Predator-prey interactions become particularly complicated when they involve organisms with many life stages.  The red-eyed treefrog, Agalychnis callidryas, suffers predation at several different life stages (eggs, tadpoles, metamorphs, adults), and are able to adjust their exposure to predators at many of these stages by adjusting their switch points from one stage to the next (e.g., hatch time, time to metamorphosis).  Work done by Karen Warkentin from Boston University shows that eggs may hatch up to 2 days early in response to predation attempts by snakes, wasps, or fungus.  In escaping predation as embryos, individuals begin the tadpole stage smaller and more susceptible to aquatic predators than individuals who hatch spontaneously.  For this reason, this species make an excellent system for studying the evolution of anti-predator behavior and development.   During the summer of 2007, I conducted research on this species with BSC undergraduate Patricia George, and compared traits from different clutches and under different hatching conditions (early versus late).  All of the developmental traits measured were strongly influenced by heritable components, and hatch time influenced their behavior in response to predator cues and their time to metamorphosis.  In addition, different clutches varied in their responses to early versus late hatching for mass and time to metamorphosis, suggesting some difference in fitness payoffs for individuals with different genetic backgrounds.  Further opportunities for undergraduates to travel to Costa Rica and conduct summer research with me are available!

                                                            

 

 

 

Click here and follow the link at the bottom of the page to see a video of eggs hatching in response to snake predation!