Herons

The Great Blue Heron (Ardea herodius) is the largest and most widely distributed heron species in Canada. During the breeding and post-breeding seasons, they venture as far north as Newfoundland and Prince William Sound in Alaska, and as far south as Mexico and the West Indies. Herons leave most of Canada for the winter, with many overwintering across the United States and farther South. The exception to this is British Columbia's coastal areas, where a vulnerable subspecies of the Great Blue Heron (Ardea herodias fannini), also known as the Pacific Great Blue Heron, can be found year-round.  The survival of this non-migratory subspecies depends on the presence of suitable foraging and nesting habitat along B.C.'s Southern Coast. They are considered a symbol of wetland conservation and environmental quality by The Committee on the Status of Endangered Wildlife in Canada. 

Adult specimens stand over 1 meter in height, significantly larger than close relatives such as the Green Heron. Adults have distinct markings on their head, which is white with a distinct black stripe extending back from the beak, over their yellow eyes, and into slender black plumes. Their back is greyish blue and the breast is white streaked with black.

In flight, their neck doubles back and the head rests against the shoulders. Herons in their first year have grey crowns and grey wings flecked with brown.

Check out these websites for more information on the life history of the Great Blue Heron:

Hinterland Who's Who

The Cornell Lab of Ornithology

The fannini subspecies of Great Blue Heron is found throughout the coastal region of British Columbia at elevations of 0-1100 m, and within 10 km of the coast or large river systems. While foraging and breeding sites are quite dispersed, this subspecies is most common on the South Coast especially in association with low elevation lakes, wetlands, sloughs and estuaries. The major nesting colonies or “heronries” on the South Coast include: Tsawwassen, Bowen Island, Deer Lake, UBC (main campus) and West Vancouver. Many of these locations support >100 nesting pairs. Other heronries occur on the Southern Gulf Islands and southeast Vancouver Island. 

It is estimated that approximately 4-5000 breeding birds make up the coastal subspecies population in BC. The Great Blue Heron Nature Reserve hosts a nesting colony of approximately 90-100 nests, which has been in use for nearly 50 years. Learn more about our colony here.

Original image and more information can be found on the Government of Canada's Species at Risk Public Registery: https://registrelep-sararegist...

The preferred habitat of the Pacific Great Blue Heron includes riparian areas, estuaries, lakes and lowland rivers and streams within 10 km of the coast or major rivers.

Foraging Habitat:

As they do not migrate, the fannini subspecies requires sufficient foraging habitat year-round. Foraging areas are found along the seacoast, in fresh and saltwater marshes, along rivers, and in grasslands. In autumn, large populations of juveniles move to occupy grasslands on the Fraser River delta, and adults occupy estuarine marshes, riverine marshes, and grasslands. During non-breeding periods, the adults roost high up in mature trees in close proximity to foraging sites. 

Nesting habitat:

Heronries are typically found within 10 km of foraging habitats in large tree stands. Though generally associated with stands of trees well away from anthropogenic noise, light, and other disturbances, some heronries (e.g. Stanley Park), have been successful in dense urban areas. Their large stick nests can be up to 1 meter across and have been recorded anywhere from 5 - 75 m above ground. They are often found in Black Cottonwood, Bigleaf Maple or conifers. Nests are lined with twigs; bark strips, coniferous boughs, and rushes. Heronries vary significantly in size, can be over 350 nests and sites are reused year after year.

Primarily a fish eater (pisciverous), the fannini subspecies also exploits a range of amphibians including invasive species such as Green Frog and American Bullfrog. 

Small mammals such as Townsend’s Vole, mice and shrews are stalked in meadows and agricultural fields and may form an important component of their diet in the winter, when amphibians are in hibernation and waterways are covered with ice.