Data from: State-space modelling of geolocation data reveals sex differences in the use of management areas by breeding northern fulmars

Effective management and conservation of terrestrially breeding marine predators requires information on connectivity between specific breeding sites and at-sea foraging areas. In the north-east Atlantic, efforts to monitor and manage the impacts of bycatch or pollution events within different Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR) management regions are currently constrained by uncertainty over the origins of seabirds occurring in each area.
Whilst Global Positioning System (GPS) loggers can now provide high resolution data on seabird foraging characteristics, their use is largely restricted to the chick-rearing period. Smaller light-based Global Location Sensors (geolocators) could provide valuable data during earlier phases of the breeding season, but additional information on their accuracy is required to assess this potential.
We used incubation trip tracking data from 11 double-tagged (GPS/geolocator) northern fulmars Fulmarus glacialis L. within a state-space modelling (SSM) framework to estimate errors around geolocator locations. The SSM was then fitted to a larger sample of geolocator data from the pre-laying exodus using the mean of these error estimates. Geolocator data were first used to compare the trip durations of males and females during this critical pre-laying period. Outputs from the SSM were then used to characterize their spatial distribution and assess the extent of within-colony variation in the use of different OSPAR management regions.
During the pre-laying exodus, fulmars from a single colony in the north-east of the United Kingdom foraged widely across several biogeographical regions, up to 2900 km from the colony. Most (60%) males remained within the North Sea region, whereas most (68%) females flew north, foraging within the Norwegian and Barents Sea. A small subset of birds (15%) travelled to the central North Atlantic. Foraging trips by males appeared to be shorter (x = 18 days, n = 20) than by females (x = 25 days, n = 19).
Policy implications. Our results of state-space modelling of geolocation data collected from northern fulmars show that within-colony variation in ranging behaviour during the breeding season results in sex differences in exposure to threats such as fisheries bycatch and marine plastics. Birds from a single colony dispersed over several north-east Atlantic management areas. These patterns have implications for interpreting trends in colony-based monitoring schemes, and European Union Marine Strategy Framework programmes using these seabirds as an indicator species for monitoring trends in marine litter and prioritizing efforts to mitigate its impact.

对陆地繁殖型海洋捕食者开展有效管理与保护，需明确其特定繁殖地与海上觅食区域之间的连通关系。在东北大西洋海域，针对不同《东北大西洋海洋环境保护公约》（OSPAR）管理区内的副渔获物或污染事件影响开展监测与管理的工作，目前因各区域内出现的海鸟来源不明而受到限制。
尽管全球定位系统（GPS）记录仪目前可提供海鸟觅食特征的高分辨率数据，但其应用大多局限于育雏阶段。体积更小的基于光照的全球位置传感器（地理定位器）能够在繁殖季更早阶段获取有价值的数据，但仍需补充其精度相关信息以评估其应用潜力。
本研究在状态空间模型（SSM）框架下，利用11只佩戴双标签（GPS/地理定位器）的北方管鼻藿（*Fulmarus glacialis* L.）的孵卵期行程追踪数据，估算地理定位器定位结果的误差。随后利用该误差估计值的均值，将状态空间模型拟合至更大样本的、采集于产卵前迁徙期的地理定位器数据。首先通过地理定位器数据对比该关键产卵前期内雌雄个体的行程时长，再借助状态空间模型的输出结果刻画其空间分布特征，并评估种群内部在不同OSPAR管理区利用上的差异程度。
在产卵前迁徙期，来自英国东北部单个繁殖种群的北方管鼻藿，会在距离种群2900公里范围内的多个生物地理区域广泛觅食。其中60%的雄性个体活动范围局限于北海海域，而68%的雌性个体向北迁徙，在挪威海域与巴伦支海觅食；另有15%的少数个体前往北大西洋中部海域。雄性个体的觅食行程时长（平均值为18天，样本量n=20）整体短于雌性个体（平均值为25天，样本量n=19）。
政策启示。本研究基于北方管鼻藿的地理定位数据开展的状态空间模型分析结果显示，繁殖季内种群内部的活动范围行为差异，会导致雌雄个体面临渔业副渔获物、海洋塑料等威胁的暴露程度存在差异。单个繁殖种群的个体可扩散至东北大西洋的多个管理区域内。上述研究结果对于解读基于种群的监测计划趋势，以及欧盟海洋战略框架计划具有重要意义——这些海鸟被用作海洋垃圾污染趋势监测的指示物种，相关结果可用于优先开展减轻海洋垃圾影响的工作。