 Every ecosystem has its balance. Some animals prevent others from overpopulating an area whilst other animals may pollinate the plant life around you. Sometimes it's clear that this is happening and sometimes it's not so clear. But there's one animal that may be the most valuable, not just to their own ecosystems, but to our societies. And it may surprise you to hear that this animal is the vulture. There are up to 23 species of vulture found around the world, split up into two groups, the old wild vultures of Europe, Asia and Africa and the new wild vultures of the Americas. They're often not the most liked of birds, with Darwin himself even calling them disgusting. Despite this, there are some surprisingly great things about these birds. For instance, vultures actually hold the title for the highest ever recorded bird flight when in 1973 a vulture collided with an aircraft at 37,000 feet. Now just for reference, this is actually above the height of Mount Everest, which stands at around 29,000 feet. And they've even been known to travel distances above 1,000 kilometers. But these accolades aren't the reason that vultures are so valuable. To see why they are, we've got to take a look at what they're probably most famous for, eating the rotting carcasses of dead animals. There are actually vultures that will feed on a varied diet of things like nuts and figs and fish, but the main part of a diet for a vulture is generally the meat from a freshly dead animal. Because of this, you might be thinking they should be getting ill from their diet, but they've actually got some tricks that help them deal with this. For starters, their famous featherless heads, which you've probably noticed before, help them from getting too unclean when rummaging through the carcasses of dead animals, which may contain harmful bacteria. Some vultures will even urinate on themselves, with acid in the urine destroying harmful pathogens after they've been standing in rotting flesh. Vultures also have an incredibly strong stomach acid, which can actually destroy bacteria, including cholera and anthrax, which could become extremely harmful to other species. They also seem to have adapted an immune resistance to some harmful pathogens. And all of this is why vultures are so valuable to us and the ecosystems that they live in, they're literally nature's cleanup crew. Their diet preferences help to stop the spread of disease by being a true dead end for pathogens, and they even help to limit the populations of other scavengers like wild dogs through competition for resources. And the need for vultures is made clear by the fact that they evolved separately multiple times in different areas. New world vultures and old world vultures aren't actually closely related. New world vultures share an ancestor with storks, whilst old world vultures likely share an ancestor with raptor birds of prey. This is an example of convergent evolution, and shows that the presence of vultures has a high ecological value. And because of this, losing them can throw an entire ecosystem off balance. Unfortunately, vultures are the fastest declining bird species ever, even faster than the dodo. One of the most tragic examples of their decline is in South Asia, where they lost 98% of their gypsy vultures in the 1990s. It was found that the main cause behind these declines was a drug called diclerfinna, which was used as a painkiller for cattle. Unfortunately, it was found that this drug is toxic to vultures who would become poisoned by when they would feed on carcasses of cattle. The sudden collapse of these vulture populations has let other scavengers like rats and wild dogs grow in population numbers. And what's worse is that they've now become carriers of diseases like anthraxin plague, which otherwise may have been dealt with by the pathogen dead end system of vultures. And unfortunately, this has likely indirectly led to thousands of human deaths. Vulture population decline like this has been reported around the world, but with conservation efforts underway in some areas, certain populations of vultures have shown signs of recovery, especially since the ban of certain threats including the drug diclerfinna in Asian areas. It is clear that more work needs to be done though. This all just goes to show that even one of the least loved animals in the world can play an invaluable role in an ecosystem, not just for wild animals, but also for us humans. So next time you take a look at a vulture and your stomach turns, that's completely understandable. But maybe just take a second and appreciate the fact that that may be one of the most important animals in the world. Thanks for watching, really hope you enjoyed it and that your stomach wasn't turned too much from all of this vulture talk. But we do think it's really important that people understand from a conservation perspective it's not always the same animals that are the most important. Sometimes it's really good to learn about other animals that maybe people haven't considered which could be more important for sustaining an ecosystem. But feel free to let us know what you think of this episode in the comment section below and let us know what topics you'd like us to cover in future episodes. Please feel free to leave a like, it'll help us out a lot and consider subscribing, we've got a lot more to come. And definitely go and check out the Aspect Science Instagram page where we do bite-sized chunks of science. As always the link for that and more will be in the description below. And we'll see you next time.