The extinction of California’s flightless duck, Chendytes lawi, stands out in the faunal history of North America because it involved a marine animal that disappeared in the late Holocene, not in the terminal Pleistocene when humans arrived from Asia, nor with the more recent entry of Europeans and associated resource exploitation. Here we evaluate the duck’s ecology by combining a stable isotopic evaluation of its feeding niche with records of human predation and climatic variation to evaluate (1) alternative influences on the duck’s extinction and (2) possible ecological consequences of its disappearance. Results indicate that a mid-late Holocene increase in human population density coincided with a decrease in mean sea surface temperatures (SST) and an increase in SST variance, all of which were contemporaneous with the demise of the flightless duck ca. 2500 cal BP. Climate appears to be a main exogenous driver of this extinction event by not only negatively impacting flightless duck food availability, but positively impacting one of the duck’s main predators: humans. Isotopic findings indicate the duck had a unique feeding ecology that overlapped equally with analog species reliant mostly on marine invertebrates (sea otters [Enhydra lutris]) and on fish (harbor seals [Phoca vitulina]). This dietary niche overlap suggests the duck’s extinction could have opened foraging opportunities for harbor seals and sea otters. Otter numbers appear to have increased coincident with the duck’s decline which also correlates with a decrease in size and abundance of red abalone (Haliotis rufescens), one of the otter’s preferred prey. These correlations suggest that new feeding opportunities may have emerged for otters in the face of the duck’s extinction, encouraging an increase in otter populations, which then had negative impacts on abalone that also were targeted by humans. Overall findings suggest the possibility of an unanticipated prehistoric precursor to the historic baseline of this nearshore ecosystem.

加利福尼亚的不会飞的鸭子Chendytes lawi的灭绝，之所以在北美的动物史上与众不同，是因为它涉及一种海洋动物，这种动物在全新世晚期消失了，而不是人类从亚洲到达时在更新世末期消失的，也不是随着欧洲人的进入和最近的资源开发而消失的。在这里，我们通过对鸭的摄食位点进行稳定的同位素评估与人类捕食和气候变化的记录相结合来评估鸭的生态，以评估（1）对鸭灭绝的其他影响以及（2）鸭消失的可能的生态后果。结果表明，全新世中期人口密度的增加与平均海面温度（SST）的降低和SST方差的增加是一致的，所有这些都与不飞鸭的灭亡是同时发生的。2500 cal BP。气候似乎是这一灭绝事件的主要外来驱动因素，不仅对无法飞翔的鸭子食物的供应产生了负面影响，而且对鸭子的主要捕食者之一人类也产生了积极影响。同位素研究结果表明，鸭具有独特的摄食生态学，与主要依靠海洋无脊椎动物（海獭[食水菌（Enhydra lutris））和鱼类（海豹（Phoca vitulina））。饮食上的利基重叠说明鸭子的灭绝可能为海豹和海獭打开了觅食的机会。水獭数量似乎随着鸭子的下降而增加，这也与红鲍鱼的大小和数量的减少有关（Haliotis rufescens），是水獭的首选猎物之一。这些相关性表明，面对鸭子的灭绝，水獭可能出现了新的觅食机会，这鼓励了水獭数量的增加，进而对鲍鱼产生了负面影响，鲍鱼也是人类的目标。总体研究结果表明，这种近岸生态系统的历史基线可能有史无前例的前兆。