National Geographic : 2006 Nov
says Gomez-Mestre. But premature hatching under predatory threat wasn't known until Warkentin observed it. Now, other scientists report the behavior in various amphibians, a spider, and a fish, suggesting that the ability has evolved independently many times. But how the embryos sense danger and make their Houdini like escape is still a mystery. What happens to the embryos after the fall? No pocket of rain forest is benign, and having squeezed from egg membrane into waiting 146 NATIONAL GEOGRAPHIC * NOVEMBER 2006 pond and dropped to the bottom, the prema ture tadpoles face new threats: invertebrates such as shrimp and giant water bugs, and, at some sites, fish. But many endure and com plete their development, in coming weeks sprouting legs and growing the lung power they'll need on land. A gantlet of new predators awaits them there-large spiders, birds, snakes -but the fittest survive yet again to master another novel environment, climbing to safety in the tall trees.