The Great Blue Heron is one of the most distinctive North American birds. The Pacific Great Blue Herons (fannini subspecies) do not migrate and depend entirely on their wetland habitat in the Lower Mainland and Vancouver Island for survival. The fannini subspecies is provincially and federally ranked as a Species at Risk and requires significant conservation efforts to ensure the long-term viability of its population.
Because of their sensitivity to human activity and declining population, the fannini subspecies is Blue-listed (a species of Special Concern) both provincially and federally. The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) has designated the Pacific Great Blue Heron as Vulnerable.
In British Columbia, the Great Blue Heron, its nests and eggs are protected year-round from hunting and other forms of human persecution.
On the Great Blue Heron Nature Reserve, land is carefully managed throughout the year to provide suitable foraging and nesting conditions. Trails on the Nature Reserve that come in close proximity to the colony are closed during the breeding season.
Although the Pacific Great Blue Heron is commonly seen in parts of B.C., the productivity of the subspecies is decreasing. Much of their range along the coast and the southern interior is affected by significant urbanization, draining and infilling of wetlands, foreshore development, logging, and removal of riparian forests. These human disturbances pose some of the largest threats to the heron population, causing the loss of quiet wooded areas which are preferred nesting sites, and reducing the subspecies' ability to reproduce successfully.
The presence of humans as close as 200 meters from a colony can cause the birds to abandon the site. In some circumstances, however, the herons may become used to people. Herons have been nesting in Vancouver’s busy Stanley Park for over 75 years.
Known natural disturbances include increased predation by the recovering bald eagle population, which may result in low breeding success and abandonment of some nesting colony sites.