Measures of physiological stress are being increasingly used by ecologists to determine the sub-lethal impacts of environmental conditions on wild populations. However, current conditions are not the only factors that may influence stress physiology: studies using laboratory animals have shown that early-life experiences may impact an organism’s response to stressors through adulthood. I present here a three-part study that combines work in the field and lab to show that larval stressors experienced in the aquatic stage may subsequently affect fitness in the terrestrial juvenile and adult stages of the wood frog, Rana sylvatica.
Results/Conclusions
Specifically, I found that variation in stress hormone production among tadpoles in 10 different ponds corresponds to variation in their aquatic communities. I also show that one of these stressors, predator presence, not only affects tadpole physiology but goes on to change the activity and reactivity of the stress axis even after metamorphosis. Finally, I found that individuals that experienced predation cues as tadpoles are subsequently less able to resist desiccation as juveniles, an effect that is likely tied to survival in the terrestrial environment. Together these results demonstrate the need to consider the long-term consequences of early experiences in relation to environmental stressors.
