Great Blue Heron
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 and Central America as well as the West Indies and the Galápagos Islands. It is a rare vagrant to Europe, with records from Spain, the Azores and England. An all-white population found only in the Caribbean and southern Florida was once known as a separate species, the Great White Heron.
The Great Blue Heron was one of the many species originally described
by Carolus Linnaeus in his 18th century work, Systema Naturae.
The Great Blue Heron is replaced in the Old World by the very similar Grey Heron, which differs in being somewhat smaller (90–98 cm), with a pale gray neck and legs, lacking the browner colors that Great Blue Heron has there. It forms a superspecies with this and also with the Cocoi Heron from South America, which differs in having more extensive black on the head, and a white breast and neck.
It is the largest North American heron, with a head-to-tail length of 91–140 cm (36–55 in), a wingspan of 167–201 cm (66–79 in), and a weight of 2–3.6 kg (4.4–8 lbs). Notable features include slaty flight feathers, red-brown thighs, and a paired red-brown and black stripe up the flanks; the neck is rusty-gray, with black and white streaking down the front; the head is paler, with a nearly white face, and a pair of black plumes running from just above the eye to the back of the head. The feathers on the lower neck are long and plume-like; it also has plumes on the lower back at the start of the breeding season. The bill is dull yellowish, becoming orange briefly at the start of the breeding season, and the lower legs gray, also becoming orangey at the start of the breeding season. Immature birds are duller in color, with a dull blackish-gray crown, and the flank pattern only weakly defined; they have no plumes, and the bill is dull gray-yellow.
The heron stride is around 22 cm (9 in), almost in a straight line. Two of the three front toes are generally closer together. In a track the front toes as well as the back often show the small talons.
The "Great White Heron" could be confused with Great Egret but is larger, with yellow legs as opposed to the Great Egret's black legs. The Reddish Egret and Little Blue Heron could be mistaken for the Great Blue Heron, but are much smaller, and lack white on the head and yellow in the bill. In the southern reaches of its range, the Great Blue sometimes overlaps in range with the closely-related and similarly-sized Cocoi Heron. The Cocoi is distinguished by a striking white neck and solid black crown, but the duller juveniles are more easily confused. More superficially similar is the slightly smaller Grey Heron, which may sometimes vagrate to the Northern coasts of North America. The Grey (which occupies the same ecological niche in Eurasia as the Great Blue Heron) has very similar plumage but has a solidly soft-gray neck. Erroneously, the Great Blue Heron is sometimes referred to as a "crane".