Gray Heron
Ardea cinerea
Lakes and wetlands all over Asia Pacific
The Gray 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.
The Gray Heron is a distinctive species with grey, black, and white plumage. It is often seen along rivers or lake margins, or standing in flooded fields. In flight their large size, impressive wingspan, long legs, and folded neck give them an unmistakable silhouette. Largely silent away from colonies, their flight is sometimes accompanied by a harsh ‘kraank’ call. Gray Herons gather to nest in treetop sites called heronries, some of which have been occupied for many decades. These have been monitored in a lot of areas and habitats and in general the breeding population has increased, with numbers peaking in the early 2000, but with some more recent declines.
The birds you see here are from a number of varied locations and habitats like the Loyang Rock, Himayath Sagar Lake, Ammavaripeta Cheruvu and the Bhigwan Bird Sanctuary.
Lakes and water bodies in Telangana are locally known as cheruvu, kunta & tanks. Quite a few of these lakes, like Tigal Kunta, Somajiguda Tank, Mir Jumla tank, Pahar Tigal Kunta, Kunta Bhawani Das, Nawab Saheb Kunta, Afzalsagar, Nallakunta, Masab Tank etc, have completely disappeared and the surface area of most of the surviving lakes have shrunken and turned into tiny ponds and cesspools. Lakes like the Hussain Sagar Lake, Kunta Mallaiyapalli have shrunk drastically. Of the thousands of water bodies existing in 1970s in various sizes in and around Hyderabad, today only about 70 to 500 of them have survived. Most of them have disappeared due to encroachment or have been illegally drained for real estate projects by private or government agencies. The existing lakes have been used to dump garbage and sewage water.
Most of these lakes and tanks were built during the regime of the Qutb Shahis in 16th and 17th century and later by the Nizams as sources of drinking water for the residents of Hyderabad. The area of Hussain Sagar, which is the largest lake in Hyderabad shrunk by more than 40% i.e. from 550 ha to 349 ha in just 30 years. This lake was built in 1575 AD and since 1930 is not being used as a source for drinking water. Another such lake is the Ameenpur Lake on the western fringe of Hyderabad, surrounded by fantastic primordial rock formations, modern apartments, factories and a village. Ameenpur Lake is an ancient sprawling man-made lake dating back to the time of Ibrahim Qutb Shah, who ruled the kingdom of Golconda between 1550 and 1580. According to one account, the tank was excavated to irrigate a large public garden. The lake is now divided into two parts called Pedda Ameenpur and Chinna Cheruvu.
For a long time, there has been a certain rock located near Changi Village is known traditionally as “Batu Puteh” (“white rock” in Malay). Where exactly is this rock and how did it come by its name?
Situated across from the Changi Beach Club is the Loyang Rock, otherwise known as the Squance Rock, and due to its colour, it was also called batu puteh. The village located along the shores here was known as Kampong Batu Puteh. In 1986, Hasim bin Ismail explained in an oral history interview that his village, Kampung Batu Puteh, derived its name from a rocky outcrop out at sea, about 250m away from the beach - (1.391797, 103.972199) - seen as an elongated grey patch under cloud cover on the map here - across and to the left from the Changi Beach Club. Wildlife Consultant Subaraj Rajathurai later mentioned in 2002 that this outcrop, known as Loyang Rock or Squance Rock, has been a traditional nesting site for the Black-naped Tern (featured in Singapore’s old $1 note) for decades. The word “Puteh” in the rock’s name refers to this bird’s droppings. Having said that, not all rocks described as “white” acquire this name from bird droppings. Other rocks known as “Batu Puteh” might simply be made of whitish limestone or granite.
