Great Blue Heron

The Great Blue Heron , Ardea herodias, is a wading bird in the heron family Ardeidae, common over most of North and Central America as well as the West Indies and the Galapagos Islands, except for the far north and deserts and high mountains where there is no water for it to feed in. It is an extremely rare vagrant to Europe, with records from Spain, the Azores and England.

It is the largest North American heron, with a head-to-tail length of 91-137 cm (36-54 in), a wingspan of 180 cm (71 in), and a weight of 2.2-3.6 kg (4.8-8 lbs). It is blue-gray overall, with black 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. 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.

Known Subspecies differ only slightly in size and plumage tone, with the exception of subspecies occidentalis, which as well as normal colored birds, also has a distinct a white morph, known as the Great White Heron. This was long thought to be a separate species, and is mainly found in the Florida Keys.

There is an ongoing discussion on whether The Great White Heron is to be considered a subspecies or a mere aberration of nature.

Birds intermediate between the normal morph and the white morph are known as Wurdemann's Heron. They are general more pale and sport a white top.

The call is a harsh croak; they are most vocal during the breeding season, but will call occasionally at any time of the year in territorial disputes or if disturbed.

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