technical paper
Plastic responses of amphibians to shortened pond duration and increased drought and temperature
keywords:
developmental plasticity
carry-over effects
climate change
Amphibians are resilient species that have adapted during their long evolutionary history to rather diverse environmental conditions. Current climate change, however, is pushing many species tolerance limits, especially as it is translating into not only increased temperature but also, increased drought and shortened pond duration. Some species have evolved the ability to adaptively alter their phenotype in response to some of these factors, but the combination of hazards and the rate at which they are taking place, may exceed the ability of amphibians to cope. Reduced pond duration may trigger developmental acceleration in amphibian larvae, allowing them to reach metamorphosis sooner, but at the cost of doing so smaller and with depleted fat reserves. Moreover, if they metamorphose onto a harsher environment, the odds of survival during the juvenile stage may be severely reduced. We are studying the plastic responses of tadpoles of the spadefoot toad, Pelobates cultripes, to risk of pond drying, which is a complex combination of reduced water level, increased temperature, increased larval density and reduced food availability. We then also studied the carry-over effects of the developmental alterations experienced by larvae onto the juvenile stage, especially when they then face drier and warmer environments, monitoring juvenile survival, growth, activity pattern, hormonal levels and thermal tolerance.