Given the extraordinary distances over which birds migrate, it is absolutely essential that they have precise navigation skills. Failure to find a place to land, rest, and/or feed will nearly guarantee a wayward bird’s death.

“It’s not just us,” said Harriett.  “One-fifth of Earth’s 10,000 bird species migrate over great distances, crossing insurmountable obstacles as they follow the seasons and their instincts.
The Doctor is delighted.  Harriett is finally sharing her knowledge with him.

“How do we navigate? I will tell you.”

“Yes”, said the Doctor emphatically. “I need to know.”  But then he paused, “or at least, I want to know,” he said sheepishly.

Harriett

“I can see the Earth’s magnetic field.  I have special molecules, proteins, called cryptochrome in my retina. They are light activated and create entanglement. You don’t realize it, but  quantum mechanics are part of the fundamental laws of the living cell.

One of the most perplexing interactions in the realm of physics is Quantum entanglement.

“Kiss,” said the Doctor.

For those uninitiated into the world of quantum physics, entanglement basically describes two electrons that are inextricably linked. Any time you subject an electron to a magnetic field, you affect its “spin.”  However, if that electron is entangled with another, then any time electron “A” changes its spin, electron “B” will react as well, even though it was never subjected to the magnetic field. This is a concept that dates back to Einstein, who famously described it as “spooky action at a distance.”

As difficult as entanglement is to believe, it is a well-established property of quantum mechanics.”

“We figured it out way before H. sapiens even considered the concept.  Migrating birds have built in compasses and GPS is in their brains, and their eyes, and in their beaks.  They use quantum mechanics to find where is South.”

“But why South?  South where?” Asked the Doctor.

“South America.”

The Doctor

The Doctor paused. He said back in his chair, interlocked his fingers, rubbed the tips of his thumbs together. He contemplated Harriett’s words. He reflected deeply on Harriett and the subject.  “Harriett’s can be whimsical,” the thought.

“You’re making this up, aren’t you.”

Harriett ended the telepathic session without further comment.