By Peter Tyson – Posted 11.18.03 – NOVA
Would a dramatic change in the Earth’s magnetic field affect creatures that rely on it during migration?
Late on a January night in 1993 I found myself on a beach on the Pacific coast of Costa Rica, kneeling in the sand beside a leatherback sea turtle. Like a giant mango with wings, the huge black turtle had hauled herself up the beach in great stentorian gasps of air and was laying her eggs in a pit she had laboriously scooped out with her hind flippers.
Knowing basic facts about her ecology and physiology, I was in awe. How her kind, the largest living reptiles, had been around for 120 million years. How she lived solely on jellyfish, a thing more water balloon than animal. How she could collapse her lungs and dive to depths that would cause you or me to implode. How she had traveled thousands of miles around the Pacific Ocean, only to return there to the very beach she was born on years before. …more