(Table 1) Movement parameters of nine adult female snowy owls (Bubo scandiacus) tracked during the winter period 07/08 and 08/09 around Hudson Strait, Canada

Top predators of the arctic tundra are facing a long period of very low prey availability during winter and subsidies from other ecosystems such as the marine environment may help to support their populations. Satellite tracking of snowy owls, a top predator of the tundra, revealed that most adult females breeding in the Canadian Arctic overwinter at high latitudes in the eastern Arctic and spend several weeks (up to 101 d) on the sea-ice between December and April. Analysis of high-resolution satellite images of sea-ice indicated that owls were primarily gathering around open water patches in the ice, which are commonly used by wintering seabirds, a potential prey. Such extensive use of sea-ice by a tundra predator considered a small mammal specialist was unexpected, and suggests that marine resources subsidize snowy owl populations in winter. As sea-ice regimes in winter are expected to change over the next decades due to climate warming, this may affect the wintering strategy of this top predator and ultimately the functioning of the tundra ecosystem.

北极苔原的顶级捕食者在冬季面临长期的猎物极度匮乏状况，而来自海洋环境等其他生态系统的资源补给或可助力维持其种群规模。对苔原顶级捕食者雪鸮的卫星追踪研究显示，多数在加拿大北极地区繁殖的成年雌性雪鸮会前往北极东部的高纬度区域越冬，并于12月至次年4月期间在海冰上停留数周（最长可达101天）。对海冰高分辨率卫星影像的分析表明，雪鸮主要聚集在海冰中的冰间开阔水域周边——这类水域常被越冬海鸟使用，而越冬海鸟正是雪鸮的潜在猎物。此前被认为是小型哺乳动物专食者的苔原捕食者，竟会大规模利用海冰环境，这一发现出乎预料，同时也表明海洋资源或在冬季为雪鸮种群提供了补给支持。由于未来数十年内冬季海冰格局将因气候变暖发生改变，这或会影响该顶级捕食者的越冬策略，并最终改变北极苔原生态系统的运转过程。