Geographic Variation In The Effects Of Hydroperiods On Wood Frog (RANA SYLVATICA) Tadpoles

Climatic variability is increasing globally and can be detrimental to taxa, such as amphibians, that are sensitive to changes to environmental factors. Changes to breeding habitats (e.g., hydroperiod of temporary ponds) can lead to local population declines with mass mortality of embryos and tadpoles. To determine how different populations of Wood frogs (Rana sylvatica) would respond to shortened hydroperiods, I examined the effects of pond drying on the growth and survival of R. sylvatica tadpoles. Pond drying significantly affected both mean size at metamorphosis and survival of tadpoles to metamorphosis. Metamorphs from the longest hydroperiods had a larger mean size and higher survival than metamorphs from replicate pond communities with the shortest hydroperiods. The origin of egg clutches had no significant effect on mean size at metamorphosis but did affect survival to metamorphosis. The northern populations had the highest survival, and the southern populations had the lowest survival. My results suggest that populations of a widespread amphibian may vary in their ability to respond to environmental stressors.