Domestic pigeon
The domestic pigeon (Columba livia domestica) is a pigeon subspecies that was derived from the rock pigeon. The rock pigeon is the world's oldest domesticated bird. Mesopotamian cuneiform tablets mention the domestication of pigeons more than 5,000 years ago, as do Egyptian hieroglyphics.Research suggests that domestication of pigeons occurred as early as 10,000 years ago.
Pigeons have made contributions of considerable importance to humanity, especially in times of war. In war the homing ability of pigeons has been put to use by making them messengers. So-called war pigeons have carried many vital messages and some have been decorated for their services. Medals such as the Croix de guerre, awarded to Cher Ami, and the Dickin Medal awarded to the pigeons G.I. Joe and Paddy, amongst 32 others, have been awarded to pigeons for their services in saving human lives.
| Domestic rock pigeon | |
|---|---|
 | |
| Red Sheffield domestic homing pigeon | |
Domesticated
| |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Columbiformes |
| Family: | Columbidae |
| Genus: | Columba |
| Species: | C. livia |
| Subspecies: | C. l. domestica |
| Trinomial name | |
| Columba livia domestica Gmelin, 1789 | |
| Synonyms | |
| |
Reproduction
Domestic pigeons reproduce in a similar way to the wild rock pigeon. Generally humans will select breeding partners. Crop milk produced by parent birds may occasionally be replaced with artificial substitutes. Pigeons are extremely protective of their eggs, and in some cases will go to severe lengths to protect their productive eggs and have been known to seek revenge on those who interfere with their productive process. Baby pigeons are called squeakers or squabs.
Homing pigeons
Trained domestic pigeons are able to return to the home loft if released at a location that they have never visited before and that may be up to 1000 km away. A special breed, called homing pigeons has been developed through selective breeding to carry messages and members of this variety of pigeon are still being used in the sport of pigeon racing and the white release dove ceremony at weddings and funerals.
The ability a pigeon has to return home from a strange location necessitates two sorts of information. The first, called "map sense" is their geographic location. The second, "compass sense" is the bearing they need to fly from their new location in order to reach their home. Both of these senses, however, respond to a number of different cues in different situations. The most popular conception of how pigeons are able to do this is that they are able to sense the Earth's magnetic field with tiny magnetic tissues in their head (magnetoception)[citation needed]. This is all the more surprising as they are not a migratory species, which is a fact used by some ornithologists to dispute this theory[citation needed]. Another theory is that pigeons have compass sense, which uses the position of the sun, along with an internal clock, to work out direction. However, studies have shown that if magnetic disruption or clock changes disrupt these senses, the pigeon can still manage to get home. The variability in the effects of manipulations to these sense of the pigeons indicates that there is more than one cue on which navigation is based and that map sense appears to rely on a comparison of available cues
Other potential cues used include:
- The use of a sun compass
- Nocturnal navigate by stars
- Visual landmark map
- Navigation by infrasound map
- Polarised light compass
- Olfactory stimuli
-
- see: Olfactory navigation
Other purposes of pigeon breeding
For food
Pigeons are also bred for meat, generally called squab and harvested from young birds. Pigeons grow to a very large size in the nest before they are fledged and able to fly, and in this stage of their development (when they are called squabs) they are prized as food. For commercial meat production a breed of large white pigeon, named "King pigeon," has been developed by selective breeding. Breeds of pigeons developed for their meat are collectively known as utility pigeons.
Exhibition breeds
Pigeon fanciers developed many exotic forms of pigeon. These are generally classed as fancy pigeons. Fanciers compete against each other at exhibitions or shows and the different forms or breeds are judged to a standard to decide who has the best bird. Among those breeds are the English carrier pigeons, a variety of pigeon with wattles and a unique, almost vertical, stance (pictures). There are many ornamental breeds of pigeons, including the "Duchess" breed, which has as a prominent characteristic feet that are completely covered by a sort of fan of feathers. The fantail pigeons are also very ornamental with their fan-shaped tail feathers.
Flying/Sporting
Pigeons are also kept by enthusiasts for the enjoyment of Flying/Sporting competitions. Breeds such as tipplers are flown in endurance contests by their owners.
Experimentation
Domestic pigeons are also commonly used in laboratory experiments in biology, medicine and cognitive science.
Cognitive science
Pigeons have been trained to distinguish between cubist and impressionist paintings, for instance. In Project Sea Hunt, a US coast guard search and rescue project in the 1970s/1980s, pigeons were shown to be more effective than humans in spotting shipwreck victims at sea. Research in pigeons is widespread, encompassing shape and texture perception, exemplar and prototype memory, category-based and associative concepts, and many more unlisted here (see pigeon intelligence).
Pigeons are able to acquire orthographic processing skills, which form part of the ability to read, and basic numerical skills equivalent to those shown in primates.
