Dunham Kylee D, Tucker Anna M, Koons David N, Abebe Asheber, Dobson F Stephen, Grand James B
Alabama Cooperative Fish and Wildlife Research Unit School of Forestry and Wildlife Sciences Auburn University Auburn AL USA.
Present address: Department of Biological Sciences University of Alberta Edmonton AB Canada.
Ecol Evol. 2021 Jul 14;11(15):10627-10643. doi: 10.1002/ece3.7873. eCollection 2021 Aug.
The Arctic is undergoing rapid and accelerating change in response to global warming, altering biodiversity patterns, and ecosystem function across the region. For Arctic endemic species, our understanding of the consequences of such change remains limited. Spectacled eiders (), a large Arctic sea duck, use remote regions in the Bering Sea, Arctic Russia, and Alaska throughout the annual cycle making it difficult to conduct comprehensive surveys or demographic studies. Listed as Threatened under the U.S. Endangered Species Act, understanding the species response to climate change is critical for effective conservation policy and planning. Here, we developed an integrated population model to describe spectacled eider population dynamics using capture-mark-recapture, breeding population survey, nest survey, and environmental data collected between 1992 and 2014. Our intent was to estimate abundance, population growth, and demographic rates, and quantify how changes in the environment influenced population dynamics. Abundance of spectacled eiders breeding in western Alaska has increased since listing in 1993 and responded more strongly to annual variation in first-year survival than adult survival or productivity. We found both adult survival and nest success were highest in years following intermediate sea ice conditions during the wintering period, and both demographic rates declined when sea ice conditions were above or below average. In recent years, sea ice extent has reached new record lows and has remained below average throughout the winter for multiple years in a row. Sea ice persistence is expected to further decline in the Bering Sea. Our results indicate spectacled eiders may be vulnerable to climate change and the increasingly variable sea ice conditions throughout their wintering range with potentially deleterious effects on population dynamics. Importantly, we identified that different demographic rates responded similarly to changes in sea ice conditions, emphasizing the need for integrated analyses to understand population dynamics.
北极地区正经历着快速且加速的变化，以应对全球变暖，改变着整个地区的生物多样性模式和生态系统功能。对于北极特有物种而言，我们对这种变化所带来后果的了解仍然有限。丑鸭是一种大型北极海鸭，在整个年度周期中都利用白令海、俄罗斯北极地区和阿拉斯加的偏远地区，这使得进行全面调查或种群统计学研究变得困难。根据美国《濒危物种法》，丑鸭被列为受威胁物种，了解该物种对气候变化的反应对于制定有效的保护政策和规划至关重要。在此，我们开发了一个综合种群模型，利用1992年至2014年间收集的标记重捕、繁殖种群调查、巢穴调查和环境数据来描述丑鸭的种群动态。我们的目的是估计种群数量、种群增长和种群统计学率，并量化环境变化如何影响种群动态。自1993年被列入名录以来，在阿拉斯加西部繁殖的丑鸭数量有所增加，且对当年幼鸭存活率的年度变化反应比对成年鸭存活率或繁殖率的反应更为强烈。我们发现，在越冬期海冰条件处于中等水平后的年份里成年鸭存活率和巢穴成功率都最高，而当海冰条件高于或低于平均水平时，这两个种群统计学率都会下降。近年来，海冰范围已达到新的历史低点，并且连续多年整个冬季都低于平均水平。预计白令海的海冰持续时间将进一步下降。我们的结果表明，丑鸭可能易受气候变化以及其整个越冬范围内日益多变的海冰条件的影响，这可能对种群动态产生有害影响。重要的是，我们发现不同的种群统计学率对海冰条件变化的反应相似，这强调了进行综合分析以了解种群动态的必要性。
