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

Abstract: 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.

摘要：1. 为深入理解并精准预测种群对气候变化的响应，亟需开展气候变化驱动的种群变化机制相关研究。长寿迁徙物种在繁殖季与非繁殖季均受不同气候条件与能量需求的约束，因此对气候变化尤为脆弱。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阶段。非繁殖季经历的环境条件，可能对年度生命周期的其他阶段产生后续效应；若未对这类效应开展研究，可能会导致种群动态相关推论出现偏差。
2. 本研究整合了2006年至2013年在克尔格伦群岛针对长寿迁徙海鸟黑眉信天翁（Black-Browed Albatross, Thalassarche melanophris）收集的种群统计数据与追踪数据，探讨了非繁殖季海表面温度与行为及物候性状（海上行为与迁徙节律）之间的关联，同时纳入了不同性别与繁殖状态（此前繁殖失败或成功繁殖的个体）的种内响应差异。随后，本研究探究了觅食行为与春季迁徙时间的变异是否会影响后续的繁殖表现。
3. 研究结果显示，觅食活动与迁徙节律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制约因素。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质量）与更早离开越冬地、延长的繁殖前期存在关联。然而，更早的春季迁徙以及更早返回克尔格伦群岛海域，却与更低的繁殖成功率相关。
4. 本研究结果表明，非繁殖季的部分阶段——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。