The great egret makes for exciting sighting

A great egret forages for food. Note the dark black legs that make identification easy.
A white great blue heron would have yellow legs. (Bill Danielson)

By Bill Danielson Special To The Times Union
Published: 12:00 a.m., Sunday, October 10, 2010

During the school year, I am trapped inside during the most productive birding hours of the day. As the days get shorter and shorter, there is less of a chance for me to do any birding at all. Mornings don't offer much, but autumn afternoons can sometimes produce some good sightings and tend to keep my eyes peeled for anything interesting while I'm in the car.

For instance, consider my drive home last week. I had made it all the way back to the Watervliet Reservoir without much interesting to report, when all of a sudden I saw something quite exciting. I saw a ghostly figure standing among the withering water chestnuts. It was a great egret and it was a great sighting!

Anyone familiar with the great blue heron (Ardea herodias) will immediately notice a similarity between herons and egrets. In fact, the great blue heron has a rare all-white form that looks almost identical to a great egret, except for one important difference. Great blue herons have yellow legs, whereas great egrets have black legs. Since the bird I saw had black legs, I knew this was an egret on walkabout.

The great egret has had a long and interesting history with its scientific name. Twenty-five years ago, the great egret was known as Casmerodius albus. "Casmerodius" was a combination of the Greek word "kasis," meaning "brother or sister" (a relative), and the Greek word "herodios," or "heron." The word "albus" is simply Latin for "white." Translated, the name would be something like, "the white brother of the herons."

According to the Dictionary of American Bird Names, by Ernest A. Chohate, a German ornithologist by the name of Constantin Gloger may have intended the genus name to be "Cosmerodius" with an "o." There is a Greek word "kosmos," one of the meanings of which is "decoration." Had this been the actual root of the name, the translation would be something like, "the white, decorated heron." Given the opulence of the egret's feathers during the breeding season, it is not too hard to imagine that this may have been the true intention of Gloger.

Today, the great egret's scientific name is Ardea albus. The word "ardea" is Latin for "heron," so the translation of the newest name is simply "the white heron." This name also suggests that the great egret is a close relative of its very similar cousin, the great blue heron.

Great egrets, like the other species in the heron family, are bedecked in glorious nuptial plumage in the height of the breeding season. So fantastically gorgeous are these delicate, lacy feathers that they were once highly prized as decorations for hats and clothing. The millinery had a catastrophic impact on bird populations, because the feathers could only be harvested by killing breeding birds.

The great egret seems to be a species born with wanderlust. Its breeding range extends from the Gulf of Mexico up the basin of the Mississippi River to Michigan. There is then a very thin arm that hugs the coast of the eastern United States as far north as Long Island. Clearly, the great egret is a bird dependent upon water for its living.

While the breeding range of the great egret is rather narrowly confined, the range over which it can be found is immense. Draw a line from the middle of Texas, up to the Great Lakes, and then east to Nova Scotia. Non-breeding birds, it seems, like to explore.

Late summer and early autumn seem to be the times when these rather exotic-looking nomads turn up in the strangest places, and I was happy to see that one had found its way so close to my home. Anyone who travels by train from Albany to New York is likely to see increasing numbers of these birds as the train moves south. The Hudson is a natural conduit for the movements of such coastal birds.

Keep your eyes peeled for great blue herons, great egrets and any other interesting birds in the next couple of weeks. As soon as temperatures fall and we have our first frost, most of these birds will probably clear out, but you never know.

Sometimes stubborn adults or inexperienced immature birds will stay far longer than seems wise.

Cold weather won't really chase them away until ice starts to prevent them from hunting, and in the meantime they can offer exciting sightings for any birders desperate for a glimpse of nature on the way home from work.

Bill Danielson is a freelance writer living in Altamont. Send your questions about the natural world to him at billd@speakingofnature.com.

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