Malays named coastal rock formations like this one for navigational purposes. Batu Puteh — like Batu Berlayar at Labrador, Batu Gajah at Pulau Brani, Batu Berleher at Pulau Tekong, and Batu Kepala Todak at the Singapore River — were all traditional sea markers used by seafarers before modern nautical markers were introduced. Today, some have identified a large rock along Changi Boardwalk as Batu Putih, or the Loyang Rock. However, this is not correct since that rock is not actually in the Loyang area, which is roughly a kilometre away. Navigational rocks need to be located in the areas they are named after, like Batu Gedong which is found at Sungei Gedong. The large rock along Changi Boardwalk is really just another rock. Some of this material was sourced from the Urban Explorers of Singapore who have explored and written extensively about this and other fascinating locations in and around Singapore.
The Loyang Rock is a traditional nesting site for the rare Black-naped Terns which arrive in March, these birds start roosting on the rock between April to August, before leaving for the South China Sea after. Sir T. Stamford Raffles, described this species of tern in 1822, and many other animals during his career. Refer my blog on the Black-naped Terns.
Located 3 kilometers from the historic town of Srirangapattana and 16 kilometres north of Mysore, Ranganathittu is known as the The Pakshi Kashi (the Kashi for birds just as the city of Varanasi is known and revered by Hindus) of Karnataka. It is a bird sanctuary in the Mandya district of Karnataka & is the largest bird sanctuary in the state. Measuring 40 acres in area it is comprised of six islets on the banks of the Cauvery River.
Ranganathittu's islets were formed when an embankment across the Kaveri river was built between 1645 and 1648 by the then king of Mysore, Kanteerava Narasimharaja Wadiyar. These islets, originally numbering 25, soon started attracting birds. The ornithologist Salim Ali observed that the islets formed an important nesting ground for a large variety of birds, and persuaded the king of Mysore to declare the area a protected area in 1940. The sanctuary is currently maintained by the Forest Department of Karnataka and efforts are ongoing to improve the sanctuary, including purchasing nearby private land to expand the protected area. In 2014, around 28 square km around the sanctuary was declared as an eco-sensitive zone, meaning that certain commercial activities cannot take place without the government’s permission.
The sanctuary with its islets experience heavy flooding during certain rainy seasons when water is released from Krishna Raja Sagara dam upstream, due to heavy rains. During heavy flooding boating is suspended and tourists are allowed to watch the nesting birds from a distance. Frequent flooding has also damaged some portions of three islands over past few decades.
The sanctuary has been designated as a protected Ramsar site since 2022. Ramsar sites are wetland sites designated to be of international importance under the Ramsar Convention, also known as "The Convention on Wetlands", an intergovernmental environmental treaty established in 1971 by UNESCO, which came into force in 1975. It provides for national action and international cooperation regarding the conservation of wetlands, and wise sustainable useof their resources. Ramsar identifies wetlands of international importance, especially those providing waterfowl habitat.
Gray Heron
Standing up to 1 metre (3 ft 3 in) tall, adult Gray Herons weigh from 1 to 2 kg. 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.
Gray Herons belong to the subfamily Ardeinae, along with the majority of extant species, which are known as the “typical herons”. The Gray Heron was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae. He placed it with the Cattle Egret and the Great Egret in the genus Ardea and coined the binomial name Ardea cinerea. The scientific name comes from the Latin ardea meaning “heron“ and cinereus meaning “ash-grey“ or “ash-coloured“.
Four subspecies are generally recognised:
Ardea cinerea cinerea – Linnaeus, 1758: the nominate race found in Europe, Africa, western Asia
Ardea cinerea jouyi – Clark, 1907: found in eastern Asia
Ardea cinerea firasa – Hartert, 1917: found in Madagascar
Ardea cinerea monicae – Jouanin & Roux, 1963: found on islands off Banc d'Arguin, Mauritania.
The Gray Heron 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 Ardea cinerea monicae should be considered a separate species. 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). The Australian White-faced Heron is often incorrectly called a Gray Heron. In Ireland, the grey heron is often colloquially called a "crane".
