Reproductive success is strongly related to local and regional climate in the Arctic snow bunting ( Plectrophenax nivalis )

Global climate change is regarded as one of the major threats to biodiversity. Both local and regional climate parameters can have strong effects on ecological processes affecting the survival and reproduction of plants and animals. High Arctic ecosystems are characterized by low species diversity and the local species have often evolved specific adaptations to the harsh Arctic environment. Here, we investigate the effect of local and regional climate parameters on snow bunting ( Plectrophenax nivalis ) reproductive success in the Arctic using a long-term dataset of 15 years. We found strong relationships between both local weather and the Arctic oscillation (AO), a regional climate index, with several breeding parameters. Onset of breeding was earlier in years with high spring temperatures and later in years with high AO index the preceding winter. Importantly, high AO winter index also increased the number of successful fledglings the following summer, possibly mediated via spring phenology. Nestling weight was negatively associated with the AO index during the breeding season. The strong effects of local and regional climate suggest that the ongoing global climate change could potentially have a large effect on this Arctic passerine population.