What does a pigeon rely on to tell its direction?

Use the magnetic field to identify the direction. The earth's magnetic field changes in different positions and directions in a large range, thus providing location information for pigeons.

Magnetic field strength, magnetic dip angle and magnetic declination angle can form a highly non-orthogonal network. These components are basically unchanged for hundreds of kilometers. But on the whole surface of the earth, it is gradually changing. The gradient network composed of these changes is called navigation map, which can be used to locate. Experiments in recent years have confirmed the existence of magnetic navigation.

When the artificial magnet with specific polarity is added to the pigeon warhead, the flying direction of the pigeon cannot be positioned correctly; When the solar proton activity is strong, the earth's magnetic field is disturbed, and the homing rate of pigeons is greatly reduced. In addition, the preliminary study shows that there are needle magnets with the size of about 0. 1 micron in the forebrain under the skull of pigeons.

Extended data

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A way of communication between ancient people, which tied letters to the feet of pigeons and passed them on to those who wanted to pass them on. In ancient times, communication was inconvenient, and smart people used many advantages such as pigeons flying fast and knowing the direction to domesticate pigeons and improve the speed of delivering letters.

For example, I am friends with users. Of course, my friends and I live in the same place. Later, I will go to other places, so I will leave my hometown with my pigeons. One day I contacted my friend for something. I will put a note in a special letter-put something on the pigeon's foot, and then let it out, and the pigeon will fly to my hometown. My friends will find pigeons and my letters, and so will swallows. It's all about using the habits of birds.

Baidu encyclopedia-flying pigeon biography