Data from: Aeroecology of a solar eclipse

Light cues elicit strong responses from nearly all forms of life, perhaps
most notably as circadian rhythms entrained by periods of daylight and
darkness. Atypical periods of darkness, like solar eclipses, provide rare
opportunities to study biological responses to light cues. By using a
continental scale radar network, we investigated responses of flying
animals to the total solar eclipse of 21 August 2017. We quantified the
number of biological targets in the atmosphere at 143 weather radar
stations across the continental United States to investigate whether the
decrease in light and temperature at an atypical time would initiate a
response like that observed at sunset, when activity in the atmosphere
usually increases. Overall, biological activity decreased in the period
leading to totality, followed by a short low-altitude spike of biological
activity during totality in some radars. This pattern suggests that cues
associated with the eclipse were insufficient to initiate nocturnal
activity comparable to that occurring at sunset but sufficient to suppress
diurnal activity.

光信号可触发几乎所有生命类群的强烈响应，其中最具代表性的当属由昼夜明暗周期所调控的昼夜节律（circadian rhythms）。非典型的黑暗时段，例如日食，为研究生物对光信号的响应提供了难得的契机。本研究依托大陆尺度雷达网，针对2017年8月21日的日全食（total solar eclipse），探究了飞行动物的响应行为。我们对美国本土143个气象雷达站监测到的低空大气生物目标数量开展了量化分析，旨在探究在这一非典型时段内，光照与温度的下降是否会触发类似日落时的响应——彼时大气中的生物活动通常会显著增强。整体而言，在全食阶段来临前的时段内，生物活动呈下降趋势；而部分雷达站的监测数据显示，全食阶段还出现了一次短暂的低空生物活动峰值。这一模式表明，与日食相关的光信号不足以触发与日落时相当的夜间活动，但足以抑制日间活动。