Words Miriam Mannak, pics supplied
It’s blistering hot in Thakadu Bush Camp, situated in western Botswana—leaving even the normally eardrum-shattering cricket orchestra struggling with the swelter. The Land Cruiser, however, doesn’t seem fazed by soaring mercury levels, and effortlessly ploughs its way over the sand path, with overhanging camel thorn branches leaving the occasional grasshopper behind on the bonnet.
A red-billed hornbill flies up from the ground and into a tree, mocking us for disturbing its rendezvous with a companion.
Suddenly, the air starts to fill itself with the pungent stench of rotting flesh, a foulness that becomes more and more pronounced as we go along. Then the car stops. On the right side, scattered amid the trees, lie dozens of livestock carcasses in various stages of decomposition. Some are bloated, which indicates a relative freshness, while others are nothing but a messy, dried out heap of leathery skin, hooves and bones.
In the not so far distance, in between shrubbery so typical of this region, half a dozen white-backed vultures are ferociously feasting on the remains of a brown cow. As the birds bury their razor-sharp beaks into the decomposing flesh, pulling it out from underneath the hide, others are watching closely from the treetops. The vultures abruptly abort their luncheon when one of them spots the vehicle. One by one, they spread their enormous wings and join their mates in the trees.
“Welcome to our vulture restaurant,” says Hanri Ehlers, co-founder of Kanabo Conservation Link (KCL). Born and bred in South Africa, she heads the organisation’s research camp at Thakadu. For the past few years, KCL has supported various conservation projects in South Africa, Namibia and Botswana. Other activities include finding ways to involve local communities in nature conservation initiatives, and raising awareness around the plight of various threatened and vulnerable species—vultures included. The research camp at Thakadu and the vulture restaurant form part of that.
“This is not for everyone,” says Ehlers with a smirk. “It looks a bit like a war zone at the moment. However, one must remember that vulture restaurants play a crucial role in vulture conservation.”
Over the past years, various studies have shown that African vulture populations have plummeted across the continent, particularly since the 1980s. While the figures vary, the overall message is clear: Vultures in Africa, like they are elsewhere, are under threat. According to a coalition of nature conservation organisations, including Raptors Botswana and the Endangered Wildlife Trust, the number of western African vulture species has dropped by as much as 97% over the past three decades. Their southern African counterparts have shown a decline of 50% to 60% in that very same period.
One of the culprits is diclofenac, an anti-inflammatory often used in the livestock sector to treat lameness and fever. The drug causes acute kidney failure in vultures, which they ingest after feeding on deceased cattle. Says Ehlers, “While these birds are incredibly strong and are able to break down diseases, rabies and anthrax in their gut, they are also highly sensitive to, for instance, diclofenac.”
A prime example of the drug’s destructive impact on the well-being of these carrion-loving raptors is India, which saw its vulture population drop from some 60 million to an estimated 40 000 within a decade. “In South Asia, the populations of the endemic Oriental white-backed, slender-billed and long-billed vultures have declined by more than 95% since the early 1990s,” states a 2008 paper by the World Organisation for Animal Health.
While the Indian government and farmers were aware of the problem, no one realised what the reason was. In 2003, an international team of scientists came with a conclusive answer: diclofenac. Since then, India and various neighbouring countries including Nepal and Pakistan have banned the local manufacturing of the substance in livestock.
BirdLife International’s African branch estimates that diclofenac is used in over a dozen African countries. It is, however, uncertain to which extent. This is where the KCL vulture restaurant comes in, Ehlers explains: “The carcasses we give them are donated by local farmers from the Ghanzi region and Kentrek Feedlot. These are free from diclofenac and other substances that are lethal to vultures.”
She adds that the initiative has another benefit: “It enables scientists and nature conservationists to study vultures in their natural habitat. We need to know more about vultures in order to be able to protect them.”
Some 270 kilometres southeast from Thakadu, near the dusty Kalahari town of Kang, Beckie Garbett from Raptors Botswana has her eyes firmly locked on a handful of circling vulture silhouettes. Using the thermals, the birds effortlessly hover through the sky, their wings outstretched and their heads aimed at the ground.
Garbett has been studying Botswana’s vultures for the past year, with a strong focus on the lappet-faced species. With a wingspan of up to 3m, it’s one of the largest vultures in southern Africa. It is also one of the most vulnerable: BirdLife International estimates the population of the lappet-faced vulture at 5 700 mature adults. This is the lowest out of all southern African vulture species.
