Great Blue Heron
(Ardea herodias)

Overview

Summary

© Jukka Jantunen (flickr.com/photos/jukka_jantunen)
For additional photos and vocalizations, visit Dendroica. (Link opens in a new window.)

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 31% since 1970, although regional trends vary. The fannini subspecies, resident only in coastal British Columbia, 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). This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.

Designations

Population status

Population estimate

Distribution maps

• BirdLife International / NatureServe
• Breeding Bird Survey (BBS): Relative Abundance and Breeding Distribution (1993-2012)

Migration strategy, occurrence

Responsibility for conservation of world population

Conservation and management

Great Blue Herons were once subject to intense hunting for feathers, and more recently are vulnerable to wetland habitat change and pesticides that have affected many other waterbirds (COSEWIC 2008g). Disturbance at nesting sites and destruction of marshes likely continue to threaten breeding colonies (COSEWIC 2008g), but recent declines in central Canada may be more closely linked to changing amphibian populations, a major food source, than to habitat loss or forestry impacts (Naylor 2007). The fannini subspecies in British Columbia is thought to be particularly vulnerable to predation and human-caused habitat alteration (COSEWIC 2008g).

Bird conservation region strategies

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:

• conservation concerns (i.e., species vulnerable due to population size, distribution, population trend, abundance, or threats)
• stewardship responsibilities (i.e., species that typify the regional avifauna or have a large proportion of their range or population in the sub-region)
• management concerns (i.e., species that require ongoing management because of their socio-economic importance as game species, or because of their impacts on other species or habitats)
• other concerns (i.e., species deemed a priority by regional experts for other reasons than those listed above or because they are listed as species at risk or concern at the provincial level)

Select any of the sub-regions below to view the BCR strategy for additional details.

References

• COSEWIC. 2008g. COSEWIC Assessment and Update Status Report on the Great Blue Heron fannini subspecies Ardea herodias fannini in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vii + 39 pp. COSEWIC. 2008g. COSEWIC Assessment and Update Status Report on the Great Blue Heron fannini subspecies Ardea herodias fannini in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vii + 39 pp. (Link)
• Naylor, B. 2007. Great Blue Heron. pp. 158-159 in: Atlas of the Breeding Birds of Ontario, 2001-2005. Cadman, M.D., D.A. Sutherland, G.G. Beck, D. Lepage and A.R. Couturier, Eds. Bird Studies Canada, Environment Canada, Ontario Field Ornithologists, Ontario Ministry of Natural Resources, and Ontario Nature, Toronto, Ontario.
• Vennesland, R. and R.W. Butler. 2011. Great Blue Heron (Ardea herodias), The Birds of North America Online (A. Poole, Ed.). Cornell Lab of Ornithology, Ithaca, New York. Vennesland, R. and R.W. Butler. 2011. Great Blue Heron (Ardea herodias), The Birds of North America Online (A. Poole, Ed.). Cornell Lab of Ornithology, Ithaca, New York. (Link)