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 life cycle. Environmental conditions experienced in the non-breeding season may have downstream effects on the other stages of the annual life cycle. 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 whether 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. 亟需开展气候驱动种群变化的内在机制研究，以更好地理解并精准预测种群对气候变化的响应。长寿命洄游物种可能尤其易受气候变化影响，因为它们在繁殖季与非繁殖季均受不同气候条件及能量需求的制约。然而，现有多数研究主要聚焦于该类物种生命周期中的繁殖季。非繁殖季所经历的环境条件，可能对年度生命周期的其他阶段产生下游效应。若未探究此类效应，可能会对种群动态做出错误推论。
2. 本研究结合2006年至2013年在凯尔盖朗群岛针对长寿命洄游海鸟——黑眉信天翁（Black-Browed Albatross, Thalassarche melanophris）采集的种群统计数据与追踪数据，探究了非繁殖季海表温度（sea surface temperature）与行为及物候特征（海上行为与洄游日程）之间的关联，同时纳入了不同性别、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，觅食活动与洄游日程因性别与繁殖状态而异，表明不同个体间存在不同的能量需求与制约因素。晚冬时段较高的海表温度（通常代表冬季环境质量较差）与更早离开越冬地、延长的繁殖前期相关。然而，更早开展春季迁徙并更早返回凯尔盖朗群岛海域，却与更低的繁殖成功率相关。
4. 本研究结果表明，非繁殖季部分时段（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，在预测气候对种群动态的影响时，需充分考虑年度生命周期的所有阶段。