School of Environmental Sciences, University of East Anglia, Norwich, Norfolk, UK.
CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Laboratório Associado, Universidade do Porto, Campus Agrário de Vairão, 4485-661, Vairão, Portugal.
Sci Rep. 2021 Jan 13;11(1):935. doi: 10.1038/s41598-020-80341-x.
Migration may expose individuals to a wide range of increasing anthropogenic threats. In addition to direct mortality effects, this exposure may influence post-migratory reproductive fitness. Partial migration-where a population comprises migrants and residents-represents a powerful opportunity to explore carryover effects of migration. Studies of partial migration in birds typically examine short-distance systems; here we studied an unusual system where residents breed in mixed colonies alongside long-distance trans-Saharan migrants (lesser kestrels (Falco naumanni) in Spain). Combining geolocator data, stable isotope analysis and resighting data, we examined the effects of this stark difference in migratory strategy on body condition, breeding phenology and breeding success. We monitored four colonies in two regions of southern Spain for five consecutive years (2014-2018), yielding 1962 captures, determining migratory strategy for 141 adult bird-years. Despite a 3000-km difference in distance travelled, we find no effect of strategy on breeding parameters. We find weak evidence for a short-term negative carryover effect of migration on body condition, but this was only apparent in the breeding region with lower primary productivity. Our results indicate that carryover effects of even highly divergent migratory strategies may be minimal relative to effects of conditions experienced on breeding grounds.
迁移可能会使个体面临广泛的人为威胁。除了直接的死亡率影响外，这种暴露还可能影响迁徙后的生殖适应性。部分迁徙——一个种群由迁徙者和居民组成——为探索迁徙的滞后效应提供了一个强有力的机会。鸟类部分迁徙的研究通常研究短距离系统；在这里，我们研究了一个不寻常的系统，居民与长距离跨撒哈拉迁徙者（西班牙的小隼(Falco naumanni)）一起在混合群体中繁殖。结合地理定位器数据、稳定同位素分析和重见数据，我们研究了这种截然不同的迁徙策略对身体状况、繁殖物候和繁殖成功率的影响。我们连续五年（2014-2018 年）在西班牙南部的两个地区监测了四个殖民地，共进行了 1962 次捕获，确定了 141 只成年鸟年的迁徙策略。尽管迁徙距离相差 3000 公里，但我们发现策略对繁殖参数没有影响。我们发现迁徙对身体状况有短期的负面影响，但这种影响仅在初级生产力较低的繁殖区明显。我们的研究结果表明，即使是高度不同的迁徙策略的滞后效应相对于繁殖地所经历的条件的影响也可能是最小的。
