Designated as a Species of Special Concern in 2008, the entire range and potential area of occupancy for the Great Blue Heron is defined as terrestrial areas within the Coastal Douglas Fir and Coastal Western Hemlock Biogeoclimatic zones that are less than 10 km from a potential foraging area (potential foraging areas are defined as the entire coastline and major river systems). The distribution of the Pacific Great Blue Heron is confined to the coast from Prince William Sound, Alaska south to Puget Sound, Washington. The major factors currently limiting the persistence of heron populations are nesting failure and reduced nesting productivity arising from eagle predation, human disturbance and habitat declines from development.
Refer to the, "COSEWIC Assessment and Update Status Report on the Great Blue Heron (Ardea herodias fannini) in Canada," for more information.