By Tom Dennis
Great Blue Heron, Ardea herodias
Great Blue Herons are the largest heron in North America and what they lack in musical vocalization skills is more than made up for in striking beauty. If you’re in the habit of calling them herrings, well there’s something rather fishy about that! Let’s take a closer look at this wonderful wading bird.
Males and females are identical in appearance and weigh on average about five pounds with large individuals tipping the scales at eight pounds. Their flight feathers are slate-gray with a slight azure blue sheen and they have a rusty gray neck with black and white streaking of plume-like feathers and a paired red-brown and black stripe up the flanks. They show plumes on the back during breeding season. The dagger-like bill is dull yellow to orange and legs are yellow-grey to yellow-orange during breeding season. A white morph that is common in southern Florida can be distinguished from the Great Egret which is smaller and has black legs. Great Blue Herons have a wingspan of up to 82 inches and fly with their neck folded into the shape of an “S” and legs extended. They can be easily differentiated from Cranes which fly with the neck and legs extended.
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Great Blue Herons nest in colonies, in trees close to lakes or water. These groups are called a heronry and they contain from five to five hundred nests that are close to ideal fishing sites. They are typically difficult to reach on foot with islands, swamps, and high branches preferable as protection from egg predators and human interference. They return to these locations using the same bulky stick nests for many years. Adult birds have few predators due to their large size and formidable bill. They are occasionally eaten by alligators and eagles and in turn have been known to mortally wound an attacking Bald Eagle. Their preferred food is fish but they also consume frogs, insects, and small mammals including mice and shrews.
There are sixty-seven species of herons and egrets found world-wide on all continents except Antarctica and twenty-eight species in North America that include the graceful egrets and herons and the stocky night-herons. Great Blue Herons are found throughout North America, as far north as Alaska and in winter their range extends to Central and northern South America. The scientific name comes from the Latin name ardea, and Ancient Greek erodios, both meaning “heron”. Most birds in our area migrate south but they are hardy and some remain through cold northern winters as long as unfrozen, fish-bearing water remains available.
Great Blue Herons often congregate at fish hatcheries, potentially creating problems for fish farmers, however studies show that they tend to eat unhealthy fish that would likely not otherwise survive. They have been known to choke to death on prey that is too large. Great Blue Herons are often featured on artwork of varied forms ranging from sculptures, paintings, carvings and photography.
The sound is not anything song-like and is described as a squawk or deep croak.
You can see and often hear them on local waters including the wild stretches of the Black River where quiet kayakers are often rewarded by one or two flying companions. They are also common around the Bluewater Riverwalk and often are seen fishing at the confluence of the Black and St. Clair Rivers.
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Tom Dennis is a resident of Fort Gratiot where he and Laurie Melms Dennis, his wife of 45 years, tend to their bird and butterfly friendly gardens. He is a speaker and free-lance writer, passionate birder, advanced master gardener, creation scientist, and naturalist, with degrees from Michigan State University in Zoology and Biology. Tom is an active member of Blue Water Audubon Society, Master Gardeners of St. Clair County, Port Huron Civic Theater, Ross Bible Church, Tapestry Garden Club, Blueways of St. Clair, and is a steward of the Blue Water Riverwalk with Friends of the St. Clair River.
