Chemicals probably trigger a three-stage emergency early hatching process
Karen M. Warkentin
Tree frog tadpoles are the ultimate escape artists. To avoid becoming breakfast, the embryos of red-eyed tree frogs (Agalychnis callidryas) prematurely hatch and wriggle away from a snake’s jaws in mere seconds, as seen above. Embryos also use this maneuver to flee from flooding, deadly fungi, egg-eating wasps and other threats. Adding to the drama, red-eyed tree frogs lay their eggs on the undersides of leaves that hang a few inches to several feet above ponds. So the swimmers perform this feat suspended on a leaf, breaking free in midair and cannonballing into the water below.
High-speed video, captured by Kristina Cohen of Boston University and her colleagues, of unhatched eggs collected from Panamanian ponds shows that the embryos’ trick plays out in three stages. First, upon sensing a threat, an