Bird navigation

Most people know that pigeons could choose right directions back home even if they go thousands of miles away. How they realize this has caught scientists’ interest for many years.

At first scientists assumed that pigeons found ways because they recognized major landmarks such as bends in major rivers and curves in coastline as human did. Via radar, which can pick up flocks of migrating birds, scientists found that pigeons ignore geographical features.

In 1950s, the German Gustav Kramer did an experiment with birds and found that birds could determine directions according to the position of the sun. But a scientist did an similar experiment with birds which showed that birds with glued magnet block on their backs fled in confused direction even though in blindfolds.

Now people make it clear that pigeons recognize ways because of magnetic fields and know that there are certain substances in pigeons’ cells which could make pigeons identify directions.

Days ago, the Keays lab at the Research Institute of Molecular Pathology in Vienna announced that they discovered substance-iron balls in neuron cells responsible for detecting sound and gravity. The discovery of iron balls was published in Current Biology. But we're a long way off to understanding how magnetic sensing works -- we still don't know what these mysterious iron balls are doing ,said Dr Keays.