Effects of summer weather on reproductive success of the red-backed shrike (Lanius collurio)

Abstract

Capsule Summer weather affects reproductive success in the Red-backed Shrike (Lanius collurio). Aims To investigate the relationship between reproductive success and weather conditions in the European breeding areas. Methods Using a Principal Component Analysis, we investigate how summer (July) weather affects reproductive success in two populations in northwestern Europe. Further, we assess the general relationship between reproductive success and weather in a review of published results. Results Weather is correlated with reproductive success in five out of six European populations, including the two populations at the northwestern range edge as well as three out of the four reviewed populations, all in central Europe. In general, sunny, warm and dry weather increases reproductive success, while rainy and cold weather has the opposite effect. Conclusion Our findings suggest that the warmer summers predicted under a future climate could increase the reproductive success of the Red-backed Shrike. Yet the effect of more extreme weather is yet to be examined. Future investigation of the relationship between weather and the population dynamics across a large spatial scale could help us estimate for which species we should expect general effects of climate change. © 2013 British Trust for Ornithology.