Nun Pigeon

Bird

The Nun is a breed of fancy pigeon developed over many years of selective breeding, was also known as the Dutch Shell Pigeon in continental Europe. Nuns, along with other varieties of domesticated pigeons, are all descendants from the Rock Pigeon (Columba livia). The Nun is one of the oldest breeds and was originally a flying tumbler before being developed for exhibition. It is a mostly white breed, with a hood of feathers which gives the name to the breed.

http://en.wikipedia.org/wiki/Nun_(pigeon)