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 (3ft 3in) tall, adults weigh from 1 to 2kg (2 to 4lb). 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.
It is closely related and similar to the North American great blue heron (Ardea herodias), which differs in being larger, and having chestnut-brown flanks and thighs; and to the cocoi heron (Ardea cocoi) from South America, with which it forms a superspecies. Some authorities believe that the subspecies A. c. monicae should be considered a separate species.[6] It has been known to hybridise with the great egret (Ardea alba), the little egret (Egretta garzetta), the great blue heron and the purple heron (Ardea purpurea).[7] The Australian white-faced heron is often incorrectly called a grey heron.[8] In Ireland, the grey heron is often colloquially called a "crane".[9]
Description
Head, with neck retracted
The grey heron is a large bird, standing up to 100cm (40in) tall and measuring 84–102cm (33–40in) long with a 155–195cm (61–77in) wingspan.[10] The body weight can range from 1.02–2.08kg (2lb 4oz– 4lb 9+1⁄4oz).[11] The plumage is largely ashy-grey above, and greyish-white below, with some black on the flanks. Adults have a white head and neck with a broad black supercilium that terminates in the slender, dangling crest, and bluish-black streaks on the front of the neck. The scapular feathers and the feathers at the base of the neck are somewhat elongated. Immature birds lack the dark stripe on the head and are generally duller in appearance than adults, with a grey head and neck, and a small, dark grey crest. The pinkish-yellow beak is long, straight, and powerful, and is brighter in color in breeding adults. The iris is yellow and the legs are brown and very long.[12]
The main call is a loud croaking "fraaank", but a variety of guttural and raucous noises are heard at the breeding colony. The male uses an advertisement call to encourage a female to join him at the nest, and both sexes use various greeting calls after a pair bond has been established. 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.[12]
Distribution and habitat
Range of A. cinerea
Breeding
Resident
Non-breeding
Vagrant (seasonality uncertain)
Extant & Introduced (resident)
Grey heron flies a short distance in a Tokyo park, 2021
The grey heron has an extensive range throughout most of the Palearctic realm. The range of the nominate subspecies A. c. cinerea extends to 70° N in Norway and 66°N in Sweden, but its northerly limit is around 60°N across the rest of Europe and Asia, as far eastwards as the Ural Mountains. To the south, its range extends to northern Spain, France, central Italy, the Balkans, the Caucasus, Iraq, Iran, India, The Maldives and Myanmar (Burma). It is also present in Africa south of the Sahara Desert, the Canary Islands, Morocco, Algeria, Tunisia, and many of the Mediterranean Islands. It is replaced by A. c. jouyi in eastern Siberia, Mongolia, eastern China, Hainan, Japan, and Taiwan. In Madagascar and the Aldabra Islands, the subspecies A. c. firasa is found, while the subspecies A. c. monicae is restricted to Mauritania and offshore islands.[12]
Over much of its range, the grey heron is resident, but birds from the more northerly parts of Europe migrate southwards, some remaining in Central and Southern Europe, others travelling on to Africa south of the Sahara Desert.[12]
The grey heron is also known to be vagrant in the Caribbean, Bermuda, Iceland, Greenland, the Aleutian Islands, and Newfoundland, with a few confirmed sightings in other parts of North America including Nova Scotia and Nantucket.[13]
Within its range, the grey heron can be found anywhere with suitable watery habitat that can supply its food. The water body must be either shallow enough, or have a shelving margin in it, so that it can wade. Although most common in the lowlands, it also occurs in mountain tarns, lakes, reservoirs, rivers, marshes, ponds, ditches, flooded areas, coastal lagoons, estuaries, and the sea shore. It sometimes forages away from water in pasture, and it has been recorded in desert areas, hunting for beetles and lizards. Breeding colonies are usually near feeding areas, but exceptionally may be up to eight kilometres (five miles) away, and birds sometimes forage as much as 20km (12mi) from the nesting site.[12]
Behaviour
The grey heron has a slow flight, with its long neck retracted in an S-shape. This is characteristic of herons and bitterns, and distinguishes them from storks, cranes, and spoonbills, which extend their necks.[12] It flies with slow wing-beats and sometimes glides for short distances. It sometimes soars, circling to considerable heights, but not as often as the stork. In spring, and occasionally in autumn, birds may soar high above the heronry and chase each other, undertake aerial manoeuvres or swoop down towards the ground. The birds 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.[12]
