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 ov...

在所有生物类群中，两栖类是响应气候变化时物候变化最为显著的类群之一。随着气候变暖，两栖类与其他动物本应依据温度信号提前进入繁殖期。然而，若物种依赖日照时长等固定环境信号，其繁殖时间可能保持不变，进而导致其生活史与环境条件出现脱节。林蛙（Rana sylvatica）作为一种耐寒物种，会在早春繁殖水塘完全解冻后立刻开展繁殖。我们通过对64个繁殖水塘开展的20年林蛙产卵时间长期监测研究显示：尽管研究区域的年平均温度以每十年0.29℃的速率升高，但自2000年以来，林蛙的繁殖物候反而推迟了2.8天（即每十年推迟1.4天，每升温1℃则推迟4.8天）。这一反直觉的模式很可能源于积雪积累与消融时间的变化。最后，我们利用气候与产卵...