Birds Navigate by Magnets in Their Heads
Every year millions of birds make heroic journeys guided by the earth’s magnetic field. How they detect magnetic fields has puzzled scientists for decades. Now biologists have figured out how they do it–they’ve found tiny magnets inside their ears.
These magnetic cells, called hair cells, are responsible for detecting sound and gravity.
What are birds saying? The world is full of them–of one kind or another (NOTE: Subscribers can still listen to this show).
Charles Darwin speculated that "The sounds uttered by birds offer in several respects the nearest analogy to language." Language, he thought, might have had its origins in singing, which "might have given rise to words expressive of various complex emotions."read more