Illegal predator killing by enthusiasts
In the United States, some pigeon keepers illegally trap and kill hawks and falcons to protect their pigeons. In American pigeon-related organizations, some enthusiasts have openly shared their experiences of killing hawks and falcons, although this is frowned upon by the majority of fanciers. None of the major clubs condone this practice. It is estimated that almost 1,000 birds of prey have been killed in Oregon and Washington, and that 1,000–2,000 are killed in southern California annually. In June 2007, three Oregon men were indicted with misdemeanour violations of the Migratory Bird Treaty Act for killing birds of prey. Seven Californians and a Texan were also charged in the case.
In the West Midlands region of the United Kingdom pigeon fanciers have been blamed for a trap campaign to kill peregrine falcons. Eight illegal spring-loaded traps were found close to peregrine nests and at least one of the protected birds died. The steel traps are thought to have been set as part of a "concerted campaign" to kill as many of the birds as possible in the West Midlands.
Pigeon breeders sometimes suffer from an ailment known as bird fancier's lung or pigeon lung. A form of hypersensitivity pneumonitis, pigeon lung is caused by the inhalation of the avian proteins found in feathers and dung. It can sometimes be combated by wearing a filtered mask. Other pigeon related pathogens causing lung disease are Chlamydophila psittaci (which causes psittacosis, Histoplasma capsulatum (which causes histoplasmosis and Cryptococcus neoformans, which causes cryptococcosis.
Feral pigeons
Many domestic birds have escaped or been released over the years, and have given rise to the feral pigeon. These show a variety of plumages, although some look very like pure rock pigeons. The scarcity of the pure wild species is partly due to interbreeding with feral birds. Domestic pigeons can often be distinguished from feral pigeons because they usually have a metal or plastic band around one (sometimes both) legs which shows, by a number on it, that they are registered to an owner.
Sexual dimorphism
Male and female pigeons (cocks and hens, respectively) can be differentiated by physical characteristics of the head, beak, height, and breast, though visual identification of sex by physical characteristics alone can be inaccurate. Males usually stand taller, and have larger beaks, crops, wattles,and eye ceres (fleshy growth around the eyes), as well as round heads and thicker napes. Females, on the other hand, tend to be shorter with smaller beaks, wattles, and ceres, as well as flatter heads and fuller breasts.
Male and female pigeons show different behaviours. The "coo" of males is louder and more insistent, especially when courting. Display behaviour also differs between the sexes. Most notably, a male often turns 360 degrees with an inflated crop and a loud "coo", to show interest in a female or to defend or discourage another pigeon from entering its territory (usually a nesting box), while females almost never turn full circle, but rather do a 270-degree back-and-forth rotational motion.[citation needed]
Reproduction
During breeding season, usually during the warmer months, a male pigeon will court the female by puffing out his chest, bobbing his head and strutting in circles around her, all the while cooing his affections. If she accepts, she will allow him onto her back in order to copulate. After mating, the male will build a nest out of gathered sticks in a suitable crevice, while the female watches and makes changes. Urban birds will gladly use a roof on a building. The female will usually lay two eggs. The first egg would be laid late in the evening, and the other egg forty hours after, which will hatch in 17 to 20 days, depending on the weather. Both parents aid in rearing the nestlings. Fledglings usually leave the nest around four to five weeks after hatching.
History
The sport of flying homing pigeons was well-established as early as 3000 years ago.They were used to proclaim the winner of the Olympics.Messenger pigeons were used as early as 1150 in Baghdad and also later by Genghis Khan. By 1167 a regular service between Baghdad and Syria had been established by Sultan Nour-Eddin. In Damietta, by the mouth of the Nile, the Spanish traveller Pedro Tafur saw carrier pigeons for the first time, in 1436, though he imagined that the birds made round trips, out and back. The Republic of Genoa equipped their system of watch towers in the Mediterranean Sea with pigeon posts. Tipu Sultan used homing pigeons. They returned to the Jamia Masjid mosque in Srirangapatna, which was his headquarters. The pigeon holes may be seen in the mosque's minarets to this day.
In 1818, a great pigeon race called the Cannonball Run took place at Brussels. In 1860, Paul Reuter, who later founded Reuters press agency, used a fleet of over 45 pigeons to deliver news and stock prices between Brussels and Aachen, the terminus of early telegraph lines. The outcome of the Battle of Waterloo was also first delivered by a pigeon to England. During the Franco-Prussian War pigeons were used to carry mail between besieged Paris and the French unoccupied territory. In December 1870, it took ten hours for a pigeon carrying microfilms to fly from Perpignan to Bruxelles.
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 the Auckland, New Zealand, suburb of Newton and Great Barrier Island in November 1897, possibly the first regular air mail service in the world. The world's first 'airmail' stamps were issued for the Great Barrier Pigeon-Gram Service from 1898 to 1908.
