Pigeons and migratory birds are known to use the earth's magnetic field for navigation. But experiments in this area of study are found to be difficult to replicate. There are times when researchers fail to see any evidence of magnetic navigation in birds. A recent paper in Nature 509, 353–356 (2014) gives us a clue why: radio waves!
Radio waves in the range of 50 kHz to 5 MHz seem to suppress the ability of the birds to use the magnetic field. Our radio stations seem to disrupt a sensibility that has evolved over millions of years.
Strange, though it may seem, it becomes quite understandable when we consider that there are radio waves that are not produced by radio stations. Changes in solar activity induces changes in the ionosphere of the earth and cause the whistlers - strange sounds that you hear when you try and tune amplitude modulated (AM) radio. This is the time when there are also magnetic storms and using magnetic navigation would cause the birds to go astray anyway. So shutting down the sense of magnetic navigation momentarily is, in a way, useful.
But consider that the radio stations are mostly 24/7 - unlike whistlers. :(
Radio waves in the range of 50 kHz to 5 MHz seem to suppress the ability of the birds to use the magnetic field. Our radio stations seem to disrupt a sensibility that has evolved over millions of years.
Strange, though it may seem, it becomes quite understandable when we consider that there are radio waves that are not produced by radio stations. Changes in solar activity induces changes in the ionosphere of the earth and cause the whistlers - strange sounds that you hear when you try and tune amplitude modulated (AM) radio. This is the time when there are also magnetic storms and using magnetic navigation would cause the birds to go astray anyway. So shutting down the sense of magnetic navigation momentarily is, in a way, useful.
But consider that the radio stations are mostly 24/7 - unlike whistlers. :(
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