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Great Blue Heron
Ardea herodias
Family: ARDEIDAE
Order: Ciconiiformes
Spanish Common Name: Garza morena, Garza blanca granda, Gallinaza
French Common Name: Grand héron
(c) Glen Tepke |
Courtesy Kenn Kaufman |
Annual Population Indices |
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Conservation Status
Global Population: Unknown
Continental Population: 124,500
Watchlist Status: 
Audubon State of the Birds Status: no current conservation concerns
Statuesque and graceful in movement, the Great Blue Heron is one of North America’s most familiar and adaptable wading birds. At four feet tall, with a six-foot wingspan, it is also the continent’s largest heron species. While vocal in flight, Great Blue Herons are frequently observed standing silent and motionless along shorelines. The bird takes to the sky with slow, deep wingbeats, its long neck curved into an S-shape, and its head hunched back upon its shoulders.
Range & Distribution
Widespread across North America, Great Blue Herons thrive year-round in both freshwater and saltwater habitats from southern Alaska to Central America, across much of the United States, and into the Caribbean Islands. During breeding season, they extend their northern range into central Canada and eastward to Nova Scotia. Colonies also nest on Ecuador’s Galapagos Islands. In winter, the species can be found as far south as the coastlines of Colombia and Venezuela.
A legend for the range map to the right can be found here.
Population Status & Trends
Early in the 20th century, Great Blue Herons suffered from unrestricted hunting, but today, with legal protection and greater awareness about conservation, they are among the most abundant wading birds in North America.
An explanation of the Annual Indices graph displayed to the right can be found here.
Conservation Issues & Efforts
Great Blue Herons were impacted less by plume hunters and pesticides than other heron species, and their numbers have remained strong over a broad range. However, colonies are vulnerable to disturbance. The birds may abandon rookeries or experience diminished reproductive success when disrupted, especially early in the breeding season. Moreover, the destruction of wetland habitat is a serious threat. Clearcutting of forests and construction near heronries are also detrimental.
What You Can Do
Don’t disturb Great Blue Heron nesting sites or colonies when hiking or landing boats; the birds may abandon their nests or colonies.
Great Blue Herons can be killed or injured when ensnared in fishing tackle. Don’t discard or abandon snagged fishing lines and lures.
Be alert to local, regional, and federal land management decisions, particularly those related to wetlands. Support protection of Great Blue Heron nesting sites, feeding grounds, and winter habitats.
For actions you can take, including Audubon activities, please visit our resources page.
For More Information
References
Butler, R.W. 1992. Great Blue Heron. In The Birds of North America, No. 25 (A. Poole, P. Stettenheim, and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, DC: The American Ornithologists’ Union.
Kaufman, Kenn. Lives of North American Birds, Houghton Mifflin Company, New York, 1996.
Sibley, David Allen. The Sibley Guide to Birds. Alfred A. Knopf, New York, 2000.
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