Across Canada except in the far north, the Rockies, and parts of the prairies, south to northern South America, the Great Blue Heron (Ardea herodias) is familiar to people who live near water. This metre-tall blue-gray bird with a long sharp bill hunts for food wherever it finds surface water.
Great Blue Heron Identification
The Great Blue Heron stands out throughout its range because of its size, and because of its strikingly long legs and neck. The head has varying amounts of white and a prominent black stripe on the crown; another black patch is seen at the tip of the folded wing. During the breeding season, breeding adults have impressive plumes, and red legs. The name, however, is misleading: the typical adult Great Blue Heron is more gray than blue, and one subspecies is white.
Great Blue Herons have typical behavior as well. Though they nest in colonies, they tend to hunt alone during the day. A hunting bird will stand very still in shallow water and wait for live prey to wander near. Then, with a rapid thrust of the beak, the prey – usually fish, but also insects, reptiles, amphibians, small mammals, other birds, virtually anything the heron can catch – is caught with the sturdy beak and swallowed. Great Blue Herons sometimes walk about slowly as well, watching for movement and being careful not to frighten potential prey away. The bird often holds its neck in an S-shaped curve.
In much of its range, the Great Blue Heron is the only large bird that fits this description and therefore it’s easy to identify. Beware the rare occurrence of the similar Tricolored Heron in southwestern North America, and more commonly in many coastal areas of the United States. In South America, a similar heron is likely to be a Cocoi.
Great Blue Heron Breeding and Nesting
Great Blue Herons sometimes build solitary nests, but they generally join a colony of dozens to hundreds of nesting pairs. Males establish a territory and use display behaviors to attract a mate.
Great Blue Herons choose one mate each breeding season and nesting is timed in each region so that the young hatch when food is most abundant. Nests, usually in trees, are large, about a metre wide, and built of sticks. The female lays three to five eggs but, except where food is readily available, many young don't survive to fledge.
Incubation lasts about four weeks, and by the time the young are a month old, the adult birds leave them alone in the nest for extended periods. By six weeks, fledglings start moving about freely in their tree home. They start to fly at about two months of age.
Interesting Facts About Great Blue Herons
Ornithologists have learned some interesting facts about Ardea herodias:
- If a heron catches a large fish, or an animal with spines, the bird repeatedly drops and seizes the prey until it is rendered senseless or otherwise easier to swallow.
- Herons have patches of powder down feathers, feathers that disintegrate to a dusty substance used to clean, waterproof, and condition other feathers. The birds have a comb-shaped toe to spread the powder through the feathers.
- Great Blue Herons begin incubating their eggs before the entire clutch is laid, so nestlings are born at different times and are different ages.
- The male and female share incubating eggs and brooding chicks: the female at night, the male during the day.
- After they are able to leave the nest, young birds often return to the wrong nest in a colony. This sometimes results in young of the second nest being expelled.
Great Blue Herons migrate south where winters are cold, but live year round in many regions. Watch for them as they hunt the shorelines of North America wherever the weather is warm and food is abundant.
Sources
“About Herons.” The Heron Working Group. sfu.ca
Firefly Encyclopedia of Birds. Perrins, Christopher ed. Buffalo: Firefly Books, 2003
“Great Blue Heron.” Hinterland Who’s Who. hww.ca
Smithsonian Field Guide to the Birds of North America Floyd, Ted. New York: HarperCollins; 2008.
Rosemary Drisdelle - Rosemary Drisdelle has been published many times as a nonfiction writer and several times as a poet. Her first book, Parasites: Tales of ...
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