Homing Pigeon

Bird

The homing pigeon is a variety of domestic pigeon derived from the Rock Pigeon (Columba livia domestica) selectively bred to find its way home over extremely long distances. The wild rock pigeon has an innate homing ability,meaning that it will generally return to its own This made it relatively easy to breed from the birds that repeatedly found their way home over long distances nest and its own mate.
Homing pigeons are referred to as carrier pigeons when they are used to carry messages.

http://en.wikipedia.org/wiki/Homing_pigeon