Warmer springs advance the breeding phenology of golden plovers Pluvialis apricaria and their prey (Tipulidae)

Most studies of climate-driven changes in avian breeding phenology have focused on temperate passerines, yet the consequences of such environmental change may be more deleterious for other avian taxa, such as arctic and sub-arctic waders (Charadrii). We therefore examine large-scale climatic correlates of the breeding phenology of one such species (golden plover Pluvialis apricaria), and the timing of emergence of their adult tipulid prey, to assess the potential for climate change to disrupt breeding performance. Golden plover first-laying dates were negatively correlated with both March and April temperature, the mean laying date of first clutches was additionally negatively correlated with March rainfall. The timing of final laying dates were negatively correlated with April temperature only. The timing of tipulid emergence was negatively correlated with May temperature. In combination with historical climatic data, these models suggest a 9-day advancement of golden plover first-laying dates occurred during the 1990s, although this remains within the range of natural variation for the twentieth century. The magnitudes of predicted changes in mean and final laying dates, and the timing of tipulid emergence, were smaller. Climate predictions for 2070-2099 suggest potential advances in first-laying dates by 25 days, whilst the timings of mean and final laying dates are predicted to change by 18 days and 13 days, and tipulid emergence by 12 days. Given the importance of adult tipulids to young golden plover chicks, these changes may result in a mismatch between the timing of first-laying dates and tipulid emergence, so reducing the success of early breeding attempts. Modelling suggests that these changes could reduce breeding success in a South Pennines population by about 11%.