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 yr 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 d since 2000 (1.4 d per decade; 4.8 d 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.

中文翻译：

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尽管木蛙林蛙生殖时间变暖，但物候延迟：一项为期20年的研究

在所有分类单元中，两栖动物在响应气候变化时表现出一些最强烈的物候变化。随着气候变暖，预计两栖动物和其他动物会根据温度提示提前繁殖。但是，如果物种使用固定的提示（例如日光），则其繁殖时机可能会保持固定，从而可能在其生活史和环境条件之间造成脱节。木蛙林蛙是适应寒冷的物种，繁殖池中没有冰后立即在早春繁殖。我们对20年以上的64个繁殖池的蛙进行了长期调查，结果表明，尽管每年温度每十年出现0.29°C的增温，但蛙的繁殖物候自2000年以来已改变了2.8 d（1.4 d每十年; 4.8 d每摄氏度）。这种违反直觉的模式很可能是积雪堆积和融化时间变化的结果。最后，我们利用2000年至2018年之间的气候与产卵之间的关系来预测气候记录中的产卵日期，以模拟1980年以来的长期趋势。