The Antarctic seasonal sea-ice zone (SIZ) is one of the most extensive and dynamic habitats on Earth. In summer, increased insolation and ice melt cause primary production to peak, sustaining large populations of locally-breeding seabirds. Due to their hypermobility, large Procellariiformes, including albatrosses, breeding in the subantarctic also have the potential to access the SIZ and track macroscale resource waves over the Sothern Ocean but the extent to which they do this is poorly known. Here, we analysed the foraging movements of breeding albatrosses and large petrels (seven species, 1298 individuals) recorded using GPS loggers and satellite-transmitters to quantify their use of sea-ice habitats and test whether they tracked seasonal drivers of primary production. Foraging latitudes of white-chinned petrels and black-browed , grey-headed and wandering albatrosses varied sinusoidally over the breeding season, presumably in response to lagged effects of solar irradiance on primary production. Foraging latitudes of northern and southern giant petrels ( and ), and light-mantled albatrosses , exhibited no strong seasonal trend, but the latter two species spent ≥ 20 % of their time in the SIZ during incubation and post-brood, prior to or at the time of the spring ice breakup. Southern giant petrels travelled hundreds of km into the pack ice, encountering sea-ice concentrations up to 100 %, whereas light-mantled albatrosses remained almost exclusively in open water near the Marginal Ice Zone (MIZ). The remaining species spent up to 15 % of their time in the SIZ, typically from 5-7 weeks after breakup, and avoided the MIZ. This supports hypotheses that sea ice presents albatrosses but not giant petrels with physical barriers to flight or foraging, and that open-water-affiliated species use the SIZ only after primary production stimulated by ice melt transfers to intermediate trophic levels. Given that all seven species used the SIZ, it is likely that the phenology and demography of these and many other subantarctic-breeding seabirds are mechanistically linked to sea-ice dynamics. Declines in Antarctic sea ice predicted under climate change could therefore modulate and exacerbate the already unsustainable anthropogenic impacts being experienced by these populations.

中文翻译：

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信天翁和大型海燕对海冰觅食栖息地的季节性资源跟踪和利用


南极季节性海冰区（SIZ）是地球上最广泛和最具活力的栖息地之一。夏季，日照增加和冰雪融化导致初级生产达到顶峰，维持了大量当地繁殖的海鸟。由于它们的超强活动性，在亚南极繁殖的大型原腹鱼（包括信天翁）也有可能进入 SIZ 并跟踪南大洋上空的宏观资源波，但它们这样做的程度却鲜为人知。在这里，我们分析了使用 GPS 记录仪和卫星发射器记录的繁殖信天翁和大型海燕（7 个物种，1298 只）的觅食活动，以量化它们对海冰栖息地的使用，并测试它们是否跟踪初级生产的季节性驱动因素。白下巴海燕和黑眉、灰头和漂泊信天翁的觅食纬度在繁殖季节呈正弦变化，这可能是为了响应太阳辐照度对初级生产的滞后影响。北部和南部巨型海燕和轻披信天翁的觅食纬度没有表现出强烈的季节性趋势，但后两个物种在孵化期间和育雏后、之前或之后有 ≥ 20 % 的时间在 SIZ 中度过。春天冰层融化的时间。南方巨型海燕在浮冰中行进数百公里，遇到的海冰浓度高达 100%，而轻幔信天翁几乎只停留在边缘冰区 (MIZ) 附近的开阔水域。其余物种将 15% 的时间花在 SIZ 中，通常是分手后 5-7 周，并避开 MIZ。 这支持了这样的假设：海冰代表信天翁，而不是巨型海燕，它们对飞行或觅食有物理障碍，并且开放水域附属物种只有在冰融化刺激初级生产转移到中间营养级后才使用 SIZ。鉴于所有七个物种都使用 SIZ，这些海鸟和许多其他亚南极繁殖海鸟的物候和种群特征很可能与海冰动态存在机械联系。因此，气候变化下预测的南极海冰减少可能会调节和加剧这些人群所经历的本已不可持续的人为影响。