Species Spotlight: Pacific Great Blue Heron
|Great Blue Heron on the Cow River in British Columbia
© Dave Polster
Common name: Great Blue Heron (fannini subspecies) — also known as Pacific Great Blue Heron
Latin name: Ardea herodias fannini
Status under SARA: Special Concern
Range: Pacific Coast, from the regions of Prince William Sound in Alaska to Puget Sound in Washington State. In Canada, the fannini subspecies is found only on the northern and southern coasts of British Columbia, including its large coastal islands.
Size:While standing and with its neck extended, averages heights over 1 m and measures 97 to 137 cm in length.
Population estimate:Best available estimates suggest Canadian populations of nesting adult herons are 4,000 to 5,000.
- Currently, there are five subspecies of the Great Blue Heron identified, and of these two reside in British Columbia.
- Great Blue Heron breeding couples are monogamous and both participate in incubating the eggs.
- The main predator of the species in British Columbia is the Bald Eagle.
Many Canadians are familiar with the sight of this beautiful, tall, and graceful wading bird. With long wings, thin legs and a short tail, it is the biggest heron species in North America. It has blue and grey plumage combined with a black stripe that extends from its eyes to the back of the head. It is easy to identify this large bird fishing along shorelines and even in suburban ponds. The fannini subspecies is actually smaller and slightly darker in colouration when compared to the Great Blue Heron (herodiassubspecies) in the rest of North America.
This subspecies lives year round on the Pacific Coast and mostly breeds in the Strait of Georgia. During this time, the fannini gathers in colonies for courtship, nesting and rearing its young in large platform-like stick nests usually situated high in trees. Less than two chicks from an average of four eggs will fledge, and less than 25% of juveniles survive their first winter.
The Great Blue Heron fannini subspecies typically hunts a wide selection of animals, but concentrates on small fish during its breeding season. In the winter months it will switch to a diet that includes small mammals.
What is Being Done
There are a number of threats to the species’ continued survival. Roughly half of the species’ global population breeds in Canada. Surveys conducted on bird colonies in British Columbia suggest a significant decline in the species’ reproductive rate since the 1970s and that the proportion of nesting pairs that successfully raises at least one fledgling is considerably lower than in the past. Forested areas which provide the herons nesting grounds have declined due to urban growth, and there has also been disturbance and destruction of nesting sites by logging operations and road construction. In fact, between the periods of 1972 to 1985 and 1998 to 1999, destruction of heron habitat on British Columbia’s southern coast led to 21 colonies abandoning nesting sites.
Today, the Great Blue Heron’s nests and eggs are protected under the British Columbia government’s Wildlife Act, as well as the Migratory Birds Convention Act (1994). The last COSEWIC assessment in April 2008 designated the Great Blue Heron fannini subspecies as “Special Concern.” In February 2010, it was officially designated “Special Concern” by SARA and added as part of an amendment to the Species at Risk Act, reflecting the continued threat of extirpation and habitat destruction that the species faces in Canada. While this is a great victory and a step in the right direction, much more needs to be done for its continued presence in British Columbia’s lakes, ponds and rivers.
What You Can Do
- Participate in Nature Canada’s ongoing efforts to protect the habitat of the Great Blue Heron and other birds that are in danger of disappearing in Canada by supporting our Important Bird Area program and our species at risk work.
- Be mindful of protected areas where the Great Blue Heron nests and lives, and find out how you can continue to support and lobby for conservation laws through Nature Canada’s monthly eNewsletter (sign up below).
- Contact BC Nature and find out how you can help them support their conservation efforts.
Species at Risk Public Registry, SARA
Thanks to Nature Canada volunteer Michael Berrigan for contributing this profile.