Reproductive decisions under threat of predation: squirrel treefrog (Hyla squirella) responses to banded sunfish (Enneacanthus obesus)

Abstract

We tested whether the presence of a predator (non-lethal effect) could produce patterns of prey distribution and abundance attributed historically to direct mortality. Sixteen experimental ponds (1,000 l cattle watering tanks) were established; eight containing seven enclosed banded sunfish, Enneacanthus obesus, and eight predator-free controls. Ponds were colonized by ovipositing squirrel treefrogs, Hyla squirella, and a total of 33,128 eggs and tadpoles were recovered from the experimental ponds. Significantly more eggs and tadpoles (94.8%) were recorded from the predator-free treatments. These data support an alternative mechanism, based primarily on maternal behavior, explaining classic patterns of anuran species composition across a landscape of breeding sites.