P1.2 Wednesday, Jan. 4 Ontogeny of risk across the aquatic-terrestrial interface: how changing behavior and morphology affect predation through anuran metamorphosis JIMENEZ, R.R.; ABINETTE, S.H.*; TOUCHON, J.C. ; VONESH, J.R. ; WARKENTIN, K.M. ; Univ. Nac. de Costa Rica; Virginia Commonwealth Univ.; Boston Univ.; Virginia Commonwealth Univ.; Boston Univ. email@example.com
Metamorphosis dramatically changes morphology, physiology, behavior and performance. As anurans change from aquatic tadpoles to terrestrial juveniles, they pass through a period of poor locomotor performance and high predation risk, and individuals behaviorally determine when they shift habitats. Red-eyed treefrogs, Agalychnis callidryas, alter when they move onto land in response to aquatic giant water bugs and semi-terrestrial fishing spiders. We conducted predation trials and behavioral experiments at multiple stages to assess changes in the interactions of A. callidryas with each predator through metamorphosis. In aquatic trials, A. callidryas reduced activity with both forelimb emergence and chemical cues from water bugs. Nonetheless, forelimb emergence substantially increased the predation rate. In semi-terrestrial trials, conducted in shallow water with dense floating vegetation, metamorph activity increased as tails were resorbed, and metamorphs did not reduce activity in the presence of a spider. Predation by spiders increased as metamorphs resorbed their tails. Close observation in small venues revealed that most spider attacks occurred after metamorph movements, and attack rates on shorter-tailed metamorphs were higher. Longer-tailed metamorphs were, however, less likely to escape from attacks. Thus, the ability of metamorphs to behaviorally compensate for morphological constraints on escape ability appears to be better out of the water. Nonetheless, in natural ponds, the effect of activity on the rate of encounters with pond-associated predators will depend on how rapidly metamorphs leave the environs of the pond.