Data from: Long-term, not short-term, temperatures predict timing of egg-laying in European Starling (Sturnus vulgaris)
Data files
Apr 26, 2023 version files 5.53 MB
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All_temp_per_01Apr2021.csv
4.97 MB
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All_temp2001_2021_swa.csv
231.07 KB
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All_temp2001_2021.csv
313.16 KB
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Ann_rep_2021_climwin.csv
425 B
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Ann_rep_2021.csv
324 B
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README.md
12.48 KB
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tempcvLD_15Oct21.csv
4.64 KB
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winrep__temp.csv
3.67 KB
Abstract
Temperature is thought to be an important supplemental cue used by female birds to time breeding. It is widely assumed that late spring temperatures, within ~1 month of egg-laying, are most predictive of laying date, consistent with the idea that temperature is used to fine-tune timing of breeding to year-specific local conditions at the time of laying. Here we show that a relatively broad, long-term, temperature window (Jan 2 – Apr 4, 92 days; r2 = 0.73) best predicted timing of egg-laying in European Starlings (Sturnus vulgaris). A “mid-winter” temperature window was also strongly correlated with laying date (r2 = 0.58) but there was no support for an influence of short-term temperatures immediately before egg-laying. We assessed the relationship between ambient temperature and timing of egg-laying using three complimentary approaches: a) an “unconstrained”, exploratory analysis, b) a traditional sliding window approach, and c) specific, biologically-informed temperature windows. Our results contrast markedly with the widely held view, in the avian breeding phenology literature, that immediate, pre-breeding, temperatures best predict short-term variation in laying because they allow birds to fine-tune timing of breeding to local conditions around the time of egg-laying. This means that mechanisms that allow integration of long-term temperature information must exist in birds – perhaps most parsimoniously involving direct effects of temperature on growth of the bird's ectothermic insect prey– even though these are currently poorly characterized.