Raynor Edward J, Powell Larkin A, Schacht Walter H
School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE, United States of America.
Department of Agronomy and Horticulture, University of Nebraska-Lincoln, Lincoln, NE, United States of America.
PLoS One. 2018 Feb 7;13(2):e0191233. doi: 10.1371/journal.pone.0191233. eCollection 2018.
Better understanding animal ecology in terms of thermal habitat use has become a focus of ecological studies, in large part due to the predicted temperature increases associated with global climate change. To further our knowledge on how ground-nesting endotherms respond to thermal landscapes, we examined the thermal ecology of Sharp-tailed Grouse (Tympanuchus phasianellus) during the nesting period. We measured site-specific iButton temperatures (TiB) and vegetation characteristics at nest sites, nearby random sites, and landscape sites to assess thermal patterns at scales relevant to nesting birds. We asked if microhabitat vegetation characteristics at nest sites matched the characteristics that directed macrohabitat nest-site selection. Grouse selected sites sheltered by dense vegetation for nesting that moderated TiB on average up to 2.7°C more than available landscape sites. Successful nests were positioned in a way that reduced exposure to thermal extremes by as much as 4°C relative to failed nests with an overall mean daytime difference (±SE) of 0.4 ±0.03°C. We found that macrohabitat nest-site selection was guided by dense vegetation cover and minimal bare ground as also seen at the microhabitat scale. Global climate projections for 2080 suggest that TiB at nest sites may approach temperatures currently avoided on the landscape, emphasizing a need for future conservation plans that acknowledge fine-scale thermal space in climate change scenarios. These data show that features of grassland landscapes can buffer organisms from unfavorable microclimatic conditions and highlight how thermal heterogeneity at the individual-level can drive decisions guiding nest site selection.
从热栖息地利用的角度更好地理解动物生态学已成为生态学研究的一个重点，这在很大程度上是由于预计与全球气候变化相关的气温上升。为了进一步了解地面筑巢的恒温动物如何应对热景观，我们研究了尖尾榛鸡（Tympanuchus phasianellus）在筑巢期的热生态学。我们测量了巢址、附近随机地点和景观地点的特定地点iButton温度（TiB）和植被特征，以评估与筑巢鸟类相关尺度上的热模式。我们询问巢址的微生境植被特征是否与指导宏观生境巢址选择的特征相匹配。榛鸡选择由茂密植被遮蔽的地点筑巢，这些地点使TiB平均比可用景观地点降低多达2.7°C。成功的巢穴的位置相对于失败的巢穴减少了多达4°C的极端温度暴露，白天总体平均差异（±标准误差）为0.4±0.03°C。我们发现，宏观生境巢址选择受茂密植被覆盖和最小裸地的指导，这在微生境尺度上也可见。2080年的全球气候预测表明，巢址的TiB可能接近目前景观上避免的温度，这强调了未来保护计划需要在气候变化情景中考虑精细尺度的热空间。这些数据表明，草原景观特征可以缓冲生物免受不利的小气候条件影响，并突出了个体水平的热异质性如何驱动指导巢址选择的决策。
