Nun:

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 .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.

The Nun is given its name by the raised feathers which form a kind of hood which covers the back of the neck and head. Continental Europe previously referred to the Nun as the Dutch Shell Pigeon during the early part of the 20th century. It resembles the tumbler from which this breed of pigeon originated; although as with all domestic pigeons they are descended from the Rock Pigeon . They have mostly white bodies and are designated according to the color of their head, i.e. a Black headed Nun, or a Yellow headed Nun