A pigeon’s got cells in its brain
That link up with its inner ear.
Despite any wind, fog, or rain,
These talented birds, they can steer!
The magnetic field is their guide
(At bygone reversals: a rumpus?)
A field vector’s measured inside
A bird-brain equipped with a compass!
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Further reading:
Neural Correlates of a Magnetic Sense, Wu & Dickman, Science, 2012
Katherine Allen is a researcher in geochemistry and paleoclimate at the Lamont-Doherty Earth Observatory.