poisoning is also thought to be a problem. In Cambodia vultures are still threatened by extremely low population densities of wild ungulates, a decline in the number of free-ranging domestic ungulates, felling of nesting trees for timber and accidental poisoning at carcasses laced with pesticides to kill stray dogs.
Conservation
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. The use of diclofenac has since declined by 90% across parts of Nepal; however, its complete elimination from the scavenger food chain has yet to be achieved. 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. 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. While these bans have been introduced and have led to a reduction of diclofenac within ungulate carcasses (the main 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. 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 in 2015, which is predicted to make the drug too expensive and too complicated to use on large-bodied animals and thereby stop its misuse in livestock. 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. An alternative drug, meloxicam, which is out of patent and manufactured in Asia has been tested on Gyps vultures with no ill-effects, and exchanges of diclofenac with this drug are taking place. 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 focussed on eliminating the use of diclofenac and other vulture-toxic drugs. There are currently 12 provisional Vulture Safe Zones being established in countries including India, Nepal and Bangladesh. These areas will provide a safe environment into which birds bred in captivity can be released. To aid in the reduction of diclofenac and other NSAIDs two separate Vulture Conservation Action Plans have been launched in Nepal.
Vulture restaurants are used as ecotourism attractions in parts of the species's range to raise awareness and fund supplementary feeding programmes and research - in Cambodia these are run by The Cambodia Vulture Conservation Project and a partnership between national and international conservation NGOs. The studying of populations of this species visiting vulture restaurants in Cambodia have shown that between 2004 and 2008 the number of Slender-billed Vultures visiting increased by 50%, and have remained roughly similar since. Birds have been satellite tagged in various parts of their range to improve understanding of their movements, foraging range, site fidelity etc., in order to develop suitable conservation strategies for the species. Socioeconomic surveys in Nepal have shown that local people are strongly in favour of vulture conservation because of the associated ecological services that they provide. 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. Captive breeding efforts began in 2006 when 18 Slender-billed Vultures were captured for the captive-breeding facility in Pinjore, India. The centre is part of a captive breeding programme established by the RSPB and Bombay Natural History Society. In April 2008, there were 28 birds at the three Indian breeding centres, increasing to 35 birds in 2009. Two individuals bred in captivity for the first time in 2009. By November 2015, the total number in breeding centres in India was 218, 15 at a centre in Pakistan and 57 at a centre in Nepal. The Central Zoo Authority of India has also set up several Vulture Consevration Breeding centres. A website has been set up to allow researchers to contribute data on known colonies to identify founder individuals for captive breeding efforts that represent the full geographical spread of the species. Captive breeding centres often receive vultures that have been found poisoned and then rehabilitated by rescue centres such as the Centre for Wildlife Rehabilitation and Conservation, Assam, which is run by the International Fund for Animal Welfare and the Wildlife Trust of India. Surveys utilising vulture restaurants were carried out in Myanmar in late 2006 and early 2007, accompanied by searches for nesting colonies, research into vulture deaths and investigation of possible diclofenac use in livestock.
In 2012 the governments of India, Pakistan, Nepal and Bangladesh adopted a number of priority actions for 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. An action plan for vulture conservation in India was written in 2006, but has not been updated. Cambodia and Nepal have updated their 10-year and 6-year action plans. In 2012, the governments of India, Pakistan, Nepal and Bangladesh formed a Regional Steering Committee and adopted a number of priority actions for the conservation of vultures proposed by SAVE in the 2012 Delhi Regional Agreement. These include banning large multi-dose vials of human diclofenac, testing other NSAIDs for toxicity to vultures and expanding the Vulture Safe Zones initiative. 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. A multi-species action plan for African-Eurasian Vultures is under development and is due to be considered by CMS at COP12 in October 2017.
Conservation Actions Proposed
Multiple Conservation Actions were proposed as part of SAVE (2014) and SAVE (2015). Measure the frequency of diclofenac treated carcasses available to vultures. Support the ban on the veterinary use of diclofenac (as well as the removal of human-use diclofenac in vials of >3 ml), and attempt to implement a ban on other vulture-toxic NSAIDs. Regulate the production of veterinary drugs to identify vulture-safe NSAIDs. Support species management or restoration, as needed. Initiate public awareness and public support programmes. Identify the location and number of remaining individuals and identify actions required to prevent extinction. Monitor remaining populations, in particular replicate conservation and research activities in Myanmar that have been implemented in Cambodia. Provide supplementary food sources where necessary for food-limited populations in South-East Asia, and maintain and promote Vulture Safe Zones, including trans-boundary efforts. Within VSZs, promote livestock management training and provide free veterinary camps. Support captive breeding efforts at a number of separate centres, and identify the most appropriate sites for release of captive-bred individuals. Attempt to estimate the potential value, in terms of ecosystem services, provided by wild vultures. Protect nesting areas.