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Solar activity affects avian timing of reproduction

Visser, M.E. and Sanz, J.J. (2009) Solar activity affects avian timing of reproduction. Biology Letters, 5, 739-742. ISSN 1744-9561.

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Official URL: http://dx.doi.org/10.1098/rsbl.2009.0429

Abstract

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.

Item Type:Article
Institutes:Nederlands Instituut voor Ecologie (NIOO)
ID Code:6352
Deposited On:10 Jun 2010 02:00
Last Modified:24 Apr 2012 16:44

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