A species of wetland habitat, the Great Blue Heron is widely distributed in Canada. Results from the Breeding Bird Survey suggest that abundance has decreased by 30% since 1970, although regional trends vary. The fannini subspecies, resident only in coastal British Columbia, has shown a large decrease since 1970. The subspecies was designated as Special Concern by the Committee on the Status of Endangered Wildlife in Canada in 1997 and again in 2008 because of its small numbers, declining productivity, and uncertain trends (COSEWIC 2008g); it was listed as such under the Species at Risk Act in 2010. This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.
Great Blue Herons are vulnerable to wetland habitat loss and degradation throughout their range; disturbance at nesting sites and destruction of marshes likely continue to threaten breeding colonies (COSEWIC 2008g). However, recent declines in central Canada may be most closely associated with changing amphibian populations, a major food source, rather than a direct consequence of habitat loss (Naylor 2007). The species is tracked as an indicator of trends in contaminants, and levels of regulated contaminants such as DDT and PCBs have declined significantly since the 1990s in some portions of the range (Champoux and Boily 2017). A growing population of Bald Eagles in British Columbia may be disturbing nesting fannini herons and usurping their nesting colonies, forcing the herons to relocate (e.g., Myrvold and Kennedy 2018), as well as increasing predation pressure on the population (Environment Canada 2016e). Finally, colony sites are limited to areas within reach for foraging areas (Knight et al. 2016), so increasing urban development in those areas may further increase pressure on these birds.
Environment and Climate Change Canada and partners have developed Bird Conservation Region Strategies in each of Canada’s Bird Conservation Regions (BCRs). In these strategies, selected species are identified as priorities for one or more of the following reasons:
Select any of the sub-regions below to view the BCR strategy for additional details.
