Great Blue Heron

Ardea herodius

The great blue heron is a tall, bluish-gray wading bird with:

• A white head with long, black, feathery plumes.
• A long gray to brownish-colored neck with long, feathery plumes (during breeding).
• Black-, brown- and white-streaked underparts.
• A yellow, spear-like bill.
• Long chestnut-colored legs.

Great blue herons grow to about 4 feet tall with a wingspan of about 6 to 7 feet.

Where does the great blue heron live?

Great blue herons are year-round residents of the Bay and its tributaries. They can be found wading in:

• The shallows of open water channels, creeks and mudflats in tidal rivers and marshes.
• Freshwater ponds and ditches in wet meadows and fields.

What does the great blue heron eat?

Great blue herons feed mostly on small fish, amphibians, crustaceans and aquatic insects.

• Herons are shallow-water stalkers, quietly standing in or slowly wading through the water before plunging their bill in to capture their prey.
• Great blue herons spend about 90 percent of their waking hours hunting for food.

What does the great blue heron sound like?

When alarmed, great blue herons will make three or four hoarse croaks.

Where does the great blue heron nest and breed?

Most great blue herons breed in localized colonies (called rookeries or heronries) of sometimes hundreds of nesting pairs. Colonies are located at isolated sites where ground predator and human access is limited, such as woodland swamps and small islands.

• The male heron builds a nest of sticks and twigs high in the canopy of a tree, safe from predators.
• Great blue herons may begin breeding activities as early as February. New breeders may continue to arrive at the colonies well into May.
• The peak of egg-laying season occurs from mid-March to mid-June. Clutch size varies from three to seven eggs, with an average of four eggs.
• Both parents incubate the eggs for about 28 days, and the peak of hatching takes place from mid-April to mid-July.
• Though they may have several eggs, great blue heron pairs usually only raise one or two young; the others starve after hatching.
• Fledging occurs at about 60 days. Immature great blue herons have a solid black crown without plumes.

Other facts about the great blue heron:

• The great blue heron is the largest heron in North America.
• As it takes off from a perch, a great blue heron holds its neck in an S-shaped position and flies with slow, deep wingbeats.
• Great blue herons can live to about 15 years.