Prey items vary in size from 1 cm-long fish and invertebrates, weighing less than 1g, to 30 cm-long carps and 57cm eels. While chicks tend to have smaller prey, individual prey caught by fully-grown Grey Herons commonly exceed 100g in weight and occasionally exceed 500g.[19] One paper reports that an adult heron managed to catch and swallow sea trout weighing 680g.[20] It may stand motionless in the shallows, or on a rock or sandbank beside the water, waiting for prey to come within striking distance. Alternatively, it moves slowly and stealthily through the water with its body less upright than when at rest and its neck curved in an "S". It is then able to straighten its neck and strike with its bill very quickly.[12] Small fish are swallowed head first, and larger prey and eels are carried to the shore where they are subdued by being beaten on the ground or stabbed by the bill. They are then swallowed or have hunks of flesh torn off. For prey such as small mammals and birds or ducklings, the prey is held by the neck and either drowned, suffocated, has its neck snapped with the heron's beak, or is bludgeoned against the ground or a nearby rock, before being swallowed whole. The bird regurgitates pellets of indigestible material such as fur, bones, and the chitinous remains of insects. The main hunting periods are around dawn and dusk, but it is also active at other times of the day. At night it roosts in trees or on cliffs, where it tends to be gregarious.[12]
Breeding
Grey heron flying with nesting material in Stockholm, Sweden
This species breeds in colonies known as heronries, usually in high trees close to lakes, the seashore, or other wetlands. Other sites are sometimes chosen, and these include low trees and bushes, bramble patches, reed beds, heather clumps and cliff ledges. The same nest is used year after year until blown down; it starts as a small platform of sticks but expands into a bulky nest as more material is added in subsequent years. It may be lined with smaller twigs, strands of root or dead grasses; in reed beds, it is built from dead reeds. The male usually collects the material, while the female constructs the nest. Breeding activities take place between February and June. When a bird arrives at the nest, a greeting ceremony occurs in which each partner raises and lowers its wings and plumes.[9] In continental Europe, and elsewhere, nesting colonies sometimes include nests of the purple heron and other heron species.[12]
Courtship involves the male calling from his chosen nesting site. On the arrival of the female, both birds participate in a stretching ceremony, in which each bird extends its neck vertically before bringing it backwards and downwards with the bill remaining vertical, simultaneously flexing its legs, before returning to its normal stance. The snapping ceremony is another behaviour where the neck is extended forward, the head is lowered to the level of the feet, and the mandibles are vigorously snapped together. This may be repeated 20-40 times. When the pairing is settled, the birds may caress each other by attending to the other bird's plumage. The male may then offer the female a stick, which she incorporates into the nest. At this, the male becomes excited, further preening the female, and copulation takes place.[12]
An adult feeding juveniles
The clutch of eggs usually numbers three to five, though as few as two and as many as seven eggs have been recorded. The eggs have a matt surface and are greenish-blue, averaging 60mm ×43mm (2+3⁄8in ×1+11⁄16in). The eggs are normally laid at two-day intervals and incubation usually starts after the first or second egg has been laid. Both birds take part in incubation and the period lasts about 25 days. Both parents bring food for the young. At first, the chicks seize the adult's bill from the side and extract regurgitated food from it. Later, the adult disgorges the food at the nest and the chicks squabble for possession. They fledge at 7-8 weeks. Usually, a single brood is raised each year, but two broods have been recorded.[12]
The oldest recorded bird lived for 23 years, but the average life expectancy in the wild is about 5 years. Only about a third of juveniles survive into their second year, many falling victim to predation.[9]
City life
Seeking food from a zoo penguin enclosure
Grey herons have the ability to live in cities where habitats and nesting space are available. In the Netherlands, it has established itself over the past decades in great numbers in urban environments. In cities such as Amsterdam, they are ever present and well adapted to modern city life.[21] They hunt as usual, but also visit street markets and snack bars. Some individuals make use of people feeding them at their homes or share the catch of recreational fishermen. Similar behaviour on a smaller scale has been reported in Ireland.[22] Garden ponds stocked with ornamental fish are attractive to herons, and the easy prey may provide young birds with a learning opportunity on how to hunt.[23]
Herons have been observed visiting water enclosures in zoos, such as spaces for penguins, otters, pelicans, and seals, and taking food meant for the animals on display.[24][25][26]
Predators and parasites
Being large birds with powerful beaks, grey herons have few predators as adults, but the eggs and young are more vulnerable. The adult birds do not usually leave the nest unattended, but may be lured away by marauding crows or kites.[27] A dead grey heron found in the Pyrenees is thought to have been killed by an otter. The bird may have been weakened by harsh winter weather causing scarcity of its prey.[28]
A study performed by Sitko and Heneberg in the Czech Republic between 1962 and 2013 suggested that Central European grey herons host 29 species of parasitic worms. The dominant species consisted of Apharyngostrigea cornu (67% prevalence), Posthodiplostomum cuticola (41% prevalence), Echinochasmus beleocephalus (39% prevalence), Uroproctepisthmium bursicola (36% prevalence), Neogryporhynchus cheilancristrotus (31% prevalence), Desmidocercella numidica (29% prevalence), and Bilharziella polonica (5% prevalence). Juvenile grey herons were shown to host fewer species, but the intensity of infection was higher in the juveniles than in the adult herons. Of the digenean flatworms found in Central European grey herons, 52% of the species likely infected their definitive hosts outside Central Europe itself, in the premigratory, migratory, or wintering quarters, despite the fact that a substantial proportion of grey herons does not migrate to the south.[29]
