When India accidentally wiped out its vultures, half a million people died in five years. The bird doing zoomies in this video runs the most extreme digestive system in the animal kingdom. Vulture stomach acid sits near pH 1, strong enough to destroy anthrax, rabies, and botulism in the carcasses they eat. A flock strips a cow to bone in about 45 minutes. India had 50 million of them. Free sanitation at national scale, in a country where religious custom means most cattle die natural deaths and every dead cow becomes a carcass someone has to deal with. Then the patent on diclofenac expired in 1994. Farmers started using the cheap painkiller on livestock. Trace amounts left in a carcass cause kidney failure in vultures. Within a decade, 50 million birds fell to a few thousand. The fastest collapse of any bird species since the passenger pigeon. The carcasses didn't disappear. Feral dogs took the vultures' place and brought rabies with them. Rotting remains leached into waterways. In districts where vultures once thrived, human death rates rose more than 4 percent. Economists at Chicago and Warwick put the toll at 100,000 extra deaths a year and $69 billion in annual damages. So yes, the goofy bird sprinting down the walkway is adorable. It's also a disease firewall that evolution spent millions of years building and one generic painkiller nearly erased in ten.