Seasonal environmental conditions shape the behavior and life history of virtually all organisms. Climate change is modifying these seasonal environmental conditions, which threatens to disrupt population dynamics. It is conceivable that climatic changes may be beneficial in one season but result in detrimental conditions in another because life-history strategies vary between these time periods. We analyzed the temporal trends in seasonal survival of yellow-bellied marmots (Marmota flaviventer) and explored the environmental drivers using a 40-y dataset from the Colorado Rocky Mountains (USA). Trends in survival revealed divergent seasonal patterns, which were similar across age-classes. Marmot survival declined during winter but generally increased during summer. Interestingly, different environmental factors appeared to drive survival trends across age-classes. Winter survival was largely driven by conditions during the preceding summer and the effect of continued climate change was likely to be mainly negative, whereas the likely outcome of continued climate change on summer survival was generally positive. This study illustrates that seasonal demographic responses need disentangling to accurately forecast the impacts of climate change on animal population dynamics.

季节性环境条件影响着几乎所有生物的行为和生活史。气候变化正在改变这些季节性环境条件，这有可能破坏人口动态。可以想象，气候变化在一个季节可能是有益的，但在另一个季节会导致不利条件，因为生命史策略在这两个时间段之间会有所不同。我们分析了黄腹土拨鼠（Marmota flaviventer），并使用来自美国科罗拉多洛矶山脉的40年数据集探索了环境驱动因素。生存趋势揭示了不同的季节性模式，在各个年龄段中相似。土拨鼠的生存率在冬季下降，但在夏季总体上增加。有趣的是，不同的环境因素似乎推动了各个年龄段的生存趋势。冬季生存在很大程度上受前一个夏季条件的影响，持续的气候变化可能主要是消极的，而持续的气候变化对夏季生存的可能的结果通常是积极的。这项研究表明，季节性人口响应需要解开，才能准确预测气候变化对动物种群动态的影响。