Data from: The influence of weather conditions during gestation on life histories in a wild Arctic ungulate

The internal predictive adaptive response (internal PAR) hypothesis predicts that individuals born in poor conditions should start to reproduce earlier if they are likely to have reduced performance in later life. However, whether this is the case remains unexplored in wild populations. Here, we use longitudinal data from a long-term study of Svalbard reindeer to examine age-related changes in adult female life-history responses to environmental conditions experienced in utero as indexed by rain-on-snow (ROSutero). We show that females experiencing high ROSutero had reduced reproductive success only from 7 years of age, independent of early reproduction. These individuals were able to maintain the same annual reproductive success between 2 and 6 years as phenotypically superior conspecifics that experienced low ROSutero. Young females born after high ROSutero engage in reproductive events at lower body mass (about 2.5 kg less) than those born after low ROSutero. The mean fitness of females that experienced poor environmental conditions in early life was comparable with that of females exposed to good environmental conditions in early life. These results are consistent with the idea of internal PAR and suggest that the life-history responses to early-life conditions can buffer the delayed effects of weather on population dynamics.

内源性预测适应性反应（internal PAR）假说提出，若个体在晚年的生存表现可能下降，则在恶劣环境中出生的个体应更早启动繁殖。然而，这一推论在野生种群中尚未得到探索验证。本研究依托对斯瓦尔巴驯鹿的长期纵向监测数据，以雪上降雨（ROSutero）作为子宫内环境暴露的量化指标，探究成年雌性个体的生活史响应随年龄变化的规律，及其与子宫内环境条件的关联。研究结果显示：子宫内暴露于高雪上降雨环境的雌性个体，仅在7岁及以后才会出现繁殖成功率下降的情况，且该现象与早期繁殖行为无关；这类个体在2至6岁期间的年繁殖成功率，与子宫内暴露于低雪上降雨环境的表型更优的同种个体持平。子宫内暴露于高雪上降雨环境的年轻雌性，参与繁殖活动时的体重要低于子宫内暴露于低雪上降雨环境的个体（约低2.5千克）。早年暴露于恶劣环境的雌性个体的平均适合度，与早年暴露于优良环境的个体相当。上述结果与内源性预测适应性反应（internal PAR）假说相符，同时表明，针对早年环境条件的生活史响应，能够缓冲气候对种群动态的滞后影响。