Abstract Assessing the migratory behaviour of individual and groups of animals is key to understand the function of migration, its evolution, and how it is affected by environment and human activities. In the eastern North Atlantic, killer whales (Orcinus orca) presumably track herring stocks as they migrate between across the region. However, the detailed migratory and foraging behaviour of eastern North Atlantic killer whales is poorly understood. We report on the behaviour of 15 adult male killer whales equipped with Argos satellite transmitters during the winter of 2015–2016 along the coast of Troms, northern Norway. The animals were tracked for 8–104 days (mean: 41 days), during which they migrated 302–7608 Km (mean: 2646 Km). The observed movement of killer whales south to 64.2°N along the Norwegian coast following NSS-herring to their spawning grounds is in agreement with previous studies. However, our study is the first to also document northern migration of three of the Norwegian killer whales into the Barents Sea region towards Novaya Zemlya Island about 900 km from the Norwegian coast approaching 77.0°N. Importantly, using a Bayesian state-space model, we offer new insights on killer whale searching and transit movements, as well as diurnal patterns in swimming speed, preferred foraging habitat and feeding behaviour. The 15 tagged killer whales spend 75.0% of the time in an area restricted search (ARS) mode (range: 55.2–95.2%), 3.9% of the time in a transit mode (range: 0.0–16.1%) and 21.1% (range: 4.8–36.3%) in uncertain mode. The restricted search behaviour peaked at the end of January and beginning of February, after which the killer whales gradually performing transit behaviour as they followed the migrating herring out of the region, or shifted to other prey items.

中文翻译：

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北大西洋虎鲸（Orcinus orca）在挪威北部的迁徙和昼夜活动

摘要 评估动物个体和群体的迁徙行为是了解迁徙功能、演化以及它如何受环境和人类活动影响的关键。在北大西洋东部，虎鲸（Orcinus orca）可能会在鲱鱼在该地区之间迁移时追踪它们。然而，人们对北大西洋东部虎鲸的详细迁徙和觅食行为知之甚少。我们报告了 15 头配备 Argos 卫星发射器的成年雄性虎鲸在 2015-2016 年冬季沿着挪威北部特罗姆斯海岸的行为。这些动物被追踪了 8-104 天（平均：41 天），在此期间它们迁移了 302-7608 公里（平均：2646 公里）。观察到的虎鲸向南移动到 64。NSS 鲱鱼到达产卵地后沿挪威海岸的 2°N 与之前的研究一致。然而，我们的研究首次记录了三头挪威虎鲸向北迁移到巴伦支海地区，向距离挪威海岸约 900 公里、接近 77.0°N 的新地岛迁移。重要的是，使用贝叶斯状态空间模型，我们提供了关于虎鲸搜索和过境运动的新见解，以及游泳速度的昼夜模式、首选觅食栖息地和觅食行为。15 头标记的虎鲸有 75.0% 的时间处于区域限制搜索 (ARS) 模式（范围：55.2–95.2%），3.9% 的时间处于过境模式（范围：0.0–16.1%）和 21.1%（范围：4.8–36.3%）在不确定模式下。受限搜索行为在 1 月底和 2 月初达到顶峰，