The Pouter pigeons are domesticated

Domestication

Domestication or taming is the process whereby a population of animals or plants, through a process of selection, becomes accustomed to human provision and control. In the Convention on Biological Diversity a domesticated species is defined as a 'species in which the evolutionary process has been...

 varieties of the Rock Pigeon

Rock Pigeon

The Rock Dove or Rock Pigeon, is a member of the bird family Columbidae . In common usage, this bird is often simply referred to as the "pigeon"....

, Columba livia, characterized by a very large, inflatable crop

Crop (anatomy)

A crop is a thin-walled expanded portion of the alimentary tract used for the storage of food prior to digestion that is found in many animals, including gastropods, earthworms, leeches, insects, birds, and even some dinosaurs.- Bees :Cropping is used by bees to temporarily store nectar of flowers...

. They are kept as ornamental or fancy breeds, valued for their unusual appearance. There are many varieties of pouter with little in common except for the nature of the crop. The origin of the breed is unknown, but Pouters have been bred in Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 for at least 400 years.

Common varieties

• Brunner Pouter
  Brunner Pouter
  The Brunner Pouter is a breed of fancy pigeon developed over many years of selective breeding. Brunner Pouters along with other varieties of domesticated pigeons are all descendants from the Rock Pigeon ....
  
  
• English Pouter
  English Pouter
  The English Pouter is a breed of fancy pigeon developed over many years of selective breeding. English Pouters, along with other varieties of domesticated pigeons, are all descendants from the Rock Pigeon...
  
  
• Norwich Cropper
  Norwich Cropper
  The Norwich Cropper is a breed of fancy pigeon developed over many years of selective breeding. The Norwich Cropper along with other varieties of domesticated pigeons are all descendants from the Rock Pigeon . The Norwich Cropper is thought to have been developed from a breed called the Oploper and...
  
  
• Pigmy Pouter
  Pigmy Pouter
  The Pigmy Pouter is a breed of fancy pigeon developed over many years of selective breeding. Pigmy Pouters, along with other varieties of domesticated pigeons, are all descendants from the Rock Pigeon ....