ETHIOPIAN VULTURE DECLINE CAUSES ECOSYSTEM SHIFT
Today, on the International Day for Vulture Awareness, it is time to reflect on India’s journey in vulture conservation and the strides that have been made since 2000, while also acknowledging the challenges that lie ahead.
Vultures play a critical role in maintaining the ecological balance by scavenging ungulate carcasses and preventing the spread of diseases. However, the populations of these majestic birds have faced a steep decline over the years, primarily due to the use of diclofenac-based veterinary drugs.
India, home to nine species of vultures, has been at the forefront of conservation efforts. The recent ban on aceclofenac and ketoprofen, both harmful to vultures, has provided a glimmer of hope, but there is still much work to be done.
India’s vulture populations started plummeting in the 1990s due to the widespread use of diclofenac, a nonsteroidal anti-inflammatory drug (NSAID), in veterinary medicine. When vultures fed on the carcasses of animals treated with diclofenac, they experienced kidney failure, leading to their rapid decline. Populations of some vulture species have decreased by over 99 per cent, pushing these birds to the brink of extinction.
In an encouraging turn of events, the Indian government banned the veterinary use of diclofenac in 2006. However, this ban was often poorly enforced, and other NSAIDs proven to be toxic to vultures, such as aceclofenac and ketoprofen, continued to pose threats to vultures. The recent ban on these drugs, heralded as a significant step forward, holds promise for vulture conservation in India. With the elimination of these toxic substances from the environment, the vulture population has a chance to rebound.
The prospects for vultures in India over the coming years are a mix of hope and caution. The ban on harmful drugs represents a positive shift but is just one piece of the puzzle. Vulture populations take time to recover, and the effects of past decades still linger.
While the recent ban on aceclofenac and ketoprofen is undoubtedly a significant step forward, the battle for vulture conservation is far from won. Nimesulide, another NSAID that is also harmful to vultures, still remains in use. This underscores the importance of a comprehensive approach that addresses all threats to these majestic birds. The journey towards vulture recovery demands a unified effort to eliminate all toxic substances from the environment.
Releasing captive-bred vultures back into the wild is a crucial aspect of conservation efforts. However, this endeavor is not without its challenges. The lingering presence of harmful drugs like nimesulide in the environment poses a serious risk to these released birds. To ensure the survival of these captive-bred individuals, it is imperative to remove all potential threats from their habitat. This underscores the urgency of not only banning vulture-toxic drugs but also eradicating their presence from the ecosystem.
Beyond pharmaceutical threats, vultures in India face a range of other challenges. Electrocution from power lines, which have become increasingly prevalent across the country, poses a grave danger to these birds. Vultures, often using these structures as perches, can accidentally come into contact with live wires, leading to fatalities. Addressing this threat requires a combination of regulatory measures, technological solutions, and public awareness campaigns to ensure that power lines are vulture-friendly.
The issue of accidental poisoning further compounds the challenges faced by vultures. When vultures consume carcasses of animals that have been poisoned with an intent to kill predators/scavengers or poaching, they fall victim to this threat. Such incidents highlight the intricate linkages between vultures and broader ecological issues, such as wildlife management practices. To combat secondary poisoning, vultures not only must be protected but also more holistic approaches to managing wildlife conflicts must be adopted.
It is worth acknowledging the vital role that protected areas (PAs) play in vulture conservation. PAs provide relatively safe havens for these birds, offering protected spaces for breeding and nesting. However, focusing solely on PAs might not be sufficient. Vultures often traverse large areas in search of food, and their survival depends on a landscape-level approach to conservation. The focus must now be on providing safe food sources for vultures and creating conducive habitats for breeding and nesting. Encouraging vulture-friendly practices outside PAs, such as promoting safe disposal of carcasses and reducing threats like poisoning, is equally essential.
As India commemorates the International Vulture Awareness Day, we are reminded of the intricate web of challenges and opportunities that define vulture conservation in the country. Besides the ban on the veterinary use of diclofenac, aceclofenac, and ketoprofen, a ban on nimesulide is also urgently required, along with a more comprehensive approach mandating pharmaceutical companies to conduct / fund safety testing of new NSAIDs on vultures before they are introduced in the market.
The lingering presence of nimesulide serves as a stark reminder that a comprehensive approach is necessary to ensure the survival of vultures. While captive breeding and release programs hold promise, they must be coupled with efforts to eliminate harmful drugs from the environment. Addressing threats like electrocution and secondary poisoning requires a multi-pronged approach that involves regulatory measures, technological innovations, and community engagement.
Vulture conservation is a testament to the interconnectedness of ecosystems and human actions. The decline of vultures serves as a warning about the unintended consequences of certain practices. Conversely, vulture recovery can serve as a beacon of hope, illustrating the positive outcomes of collective conservation action. As we move forward, let us redouble our efforts to protect these magnificent birds and ensure that India’s skies remain graced by the presence of vultures for generations to come.
