Double Duty: First Record of Double Brooding in Snow Buntings in the Canadian Arctic

Urbanization is increasing worldwide, leading to changes in urban animal behaviour, physiology, fitness, and reproductive outcomes. As climate change effects in northern regions generate earlier spring melt and later fall freeze-up, some Arctic-breeding songbird species previously limited to single breeding attempts per season may now have the opportunity to produce multiple broods a year. Climate change effects may be further accelerated for species breeding in urban environments. Here, we report the first known case from the North American Arctic of Snow Buntings (Plectrophenax nivalis) fledging two successful broods within a single breeding season. We documented two female Snow Buntings nesting in Iqaluit, Nunavut, Canada, that, after successfully fledging their first broods, initiated a second clutch and successfully hatched or fledged nestlings from that second attempt. These females attempting a second brood were some of the earliest nesting birds and represent 2.7% (2 of 73) of females found nesting in Iqaluit during the 2024 field season. These findings demonstrate flexibility in the breeding decisions of Snow Buntings and could provide an early insight into how birds may be able to respond to future effects of climate change.