The grey heron – Diệc Xám (Order: Pelecaniformes, Family: Ardeidae, Genus: Ardea) is a long-legged predatory wading bird of the heron family, Ardeidae. It is resident in much of its range, but some populations from the more northern parts migrate southwards in autumn. Those birds (in the photo) were seen on the sea coast in Spring 2017. It feeds mostly on aquatic creatures which it catches after standing stationary beside or in the water or stalking its prey through the shallows.
Standing up to a metre tall, adults weigh from 1 to 2 kg (2.2 to 4.4 lb). They have a white head and neck with a broad black stripe that extends from the eye to the black crest. The body and wings are grey above and the underparts are greyish-white, with some black on the flanks. The long, sharply pointed beak is pinkish-yellow and the legs are brown.
The birds breed colonially in spring in “heronries”, usually building their nests high in trees. A clutch of usually three to five bluish-green eggs is laid. Both birds incubate the eggs for a period of about 25 days, and then both feed the chicks, which fledge when seven or eight weeks old. Many juveniles do not survive their first winter, but if they do, they can expect to live for about five years.