The five subspecies are: 1 A. h. herodias Linnaeus, 1758, most of North America, except as below 2 A. h. fannini Chapman, 1901, the Pacific Northwest from southern Alaska south to Washington; coastal 3 A. h. wardi Ridgway, 1882, Kansas and Oklahoma to northern Florida, sightings in southeastern Georgia 4 A. h. occidentalis Audubon, 1835, southern Florida, Caribbean islands, formerly known as a separate species, the great white heron 5 A. h. cognata Bangs, 1903, Galápagos Islands
The great blue heron is the largest heron native to North America. Among all extant herons, it is surpassed in size only by the goliath heron ( Ardea goliath) and the white-bellied heron ( Ardea insignis ).
The great blue heron ( Ardea herodias) is a large wading bird in the heron family Ardeidae, common near the shores of open water and in wetlands over most of North America and Central America, as well as the Caribbean and the Galápagos Islands. It is a rare vagrant to coastal Spain, the Azores, and areas of far southern Europe.
The image was engraved and colored by Robert Havell' s London workshops. The original watercolor by Audubon was purchased by the New-York Historical Society.
Birds intermediate between the normal morph and the white morph are known as Würdemann's heron; these birds resemble a "normal" great blue with a white head. The theory that great white herons may be a separate species ( A. occidentalis) from the great blue heron has again been given some support by David Sibley.
The scientific name comes from Latin ardea, and Ancient Greek ἐρῳδιός ( erōdios ), both meaning "heron".
It is also known to opportunistically feed on a wide range of shrimp, crabs, aquatic insects, rodents, and other small mammals, amphibians, reptiles, and birds, especially ducklings.