SummaryRuddy-headed Goose Chloephaga rubidiceps is the smallest of the five South American sheldgeese and has two separate populations: one sedentary, which resides in the Malvinas/Falkland Islands and one migratory that overwinters mainly in the Pampas region, Argentina and breeds in Southern Patagonia. The Ruddy-headed Goose’s continental population has decreased considerably, and recent estimates indicated that the population size is less than 800 individuals. In Argentina and Chile, this population is categorised as endangered. Understanding migration across vast landscapes is essential for the identification of factors affecting the survival of this endangered population and for the application of effective conservation measures. We aim to provide the first documentation of the complete migration cycle of Ruddy-headed Goose, and to analyse their annual migration in detail, including identification of stop-over, breeding and wintering sites, and to compare migration timing during spring and autumn migration. Adults were captured in the southern Pampas and equipped with solar satellite transmitters in 2015 and 2016. We analysed the influence of season (spring vs autumn migration) on the number and duration of stop-overs, distance travelled and overall migration speed using Generalized Linear Mixed Models. Our results showed that tracked geese used the eastern Patagonian route to reach their breeding grounds and take the same route after breeding. Spring migration was significantly faster than autumn migration, at least based on the number of days spent in their stop-overs. Stop-overs were closer to the final destination, either during spring and autumn migrations, though some of them were not used during subsequent migrations. Our migration cartography for Ruddy-headed Geese, together with the timing and location data, should be used to improve conservation efforts directed at this species and might contribute to the modification of the current status of ‘Least Concern’ under the IUCN criteria.

中文翻译：

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使用卫星标记的南美洲南部红头雁迁徙的时空变化

摘要红头鹅茯苓是五种南美雪貂中最小的一种，有两个不同的种群：一种是久坐的，居住在马尔维纳斯/福克兰群岛，另一种是迁徙的，主要在阿根廷的潘帕斯地区越冬并在巴塔哥尼亚南部繁殖。红头雁的大陆种群数量已大大减少，最近的估计表明种群规模不到 800 只。在阿根廷和智利，这一人口被归类为濒危物种。了解跨广阔景观的迁移对于确定影响这一濒危人口生存的因素和应用有效的保护措施至关重要。我们的目标是提供第一份关于红头鹅完整迁徙周期的文档，并详细分析它们的年度迁徙情况，包括确定中途停留、繁殖和越冬地点，以及比较春季和秋季迁徙期间的迁徙时间。成年人在 2015 年和 2016 年在南潘帕斯被捕获并配备了太阳能卫星发射器。我们使用广义线性混合分析了季节（春季与秋季迁徙）对中途停留次数和持续时间、行进距离和整体迁徙速度的影响楷模。我们的研究结果表明，被跟踪的鹅使用东部巴塔哥尼亚路线到达它们的繁殖地并在繁殖后采取相同的路线。春季迁徙的速度明显快于秋季迁徙，至少从他们中途停留的天数来看是这样。在春季和秋季迁徙期间，中途停留更接近最终目的地，尽管其中一些在随后的迁移中没有使用。我们的红头雁迁徙制图，连同时间和位置数据，应用于改进针对该物种的保护工作，并可能有助于修改 IUCN 标准下“最不关心”的现状。