Grey Heron

## Description

The grey heron (Ardea cinerea ) is a long-legged wading bird of the heron family, Ardeidae, native throughout temperate Europe and Asia and also parts of Africa. It is resident in much of its range, but some populations from the more northern parts migrate southwards in autumn. A bird of wetland areas, it can be seen around lakes, rivers, ponds, marshes and on the sea coast. 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 1 metre (3 ft 3 in) tall, adults weigh from 1 to 2 kg (2 to 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 around 25 days, and then both feed the chicks, which fledge when 7-8 weeks old. Many juveniles do not survive their first winter, but if they do, they can expect to live for about 5 years.

In Ancient Egypt, the deity Bennu was depicted as a heron in New Kingdom artwork. In Ancient Rome, the heron was a bird of divination. Roast heron was once a specially prized dish; when George Neville became Archbishop of York in 1465, 400 herons were served to the guests.

## Appearance

Grey herons are long-legged wading birds native to Europe, Asia, and parts of Africa. 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. Their pinkish-yellow beak is long, straight, and powerful, and is brighter in color in breeding adults.

## Distribution

Grey herons occur in most parts of Europe, Asia, and Africa. Over much of their range, these birds are resident, but populations from the more northerly parts of Europe migrate southwards; some remain in Central and Southern Europe, others travel on to Africa south of the Sahara Desert. Grey herons can be found anywhere with suitable watery habitats that can supply their food. Although most common in the lowlands, they also occur in mountain tarns, lakes, reservoirs, large and small rivers, marshes, ponds, ditches, flooded areas, coastal lagoons, estuaries, and the sea shore. They sometimes forage away from water in the pasture, and can even be found in desert areas, hunting for beetles and lizards.

## Behavior

Grey herons are social birds; they may feed alone or in groups and at night they roost in trees or on cliffs and tend to be gregarious. During the breeding season, they nest in big colonies. Grey herons usually hunt around dawn and dusk but they may also be active at other times of the day. They often perch in trees, but spend much time on the ground, striding about or standing still for long periods with an upright stance, often on a single leg. The main call of Grey herons is a loud croaking "fraaank", but a variety of guttural and raucous noises is heard at the breeding colony. A loud, harsh "schaah" is used by the male in driving other birds from the vicinity of the nest and a soft "gogogo" expresses anxiety, as when a predator is nearby or a human walks past the colony. The chicks utter loud chattering or ticking noises.

## Diet

Grey herons are carnivores (piscivores) and feed mostly on fish. However, depending on the season and what is available, they also may eat amphibians, crustaceans, aquatic invertebrates, mollusks, snakes, small birds and rodents, and sometimes some plants.

## Reproduction

Grey herons are serially monogamous; they form pairs and remain together for only one breeding season, which extends from early February until May or early June. These birds breed in colonies known as heronries, usually in high trees close to lakes, the seashore, or other wetlands. Courtship involves the male calling from his chosen nesting site and on the arrival of the female, both birds participate in stretching and snapping ceremonies. Females lay 3 to 5 eggs and both parents incubate them for 25-26 days. Chicks hatch altricial and are fed by both parents, who look after them attentively; one of the adult birds stays at the nest for the first 20 days. The young can fly at about 50 days old, remaining for 10 to 20 more days more at the nest.

## Population

### Population threats

Grey herons are hunted and trapped by people. They are threatened by changes in their habitat, including deforestation and the drainage of wetlands.

### Population number

Grey herons have a wide distribution and are relatively abundant; the estimated world population of adults being between 790,000 and 3,700,000 individuals, including 223,000-391,000 breeding pairs in Europe, c.100,000-1 million breeding pairs in China, c.100-10,000 breeding pairs in Korea; c.100,000-1 million breeding pairs in Japan and c.100,000-1 million breeding pairs in Russia. The overall population size seems to be stable.

### Ecological niche

Grey herons are important for controlling fish populations in rivers, estuaries, and further bodies of water. Their nests provide shelter for insects and rodents.

## Fun Facts for Kids

In medieval times the Grey heron was a popular quarry of falconers who admired its great flying skills in evading the falcon.

In Ancient Rome, the heron was a bird of divination that gave an augury (a sign of a coming event) by its call, like the raven, stork, and owl.

"Heron" comes from French. The Old English name was "hragra". Other names from past times include harn, hernshaw and hernser.

Heronries with multiple nests can become huge. One in Great Snowden's Wood, near Brede in Sussex, in 1866 had around 400 nests.

Herons suffer much in cold winters when streams and ponds remain frozen for a long time. Recent mild weather has seen an increase in population.