Data from: Thermal and moisture habitat preferences do not maximize jumping performance in frogs

Amphibians are suffering population declines globally, and understanding
how environmental parameters influence their thermal and moisture
preferences and performance at various tasks is crucial to understanding
how these animals will be influenced by climate change. Body temperature
and hydration affect organismal performance at many fitness-related tasks.
Since amphibians are ectotherms with highly water-permeable skin,
environmental temperature and moisture directly affect their body
temperature and hydration. Therefore, amphibians should select habitats
with the optimal combination of temperature and moisture to perform tasks
necessary for survival. However, interactions between environmental
temperature and moisture can influence habitat selection and task
performance in different and often unpredictable ways, and this has only
infrequently been considered. We tested for interactions between
environmental temperature, moisture, and organismal hydration on
temperature and moisture preferences and jumping performance in Green
Frogs (Lithobates clamitans) in the laboratory, using thermal and moisture
gradients, and high-speed video and force plate data. We then integrated
the lab experiments with field data. In the thermal and moisture
gradients, frogs selected environmental conditions that minimized
cutaneous evaporative water loss, hydroregulating more stringently than
thermoregulating. These results are consistent with frogs in the field,
which had highly variable body temperatures, but were always hydrated
above 95% of their standard mass. However, conditions that minimized
evaporative water loss frequently did not maximize jumping performance
because warmer temperatures conferred greater performance. The ecology of
L. clamitans may explain the discrepancy between their preferences and
jumping performance optima because the frogs remain in wet environments
that serve as refuges from dehydration. In parts of their range where
frogs are subjected to warmer and drier conditions, they are likely to
select microhabitats that minimize the risk of dehydration, possibly at
the expense of their ability to forage and escape from predators.