Why do vultures not have feathers on their heads and necks?

Vultures are scavengers. They need to rip off pieces of meat from dead animals with their powerful beaks, and often need to stick their heads deep inside the dead body. Feathers on the head and at the neck would become dirty or get caught in something. Dead animals often pose a risk of spreading infectious diseases. Vultures eat them and so are often known as the 'health police' of nature.