Great Blue Heron

Ardea herodias

Order CICONIIFORMES - Family ARDEIDAE

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1. Cool Facts
2. Description
3. Similar Species
4. Sound
5. Range
6. Habitat
7. Food
8. Behavior
9. Reproduction
10. Conservation Status
11. Other Names

The largest and most widespread heron in North America, the Great Blue Heron can be found along the ocean shore or the edge of a small inland pond. An all white form is found from southern Florida into the Caribbean, and used to be considered a separate species, the "Great White Heron."

Cool Facts

• The white form of the Great Blue Heron, known as the "great white heron," is found nearly exclusively in shallow marine waters along the coast of very southern Florida, the Yucatan Peninsula, and in the Caribbean. Where the dark and white forms overlap in Florida, intermediate birds known as "Wurdemann's herons" can be found. They have the bodies of a Great Blue Heron, but the white head and neck of the great white heron.
• Although the Great Blue Heron eats primarily fish, it is adaptable and willing to eat other animals as well. Several studies have found that voles (mice) were a very important part of the diet, making up nearly half of what was fed to nestlings in Idaho. Occasionally a heron will choke to death trying to eat a fish that is too large to swallow.

• Great Blue Herons congregate at fish hatcheries, creating potential problems for the fish farmers. A study found that herons ate mostly diseased fish that would have died shortly anyway. Sick fish spent more time near the surface of the water where they were more vulnerable to the herons.

Description

• Size: 97-137 cm (38-54 in)
• Wingspan: 167-201 cm (66-79 in)
• Weight: 2100-2500 g (74.13-88.25 ounces)

• Large, gray bird.
• Long legs
• Long, "S"-shaped neck.
• Long, thick bill.
• White crown stripe.
• Black plume extending from behind eye to off the back of the neck.
• Shaggy feathers on neck and back.
• Bluish gray back, wings, and belly.
• Reddish or gray neck.
• White morph all white with pale legs, yellow bill.

• Front of neck streaked with white, black, and rusty brown.
• Bill yellowish.
• Legs brownish or greenish.
• Eyes yellow.
• Thighs rust colored.
• Black patch at bend of wing.
• Flight feathers blackish on top, contrasting with center of wings.
• Cinnamon patch at leading edge of underside of wing.

Sex Differences

Sexes look alike.

Immature

Juvenile similar to adult, but has gray crown, a dark upper bill, rusty brown edging to back feathers, and lacks body plumes.

Similar Species

• Sandhill Crane is larger, has a prominent tuft of bushy feathers on its rump, a shorter bill, and a red cap, and is found in fields rather than ponds.
• Little Blue Heron is much smaller and more slender, lacks plumes on the head, is entirely uniform dark blue-gray, has a dark bill with a bluish base, and greenish legs.
• Tricolored Heron is more slender, has white head plumes, and a white belly contrasting sharply with the dark chest.
• Great Egret differs from white morph by being more slender, lacking head plumes, and having black legs.

Sound

Call a deep, hoarse croak.

»listen to songs of this species

Range

Summer Range

Breeds from southern Alaska and central Canada southward to Central America and the Caribbean.

Winter Range

Winters from southern Canada southward to northern South America, and along the coasts as far north as Alaska and Nova Scotia.

Habitat

Found along calm freshwater and seacoasts. Usually nests in trees near water, but colonies can be found away from water. Great White Heron found almost exclusively in shallow marine habitats.

Food

Fish, invertebrates, amphibians, reptiles, birds, and small mammals.

Behavior

Foraging

Walks slowly, stands and stabs prey with quick lunge of the bill.

Reproduction

Nest Type

Nests in colonies, sometimes as lone pair. Nest a large platform of sticks, lined with pine needles, moss, reeds, dry grass, or twigs. Placed high in trees, occasionally on ground.

Egg Description

Dull pale blue.

Clutch Size

2-6 eggs.

Condition at Hatching

Covered in pale gray down; eyes are open and can hold head up just after hatching.

Conservation Status

The Great Blue Heron suffered less from plume hunters and pesticides than other herons, and its numbers have remained strong.

Other Names

Grande Héron (French)
Garza morena, Garza blanca granda, Gallinaza (Spanish)

Sources used to construct this page:

1. Butler, R. W. 1992. Great Blue Heron (Ardea herodias). In The Birds of North America, No. 25 (A. Poole, P. Stettenheim, and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, D.C.
2. Glahn, J. F., B. Dorr, J. B. Harrel, and L. Khoo. 2002. Foraging ecology and depredation management of great blue herons at Mississippi catfish farms. Journal of Wildlife Management 66: 194-201.