- 16.1–18.1 in
- 25.2–26.8 in
- 8.5 oz
- About the size of an American Crow; smaller than a Black-crowned Night-Heron
- Green-backed Heron (English)
- Heron vert (French)
- Garcita verde (Spanish)
- The Green Heron is one of the world’s few tool-using bird species. It creates fishing lures with bread crusts, insects, earthworms, twigs, feathers, and other objects, dropping them on the surface of the water to entice small fish.
- Like many herons, the Green Heron tends to wander outside of its breeding range after the nesting season is over. Most of the wanderers stay nearby as they search for good feeding habitat, but some travel long distances. Individuals have turned up as far away as England and France.
- The Green Heron is part of a complex of small herons that sometimes are considered one species. When lumped, they are called Green-backed Heron. When split, they are the Green Heron, the widespread Striated Heron, and the Galapagos Heron.
- Green Herons usually hunt by wading in shallow water, but occasionally they dive for deep-water prey and need to swim back to shore—probably with help from the webs between their middle and outer toes. One juvenile heron was seen swimming gracefully for more than 60 feet, sitting upright “like a little swan,” according to one observer.
- The oldest Green Heron on record was at least 7 years, 11 months old when it was found in Mexico in 1979. It had been banded in Oklahoma in 1971.
Green Herons are common breeders in coastal and inland wetlands. They nest along swamps, marshes, lakes, ponds, impoundments, and other wet habitats with trees and shrubs to provide secluded nest sites. They may even nest in dry woods and orchards as long as there is water nearby for foraging. Green Herons spend the winter in southern coastal areas of their range, and in marine and freshwater habitat throughout Mexico and Central America. In tropical areas they are common in mangrove swamps.
Green Herons eat mainly small fish such as minnows, sunfish, catfish, pickerel, carp, perch, gobies, shad, silverside, eels, and goldfish. They also feeds on insects, spiders, crustaceans, snails, amphibians, reptiles, and rodents. They hunt by standing still at the water’s edge, in vegetation, or by walking slowly in shallow water. When a fish approaches, the heron lunges and darts its head, grasping (or sometimes spearing) the fish with its heavy bill. Occasionally Green Herons hunt in deeper water by plunging on prey from above. They hunt at all times of the day and night in the shallows of swamps, creeks, marshes, ditches, ponds, and mangroves. They usually forage among thick vegetation in water that is less than 4 inches deep, avoiding the deeper and more open areas frequented by longer-legged herons.
- Clutch Size
- 3–5 eggs
- Number of Broods
- 1-2 broods
- Egg Length
- 1.3–1.7 in
- Egg Width
- 1.1–1.4 in
- Incubation Period
- 19–21 days
- Nestling Period
- 16–17 days
- Egg Description
- Pale green to bluish.
- Condition at Hatching
- Mostly helpless, but with open eyes. Covered with grayish brown down on top and white down beneath.
The male begins building the nest before pairing up to breed, but afterward passes off most of the construction to his mate. As the male gathers long, thin sticks, the female shapes them into a nest 8–12 inches across, with a shallow depression averaging less than 2 inches deep. The nest varies from solid to flimsy, and has no lining. Green Herons sometimes renovate old nests, or build in old nests of Black-crowned Night-Herons or Snowy Egrets. Occasionally they take sticks from nearby old nests and refashion them into new nests. They keep adding sticks throughout the breeding season.
The male selects a secluded site within his territory, usually in a large fork of a tree or bush, with overhanging branches to conceal the nest. Green Herons use many plant species as nest sites pines, oaks, willows, box elder, cedar, honey locust, hickory, sassafrass, and mangroves. The nest is usually on or over the water, but may be up to a half-mile away. It may be anywhere from ground level to 30 feet off the ground (occasionally higher).
Each breeding season, Green Herons pair up with one mate apiece, performing courtship displays that include stretching their necks, snapping their bills, flying with exaggerated flaps, and calling loudly. They often nest solitarily, although they may join colonies with other Green Herons or with other species. They defend breeding areas from each other and from birds like crows and grackles that prey on their nests. Other predators include snakes and raccoons. Both the male and female brood and feed the chicks, which may stay with their parents for more than a month after leaving the nest, as they learn to forage. Green Herons protect their feeding areas by driving away other species, such as American Coots, that approach too closely.
Green Herons are still common, but their population suffered a gradual decline of over 1.5% per year from 1966 to 2014, resulting in a cumulative decline of 68%, according to the North American Breeding Bird Survey. The North American Waterbird Conservation Plan rates Green Heron as a Species of Low Concern, and rates it a 12 out of 20 on the Continental Concern Score. Green Heron is not listed on the 2014 State of the Birds Report. Declines have been recorded across most of the heron's range, with only California populations showing an increase in that time. Green Herons can be found throughout the year across the U.S. (with the exception of several mid-western states), Central and northern South America. A small percentage breeds in the southwest of Canada. In the past, people hunted Green Herons for food and controlled their numbers near fish hatcheries, where the herons were perceived as a threat to the fish. Today, their biggest threat is probably habitat loss through the draining or development of wetlands, although no one knows the extent of this impact because these herons are solitary and widely dispersed.
- Davis, W. E., Jr., and J. A. Kushlan. 1994. Green Heron (Butorides virescens). In The Birds of North America, No. 129 (A. Poole, and F. Gill, eds.). The Birds of North America Online, Ithaca, New York.
- Kushlan, J.A., et al. 2002. Waterbird conservation for the Americas: the North American Waterbird Conservation Plan, version 1. Waterbird Conservation for the Americas. Washington, DC.
- North American Bird Conservation Initiative, U.S. Committee. 2014. State of the Birds 2014 Report. U.S. Department of Interior, Washington, DC.
- USGS Patuxent Wildlife Research Center. 2015. Longevity Records of North American Birds.
- USGS Patuxent Wildlife Research Center. 2014. North American Breeding Bird Survey 1966–2014 Analysis.
Resident to medium-distance migrant. Green Herons migrate north in late winter and early spring, usually at night and in large flocks. They head back south in late August through October. Eastern breeders migrate via Florida, the Gulf Coast, and the Caribbean, while western breeders head through Mexico. Those breeding in the interior of North America may take either an eastern or a western route. Florida and other southern states also appear to have resident populations. Green Herons tend to wander regionally right after breeding and before migrating, probably in pursuit of food.
Green Herons sometimes pay visits to ornamental fish ponds. A length of drain pipe placed in the pond can provide fish with a place to hide from feeding herons.
Find This Bird
Green Herons are common and widespread, but they can be hard to see at first. Whereas larger herons tend to stand prominently in open parts of wetlands, Green Herons tend to be at the edges, in shallow water, or concealed in vegetation. Visit a wetland and carefully scan the banks looking for a small, hunch-backed bird with a long, straight bill staring intently at the water. Their harsh skeow call is also a good clue. Green Herons are also distinctive in flight, with slow beats of their rounded wings making them look a bit like a tailless crow. Their habit of often briefly unfolding their neck during flight helps make them recognizable, too.