Focusing on the birds’ conservation status, flight patterns and nesting behaviours as well as threats and survival rates, Garbett hopes to get better insight into the animals’ general ecology. This data is crucial to the development of much-needed protection strategies.
Regular vulture captures, aimed at any species, form a central part of Garbett’s research. The birds are caught by using a net and bait. “After drawing some blood, taking a feather and giving them a wing tag, we release them,” she explains. “The procedure takes three minutes and is painless.”
A select few birds are fitted with a GPS transmitter the size of a small mobile phone. “These devices enable us to monitor the vulture’s movements,” Garbett says. “Over two hours or so, the transmitter gives us the location of the animal. We have, for instance, found out that lappets can cover 800km per day—we didn’t know that before.”
While diclofenac is a key threat to vultures, poisoning is a much bigger concern, she notes. “Some farmers revert to poisoning of deceased livestock to keep large predators, such as cheetah, at bay. In the process, they end up accidentally poisoning vultures because they feed off these carcasses,” Garbett explains, nothing that Botswana’s national parks are not hermetically fenced off as in South Africa. This results in incidental wildlife–human conflict.
“The upside is that farmers are approachable and willing to listen to us, as they tend to like the vultures. The birds, after all, clean up dead animals and prevent the spread of disease. Most farmers don’t realise that what they are doing is hurting the birds.”
Poachers are a much bigger concern, Garbett says. “They poison because they deliberately want to kill vultures, to protect themselves and their illegal activity. Poachers are afraid that the birds’ circling in the sky, after they have killed something, draws the attention of anti-poaching patrols. Sometimes there can be 200 vultures in the sky after something has died.”
One of the biggest poisoning episodes ever recorded dates back to July 2013, when elephant poachers deliberately poisoned some hundreds of vultures in the Namibia–Botswana border region north of the Caprivi Strip. An estimated 700 birds died after feeding on one single elephant carcass laced with, most likely, carbofuran. Marketed as Furadan and Curater, this agricultural substance is considered one of the most toxic carbamate pesticides on the market.
Garbett’s own research has been affected by poisoning. “Three of the 14 lappet-faced vultures we fitted with GPS transmitters have died as a result of it,” she says. “Once a transmitter stops moving and gives us the same location day after day, we know we have a problem.”
While poisoning by poachers is a huge problem, it’s difficult to give an idea of the real scope, Garbett says: “The southern African region is so vast. There could be a hundred percent more poisoning episodes than we know about, simply because we can’t get to them.”
A third important threat are the traditional healers. “Vulture bones allegedly give someone clairvoyant powers. In Botswana it is not such a big problem, but it is in South Africa and western Africa,” Garbett says. She stresses that this doesn’t mean Botswanan vultures are safe from sangomas. “Lappets can, after all, fly 800km per day. This makes them vulnerable elsewhere, even if they are safe in Botswana.”
Why save vultures?
Protecting vultures is important—for the birds, people and even the economy. Take the Indian vulture crisis: As the vulture population in India got wiped out, the prevalence of human and animal rabies and other diseases increased. Researcher Anil Markandya estimates the costs of the Indian vulture crisis at $34 billion (about R396 billion) as a result of up to 48 800 additional rabies deaths.
• Of the total 23 vulture species in the world, 11 are endemic to Africa and 14 are considered vulnerable, threatened or endangered.
• Of the nine species in South Africa, seven are facing a certain degree of threat of extinction. The Egyptian vulture is one of two bird species in South Africa listed as ‘regionally extinct’.
• A group of vultures is called a ‘kettle’ when in flight; a ‘wake’ when feeding on a carcass; and ‘committee’, ‘volt’ or ‘venue’ when resting in trees.
• Many vultures have bare necks and heads, preventing the bacteria of rotting flesh to stick to their feathers and cause infections.
• The highest vulture flight recorded was by a Rüppell’s vulture in 1973. The bird was allegedly spotted from a plane at 37 000 feet (about 11 200m) above sea level—higher than Mount Everest (8 848m).
• The diet of bearded vultures (lammergeiers) consists of 70% to 90% bone and marrow. Stomach acid with a pH of 1 allows them to do so. (Human stomach acid has a pH of 1.5 to 3.)
Source: The Intrepid Explorer