Occupancy of breeding sites in the non-breeding season, site quality and breeding success data for a population of common guillemots (Uria aalge) on the Isle of May, Scotland, 2017-2020

This dataset contains information on the occupancy of breeding sites in the non-breeding season, breeding timing and success, and breeding site quality for a sample of common guillemots breeding on the Isle of May, Scotland. Data is available for all attributes for the non-breeding season of 2017/18, 2018/19 and 2019/20. These data are part of the Isle of May long-term study to assess population trends of seabirds under environmental change (IMLOTS).