Why do vultures have bald heads?

Vultures feed on carrion, which exposes them to mess and microbes. A bald head makes it easier for them to reach deep into carcasses without soiling feathers, and bare skin can be easier to keep clean in sun and rain. The exposed skin may also play a role in thermoregulation, helping some species warm up or cool down. Since feathers are harder to disinfect than skin, a bare head is a practical adaptation for a scavenging lifestyle. It is one of the clearest examples of a form shaped by diet.