As gruesome as they may appear, vultures provide a vital ecosystem service. If they didn’t specialize in tearing into carcasses, the diseases and parasites that inhabit rotting flesh could hang around longer on the landscape waiting for new hosts to arrive.
The trouble is, vultures are declining around the world due to factors like poisoning, both intentional and unintentional. While many people might not be that concerned—for most people, vultures lack the charisma of threatened species like cheetahs (Acinonyx jubatus) or giant pandas (Ailuropoda melanoleuca)—new research tracking vulture decline in Ethiopia shows they should pay more attention.
“It’s a big conservation concern,” said Evan Buechley, vice president of the international program of the Peregrine Fund.
In a study published recently in the Journal of Wildlife Management, Buechley and his colleagues wanted to track what was happening to vultures in Ethiopia, which has one of the highest diversities and abundance of vultures in the world. “It is also a country with high potential for and concern about zoonotic disease spread and emergence due to the levels of poverty and livestock husbandry practices,” Buechley said.
“Vultures are very important because they provide ecosystem service in scavenging carcasses of dead animals to avoid decomposition by bacteria as well as cleaning the environment,” added Alazar Daka, a co-author of the study who was a PhD student at Addis Ababa University at the time.
The researchers ventured into the yards behind slaughterhouses—or abattoirs—around Addis Ababa to learn more about the kinds of creatures that were scavenging the discarded flesh. They set up trail cameras at six abattoirs and conducted walking surveys at least once a month from 2014 to 2019.
These surveys and photos revealed a number of species making use of the carcasses at the yards. They followed a pattern. Larger, dominant animals, like feral dogs (Canis familiaris), typically fed first.
This initial wave of larger animals was usually followed by larger species of vultures, like Rüppell’s vulture (Gyps rueppelli), pictured above, and white-backed (G. africanus) vultures. These were followed by smaller vultures like hooded vultures (Necrosyrtes monachus) and other scavenger birds, like the yellow-billed kite (Milvus aegyptius), pied crow (Corvus albus), thick-billed raven (Corvus crassirostris), African sacred ibis (Threskiornis aethiopicus) and wattled ibis (Bostrychia carunculata).
Over the study period, the researchers found that three vulture species became less common in the abattoirs they surveyed.
Rüppell’s and white-backed vultures, pictured above, which the International Union for Conservation of Nature considers critically endangered, declined by 73% (the two species were lumped together in the study due to the difficulty of telling the two apart in some photos and observations). Hooded vultures, also critically endangered, declined by 15% over the five-year period.
“We see this really fast decline in the obligate scavenging species, the vultures,” said Buechley, who was a PhD student at the University of Utah at the time of the study.
As these species began to disappear, they were replaced at carrion heaps by more species that aren’t obligate scavengers, like ibis and feral dogs.
The dogs can be a problem, Buechley said, since they can bite people, sometimes spreading disease like rabies in local communities. “While vultures are generally appreciated at the abattoirs, the dogs are seen as a big problem by locals.”
They also transmit rabies and canine distemper to native wildlife, like the endangered Ethiopian wolf (Canis simensis). The more feral dogs are on the landscape, the more chances they have to transmit disease and prey on native wildlife when carrion isn’t around.
“The dogs are a menace,” Buechler said
The researchers found the time of year affected the scavenger diversity. Vultures were much more common at the abattoirs in the wet season, for example. That may be in part because many more animals die in the harsher conditions of the dry season, giving vultures plenty to eat elsewhere. Meanwhile, other birds that feed on more than carrion find more plentiful prey elsewhere during the wet season.
The team also estimated the loss in carrion removal that occurs as vultures disappear from the abattoirs. While other species, like feral dogs, may pick up some of the slack caused by the loss of the obligate scavengers, they aren’t as efficient at consuming and removing carrion from the landscape as vultures. Dogs, for example, typically don’t share the grim work as well—alpha dogs will fight and chase others off the carrion piles until they have eaten their fill, one at a time.
The team calculated that the decline of vultures recorded at the sites contributed to a 12% loss in carrion removal—nearly 54 kilograms per day, or 20,000 kilograms per year.
One way to control the proliferation of feral dogs at these abattoirs is to build fences around the areas where they discard carrion, Buechley said. The researchers noticed much fewer dogs in yards with good fences, for example—a factor that could help the vultures get to carrion earlier and dispatch it more quickly. But many abattoirs lack the funding to build fences or repair broken ones, like the one pictured above.
“If we could invest a little bit of money in repairing these fences, there would be several benefits,” Buechley said.
This article features research that was published in a TWS peer-reviewed journal. Individual online access to all TWS journal articles is a benefit of membership.