Data from: Linking oceanographic conditions, migratory schedules and foraging behaviour during the non‐breeding season to reproductive performance in a long‐lived seabird

1. Studies of the mechanisms underlying climate-induced population changes are critically needed to better understand and accurately predict population responses to climate change. Long-lived migratory species might be particularly vulnerable to climate change as they are constrained by different climate conditions and energetic requirements during the breeding and non-breeding seasons. Yet, most studies primarily focus on the breeding season of these species lifecycle. Environmental conditions experienced in the non-breeding season may have downstream effects on the other stages of the annual lifecycle. Not investigating such effects may potentially lead to erroneous inferences about population dynamics. 2. Combining demographic and tracking data collected between 2006 and 2013 at Kerguelen Island on a long-lived migratory seabird, the Black-Browed Albatross (Thalassarche melanophris), we investigated the links between sea surface temperature during the non-breeding season and behavioural and phenological traits (at-sea behaviour and migratory schedules) while accounting for different responses between birds of different sex and reproductive status (previously failed or successful breeders). We then explored if variation in the foraging behaviour and timing of spring migration influenced subsequent reproductive performance. 3. Our results showed that foraging activity and migratory schedules varied by both sex and reproductive status suggesting different energetic requirements and constraints among individuals. Higher sea surface temperatures during late winter, assumed to reflect poor winter conditions, were associated with an earlier departure from the wintering grounds and an extended pre-breeding period. However, an earlier spring migration and an earlier return to Kerguelen grounds were associated with a lower breeding success. 4. Our results highlighted that behaviour during some periods of the non-breeding season, particularly towards the end of the wintering period and the pre-breeding period had a significant effect on the subsequent reproductive success. Therefore, caution needs to be given to all stages of the annual cycle when predicting the influence of climate on population dynamics.

1. 阐明气候驱动种群变化的内在机制，是深入理解并精准预测种群对气候变化响应的核心需求。长距离迁徙的长寿物种往往对气候变化更为脆弱，因为它们在繁殖期与非繁殖期均受到不同气候条件与能量需求的约束。然而，当前多数研究仅聚焦于该类物种生命周期中的繁殖阶段。非繁殖期所经历的环境条件，可能对年度生命周期的其他阶段产生后续效应；若忽略此类效应，可能会对种群动态做出错误推断。2. 本研究结合2006年至2013年在克尔格伦岛（Kerguelen Island）针对长距离迁徙长寿海鸟——黑眉信天翁（Black-Browed Albatross，学名Thalassarche melanophris）收集的种群统计与追踪数据，探究了非繁殖期海表面温度（sea surface temperature）与行为、物候特征（海上行为与迁徙日程）之间的关联，同时考量了不同性别与繁殖状态（此前繁殖失败或成功的个体）的个体间响应差异。随后，本研究进一步探讨了觅食行为与春季迁徙时间的变化是否会影响后续的繁殖表现。3. 研究结果显示，觅食活动与迁徙日程因性别与繁殖状态而异，表明不同个体间存在差异化的能量需求与约束条件。晚冬时节更高的海表面温度被认为反映了较差的冬季环境，其与更早离开越冬地以及更长的繁殖前期相关。但春季迁徙更早、返回克尔格伦岛的时间更早，则与更低的繁殖成功率相关。4. 本研究结果表明，非繁殖期部分阶段——尤其是越冬末期与繁殖前期的行为，会对后续繁殖成功率产生显著影响。因此，在预测气候变化对种群动态的影响时，需充分考量年度生命周期的所有阶段。