Data from: Phenological delay despite warming in wood frog (Rana sylvatica) reproductive timing: a 20-year study

Across all taxa, amphibians exhibit some of the strongest phenological
shifts in response to climate change. As climates warm, amphibians and
other animals are expected to breed earlier in response to temperature
cues. However, if species use fixed cues such as daylight, their breeding
timing might remain fixed, potentially creating disconnects between their
life history and environmental conditions. Wood frogs (Rana sylvatica) are
a cold-adapted species that reproduce in early spring, immediately after
breeding ponds are free of ice. We used long-term surveys of wood frog
oviposition timing in 64 breeding ponds over 20 years to show that,
despite experiencing a warming of 0.29 °C per decade in annual
temperature, wood frog breeding phenology has shifted later by 2.8 days
since 2000 (1.4 days per decade; 4.8 days per °C). This counterintuitive
pattern is likely the result of changes in the timing of snowpack
accumulation and melting. Finally, we used relationships between climate
and oviposition between 2000 and 2018 to hindcast oviposition dates from
climate records to model longer-term trends since 1980. Our study
indicates that species can respond to fine-grained seasonal climate
heterogeneity within years that is not apparent or counterintuitive when
related to annual trends across years.