Bennu, an ancient Egyptian deity associated with the sun, creation, and rebirth, was depicted as a heron in New Kingdom artwork.[30]
In ancient Rome, the heron was a bird of divination that gave an augury (sign of a coming event) by its call, like the raven, stork, and owl.[31]
Roast heron was once a specially prized dish in Britain for special occasions such as state banquets. For the appointment of George Neville as Archbishop of York in 1465, 400 herons were served to the guests. Young birds were still being shot and eaten in Romney Marsh in 1896. Two grey herons feature in a stained-glass window of the church in Selborne, Hampshire.[32]
The Englishsurnames Earnshaw, Hernshaw, Herne, and Heron all derive from the heron, the suffix -shaw meaning a wood, referring to a place where herons nested.[33]
The bird is common in the Maldives under the name of Maakana and has given its name to the character of a satirical TV show.[34]
Related Research Articles
The great blue heron 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 far northwestern South America, the Caribbean and the Galápagos Islands. It is occasionally found in the Azores and is a rare vagrant to Europe. An all-white population found in south Florida and the Florida Keys is known as the great white heron. Debate exists about whether this represents a white color morph of the great blue heron, a subspecies of it, or an entirely separate species.
Herons are long-legged, long-necked, freshwater and coastal birds in the family Ardeidae, with 72 recognised species, some of which are referred to as egrets or bitterns rather than herons. Members of the genera Botaurus and Ixobrychus are referred to as bitterns, and, together with the zigzag heron, or zigzag bittern, in the monotypic genus Zebrilus, form a monophyletic group within the Ardeidae. Egrets do not form a biologically distinct group from herons, and tend to be named differently because they are mainly white or have decorative plumes in breeding plumage. Herons, by evolutionary adaptation, have long beaks.
The purple heron is a wide-ranging heron species. It breeds in Africa, central and southern Europe, and southern and eastern Palearctic. The Western Palearctic populations migrate between breeding and wintering habitats whereas the African and tropical-Asian populations are primarily sedentary, except for occasional dispersive movements.
The great egret (Ardea alba), also known as the common egret, large egret, or great white egret or great white heron, is a large, widely distributed egret. The four subspecies are found in Asia, Africa, the Americas, and southern Europe. Recently it is also spreading to more northern areas of Europe. Distributed across most of the tropical and warmer temperate regions of the world, it builds tree nests in colonies close to water.
The green heron is a small heron of North and Central America. Butorides is from Middle English butor "bittern" and Ancient Greek -oides, "resembling", and virescens is Latin for "greenish".
The yellow-crowned night heron, is one of two species of night heron in genus Nyctanassa. Unlike the black-crowned night heron, which has a worldwide distribution, the yellow-crowned is restricted to the Americas. It is known as the bihoreau violacé in French and the pedrete corona clara or yaboa común in some Spanish-speaking countries.
The black-crowned night-heron, or black-capped night-heron, commonly shortened to just night-heron in Eurasia, is a medium-sized heron found throughout a large part of the world, including parts of Europe, Asia, and North and South America. In Australasia it is replaced by the closely related nankeen night-heron, with which it has hybridized in the area of contact.
The cattle egret (Bubulcus) is a cosmopolitan genus of heron found in the tropics, subtropics, and warm-temperate zones. According to the IOC bird list, it contains two species, the western cattle egret and the eastern cattle egret, although some authorities regard them as a single species. Despite the similarities in plumage to the egrets of the genus Egretta, it is more closely related to the herons of Ardea. Originally native to parts of Asia, Africa, and Europe, it has undergone a rapid expansion in its distribution and successfully colonised much of the rest of the world in the last century.
Forster's tern is a tern in the family Laridae. The genus name Sterna is derived from Old English "stearn", "tern", and forsteri commemorates the naturalist Johann Reinhold Forster.
The western reef heron, also called the western reef egret, is a medium-sized heron found in southern Europe, Africa and parts of Asia. It has a mainly coastal distribution and occurs in several plumage forms: a slaty-grey plumage in which it can only be confused with the rather uncommon dark morph of the Little egret ; a white form which can look very similar to the little egret although the bill tends to be paler and larger and the black form with white throat E. g. gularis of West Africa. There are also differences in size, structure and foraging behaviour. There have been suggestions that the species hybridizes with the Little Egret, and based on this, some authors treat schistacea and gularis as subspecies of Egretta garzetta. Works that consider the Western Reef Heron as a valid species include the nominate gularis and schistacea as subspecies.