Homing pigeons were still employed in the 21st century by certain remote police departments in Odisha state in eastern India to provide emergency communication services following natural disasters. In March 2002, it was announced that India's Police Pigeon Service messenger system in Odisha was to be retired, due to the expanded use of the Internet. The Taliban banned the keeping or use of homing pigeons in Afghanistan.
To this day, pigeons are entered into competitions, with the winner receiving prize money at the end.
Research has been performed with the intention of discovering how pigeons, after being transported, can find their way back from distant places they have never visited before. Most researchers believe that homing ability is based on a "map and compass" model, with the compass feature allowing birds to orient and the map feature allowing birds to determine their location relative to a goal site (home loft). While the compass mechanism appears to rely on the sun, the map mechanism has been highly debated. Some researchers believe that the map mechanism relies on the ability of birds to detect the Earth's magnetic field. Birds can detect a magnetic field to help them find their way home.
Scientists[who?]have found that on top of a pigeon's beak large number of iron particles are found which remain aligned to north like a man-made compass, thus it acts as compass which helps pigeon in determining its home. A light-mediated mechanism that involves the eyes and is lateralized has been examined somewhat, but developments have implicated the trigeminal nerve in magnetoception. Research by Floriano Papi (Italy, early 1970s) and more recent work, largely by Hans Wallraff, suggest that pigeons also orient themselves using the spatial distribution of atmospheric odors, known as olfactory navigation. Near their home lofts, in areas they have previously visited, pigeons probably are guided by visual landmarks.
Research by Jon Hagstrum of the US Geological Survey suggests that homing pigeons use low-frequency infrasound to navigate. Sound waves as low 0.1 Hz have been observed to disrupt or redirect pigeon navigation. The pigeon ear, being far too small to interpret such a long wave, directs pigeons to fly in a circle when first taking air, in order to mentally map such long infrasound waves.
Various experiments suggest that different breeds of homing pigeons rely on different cues to different extents. Charles Walcott at Cornell University was able to demonstrate that while pigeons from one loft were confused by a magnetic anomaly in the Earth it had no effect on birds from another loft 1.6 km (1 mile) away. Other experiments have shown that altering the perceived time of day with artificial lighting or using air conditioning to eliminate odors in the pigeons' home roost affected the pigeons' ability to return home.[citation needed]
Some research also indicates that homing pigeons navigate by following roads and other man-made features, making 90-degree turns and following habitual routes, much the same way that humans navigate.
GPS tracing studies also indicate that gravitational anomalies also play a role.
Roles
As postal carriers
When used as carrier pigeons in pigeon post a message is written on thin light paper and rolled into a small tube attached to the bird's leg. Pigeons can only go back to one "mentally marked" point that they have identified as their home, so "pigeon mail" can only work when the sender is actually holding the receiver's pigeons. White homing pigeons are used in dove-releasing ceremonies at weddings, funerals, and some sporting events.
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.
During war
Birds were used extensively during World War I. One homing pigeon, Cher Ami, was awarded the French Croix de guerre for her heroic service in delivering 12 important messages, despite having been very badly injured.
During World War II, the Irish Paddy, the American G.I. Joe and the English Mary of Exeter all received the Dickin Medal. They were among 32 pigeons to receive this award, for their gallantry and bravery in saving human lives with their actions. Eighty-two homing pigeons were dropped into the Netherlands with the First Airborne Division Signals as part of Operation Market Garden in World War II. The pigeons' loft was located in London, which would have required them to fly 390 km (240 miles) to deliver their messages. Also in World War II, hundreds of homing pigeons with the Confidential Pigeon Service were airdropped into northwest Europe to serve as intelligence vectors for local resistance agents. Birds played a vital part in the Invasion of Normandyas radios could not be used for fear of vital information being intercepted by the enemy.
In computing
The humorous IP over Avian Carriers (RFC 1149) is an Internet protocol for the transmission of messages via homing pigeon. Originally intended as an April Fools' Day RFC entry, this protocol was implemented and used, once, to transmit a message in Bergen, Norway, on April 28, 2001.
In September 2009, a South African IT company based in Durban pitted an 11-month-old bird armed with a data packed 4 GB memory stick against the ADSL service from the country's biggest internet service provider, Telkom. The pigeon, Winston, took an hour and eight minutes to carry the data 80 km (50 miles). In all, the data transfer took two hours, six minutes, and fifty-seven seconds—the same amount of time it took to transfer 4% of the data over the ADSL.
Smuggling
Homing pigeons have been reported to be used as a smuggling technique, getting objects and narcotics across borders and into prisons.
For instance, between 2009 and 2015, many pigeons have been reported to carry cell phones, SIM cards, phone batteries and USB cords into prisons on the Brazilian state of São Paulo.
Comments
Post a Comment