About the Author: is an associate professor of history at the University of South Carolina and co-director of the Ann Johnson Institute of Science, Technology and Society.
In the matter of establishing a connection between two points, nothing can defeat a dove. Except, perhaps, a rare hawk.
Avian espionage: in the 1970s, the CIA developed a tiny camera that turned carrier pigeons into spies
Carrier pigeons have carried messages for thousands of years. And they were especially useful in wartime. Julius Caesar, Genghis Khan, (during ) - they all relied on communication through birds. During World War I, the U.S. Signal Corps and the Navy kept their dovecotes. The French government has awarded an American bird named Cher Ami for valorous service during the Battle of Verdun. During World War II, the British kept over 250 carrier pigeons, 000 of which received , a special award for animals for military service [from 1943 to 1949, the medal was awarded 54 times - thirty-two pigeons, eighteen dogs, three horses and a ship / approx. transl.].
And of course, the US Central Intelligence Agency could not help but turn pigeons into spies. In the 1970s, the CIA's Department of Research and Development created a small, lightweight camera that could be strapped to a pigeon's chest. After being released, the dove flew over the spy target on its way home. A battery-powered motor inside the camera rotated the film and opened the shutter. Since pigeons fly only a few hundred meters above the ground, they could take much more detailed photographs than airplanes or satellites. Were there tests successful? We do not know. This information remains classified to this day.
However, the CIA was not the first to use this technology. The German apothecary Julius Gustav Neubronner is generally credited with being the first person to train pigeons for aerial photography. At the beginning of the XNUMXth century, Neubronner fastened cameras [own invention, using the pneumatic opening of the shutter / approx. transl.] to the chest of carrier pigeons. The camera took pictures at regular intervals as the pigeon flew home.
The Prussian military explored the possibility of using Neubronner pigeons for reconnaissance, but abandoned the idea, unable to control routes or take photographs of certain places. Instead, Neubronner began to make postcards from these pictures. Now they are collected in the 2017 book "". Some of them can be viewed online:
The main reason that pigeons can be used for messaging or surveillance is that they have - the ability to feel the Earth's magnetic field, determining its location, direction of movement and orientation.
Early observations in ancient Egypt and Mesopotamia showed that pigeons usually return home to their roost, even if they are released far from home. But only relatively recently have scientists how magnetic orientation works in birds.
In 1968, the German zoologist Wolfgang Wilchko described the magnetic compass. , migratory birds. He watched the captured robins gather at one end of the cage and look in the direction they would move if they were free. When Wilchko manipulated magnetic fields in the laboratory with , the robins reacted to this by changing their orientation in space, without visual or other cues.
Studying the magnetoreception of carrier pigeons has been more difficult because the birds have to be released into their natural environment in order for them to show their characteristic behavior. Outside the lab, there is no easy way to control magnetic fields, so it was difficult to know if birds rely on other methods of orientation, such as the position of the Sun in the sky.
In the 1970 , an ornithologist at New York University at Stony Brook, and his student Robert Green came up with a clever experiment to overcome such difficulties. First, they trained a flock of 50 carrier pigeons to fly in sunny and overcast conditions from west to east, releasing them from three different points.
After the pigeons began to return home steadily regardless of the weather, scientists dressed them up in fashionable hats. For each pigeon, they put coils of batteries - one coil around the bird's neck in the manner of a collar, and the other was glued to its head. The coils were used to change the magnetic field around the bird.
On sunny days, the presence of current in the coils had little effect on the birds. But on cloudy days, the birds flew toward or away from the house, depending on the direction of the magnetic field. This suggests that in clear weather, pigeons are guided by the sun, and on cloudy days they mainly use the Earth's magnetic field. Walcott and Green his discoveries in Science in 1974.
At the beginning of the XNUMXth century, Julius Gustav Neubronner used pigeons and cameras to take aerial photographs.
Additional research and experimentation has helped clarify the theory of magnetoreception, but so far no one has been able to pinpoint exactly where the bird's magnetoreceptors are located. In 2002, Vilchko with a team that they are located in the right eye. But nine years later, another team of scientists published a response to this work in the journal Nature, claiming that they declared result.
The second theory was the beak - more precisely, iron deposits in the upper part of the beak in some birds. This idea was also rejected in 2012, when a team of scientists that the cells there are macrophages, part of the immune system. A few months later, David Dickman and Le-ching Wu third possibility: the inner ear. So far, the search for the causes of magnetoreception remains an area of ββactive research.
Fortunately for those who want to create a "dovenet", understanding how the birds know the direction of flight is not important. They just need to be trained to fly between two points. It is best to use a time-tested stimulus in the form of food. If you feed pigeons in one place and keep them in another, you can teach them to fly along this route. It is also possible to teach pigeons to return home from unfamiliar places. IN birds can fly , although the usual range limit is considered to be a distance of 1000 km.
In the XNUMXth century, pigeons carried messages wrapped in small tubes tied to their legs. Among the typical routes were the way from the island to the mainland city, from the village to the city center, and to other places where telegraph wires had not yet reached.
A single pigeon could only carry a limited amount of conventional messages - it doesn't have the payload capacity of an Amazon drone. But the invention of microfilm in the 1850s by French photographer RenΓ© Dagron allowed a single bird to carry more words, and even images.
About ten years after the invention, when Paris was under siege during , Dagron suggested using pigeons to carry photomicrographs of official and personal messages. ended up moving microfilm, which in total contained more than a million messages. The Prussians appreciated what was happening, and took on the service of hawks and falcons, trying to intercept the winged messages.
In the XNUMXth century, the reliability of regular communication via mail, telegraph and telephone grew, and pigeons gradually moved into the area of ββ\uXNUMXb\uXNUMXbhobby and special needs, becoming the subject of study for rare connoisseurs.
For example, in the mid-1990s, a Colorado rafter included pigeon mail in her travels on the Cache-la-Pudre River. The photographic film taken along the way was loaded into small pigeon knapsacks. The birds were then released and returned to the company's headquarters. By the time the rafters returned, the photographs were already ready - pigeon mail made such souvenirs unique [in the mountainous regions of Dagestan, some residents , transferring data on flash cards / approx. transl.]
A representative of the company said that the birds had a hard time transitioning to digital technologies. Carrying SD cards instead of tapes, they strove to fly into the forest rather than return to the dovecote, perhaps because their load was much lighter. As a result, when all the tourists gradually acquired smartphones, the company had to retire the pigeons,
And my brief overview of pigeon messaging would not be complete without mentioning the RFC from David Weitzman, which he submitted on April 1, 1990 to the Internet Engineering Council. described the protocol , Internet Protocol over Avian Carriers, that is, the transmission of Internet traffic through pigeons. IN , released on April 1, 1999, mentioned more than security-related improvements (βThere are privacy issues with decoy pigeonsβ [a play on words using the concept of stool pigeon, denoting both a stuffed bird intended to lure birds on a hunt, and a police informant / approx. transl.]), but also issues of patenting (βCurrently, there are litigations over which came first - the carrier of information or the eggβ).
In real trials of the IPoAC protocol in Australia, South Africa and the UK, birds competed with local telecommunications, the quality of which left much to be desired in some places. In the end, the birds won. Serving as a messaging tool for thousands of years, pigeons have not given up to this day.
Source: habr.com