Art Lander’s Outdoors: The Green Heron is the most widespread breeding heron in Kentucky

The green heron (Butorides virescens) is found throughout Kentucky, but populations are lower in heavily forested areas because there is less suitable nesting space.

The green heron, a member of the family Ardeidae, was first described in the scientific literature in 1758 by the Swedish biologist and naturalist Carl Linnaeus and includes 72 species of freshwater and shorebirds, some of which are more commonly referred to as egrets or bitterns than herons.

Size and coloring

Compared to most herons, green herons are small and stocky, with short legs and thick necks that are often close to the body.

They have broad, rounded wings and a long, dark, dagger-like beak. They sometimes raise their crown feathers into a short crest.

Their body length is approximately 43 cm, their average weight is 225 g and their wingspan is 63 to 68 cm.

Adults have a glossy greenish-black cap, greenish back and grey-black wings graduating to greenish or blue, a chestnut-brown neck with a white stripe on the front, grey underparts and short yellow legs.

Adult females tend to be smaller than males and have duller and lighter plumage, especially during the breeding season.

Juvenile birds are browner and have light stripes on the neck, spots on the wings, a brown and white striped underside, and greenish-yellow legs and beaks.

Reach and distribution

Green herons breed in all states in the eastern half of the Lower 48, with year-round populations along the Gulf Coast and Atlantic Coast through the Carolinas to Virginia. Breeding birds also occur in states along the Pacific Coast, from Washington State to Baja California in the south.

Habitat

In Kentucky, green herons live near wooded ponds, streams, rivers, reservoirs and wetlands.

Eating habits

Green herons feed mainly on small fish, including minnows, sunfish, catfish, pike, carp, perch, shad and brown trout. They prefer clear water in streams and lakes with aquatic plants.

They also feed on insects, spiders, crustaceans, snails, amphibians, reptiles and rodents. They hunt by standing still at the water’s edge or in vegetation, or by walking slowly through shallow water. When a fish approaches, the heron lunges forward and plunges its head underwater to snatch or sometimes impale the fish with its heavy beak.

They hunt day and night, foraging in dense vegetation in water less than four inches deep, avoiding the deeper, more open areas where the longer-legged herons are found.

Calls and songs

Green herons make a shrill, explosive call that sounds like “…skeow.”

They make this call when they are sitting, flying or when they are disturbed by an approaching predator.

If disturbed at the nest, they emit a series of croaking cackling sounds: cuck-cuck-cuck-cuck. Males often snap their beaks before mating.

Courtship and nesting

Art Lander Jr. is the Outdoors Editor for the Northern Kentucky Tribune. A native Kentuckian and graduate of Western Kentucky University, he is a lifelong hunter, angler, gardener and outdoorsman. He has worked as a newspaper columnist, magazine journalist and author and was formerly an editor at Kentucky Afield Magazine, editor of the annual Kentucky Hunting & Trapping Guide and the Kentucky Spring Hunting Guide, and co-author of the Kentucky Afield Outdoors newspaper column.

Green herons that nest in Kentucky overwinter on the Gulf Coast further south in the tropics.

Breeding birds return to their breeding grounds in mid-April. Egg-laying begins in May, and late clutches last until the end of June.

Each breeding season, green herons mate with a partner and perform courtship rituals that include stretching their necks, snapping their bills, flying with exaggerated wing beats, and calling loudly. They often nest alone, although they may join colonies with other green herons.

They defend their breeding territories from each other and from birds such as crows and grackles that eat their nests. Their other predators include snakes and raccoons.

Both the male and the female feed the chicks, which may stay with their parents for more than a month after leaving the nest while they learn to forage for food.

Green herons protect their feeding areas by scaring away other species, such as American coots, that come too close.

The male chooses a secluded spot in his territory, usually a large fork in a tree or bush with overhanging branches, to conceal the nest. Green herons use many types of plants as nesting sites, from the ground to 30 feet above the ground.

The male begins building the nest before mating, but then leaves most of the construction work to his partner. The male collects long, thin sticks and the female builds a nest with a diameter of 20 to 30 centimeters and a shallow depression.

The nest is variably sturdy or flimsy and has no lining. Green herons sometimes renovate old nests or build in old nests of night herons or snowy egrets. They occasionally take sticks from old nests nearby and build new nests from them. They continue to add sticks throughout the breeding season.

The female lays three to five pale green to bluish eggs. The incubation period is 19 to 21 days. The young are covered with grey-brown down on the upper side and white down on the underside.

Green herons are not very conspicuous. They do not wade as often as larger herons and usually stand motionless at the water’s edge while they search for food.

Their plumage blends in with the riverbank vegetation, so they are naturally camouflaged.