India’s Vanishing Vultures

Annals of the New York Academy of Sciences, 2012

Vultures are nature's most successful scavengers, and they provide an array of ecological, economic, and cultural services. As the only known obligate scavengers, vultures are uniquely adapted to a scavenging lifestyle. Vultures' unique adaptations include soaring flight, keen eyesight, and extremely low pH levels in their stomachs. Presently, 14 of 23 (61%) vulture species worldwide are threatened with extinction, and the most rapid declines have occurred in the vulture-rich regions of Asia and Africa. The reasons for the population declines are varied, but poisoning or human persecution, or both, feature in the list of nearly every declining species. Deliberate poisoning of carnivores is likely the most widespread cause of vulture poisoning. In Asia, Gyps vultures have declined by >95% due to poisoning by the veterinary drug diclofenac, which was banned by regional governments in 2006. Human persecution of vultures has occurred for centuries, and shooting and deliberate poisoning are the most widely practiced activities. Ecological consequences of vulture declines include changes in community composition of scavengers at carcasses and an increased potential for disease transmission between mammalian scavengers at carcasses. There have been cultural and economic costs of vulture declines as well, particularly in Asia. In the wake of catastrophic vulture declines in Asia, regional governments, the international scientific and donor communities, and the media have given the crisis substantial attention. Even though the Asian vulture crisis focused attention on the plight of vultures worldwide, the situation for African vultures has received relatively little attention especially given the similar levels of population decline. While the Asian crisis has been largely linked to poisoning by diclofenac, vulture population declines in Africa have numerous causes, which have made conserving existing populations more difficult. And in Africa there has been little government support to conserve vultures despite mounting evidence of the major threats. In other regions with successful vulture conservation programs, a common theme is a huge investment of financial resources and highly skilled personnel, as well as political will and community support.

Environmental Science & Technology, 2009

In 2006, India, Pakistan, and Nepal banned the manufacture of veterinary formulations of the nonsteroidal anti-inflammatory drug (NSAID) diclofenac. This action was taken to halt the unprecedented decline of three Gyps vulture species that were being poisoned by diclofenac residues commonly present in carcasses of domestic livestock upon which they scavenged. To assess the affect of this ban and evaluate residue prevelances of other NSAIDs, we present a method to detect diclofenac and eight more NSAIDs by liquid chromatography-mass spectrometry and apply this to 1488 liver samples from carcasses of livestock taken across seven Indian states. Diclofenac was present in 11.1% of samples taken between April and December 2006, and meloxicam (4%), ibuprofen (0.6%), and ketoprofen (0.5%) were also detected. Although meloxicam is safe for a range of avian scavengers, including Gyps vultures, data regarding the safety of other NSAIDs is currently limited. If wild Gyps on the Indian subcontinent are to survive, diclofenac bans must be completely effective, and NSAIDs that replace it within the veterinary drug market must be of low toxicity toward Gyps and other scavenging birds.

Conservation Biology, 2012

Ambio, 2009

2012

This dissertation examines the alternative strategies used by a diverse eight species avian scavenger guild and how these enable their coexistence in Masai Mara National Reserve, Kenya.

Biodiversity and Conservation, 2012

In order to ensure that the objectives behind the conservation of biodiversity are fulfilled it is essential that policies of all stakeholders are compatible. This is the case of the application of sanitary measures for the management of animal by-products and the negative effects that such restrictions had on the population dynamics and behavioural ecology of the avian scavengers' guild. Thus, measures that allow these species to feed and that reduce risks of disease transmission must be put into practice. This study aims to improve the technical implementation of one of the commonest tools employed in the conservation of avian scavengers: supplementary feeding stations. We evaluated the permeability of three types of fences in experimental feeding stations to determine which of the models prevent non-target species from accessing the food provided. We compared R. Moreno-Opo (&) results from fenced-off feeding stations with those from random points in unfenced-off sites. The results showed that two of the models (high and low nets) were the most effective avoiding facultative mammal scavengers from gaining access into the exclosure for over two months and for 7-8 inputs of food. Avian scavengers were able to access food regardless of the type of exclosure, which did not determine the abundance of birds or the species present. The carrion consumption by non-target species can be reduced by affordable and sustainable means. We suggest proposals to optimize the management of supplementary feeding stations for threatened avian scavengers and for the design of fenced exclosures.

