Blue petrels (Halobaena caerulea Gmelin) rapidly moult their flight feathers in Antarctic waters in February–April, immediately following the breeding season, yet the behaviour of moulting birds at sea has not been described. We observed large numbers of moulting blue petrels off West Antarctica from 67–71°S and 78–119°W in mid-February 2017. Most of these birds probably breed at the Diego Ramirez archipelago, southwest of Cape Horn, which is the closest colony to this area. Moulting petrels often sit on the water in dense flocks, just outside the marginal ice zone, at sea temperatures of -0.7 to 0.9°C. Wing moult is intense, with 7–8 inner primaries (62–75% of primary length and 55–69% of primary mass), their corresponding primary coverts and all greater secondary coverts being grown at the same time. Moulting petrels need a reliable food source during this energetically demanding period, so the waters off West Antarctica are probably crucial for the Diego Ramirez population, which makes up more than half of the world's blue petrels.

中文翻译：

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蓝海燕的换羽强度和西南极洲附近的一个关键换羽地点

蓝海燕 (蓝藻Gmelin）在繁殖季节之后的 2 月至 4 月在南极水域迅速换羽，但尚未描述鸟类在海上换羽的行为。2017 年 2 月中旬，我们在 67-71°S 和 78-119°W 观察到大量蓝海燕在西南极洲附近换羽。这些鸟类中的大多数可能在合恩角西南的 Diego Ramirez 群岛繁殖，这是最近的殖民地到这个地区。蜕皮的海燕经常成群结队地栖息在水面上，就在边缘冰区之外，海水温度为 -0.7 至 0.9°C。翅膀换羽很激烈，有 7-8 个内部初生体（初生体长度的 62-75% 和初生体质量的 55-69%），它们相应的初级覆羽和所有更大的次级覆羽同时生长。