Bird count dataset for: Oiling threats to marine birds on Southern Vancouver Island, BC, Canada

We conducted year-round boat-based strip transect surveys in waters between Sidney, BC and Victoria, BC from November 2015 to August 2019 and examined seasonal variation in bird distribution and abundance. Our study area included parts of the Sidney Channel Important Bird Area, the Shoal Harbour and Victoria Harbour Migratory Bird Sanctuaries and the Chain Islets Ecological Reserve, adjacent to major shipping lanes, as well as ports and marinas. We report counts of Rhinoceros Auklet Cerorhinca monocerata, Common Murre Uria aalgae, Pigeon Guillemot Cepphus columba, Marbled Murrelet Brachyramphus marmoratus, and Ancient Murrelet Synthliboramphus antiquus., We conducted year-round strip transect surveys of alcids on the ocean between Sidney and Victoria BC, Canada.  We counted birds out to 150m and recorded time and location at 10 minute intervals.  We calculated mid points for the transect segment and report relative densities for each species at each centroid.,