Great Blue Heron
Ardea herodias

Conservation status | Formerly often shot, simply because it made a conspicuous and easy target, but this rarely occurs today. Colonies may be disrupted by human disturbance, especially early in season. Still common and widespread, numbers probably stable. |
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Family | Herons, Egrets, Bitterns |
Habitat | Marshes, swamps, shores, tideflats. Very adaptable. Forages in any kind of calm fresh waters or slow-moving rivers, also in shallow coastal bays. Nests in trees or shrubs near water, sometimes on ground in areas free of predators. "Great White" form is mostly in salt water habitats. |
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Feeding Behavior
Forages mostly by standing still or walking very slowly in shallow water, waiting for fish to swim near, then striking with rapid thrust of bill. Also forages on shore, from floating objects, and in grassland. May hunt by day or night.
Eggs
3-5, sometimes 2-7. Pale blue. Incubation is by both sexes, 25-30 days. Young: Both parents feed young, by regurgitation. Young capable of flight at about 60 days, depart nest at about 65-90 days. 1 brood per year in north, sometimes 2 in south.
Young
Both parents feed young, by regurgitation. Young capable of flight at about 60 days, depart nest at about 65-90 days. 1 brood per year in north, sometimes 2 in south.
Diet
Highly variable and adaptable. Eats mostly fish, but also frogs, salamanders, turtles, snakes, insects, rodents, birds. Has been seen stalking voles and gophers in fields, capturing rails at edge of marsh, eating many species of small waterbirds.
Nesting
Breeds in colonies, often of this species alone, sometimes mixed with other wading birds; rarely in isolated pairs. Male chooses nest site and displays there to attract mate. Displays include stretching neck up with bill pointing skyward, flying in circles above colony with neck extended, stretching neck forward with head and neck feathers erected and then snapping bill shut. Nest: Site highly variable, usually in trees 20-60' above ground or water; sometimes in low shrubs, sometimes on ground (on predator-free islands), sometimes well above 100' in tree. Nest (built mostly by female, with material gathered mostly by male) is a platform of sticks, sometimes quite large.
Illustration © David Allen Sibley.
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Text © Kenn Kaufman, adapted from
Lives of North American Birds
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Migration
Northern populations east of Rockies are migratory, some going to Caribbean, Central America, or northern South America. Migrates by day or night, alone or in flocks. Some wander well to the north in late summer. Populations along Pacific Coast may be permanent residents, even as far north as southeastern Alaska.

- All Seasons - Common
- All Seasons - Uncommon
- Breeding - Common
- Breeding - Uncommon
- Winter - Common
- Winter - Uncommon
- Migration - Common
- Migration - Uncommon
See a fully interactive migration map for this species on the Bird Migration Explorer.
Learn moreSongs and Calls
A harsh squawk.Learn more about this sound collection.
How Climate Change Will Reshape the Range of the Great Blue Heron
Audubon’s scientists have used 140 million bird observations and sophisticated climate models to project how climate change will affect this bird’s range in the future.
Zoom in to see how this species’s current range will shift, expand, and contract under increased global temperatures.
Climate threats facing the Great Blue Heron
Choose a temperature scenario below to see which threats will affect this species as warming increases. The same climate change-driven threats that put birds at risk will affect other wildlife and people, too.