The white-faced heron also known as the white-fronted heron, and incorrectly as the grey heron, or blue crane, is a common bird throughout most of Australasia, including New Guinea, the islands of Torres Strait, Indonesia, New Zealand, and all but the driest areas of Australia.
The little blue heron is a small heron of the genus Egretta. It is a small, darkly colored heron with a two-toned bill. Juveniles are entirely white, bearing resemblance to the snowy egret. During the breeding season, adults develop different coloration on the head, legs, and feet.
The medium egret, median egret, smaller egret or intermediate egret, is a medium-sized heron. Some taxonomists put the species in the genus Egretta or Mesophoyx. It is a resident breeder in southern and eastern Asia.
The nankeen night heron is a heron that belongs to the genus Nycticorax and the family Ardeidae. Due to its distinctive reddish-brown colour, it is also commonly referred to as the rufous night heron. It is primarily nocturnal and is observed in a broad range of habitats, including forests, meadows, shores, reefs, marshes, grasslands, and swamps. The species is 55 to 65 cm in length, with rich cinnamon upperparts and white underparts. The nankeen night heron has a stable population size, and is classified as a species of least concern by the International Union for Conservation of Nature (IUCN).
The white-necked heron or Pacific heron is a species of heron that is found on most of the Australian continent wherever freshwater habitats exist. It is also found in parts of Indonesia and New Guinea, but is uncommon in Tasmania. The populations of this species in Australia are known to be nomadic like most water birds in Australia, moving from one water source to another, often entering habitats they have not previously occupied, taking advantage of flooding and heavy rain where the surplus of food allows them to breed and raise their young. Irruptive movements may occur when environmental conditions are right in places where the species has been rare or absent.
The cocoi heron is a species of long-legged wading bird in the heron family Ardeidae found across South America. It has predominantly pale grey plumage with a darker grey crest. A carnivore, it hunts fish and crustaceans in shallow water.
The maguari stork is a large species of stork that inhabits seasonal wetlands over much of South America, and is very similar in appearance to the white stork; albeit slightly larger. It is the only species of its genus to occur in the New World and is one of the only three New World stork species, together with the wood stork and the jabiru.
The eastern great egret, a white heron in the genus Ardea, is usually considered a subspecies of the great egret. In New Zealand it is known as the white heron or by its Māori name kōtuku. The subspecies was first described by British ornithologist John Edward Gray in 1831.
The eastern cattle egret is a species of heron found in the tropics, subtropics and warm temperate zones. Most taxonomic authorities lump this species and the western cattle egret together as subspecies of the cattle egret, but some separate them. Despite the similarities in plumage to the egrets of the genus Egretta, it is more closely related to the herons of Ardea. It is native to southern and eastern Asia, and Australasia.
The western cattle egret is a species of heron found in the tropics, subtropics and warm temperate zones. Most taxonomic authorities lump this species and the eastern cattle egret together, but some separate them. Despite the similarities in plumage to the egrets of the genus Egretta, it is more closely related to the herons of Ardea. Originally native to parts of Asia, Africa and Europe, it has undergone a rapid expansion in its distribution and successfully colonised much of the rest of the world in the last century.
↑ Bjedov, Dora, et al. "The first analysis of heavy metals in the Grey Heron Ardea cinerea feathers from the Croatian colonies." Larus-Godišnjak Zavoda za ornitologiju Hrvatske akademije znanosti i umjetnosti 55.1 (2020): 7-25.
↑ Pistorius, P.A. (2008). "Grey Heron (Ardea cinerea) predation on the Aldabra White-throated Rail (Dryolimnas cuvieri aldabranus)". Wilson Journal of Ornithology. 120 (3): 631–632. doi:10.1676/07-101.1. S2CID84943679.
↑ Giles, N. "Summer diet of the grey heron." Scot. Birds 11 (1981): 153-159.
↑ SAWARA, Yuji, Muneki SAKUYAMA, and Gen DEMACHI. "Diets and foraging site utilization of the Grey Heron, Ardea cinerea, in the breeding season." Japanese Journal of Ornithology 43.2 (1994): 61-71.
↑ Moser, M. E. "Prey profitability for adult Grey Herons Ardea cinerea and the constraints on prey size when feeding young nestlings." Ibis 128.3 (1986): 392-405.
↑ Cook, David C. "Foraging behaviour and food of Grey Herons Ardea cinerea on the Ythan Estuary." Bird Study 25.1 (1978): 17-22.
↑ Sitko, J.; Heneberg, P. (2015). "Composition, structure and pattern of helminth assemblages associated with central European herons (Ardeidae)". Parasitology International. 64 (1): 100–112. doi:10.1016/j.parint.2014.10.009. PMID25449288.
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