CESAM - Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Aveiro, Portugal.
Department of Bird Migration, Swiss Ornithological Institute, Sempach, Switzerland.
Sci Rep. 2021 Dec 1;11(1):23258. doi: 10.1038/s41598-021-01734-0.
Understanding the relationship between migratory performance and fitness is crucial for predicting population dynamics of migratory species. In this study, we used geolocators to explore migration performance (speed and duration of migratory movements, migratory timings) and its association with breeding phenology and productivity in an Afro-Palearctic insectivore, the European bee-eater (Merops apiaster), breeding in Iberian Peninsula. Bee-eaters migrated at higher travel speeds and had shorter travel duration in spring compared to autumn. Individuals that departed earlier or spent fewer days in-flight arrived earlier to the breeding areas. Our results show overall positive, but year-specific, linkages between arrival and laying dates. In one year, laying was earlier and productivity was higher, remaining constant throughout the season, while in the subsequent year productivity was lower and, importantly, declined with laying date. These results suggest that arriving earlier can be advantageous for bee-eaters, as in years when breeding conditions are favourable, early and late breeders produce high and similar number of fledglings, but when conditions are unfavourable only early breeders experience high productivity levels.
了解迁徙表现和适应力之间的关系对于预测迁徙物种的种群动态至关重要。在这项研究中，我们使用地理定位器来探索迁徙表现（迁徙运动的速度和持续时间、迁徙时间）及其与繁殖物候和繁殖生产力的关系，研究对象是在伊比利亚半岛繁殖的非洲-古北界食虫动物欧洲食蜂鸟（Merops apiaster）。与秋季相比，食蜂鸟在春季的迁徙速度更高，迁徙持续时间更短。那些更早出发或在飞行中花费更少天数的个体更早到达繁殖区。我们的研究结果显示，整体上存在着积极的，但具有年份特异性的联系，即到达时间与产卵日期之间存在联系。在一年中，产卵时间更早，繁殖力更高，在整个季节保持不变，而在随后的一年中，繁殖力较低，重要的是，繁殖力随着产卵日期的推迟而下降。这些结果表明，对于食蜂鸟来说，提前到达可能是有利的，因为在繁殖条件有利的年份，早繁殖者和晚繁殖者产生的幼鸟数量相同且较高，但在条件不利的年份，只有早繁殖者经历高繁殖力水平。
