Current Zoology(formerly Acta Zoologica Sinica), 2011, 57(3): 351 - 362
Behavioral and life history responses to extreme climatic conditions: Studies on a migratory songbird
A. P. Møller
L a b o r a t o i r e d ' E c o l o g i e , S y s t é m a t i q u e e t E v o l u t i o n , C N R S U M R 8 0 7 9 , U n i v e r s i t é P a r i s - S u d , F r a n c e
Behavioral responses to environmental change are the mechanisms that allow for rapid phenotypic change preventing temporary or permanent damage and hence preventing reductions in fitness. Extreme climatic events are by definition rare, although they are predicted to increase in amplitude and frequency in the coming years. However, our current knowledge about behavioral responses to such extreme events is scarce. Here I analyze two examples of the effects of extreme weather events on behavior and life history: (1) A comparison of behavior and life history during extremely warm and extremely cold years relative to normal years; and (2) a comparison of behavior before and after the extremely early snowfall in fall 1974 when numerous birds died in the Alps during September-October. Behavioral and life history responses of barn swallows Hirundo rustica to extremely cold and extremely warm years were positively correlated, with particularly large effect sizes in cold years. Extreme mortality in barn swallows during fall migration 1974 in the Alps eliminated more than 40% of the breeding population across large areas in Central and Northern Europe, and this affected first arrival date, changes in timing and extent of reproduction and changes in degree of breeding sociality supposedly as a consequence of correlated responses to selection. Finally, I provide directions for research that will allow us to better understand behavior and life history changes in response to extreme climate change [Current Zoology 57 (3): 351–362, 2011].
Barn swallow, Extreme climate, Hard selection, Hirundo rustica, Laying date, Second clutches, Sociality, Truncation selection