School of Biological Sciences, Zoology Building, University of Aberdeen, Aberdeen, UK.
Fair Isle Bird Observatory Trust, Fair Isle, Shetland, UK.
Glob Chang Biol. 2024 Jul;30(7):e17400. doi: 10.1111/gcb.17400.
Species exploiting seasonal environments must alter timings of key life-history events in response to large-scale climatic changes in order to maintain trophic synchrony with required resources. Yet, substantial among-species variation in long-term phenological changes has been observed. Advancing from simply describing such variation towards predicting future phenological responses requires studies that rigorously quantify and explain variation in the direction and magnitude of changing timings across diverse species in relation to key ecological and life-history variables. Accordingly, we fitted multi-quantile regressions to 59 years of multi-species data on spring and autumn bird migration timings through northern Scotland. We demonstrate substantial variation in changes in timings among 72 species, and tested whether such variation can be explained by species ecology, life-history and changes in local abundance. Consistent with predictions, species that advanced their migration timing in one or both seasons had more seasonally restricted diet types, fewer suitable breeding habitat types, shorter generation lengths and capability to produce multiple offspring broods per year. In contrast, species with less seasonally restricted diet types and that produce single annual offspring broods, showed no change. Meanwhile, contrary to prediction, long-distance and short-distance migrants advanced migration timings similarly. Changes in migration timing also varied with changes in local migratory abundance, such that species with increasing seasonal abundance apparently altered their migration timing, whilst species with decreasing abundance did not. Such patterns broadly concur with expectation given adaptive changes in migration timing. However, we demonstrate that similar patterns can be generated by numerical sampling given changing local abundances. Any apparent phenology-abundance relationships should, therefore, be carefully validated and interpreted. Overall, our results show that migrant bird species with differing ecologies and life-histories showed systematically differing phenological changes over six decades contextualised by large-scale environmental changes, potentially facilitating future predictions and altering temporal dynamics of seasonal species co-occurrences.
物种为了与所需资源保持营养同步，必须改变关键生命史事件的时间，以应对大规模的气候变化。然而，人们观察到长期物候变化存在很大的种间差异。要从简单地描述这种变化发展到预测未来的物候反应，就需要研究严格量化和解释不同物种在时间变化方向和幅度上的变化，这些变化与关键的生态和生活史变量有关。因此，我们对苏格兰北部 72 个物种的 59 年春季和秋季鸟类迁徙时间的多物种数据进行了多分位数回归拟合。我们证明了物种间在时间变化上存在很大的差异，并测试了这种差异是否可以通过物种生态学、生活史和当地丰度的变化来解释。与预测一致的是，那些在一个或两个季节提前迁徙时间的物种，其季节性限制的饮食类型更多，适宜繁殖的栖息地类型更少，世代长度更短，每年能产多窝后代的能力更强。相比之下，那些饮食类型季节性限制较少且每年只产一窝后代的物种则没有变化。然而，与预测相反的是，长距离和短距离迁徙者的迁徙时间也同样提前了。迁徙时间的变化也随当地迁徙数量的变化而变化，因此，季节性数量增加的物种显然改变了它们的迁徙时间，而数量减少的物种则没有。这些模式与适应迁徙时间变化的预期大致一致。然而，我们证明，在给定当地丰度变化的情况下，数值采样也可以产生类似的模式。因此，任何明显的物候与丰度关系都应该仔细验证和解释。总的来说，我们的研究结果表明，具有不同生态和生活史的候鸟物种在六十年的时间里表现出系统的物候变化，这些变化与大规模的环境变化有关，这可能有助于未来的预测，并改变季节性物种共存的时间动态。