The Gray Heron is about 90–98 cm tall and weighs between 1020–2073 grams with a wingspan of 175–195 cm. The forehead, crown and throat are white with a broad black eyestripe from above the eye to back of the crown & extending as a crest plumes (which is fully developed only during the breeding season). The fore neck is grayish-white with two distinct broken black streaks along the median line, a pale gray upper back and hind neck, blue-gray lower back and upper wings. The flight feathers are dark gray to black with gray to whitish underwings, a black shoulder patch, gray flanks and tail. The belly-sides are black and pale gray to white over rest of underparts. The Gray Heron has a long, heavy yellow bill with dull brown suffusion, yellow eyes and lores, and brownish-yellow legs and feet, all of which flush deep orange to red during the breeding season. The male averages larger than female and the non-breeding adult lacks the long plumes of the breast and scapulars. Fundamentally allopatric Cocoi Heron (Ardea cocoi) (found in central and southern South America) and the Great Blue Heron (Ardea herodias) (found in North America) are greatest confusion risks, but the Gray Heron is separated from adults of the latter by their smaller size (10–40% on average), a thinner-based bill, all-black epaulettes and gray (not chestnut) thighs. Juvenile plumage is retained until the second year and is a more uniform gray (aberrant, virtually all-dark individuals have been recorded), with a brown-gray fore neck, gray underparts, duller bare parts (dark gray legs, becoming paler and tinge yellow-green on upper tibia) and no ornamental plumes. The juveniles of the Gray Heron and the Great Blue Heron can be distinctly more problematic to separate, although many of the same features that apply to adults can be useful, with rufous thighs and tips to wing-coverts being two of the most important characters that identify the Great Blue Heron at this age. In Madagascar, they might also be confused with Humblot's Heron (Ardea humbloti), but the Gray Heron has overall paler plumage, especially on the head and neck, and it is smaller, with a shorter bill and has more distinct striping on the head. Subspecies is separated on size and tone of plumage on the neck, back and wings, although there is some evidence of intergradation, e.g. in eastern Russia, between the nominate race and subspecies jouyi, in Senegal, between the nominate and monicae, and in Comoros and Seychelles, between the nominate and firasa. The nominate cinerea shows clinal variation in buff suffusion on neck, which declines from east to west. Subspecies jouyi typically lacks any buff and has a markedly paler neck, upperwing and back plumes while the subspecies firasa is larger on average than the nominate, especially in its bill and leg length, and typically has brighter bare-parts colors during courtship. The subspecies monicae (Mauritanian Heron) is much paler, being overall pale gray to white.
The Gray Heron is very adaptable when it comes to the habitat. They can bee seen near any kind of shallow water, fresh, brackish or salt, standing or flowing, provided it is ice-free for at least 4–5 months each year. They generally prefers areas with some trees, but can occupy very open areas; the subspecies monicae does not apparently use trees. The Gray Heron is equally at home inland, where frequents rivers, canals, ditches, lakes, marshes, floodplains, ricefields, fishponds, sewage farms, irrigated areas and open grassland, or along the coast, using deltas, estuaries, tidal mudflats or mangroves. Some evidence of seasonal shifts in habitat use, at least in Japan, where herons used ricefields between mid Jun and mid Aug, but not in Apr or after late Sept, while some birds used ponds, lakes and rivers in early Apr, but numbers in these habitats decreased from early Jun and increased again from mid Aug until mid Sept. They are seen from the sea level up to 500 m or even 1000 m and occasionally much higher, breeding up to 1800 m in Madagascar and Zambia, to 2000 m in Armenia, and recorded at 3500–4000 m in Ladakh, northwestern India.
The Gray 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.
Over much of its range, the Gray 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.
The Gray 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. In South America, the majority of the sightings come from Brazil, especially in Fernando de Noronha. There is also an old record from Colombia.
Within its range, the Gray 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 away, and birds sometimes forage as much as 20 km from the nesting site.
The Gray 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. 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.
