This turkey vulture caught a fish. In theory, if this vulture dropped this fish near a heat source, like a wildfire or molten lava, it could wait for it to cook and then retreive it. It could teach its offspring to do the same. And so on and so on.
Organisms that eat cooked meat increase brain mass and brain function. Over the course of a million years, the turkey vulture could become a dominant raptor within its arial species. Over the course of a billion years, it could acquire language and learn to use tools.
Vultures are Earth’s janitors. Their stomach acid is one of the strongest naturally occuring acids on Earth. This helps them digest the bacteria in rotting carcasses. Vultures can digest and eliminate the ebola virus. As a matter of fact, ebola outbreaks have been attributed to the lack of birds of prey. Read more here: Birds of Prey: Health and Disease.
Could they evolve into acid spitting, flying manbirds?