Weather packages: finding the right scale and composition of climate in ecology

Summary 1. Animals are affected by local weather variables such as temperature, rainfall and snow. However, large-scale climate indices such as the North Atlantic Oscillation (NAO) often outperform local weather variables when it comes to explain climate-related variation in life history traits or animal numbers. 2. In a recent paper, Hallet et al . (2004, Nature , 430 , 71‐75) document convincingly why this may happen. In this perspective, we identify from the literature three mechanisms why this is so: (1) the time window; (2) the spatial window; and (3) the weather composition component of climate. 3. Such an understanding may be used to derive even better ‘weather packages’ than the NAO.

[1]  A. Mysterud,et al.  Relationships between sex ratio, climate and density in red deer: the importance of spatial scale , 2000 .

[2]  Barrie R. Bonsal,et al.  An Assessment of Changes in Winter Cold and Warm Spells over Canada , 2003 .

[3]  A. Mysterud,et al.  Comparative response of Rangifer tarandus and other northern ungulates to climatic variability , 2002 .

[4]  A. Mysterud,et al.  Review article. Studying climate effects on ecology through the use of climate indices: the North Atlantic Oscillation, El Niño Southern Oscillation and beyond , 2003, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[5]  James W. Hurrell,et al.  The North Atlantic Oscillation: Climatic Significance and Environmental Impact , 2003 .

[6]  Byron J. T. Morgan,et al.  Factors influencing Soay sheep survival , 2000 .

[7]  Atle Mysterud,et al.  Nonlinear effects of large-scale climatic variability on wild and domestic herbivores , 2001, Nature.

[8]  T. H. Clutton-Brock,et al.  Why large-scale climate indices seem to predict ecological processes better than local weather , 2004, Nature.

[9]  James W. Hurrell,et al.  The North Atlantic Oscillation: Climate Significance and Environmental Impact , 2003 .

[10]  J. Hurrell,et al.  The North Atlantic Oscillation , 2001, Science.

[11]  B T Grenfell,et al.  Age, sex, density, winter weather, and population crashes in Soay sheep. , 2001, Science.

[12]  C. Elton,et al.  Periodic Fluctuations in the Numbers of Animals: Their Causes and Effects , 1924 .

[13]  N. Stenseth,et al.  Global climate change and phenotypic variation among red deer cohorts , 1997, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[14]  Nils Chr. Stenseth,et al.  CLIMATIC VARIABILITY, PLANT PHENOLOGY, AND NORTHERN UNGULATES , 1999 .

[15]  Nathalie Pettorelli,et al.  Importance of climatological downscaling and plant phenology for red deer in heterogeneous landscapes , 2005, Proceedings of the Royal Society B: Biological Sciences.

[16]  Kung-Sik Chan,et al.  Ecological Effects of Climate Fluctuations , 2002, Science.