Green-backed Heron

Also known as

Chalk-line, crab-catcher, fly-up-the-creek, green bittern, little green heron, poke, shitepoke, skeow, skow, swamp squaggin. Used to be called green heron (Butorides virescens).

What is the scientific name?

Butorides striatus

• Pronounced bew-tore-EYE-deez strih-AY-tus
• What does it mean? "Striped bittern." Butorides is of uncertain origin but butio means "bittern" in Latin. Striatus means "striped" in Latin, in reference to its striped markings.

Where are they located? How many subspecies are there?

There are approximately 30 subspecies of green-backed herons and only two live in North America. B.s. anthonyi occurs on the coast and slightly inland of Western North America, from Oregon to northern Baja California. B.s. virescens is located from South Dakota, Minnesota, Ontario, and Nova Scota south to Mexico, Central America, West Indies, and Panama (Hancock and Kushlan 1984).

Where do they live?

Near fresh and salt water lakes, streams, shores, swamps, marshes, rivers, and ponds (Hancock and Kushlan 1984).

What do they look like?

The top of the head and wings are a dark, glossy green. The back is a lighter gray-green. The cheeks, sides and back of neck are a deep chestnut. The center of the throat and neck are streaked with white and the legs are dull yellow. The male's legs may turn orange during the breeding season. The bill is blackish.

How big are they?

Green-backed herons are between 16 and 22 inches long (Peterson 1961). They have a wingspread of up to 26 inches and weigh between 5 and 7 ounces (Terres 1980).

How long do they live?

Uncertain. The longevity record is 7 years, 11 months (Clapp 1982).

How fast can they fly?

Between 20 and 34 miles per hour (Palmer 1962).

What do they eat?

Small fish, amphibians, reptiles, crustaceans, leeches, spiders, insects, and mollusks. A study by the U.S. Fish and Wildlife Service found their diet to consist of 45.39% fish, 20.64% crustaceans (such as crayfish and prawns), 23.65% insects (such as dragonflies, grasshoppers, crickets, and diving beetles), and 10.32% miscellaneous invertebrates (such as earthworms and snails), spiders, frogs, and snakes. They will sometimes also eat small mammals such as mice (Palmer 1962).

Interesting notes: This is the most widely distributed of the herons and is found all over the United States (Terres 1980). They were considered rare in Oregon as recently as 1940 (Gabrielson and Jewett 1940) but may often be seen along the Rogue River. Whereas the great blue heron nests in colonies, the green-backed heron is usually a solitary nester. In some areas of the United States, however, it will nest in small groups of six or more (Palmer 1962).

Green-backed herons are also sensitive to human activities. With the increase in rafting and other recreational uses of our wetlands, the habitat of the green-backed heron is often infringed upon. In a study performed in southeastern Missouri, researchers found that the feeding activity of green-backed herons during the weekends was adversely affected by canoe float trips, the major form of recreational use on the river under study (Kaiser and Fritzell 1984).

Green-backed herons are known to actually use bait to lure fish. In one instance, a scientist was observing birds along a lakeshore in Florida and he threw a piece of bread to a green-backed heron. The heron took the bread and dropped it in the water. At first the scientist thought the heron was simply softening up the bread. But as the bread started to float away the heron picked it up and placed it back in the same spot. Finally, a fish came up to nibble on the bread the heron speared it! The scientist continued to observe this feeding behavior for three consecutive days (Lovell 1958).

This "baiting" behavior has been observed by several other researchers as well. Green-backed herons have been seen using a variety of lures, including commercial fish bait obtained from a marine park (Sisson 1974), feathers (Norris 1975), flies, various insects, plant materials such as twigs and moss, and even garbage such as bits of styrofoam (Higuchi 1986). This kind of behavior is believed to result from the heron having "insight" (Welty and Baptista 1988), the "Aha!" experience that comes from studying a problem and the answer suddenly appearing (the light turns on!). The mechanism seems to be the linking of various bits of information into relationships. For example, the heron's "thinking" might go like this:

"fish like bread, I like fish, bread attracts the fish, if I put the bread in the water I will get fish!"