Gray Herons are apex predators in their aquatic ecosystem. Fish, amphibians, crustaceans, and insects are caught in shallow water with the heron's long bill. It has also been observed catching and killing juvenile birds such as ducklings, and occasionally takes birds up to the size of a water rail or white-throated rail. Small mammals such as water voles, rats, stoats and young rabbits are additionally caught. Recently, the Gray Heron has been observed to use the ‘stress and wash’ technique which is believed to make Great Crested Newts (Triturus cristatus) and Smooth Newts (Lissotriton vulgaris) more palatable by flushing their skin free of toxins before consumption.
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. In continental Europe, and elsewhere, nesting colonies sometimes include nests of the purple heron and other heron species.
Gray 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. 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. 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.
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.
In a variety of sources, one can find a common statement that Gray Herons, by eating large quantities of fish, is a significant pest of fisheries, causing damage to the population of valuable fish both in natural reservoirs and in ponds intended for the cultivation of cultivated fish species. In addition, large colonies of Gray Herons can have a significant impact on soil biogeochemistry and vegetation. For example, a heron colony in one study site located near the southern edge of the Republic of Tatarstan on a peninsula formed by the confluence of the Volga, the largest and longest river in Europe, and its largest tributary, the Kama, on the banks of the smaller river Myosha (a tributary of the Kama); after settling around 2006, it expanded for 15 years, leading to the intensive deposition of nutrients with faeces, food remains and feathers thereby considerably altering the local soil biogeochemistry. Thus, lower pH levels around 4.5, 10- and 2-fold higher concentrations of phosphorus and nitrogen, as well as 1.2-fold discrepancies in K, Li, Mn, Zn and Co, respectively, compared to the surrounding control forest area could be observed.
Being large birds with powerful beaks, Gray Herons have few predators as adults, but White-tailed Eagles, Golden Eagles and more rarely Eurasian Goshawks will take them as prey. 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. A dead Gray 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.
Bennu, an ancient Egyptian deity associated with the sun, creation, and rebirth, was depicted as a heron in New Kingdom artwork. 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.
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 Gray Herons feature in a stained-glass window of the church in Selborne, Hampshire. The English surnames Earnshaw, Hernshaw, Herne, and Heron all derive from the heron, the suffix -shaw meaning a wood, referring to a place where herons nested.
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.
The Gray Heron is not globally threatened and is listed as Least Concern. In Europe they have been heavily persecuted in past & the population reached nadir during the mid-20th century; since then, it has increased due to protection, warming of climate and greater availability of suitable foraging sites (including expansion of rice growing in southern Europe), and the species is now common and expanding to both north and south, colonizing much of Scandinavia (e.g. first bred in Finland as recently as 1993) and the Mediterranean in the last century, e.g. Camargue (southern France) in 1964.
Recently (Jun 2000) the Gray Heron was discovered breeding on the Cape Verde Islands and Cyprus (1993). The European population is rising, and recent estimates suggest approximately 150,000–180,000 pairs. On the other hand, it appears to be declining in the Danube Delta, Norway (although local increases reported), Albania, Moldova & Tunisia (where there were just 17 pairs in 2010). Elsewhere in Europe, important populations in Netherlands (9,000 pairs in 1989, population stable), Germany (35,000 pairs in mid 1980s, increasing), Poland (8,000–8,500 pairs in early 1980s, slowly increasing) and Ukraine (15,987–20,000 pairs in 1986). They are also common in Russia, where up to 20,000 pairs west of Urals, with tenfold increase in some populations of Far East in period 1969–1982, and perhaps still increasing, at least locally. In Southeast Asia they are fairly local but are threatened in Thailand; there are only two colonies in western Peninsular Malaysia; but they are apparently commoner in eastern Sumatra, with 242 nests found in 1986, and the species is generally abundant in China, Mongolia, Japan (where it is increasing) & Korea. Principal conservation issues are harvesting of timber and conflict between herons and owners of fish farms, with renewed hunting a threat in some areas (e.g. Bavaria) and in Scotland c. 800 herons were killed in single year at aquaculture facilities, despite evidence that effects of herons on most such operations are slight.
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