Sensitivity at the base of the homing pigeon's beak may provide the answer to the complex story - how the pigeons find their way home
Avi Blizovsky
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Scientists have discovered for the first time that homing pigeons have an organ at the base of their beaks that maps the changes in the Earth's magnetic field. The findings reinforce the idea that homing pigeons and other migratory birds use a network of visible and invisible cues to guide them across hundreds and sometimes thousands of miles of land.
Cordola Mora and his colleagues at the University of Auckland believe they have solved one of the mysteries of the homing pigeon - whether it uses anomalies in the Earth's magnetic field to build a map that will give it its position in space.
Although previous experiments have suggested that the birds can navigate themselves according to the Earth's magnetic field, there have been other experiments that have shown that they can detect slight changes in the field. A competing theory claimed that pigeons have a developed sense of smell that helps them.
Prof. Tim Guilford (Guilford) from the University of Oxford in Britain, said that the navigation of animals like the homing pigeon remains a mystery in several aspects. "Birds know how to use the sun as their main compass, and nocturnal migratory birds use magnetic field and star compass navigation. "This is the second stage, but the invisible signs, those in the first stage, were difficult to discover." said.
Dr. Mora and his colleagues in New Zealand found that pigeons can detect, and therefore also map, the tiny changes in the magnetic field. "The study shows that the pigeons have a sensor for magnetic density, almost certainly at the source, which they almost certainly use to fix their position." In an article in the journal Nature, Dr. Mora and his colleagues said: "We proved that the homing pigeon can differentiate between the presence and absence of a magnetic anomaly in experiments under controlled conditions."
The researchers trained pigeons to jump between one of two feeding surfaces depending on whether the magnetic field was turned on or off. When tiny magnets were worn at the base of the beak, or as a woman injected with local anesthesia, this ability to distinguish anomalies in the magnetic field was lost. The researchers suggest that birds originally have microscopic magnetic particles. Changes in the direction of these particles may transmit to the navigation center in the pigeon's brain.
There is little doubt that pigeons also use visual cues. Earlier this year Prof Guilford found that house pigeons use familiar routes home using landmarks. His research revealed that pigeons rarely pass through the heart of the fields because they mostly follow the roads.
For the news on the website of the British newspaper Independent
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