Temperature effects on compensatory responses in an early spring‐breeding amphibian

Shifts in phenological events (reproduction, migration, etc.) appear to be a common response to a changing climate by many taxa. Phenological shifts may elicit stronger responses in organisms with complex life histories as effects could compound across life stages. To better understand growth and survival consequences in the early‐breeding wood frog ( Rana sylvatica ), we examined larval response to hatching phenology (early and late [+14 days]) and increased pond temperatures (ambient and warm [+4.3°C above ambient]) on tadpole growth and development. We expected that tadpoles would respond to delayed hatching via accelerated growth and development. However, we hypothesized that increased temperatures would be antagonistic to a compensatory acceleration of tadpole growth and development and result in slower tadpole growth, later metamorphosis, and smaller size at metamorphosis. Contrary to our expectations, tadpole responses to delayed hatching were not temperature‐dependent. While temperature and hatch timing had significant effects on all focal response variables, their effects were independent and additive. Larvae were able to compensate for the 2‐week delay in hatch timing through accelerated growth and developmental rates. In fact, delayed tadpoles appeared to overcompensate, metamorphosing several days earlier than their early‐hatching counterparts. Finally, although accelerated growth rates in delayed treatments could help compensate for a later start, they were ultimately insufficient to equalize size at metamorphosis. Our results portray the complexity in growth and developmental rate responses due to variation in reproductive timing and temperature. They also highlight a clear need to understand the putative fitness costs of compensatory responses across life stages.