A carrier pigeon or messenger pigeon is a homing pigeon (specifically a domesticated rock pigeon, Columba livia) that is used to carry messages. Using pigeons to carry messages is generally called "pigeon post". Most homing or racing type varieties are used to carry messages. There is no specific breed actually called "carrier pigeon". Carrier pigeons that are the basic Racing Homer were used to carry messages in World War I and World War II. Thirty-two pigeons were presented with the Dickin Medal.
Historically, pigeons carried messages only one way, to their home. They had to be transported manually before another flight. However, by placing their food at one location and their home at another location, pigeons have been trained to fly back and forth up to twice a day reliably, covering round-trip flights up to 160 km (100 mi). Their reliability has lent itself to occasional use on mail routes, such as the Great Barrier Pigeongram Service established between Auckland, New Zealand and Great Barrier Island in November 1897.
With training, pigeons can carry up to 75 g (2.5 oz) on their backs. The German apothecary Julius Neubronner used carrier pigeons to deliver urgent medication. In 1977 a similar carrier pigeon service was set up for the transport of laboratory specimens between two English hospitals. Every morning a basket with pigeons was taken from Plymouth General Hospital to Devonport Hospital. The birds then delivered unbreakable vials back to Plymouth as needed. The 30 carrier pigeons became unnecessary in 1983 because of the closure of one of the hospitals. In the 1980s a similar system existed between two French hospitals located in Granville and Avranche.
Wartime use 
Before the advent of radio, carrier pigeons were frequently used on the battlefield as a means for a mobile force to communicate with a stationary headquarters. In the 6th century BC, Cyrus, king of Persia, used carrier pigeons to communicate with various parts of his empire. During the 19th-century Franco-Prussian War, besieged Parisians used carrier pigeons to transmit messages outside the city; in response, the besieging German Army employed hawks to hunt the pigeons.
During the First and Second World Wars, carrier pigeons were used to transport messages back to their home coop behind the lines. When they landed, wires in the coop would sound a bell or buzzer and a soldier of the Signal Corps would know a message had arrived. He would go to the coop, remove the message from the canister, and send it to its destination by telegraph, field phone, or personal messenger.
A carrier pigeon's job was dangerous. Nearby enemy soldiers often tried to shoot down pigeons, knowing that released birds were carrying important messages. Some of these pigeons became quite famous among the infantrymen they worked for. One pigeon, named "The Mocker", flew 52 missions before he was wounded. Another, named "Cher Ami", was injured in the last week of World War I. Though she lost her foot and one eye, her message got through, saving a large group of surrounded American infantrymen.
See also 
- English Carrier
- Racing Homer
- Passenger Pigeon
- Pigeon racing
- Pigeon photography
- IP over Avian Carriers, an RFC that was published on April Fools' Day, 1990.
- "PDSA Dickin Medal: 'the animals' VC', Pigeons — Roll of Honour". PDSA. Retrieved 28 December 2008.[dead link]
- National Research Council (1991). Micro Livestock-Little Known Small Animals With a Promising Economic Future. Sumter, S.C.: Natl Academy Pr. ISBN 0-309-04437-5.
- "Carrier pigeons still serve; Even in modern war they do messenger duty", The New York Times. April 12, 1936. p. SM26.
- "Le pigeon voyageur photographe". Les Nouveautés Photographiques (in French): 63–71. 1910..
- Pigeons flying for life, The Milwaukee Sentinel – July 23, 1977
- The Probe: Newsletter of the National Animal Damage Control Association, Issue 33 – June 1983
- "Cher Ami – The Carrier Pigeon who saved 200 men". HomeOfHeroes.com.