Green Heron

GREEN HERON

Photo Credit: Don Getty
http://www.dongettyphoto.com/

SCIENTIFIC NAME: Butorides virescens

OTHER NAMES: Green-backed heron, little green heron, swamp squaggin, fly-up-the-creek and skeow.

DESCRIPTION: The green heron (Butorides virescens) is one of the smallest members of the heron family, standing 16-20 inches tall with a wing span of 25-27 inches and weighing an average of 8 ounces. Sexes are similar with the female being slightly smaller than the male. The green heron has a dark colored bill that is relatively long for its small stocky body, and when in flight appears crow like, at a distance.

Striking coloration features include: green/black head cap, bluish to greenish back, deep chestnut neck with grayish under parts. Wings are a dark glossy green with the wing feathers edged in buff. Eye color varies from orange to yellow and both sexes have yellow legs. However, during the breeding season, the male’s legs turn orange.

DISTRIBUTION: The green heron ranges throughout the lower 48 states and southern Canada to Central America, West Indies and Panama. Breeding occurs from southern Canada through Central America and winters in the southern United States southward.

HABITAT: The green heron inhabits rivers, lakes, swamps, small streams, fresh and saltwater marshes, where favorable foraging habitat abounds. Major food items are small fish, frogs, small animals, insects and miscellaneous invertebrates. Small fish rank the highest on the heron’s food list, composing 50 percent of the diet.

FEEDING HABITS: Green herons belong to the order Ciconiiform and are adapted for wading in shallow water. This little heron prefers to slowly stalk or crouch at the edge of shallow waters. With head and neck extended it will wait motionless for prey to come by or may sometimes rake the bottom of shallow water to stir up prey. This heron has developed an unusual trait to use tools when hunting. The green heron will drop small sticks, insects, worms and even feathers onto the surface of water to lure small fish into striking distance.

LIFE HISTORY AND ECOLOGY: The green heron is very quiet when hunting but announces its arrival and departure with loud calls. Its alarm call sounds like “skeow” and it has a querulous cry of “fly-up-the-creek”, vocal sounds from which common names are derived. Its head is held near the body in flight and extended when taking flight or landing.

The green heron is a solitary secretive bird that is very alert and quick to flush when interrupted by an unexpected intruder. If the heron knows it is being watched, it will often shuffle sideways, flick tail and raise its crest.

Green herons are monogamous and have one to two broods a year. Nesting sites vary from dry woods to mangrove swamps. Green herons usually nest singly but sometimes in small colonies. During courtship the male erects his neck plumes, swells his throat and calls while hopping from foot to foot in front of the female.

The female will lay two to six light greenish/bluish eggs in a nest constructed of sticks lined with finer twigs and vegetation. The young hatch after a 19-21 day incubation period carried out by both adults. Young herons at birth are helpless and covered with grayish down. The young are well cared for by the adults which feed their regurgitated food to the new hatchlings. Young fledge and are capable of flight at about 21 days of age. However, they are still fed and cared for by the parents.

The green heron’s small size enables it to live in minute wetland habitats unsuitable for many larger wading birds. This physical attribute reduces competition for available foods and other life sustaining requirements needed by the heron.

REFERENCES:

Robbins, Chandler S., Bruun, Bretel and Zim, Herbert S., 1966, A Guide To Field Identification, Birds of North America, Golden Press, New York, Pp. 94-95.

http://www.birds.cornell.edu/program.AllAboutBirds/BirdGuide/Green_Heron_dtl.html

Terres, John K., Heron Family, 1980, The Audubon Society, Encyclopedia of North American Birds, Alfred A. Knopf, New York Pp. 500.

Author: Rick Claybrook, District IV Supervising Biologist, Division of Wildlife & Freshwater Fisheries


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