Krause Jesse S, Pérez Jonathan H, Chmura Helen E, Sweet Shannan K, Meddle Simone L, Hunt Kathleen E, Gough Laura, Boelman Natalie, Wingfield John C
Department of Neurobiology, Physiology and Behavior, University of California Davis, One Shields Avenue, Davis, CA 95616, USA.
Department of Neurobiology, Physiology and Behavior, University of California Davis, One Shields Avenue, Davis, CA 95616, USA.
Gen Comp Endocrinol. 2016 Oct 1;237:10-18. doi: 10.1016/j.ygcen.2016.07.015. Epub 2016 Jul 19.
Climate change is causing rapid shifts in temperature while also increasing the frequency, duration, and intensity of extreme weather. In the northern hemisphere, the spring of 2013 was characterized as extreme due to record high snow cover and low temperatures. Studies that describe the effects of extreme weather on phenology across taxa are limited while morphological and physiological responses remain poorly understood. Stress physiology, as measured through baseline and stress-induced concentrations of cortisol or corticosterone, has often been studied to understand how organisms respond to environmental stressors. We compared body condition and stress physiology of two long-distance migrants breeding in low arctic Alaska - the white-crowned sparrow (Zonotrichia leucophrys) and Lapland longspur (Calcarius lapponicus) - in 2013, an extreme weather year, with three more typical years (2011, 2012, and 2014). The extended snow cover in spring 2013 caused measureable changes in phenology, body condition and physiology. Arrival timing for both species was delayed 4-5days compared to the other three years. Lapland longspurs had reduced fat stores, pectoralis muscle profiles, body mass, and hematocrit levels, while stress-induced concentrations of corticosterone were increased. Similarly, white-crowned sparrows had reduced pectoralis muscle profiles and hematocrit levels, but in contrast to Lapland longspurs, had elevated fat stores and no difference in mass or stress physiology relative to other study years. An understanding of physiological mechanisms that regulate coping strategies is of critical importance for predicting how species will respond to the occurrence of extreme events in the future due to global climate change.
气候变化正在导致气温迅速变化，同时也增加了极端天气的频率、持续时间和强度。在北半球，2013年的春天因创纪录的高积雪量和低温而被视为极端天气。描述极端天气对不同分类群物候影响的研究有限，而形态和生理反应仍知之甚少。通过皮质醇或皮质酮的基线浓度和应激诱导浓度来衡量的应激生理学，常被用于研究生物体如何应对环境压力源。我们比较了2013年（极端天气年份）与另外三个典型年份（2011年、2012年和2014年）在阿拉斯加低北极地区繁殖的两种长途迁徙鸟类——白冠雀（Zonotrichia leucophrys）和拉普兰铁爪鹀（Calcarius lapponicus）——的身体状况和应激生理学。2013年春季延长的积雪导致了物候、身体状况和生理学方面的可测量变化。与其他三年相比，这两个物种的到达时间都推迟了4 - 5天。拉普兰铁爪鹀的脂肪储备、胸肌形态、体重和血细胞比容水平降低，而应激诱导的皮质酮浓度增加。同样，白冠雀的胸肌形态和血细胞比容水平降低，但与拉普兰铁爪鹀不同的是，其脂肪储备增加，体重和应激生理学与其他研究年份相比没有差异。了解调节应对策略的生理机制对于预测物种在未来由于全球气候变化而发生极端事件时的反应至关重要。
