Netherlands Institute of Ecology (NIOO-KNAW), PO Box 40, 6666 Heteren, The Netherlands.
Biol Lett. 2009 Dec 23;5(6):739-42. doi: 10.1098/rsbl.2009.0429. Epub 2009 Jul 2.
Avian timing of reproduction is strongly affected by ambient temperature. Here we show that there is an additional effect of sunspots on laying date, from five long-term population studies of great and blue tits (Parus major and Cyanistes caeruleus), demonstrating for the first time that solar activity not only has an effect on population numbers but that it also affects the timing of animal behaviour. This effect is statistically independent of ambient temperature. In years with few sunspots, birds initiate laying late while they are often early in years with many sunspots. The sunspot effect may be owing to a crucial difference between the method of temperature measurements by meteorological stations (in the shade) and the temperatures experienced by the birds. A better understanding of the impact of all the thermal components of weather on the phenology of ecosystems is essential when predicting their responses to climate change.
鸟类的繁殖时间受环境温度的强烈影响。在这里，我们展示了太阳黑子对产卵日期的额外影响，这是来自五个关于大山雀和蓝山雀（Parus major 和 Cyanistes caeruleus）的长期种群研究，首次证明了太阳活动不仅对种群数量有影响，而且还影响动物行为的时间。这种影响在统计上与环境温度无关。在太阳黑子较少的年份，鸟类产卵较晚，而在太阳黑子较多的年份，它们往往较早。太阳黑子的影响可能是由于气象站（在阴凉处）测量温度的方法与鸟类实际经历的温度之间存在重要差异。在预测生态系统对气候变化的反应时，必须更好地了解天气所有热成分对物候的影响。