Journal of Animal Ecology, 2017

1. Interspecific social information transfer can play a key role in many aspects of animal ecology from foraging to habitat selection to predator avoidance. 2. Within scavenging communities, avian scavengers often act as producers and mammalian scavengers act as scroungers, but we predict that species-specific cueing will allow for mam-malian scavengers to utilize particular avian scavenger species using preferred food sources similar to their own preferences. 3. We use empirical and theoretic approaches to assess interactions between mammalian and avian scavengers in one of the most diverse scavenging guilds in Masai Mara National Reserve, Kenya. 4. Using a spatially explicit model and data from experimental carcasses, we found evidence that mammals benefit from local enhancement provided by vultures and that mammalian-avian following patterns are consistent with the idea that species-specific cueing is occurring. 5. Results suggest that ongoing population declines in avian scavengers may have significant impacts on mammalian scavengers and potentially create trophic cascades.

Science of the Total Environment, 2019

Vultures and condors (hereafter vultures) make up one the most threatened avian guilds in the world due to a variety of human-mediated impacts and disturbances. In fact, 70% of vulture species are currently suffering im-pacted by significant conservation threats, with lead contamination being particularly important. Unfortunately, lead contamination in vulture species remains poorly studied in many regions of the world. We reviewed the existing scientific knowledge about this threat to vultures. We found 62 scientific articles studying lead contamination in vultures. Seventy-two percent of these articles were from North America and Europe, with the rest corresponding to Asia (13%), South America (8%), and Africa (7%). Most (92%) were published recently (2001–2018). Published articles included information on 13 vulture species out of a total of 23 from both the Old (9) and New World (4). Eighty-eight percent of the articles showed individuals with lead concentrations above threshold levels in some tissues sampled, with New World (Cathartidae) vultures more affected than Old World vultures (Accipitridae). The most suspected but rarely probed source of lead was lead ammunition, but other sources such as pollution or industry were also reported. It is concerning that lead contamination is considered a major threat for just 8% (2/23) of the vulture species categorized by the IUCN Red list. Our review shows that lead contamination is an important threat for several vulture species worldwide, but remains undiag-nosed and not well-recognized in some species and geographical areas. The effect of this contaminant on vulture demography is not well known but merits particular attention since it may be leading to population declines in several species.

Bird Conservation …

Asian vultures have undergone dramatic declines of 90-99% in the Indian Subcontinent, as a consequence of poisoning by veterinary use of the drug diclofenac, and are at a high risk of extinction. Cambodia supports one of the only populations of three species (White-rumped Vulture Gyps bengalensis, Slender-billed Vulture G. tenuirostris and Red-headed Vulture Sarcogyps calvus) outside of South Asia where diclofenac use is not widespread. Conservation of the Cambodian sub-populations is therefore a global priority. This study analyses the results of a long-term research programme into Cambodian vultures that was initiated in 2004. Population sizes of each species are estimated at 50-200+ individuals, ranging across an area of approximately 300 km by 250 km, including adjacent areas in Laos and Vietnam. The principal causes of vulture mortality were poisoning (73%), probably as an accidental consequence of local hunting and fishing practices, and hunting or capture for traditional medicine (15%). This represents a significant loss from such a small population of long-lived, slow breeding, species such as vultures. Cambodian vultures are severely food limited and are primarily dependent on domestic ungulate carcasses, as wild ungulate populations have been severely depleted over the past 20 years. Local people across the vulture range still follow traditional animal husbandry practices, including releasing livestock into the open deciduous dipterocarp forest areas when they are not needed for work, providing the food source. Reducing threats through limiting the use of poisons (which are also harmful for human health) and supplementary food provisioning in the short to medium-term through 'vulture restaurants' is critical if Cambodian vultures are to be conserved.