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Great Blue Heron

Great Blue Heron (Ardea herodias)
Species Code: B051

distribution map Description: The Great Blue Heron is the largest and most widespread heron in North America. It is a large bird, with a slate-gray body, chestnut and black accents, and very long legs and an "S"-shaped neck. Great Blue Herons are very tall and stand 38-54 inches (97-137 cm). In flight, the bird looks enormous, with a six-foot wingspan.

Calls: The call of the Great Blue Heron is a deep, hoarse croak.
Listen to calls of this species »

Great Blue Heron photo by Tim Knight

Range / Habitat: The Great Blue Heron is common in marshes, mud flats, and agricultural areas at low to mid elevations. They nest colonially in trees near water and then disperse to feeding areas. Along river valleys they may be found at fairly high elevations.

Great Blue Heron photo by Natures Pics

Diet: Great Blue Herons feed on fish, amphibians, reptiles, invertebrates, small mammals, and even other birds. In Washington, much of their winter hunting is on land, with voles making up a major portion of their winter diet. (Seattle Audubon Society)

Behavior: When foraging, they stand silently along the shore, waiting for prey to come by, then they stab the prey with a quick lunge of the bill. They will also stalk prey slowly and deliberately.

Both parents regurgitate food to feed the young. The young birds can first fly at about 60 days old, but they continue to return to the nest and are fed by the adults for another few weeks. Pair bonds only last for the nesting season, and adults form new bonds each year.

Great Blue Heron photo by Tim Knight

Nesting: Nesting colonies are typically found in mature forests, on islands, or near mudflats. Great blue herons do best when they are free of human disturbance and have foraging areas near by.

Great Blue Herons typically breed in colonies containing a few to several hundred pairs. Nest building begins in February when a male chooses a nesting territory and actively displays to attract a female. The large nest is usually built high up in a tree. The male gathers sticks for the female who constructs a platform nest lined with small twigs, bark strips, and conifer needles. The female lays 2-6 pale blue eggs, then both parents incubate them for 25-29 days (4 weeks) until the young hatch. The parents bring food to young at the nest for two months before the young can fly and continue feeding the birds for a few weeks after fledging the nest.

Did you know?

  • Great Blue Herons look enormous in flight, with a six-foot wingspan
  • Both parents incubate the eggs for 25-29 days (4 weeks)
  • In flight, a Great Blue Heron usually holds its head close to its body with the neck bent.
  • The young can first fly at about 60 days old

Great Blue Heron photo by Tim Knight

An adult Great Blue Heron near Portage Bay in Seattle.

More information: BirdWeb: Great Blue Heron     All About Birds: Great Blue Heron

More photos: Great Blue Heron Photos on the Wildlife Web

Great Blue Heron feathers

Citizen Science: Great Blue Heron
This is a collaborative project that takes advantage of Flickr's new geotagging capability -- allowing you to identify the location of every photograph on a global map. The goal is to collect and document the migration patterns of great blue herons.

Animal silhouettes available to purchase »

Photos: Tim Knight and Natures Pics

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