Department of Animal Ecology and Systematics, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany.
Institute of Avian Research "Vogelwarte Helgoland", An der Vogelwarte 21, 26386, Wilhelmshaven, Germany.
BMC Ecol. 2020 May 25;20(1):31. doi: 10.1186/s12898-020-00299-2.
The long-tailed duck (Clangula hyemalis) was categorized as ´Vulnerable` by the IUCN after a study revealed a rapid wintering population decline of 65% between 1992-1993 and 2007-2009 in the Baltic Sea. As knowledge about the European long-tailed duck's life cycle and movement ecology is limited, we investigate its year-round spatiotemporal distribution patterns. Specifically, we aimed to identify the wintering grounds, timing of migration and staging of this population via light-level geolocation.
Of the 48 female long-tailed ducks tagged on Kolguev Island (western Russian Arctic), 19 were recaptured to obtain data. After breeding and moulting at freshwater lakes, ducks went out to sea around Kolguev Island and to marine waters ranging from the White Sea to Novaya Zemlya Archipelago for 33 ± 10 days. After a rapid autumn migration, 18 of 19 birds spent their winter in the Baltic Sea and one bird in the White Sea, where they stayed for 212 ± 3 days. There, they used areas known to host long-tailed ducks, but areas differed among individuals. After a rapid spring migration in mid-May, the birds spent 23 ± 3 days at sea in coastal areas between the White Sea and Kolguev Island, before returning to their freshwater breeding habitats in June.
The Baltic Sea represents the most important wintering area for female long-tailed ducks from Kolguev Island. Important spring and autumn staging areas include the Barents Sea and the White Sea. Climate change will render these habitats more exposed to human impacts in the form of fisheries, marine traffic and oil exploitation in near future. Threats that now operate in the wintering areas may thus spread to the higher latitude staging areas and further increase the pressure on long-tailed ducks.
国际自然保护联盟（IUCN）在一项研究表明，1992-1993 年至 2007-2009 年间，波罗的海的越冬种群数量迅速减少了 65%之后，将长尾鸭（Clangula hyemalis）列为“易危”物种。由于对欧洲长尾鸭生命周期和迁徙生态的了解有限，我们调查了其全年的时空分布模式。具体来说，我们旨在通过光定位确定该种群的越冬地、迁徙时间和中途停留地。
在科利加夫岛（俄罗斯西部北极地区）标记的 48 只雌性长尾鸭中，有 19 只被重新捕获以获取数据。在淡水湖泊繁殖和换羽后，鸭子离开科利加夫岛出海，前往从白海到新地岛群岛的海域，停留了 33 ± 10 天。经过快速的秋季迁徙，19 只鸟中有 18 只在波罗的海越冬，有 1 只在白海越冬，在那里它们停留了 212 ± 3 天。在那里，它们使用已知有长尾鸭栖息的区域，但个体之间的区域不同。在 5 月中旬迅速的春季迁徙之后，这些鸟在白海和科利加夫岛之间的沿海地区停留了 23 ± 3 天，然后在 6 月返回淡水繁殖栖息地。
波罗的海是科利加夫岛雌性长尾鸭最重要的越冬地。重要的春季和秋季中途停留地包括巴伦支海和白海。未来气候变化将使这些栖息地更容易受到渔业、海上交通和石油开采等人类活动的影响。因此，目前在越冬地存在的威胁可能会蔓延到更高纬度的中途停留地，并进一步增加长尾鸭的压力。
