The domestic pigeon (Columba livia f. domestica) was derived from the Rock Pigeon. The Rock pigeon is the world's oldest domesticated bird. Mesopotamian cuneiform tablets mention the domestication of pigeons more than 5,000 years ago, as do Egyptian hieroglyphics. Research suggests that domestication of pigeons was as early as ten thousand years ago. People who keep domestic pigeons are generally called pigeon fanciers. Domestic pigeons can often be distinguished from feral pigeons because they usually have a metal or plastic band around one (sometimes both) legs, which shows by a number on it, that they are registered to an owner.