PARENT SESSION
Oral Session 32: Reptiles and Amphibians II: Frogs and Toads.
Presiding: C Guthrie and G Middendorf
Tuesday, August 3, 8:00 AM to 11:30 AM, Meeting Room D 136.

Predator induced phenotypic plasticity and local adaptation in pacific treefrogs (Hyla regilla).

Benard, Michael^*,1, ¹ Center for Population Biology, Davis, CA, USA

ABSTRACT- Local adaptation has been widely described in nature. However, in the face of high environmental heterogeneity or gene flow between environments, phenotypic plasticity may evolve instead of local adaptation. I tested for a genetic basis underlying differences in predator-induced phenotypic plasticity in pacific treefrog tadpoles from two ponds. These two ponds consistently differ in predator density, and thus consistently select for different tadpole phenotypes. While most traits exhibited plasticity in the presence of nonlethal predator cues, there was not a genetically based difference in phenotypes between ponds. However, there was a significant genetic difference between the two ponds in overall tail length and the increase in tail length in the presence of non-lethal predator cues. The pond with a higher predator density had the greater degree of the predator-induced tail phenotype. Additionally, there was a significant sire pond X dam pond interaction in size at metamorphosis, indicative of outbreeding depression. As these two ponds are only 3 km apart, this indicates that local adaptation can occur on relatively small spatial scales.

Key words: local adaptation, plasticity, predator, amphibian