Anthropogenic Nest Cavities Used by Snow Buntings in an Urban Arctic Landscape.

Northern and Arctic ecosystems are experiencing rapid climate change, and simultaneously, human populations in the North are growing and centralizing. The Snow Bunting () is a Holarctic-breeding songbird and abundant in urban Iqaluit (pop. 7400), Nunavut. In nonurban areas of the Arctic, nest cavities are a limited resource for breeding Snow Buntings. Our goal was to assess the extent of Snow Buntings' use of anthropogenic structures versus natural rock cavities for nesting in Iqaluit. We found 160 Snow Bunting nests (2023, 2024) in Iqaluit; 45% of these were in anthropogenic nest cavities, for example, in vents in buildings or human-made rock structures (e.g., revetment gabions). This is the first documentation of extensive anthropogenic cavity use of Snow Buntings in an urban-Arctic environment. Nests in anthropogenic structures were significantly higher off the ground than nests in natural cavities but were similar in orientation and depth. Natural cavities were exclusively in rock. Anthropogenic nesting cavities were also primarily in rock (77%) but about 10% of cavities were in other materials, including wood, metal, or buildings. Given this flexibility in nest cavity use, Snow Buntings may be less limited for nest cavities in the urban environment compared to a natural landscape, although the impacts of anthropogenic nest cavities on reproductive success remain to be explored.