About 8 million tons of plastic enters the ocean every year and one of our greatest celebrated missions at the moment is The Ocean Cleanup, undeniably a brilliant, forward-thinking model that uses the natural movement of the ocean’s currents to push water through and thus catch litter in its specially designed mechanisms. Their models show “that by utilising vast rotational ocean currents, a single 100km installation can catch almost half the Great Pacific Garbage Patch in 10 years,” whilst allowing sea life to pass beneath the solid screens floating on the surface. When you drive through the bushveld though, what you see is a pristine landscape despite countless animals living, eating, dying and breeding in it; a landscape that needs none of these technologically advanced waste dispersal systems. In fact, recently a two-ton hippo bull died on Londolozi and within 24 hours there was absolutely nothing left of it bar some of the largest bones, a corner of the roughest hide and just a hint of its scent. How on earth is this possible and who do we have to thank for it?
Well I’m going to whole-heartedly join James Souchon in saying that we have two of the African savannah’s most misunderstood creatures to thank, namely the hyena and the vulture. James wrote a while back on how deeply unappreciated hyenas are and so this post is going to focus on the importance of their avian counterparts.
Vultures provide one of the most important yet under-appreciated ecosystem services there is. They are highly specialised to rapidly dispose of large carcasses and thus play a critical role in nutrient cycling. As the vultures land they rush towards the meat on ungainly legs and fight for their share of the carcass. Astoundingly, they are able to fill their crop with up to one kilogram of meat in just 2-5 minutes and some species can eat 20% of their own body weight in one sitting! The reason for this is that there is no time to feed lazily or fill their stomachs when they’re wrestling with 50 other birds for the rapidly disappearing scraps. Filling their crops instead gives them the opportunity to grab the meat first, then move off and swallow and digest it at a later stage.
These birds also have large appetites which is another reason why they keep the bush so pristine. Vulture conservationist, Simon Thomsett, uses the Serengeti as an example. There the total biomass of dead grazing animals is estimated to exceed 40 million tonnes per year. “The [mammalian] carnivores can consume only some 36% and the rest is available to vultures. Bacteria and maggots compete with vultures for this resource, but vultures remain the largest consumers.”
Watch the video below to see the intensity at which the vultures were feeding on this hippo in order to get any share of the meat. It’ll make you see why their crops are so necessary and how it is that they can dispose of a carcass so fast. This was definitely one of the biggest vulture scrums I have ever seen and the interactions with the hyenas was just amazing to see.
Vultures are also crucial in leading other scavengers to carcasses. They typically soar in thermals at heights of about 800m and with superb eyesight (apparently able to spot something the size of a R5 coin from one kilometre away) see carcasses on the ground below. Some researchers even claim that vultures can spot carcasses from as far as 4km away and their eyesight is said to be eight times better than that of the average human. As they land, hyenas and other predators see this and know that there is meat to be had, they then rush in and further speed up the annihilation of the carcass. The efficiency at which these scavengers work means that they drastically reduce the risk of contamination by pathogens and therefore help to control the spread of disease. Without them disease such as rabies and anthrax would be a much bigger threat to humans and other animals.
Amazingly enough, vultures are actually able to resist and detoxify bacterial poisons in rotting flesh that would kill other organisms. The special acidic secretions of vultures’ stomachs can dispose of all but the most resistant spores including anthrax, botulism, and cholera bacteria. The simple truth is that these scavengers make our world a much cleaner place and should be appreciated for doing so.
It’s commonly believed that these birds are incredibly dirty but this is also far from the truth. They have bare heads and often bare necks so that when they feed on rotting carcasses, bacteria and other parasites cannot burrow into their feathers to cause infections. This allows the birds to stay healthier while feeding on material that would easily infect other animals.They are also quite fastidious cleaners and during the midday heat will be found washing themselves in water holes and then sitting with their wings outstretched, drying themselves in the sun.
Despite their ecological importance, they are highly sought after and abused for traditional medicine. Having such amazing eyesight, superstition around them abounds and there are people who actually keep vulture eyeballs under their pillows, hoping it will help them to see into the future and dream up the lottery numbers. Other uses include improved luck for betting and gambling, for improved business success, and to increase the intelligence of school children. Vulture is also prescribed by traditional healers for various ailments, including headaches. The Endangered Wildlife Trust reports that in the eastern portion of South Africa alone, there are some 59,000 consumption events of vulture pieces annually in this region. As a result, many of the species we see here now are listed as threatened, vulnerable or endangered.
One of the things I respect most about the natural world is its complete lack of waste. Bones are eaten by giraffe that lack calcium in their diets, dung breaks down, nourishing the earth and housing the next generation of dung beetles, fallen hair is intertwined into the nests of sunbirds and even the least palatable scraps of rough hippo hide are swallowed by hyenas. Nothing goes to waste. Everything is returned to the earth. The landscape remains pristine because there are animals that know to feast in times of plenty and discard nothing. In my opinion, vultures rank as one of the most important in this regard. Despite their appearance, their ungainly manner and the stigmas attached to them, we need to learn to respect and protect this unsung hero of the bush. A creature that should really serve as an example for us all.
Video and text by Amy Attenborough
Photographs by Don Heyneke