Baseline information about declining North American shorebird populations is essential to determine the effects of global warming at low-lying coastal areas of the Arctic and subarctic, where numerous taxa breed, and to assess population recovery throughout their range. We estimated population sizes on the Yukon-Kuskokwim Delta in western Alaska on the eastern edge of the Bering Sea. We conducted ground-based surveys during 2015 and 2016 at 589 randomly selected plots from an area of 35,769 km2. We used stratified random sampling in 8 physiographic strata and corrected population estimates using detection ratios derived from double sampling on a subset of plots. We detected 11,110 breeding individuals of 21 taxa. Western Sandpiper (Calidris mauri), Red-necked Phalarope (Phalaropus lobatus), Dunlin (subspecies C. alpina pacifica), and Wilson’s Snipe (Gallinago delicata) were the most abundant taxa. We estimated that ~6.9 million individual shorebirds were breeding on the entire Yukon-Kuskokwim Delta in 2015 and 2016. Our surveys of this region provided robust population estimates (CVs ≤ 0.35) for 14 species. Our results indicate that the Yukon-Kuskokwim Delta supports a large proportion of North America’s breeding populations of the Pacific Golden-Plover (Pluvialis fulva), the western population of a Whimbrel subspecies (Numenius phaeopus hudsonicus), a Bar-tailed Godwit subspecies (Limosa lapponica baueri), Black Turnstone (Arenaria melanocephala), a Dunlin subspecies (Calidris alpina pacifica), and Western Sandpiper. Our study highlights the importance to breeding shorebirds of this relatively pristine but climatically sensitive deltaic system. Estuaries and deltaic systems worldwide are rapidly being degraded by anthropogenic activities. Our population estimates can be used to refine prior North American population estimates, determine effects of global warming, and evaluate conservation success by measuring population change over time.

中文翻译：

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阿拉斯加气候敏感的育空-库斯科奎姆三角洲养育着 700 万只北极鸻鹬，其中包括北美六种鸟类中的大多数

关于北美滨鸟种群数量下降的基线信息对于确定全球变暖对北极和亚北极低洼沿海地区（那里有许多类群繁殖）的影响以及评估其整个范围内的种群恢复至关重要。我们估算了阿拉斯加西部白令海东缘育空-库斯科奎姆三角洲的人口规模。2015 年和 2016 年，我们在 35,769 平方公里的面积中随机选择了 589 个地块进行了地面调查。我们在 8 个自然地层中使用了分层随机抽样，并使用从地块子集上的双重抽样得出的检出率来校正人口估计。我们检测到 21 个类群的 11,110 个繁殖个体。西部鹬 (Calidris mauri)、红颈鹬 (Phalaropus lobatus)、石鹬 (C. alpina pacifica 亚种) 和威尔逊鹬 (Gallinago delicata) 是最丰富的类群。我们估计，2015 年和 2016 年，整个育空-库斯科奎姆三角洲约有 690 万只滨鸟繁殖。我们对该地区的调查为 14 个物种提供了可靠的种群估计（CV ≤ 0.35）。我们的研究结果表明，育空-库斯科奎姆三角洲支持了北美大部分太平洋金鸻 (Pluvialis fulva) 繁殖种群、鸻亚种 (Numenius phaeopus hudsonicus) 的西部种群、斑尾塍鹬亚种 (Limosa) lapponica baueri)、黑翻石 (Arenaria melanocephala)、黑滨亚种 (Calidris alpina pacifica) 和西部鹬。我们的研究强调了在这个相对原始但对气候敏感的三角洲系统中繁殖滨鸟的重要性。世界范围内的河口和三角洲系统正在因人类活动而迅速退化。我们的人口估计可用于完善之前的北美人口估计，确定全球变暖的影响，并通过测量人口随时间的变化来评估保护的成功。