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SEPG 2429 - Date Awarded 2005
Individual variation in phenological responses of great tits (Parus major) to climate change and food availability
Daniel H. Nussey, Erik Postma, Phillip Gienapp & Marcel E. Visser
Abstract
Many species alter their timing of breeding (phenology) in response to environmental conditions. Recent increases in spring temperature have lead to earlier breeding in many bird populations. In a population of Dutch great tits in the Hoge Veluwe National Park, egg laying dates have not changed over the last 30 years despite rising spring temperatures. However, the emergence times of the caterpillars that these birds rely on to feed their offspring have become earlier during this period, leading to a widening phenological mismatch between trophic levels. Natural selection might reduce this mismatch, by acting on any heritable component of variation between individual female great tits in their responses to spring temperature. Our analyses of the population revealed significantly heritable variation in the laying date responses of female birds. We also showed that females that responded strongly to temperature (breed earliest following warm springs) produced more viable offspring than weakly responding females, presumably because the timing of their peak in food demand for their nestlings coincided better with the peak in caterpillar availability. Selection is predicted to increase the responsiveness of these birds to temperature in future, and this could reduce the climate change induced phenological mismatch with their caterpillar prey.
Full report: SEPG2429 (This link will be made live in 2008)
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