Bird migration (1 Viewer)

[Kits]

Clues to how birds migrate using Earth's magnetic field

Scientists think they may have pinpointed an elusive "living compass" behind birds' epic migrations.

www.bbc.co.uk

 

[MJB]

Clues to how birds migrate using Earth's magnetic field

Scientists think they may have pinpointed an elusive "living compass" behind birds' epic migrations.

www.bbc.co.uk

Unravelling the mechanism by which the Robin, and doubtless other migratory species, can interpret Earth's magnetic field advances another step. However, I remember reading that (I can't find the source) in experiments where the Robin was exposed to artificial magnetic fields, it was the vertical component that the bird detected; as far as I am aware, the vertical component is the only one that does not provide navigational data, according to human understanding of magnetic fields. What is all the more remarkable is that the Robin responded to the artificial magnetic field that was around 30,000 times weaker than the Earth's magnetic field - essentially it could detect that weak signal amid a vast amount of magnetic 'noise'. A reasonable analogy would be hearing a whisper from across the pitch at Wembley at the same time the crowd is sounding its loudest!

It may be that an explanation of how the vertical component can function as a navigation input has been since proposed, possibly summing and comparing minute differences over time as the bird flies, or perhaps the idea had been disproven. Perhaps it's the ability to sense the vertical component that enables it to 'see' the Earth's magnetic field dimensionally...

However, it's the bird's seeming ability to invert the signal-to-noise discrimination in favour of noise that would be of enormous interest should its explanation have application in other fields of research...
MJB