Corn Crake
Encyclopedia
The Corn Crake, Corncrake or Landrail (Crex crex) is a bird in the rail family
. It breeds in Europe and Asia as far east as western China, and migrates
to Africa for the winter. It is a medium-sized crake with buff
- or grey-streaked brownish-black upperparts, chestnut
markings on the wings, and blue-grey underparts with rust-coloured and white bars on the flanks and undertail. The strong bill
is flesh-toned, the iris
is pale brown, and the legs and feet are pale grey. The juvenile is similar in plumage
to the adult, and the downy
chicks are black, as with all rails. There are no subspecies
, although individuals from the east of the breeding range tend to be slightly paler than their western counterparts. The male's call is a loud krek krek, from which the scientific name is derived. The Corn Crake is larger than its closest relative, the African Crake
, which shares its wintering range; that species is also darker-plumaged, and has a plainer face.
The Corn Crake's breeding habitat is grassland, particularly hay
fields, and it uses similar environments on the wintering grounds. This secretive species builds a nest of grass leaves in a hollow in the ground and lays 6–14 cream-coloured eggs that are covered with rufous
blotches. These hatch in 19–20 days, and the black precocial
chicks fledge
after about five weeks. This crake is in steep decline across much of its former breeding range because modern farming practices often destroy nests before breeding is finished. The Corn Crake is omnivorous, but mainly feeds on invertebrate
s, the occasional small frog or mammal, and plant material including grass seed and cereal grain. Natural threats include introduced
and feral mammals, large birds, and various parasite
s and diseases.
Although numbers have declined steeply in western Europe, this bird is classed as Least Concern
on the IUCN Red List
because of its huge range and large, apparently stable, populations in Russia and Kazakhstan. Numbers in western China are more significant than previously thought, and conservation
measures have facilitated an increase in population in some of the countries which had suffered the greatest losses. Despite its elusive nature, the loud call has ensured that the Corn Crake has been noted in literature, and garnered a range of local and dialect names.
are a bird family
comprising nearly 150 species. Although the origins of the group are lost in antiquity, the largest number of species and the least specialised forms are found in the Old World
, suggesting that this family originated there. The taxonomy
of the small crakes is complicated, but the closest relative of the Corn Crake is the African Crake, C. egregia, which has sometimes been given its own genus, Crecopsis, but is now more usually placed in Crex. Both species are short-billed brown birds with a preference for grassland rather the wetland
habitats typical of rails. Porzana
crakes, particularly the Ash-throated Crake
(Porzana albicollis) are near relatives of the Crex genus.
The Corn Crake was first described by Linnaeus in his Systema Naturae
in 1758 as Rallus crex, but was subsequently moved to the genus Crex
, created by German naturalist and ornithologist Johann Matthäus Bechstein
in 1803, and named Crex pratensis. The earlier use of crex gives it priority
over Bechstein's specific name pratensis, and leads to the current name of Crex crex. The binomial name, Crex crex, from the Ancient Greek
"κρεξ", is onomatopoeic, referring to the crake's repetitive grating call. The common name was formerly spelt as a single word, "Corncrake", but the official version is now "Corn Crake". The English names refer to the habit of the species of nesting in dry hay or cereal fields, rather than the marshes used by most members of this family.
, all populations show great individual variation in colouring, and the birds gradually become paler and greyer towards the east of the range. Adults undergo a complete moult after breeding, which is normally finished by late by late August or early September, before migration to south eastern Africa. There is a pre-breeding partial moult prior to the return from Africa, mainly involving the plumage of the head, body and tail. Young birds have a head and body moult about five weeks after hatching.
The Corn Crake is sympatric
with the African Crake on the wintering grounds, but can be distinguished by its larger size, paler upperparts, tawny
upperwing and different underparts pattern. In flight, it has longer, less rounded wings, and shallower wingbeats than its African relative, and shows a white leading edge to the inner wing. In both the breeding and wintering ranges it is unlikely to be confused with any other rails, since sympatric species are smaller, with white markings on the upperparts, different underparts patterns and shorter bills. A flying Corn Crake can resemble a gamebird
, but its chestnut wing pattern and dangling legs are diagnostic.
to make a singing male's location clear, as this species hides in vegetation. The frequency of calling reduces after a few weeks, but may intensify again near the end of the laying period before falling away towards the end of the breeding season. To attract males, mechanical imitations of their call can be produced by rubbing a piece of wood down a notched stick, or by flicking a credit card against a comb or zip-fastener
. The male also has a growling call, given with the bill shut and used during aggressive interactions.
The female Corn Crake may give a call similar to that of the male, but additionally has a distinctive barking sound, with a similar rhythm to the main call, but lacking the grating quality. The female also has a high-pitched cheep call, and a oo-oo-oo sound to call the chick. The chicks make a quiet peeick-peeick contact call, and a chirp used to beg for food. Because of the difficulty in seeing this species, it is usually census
ed by counting males calling between 11 pm and 3 am; the birds do not move much at night, whereas they may wander up to 600 m (650 yd) during the day, which could lead to double-counting if monitored then. Identifying individual males suggests that just counting calling birds underestimates the true count by nearly 30%, and the discrepancy is likely to be greater, since only 80% of males may call at all on a given night. The Corn Crake is silent in Africa.
.
The Corn Crake winters mainly in Africa, from the Democratic Republic of the Congo
and central Tanzania south to eastern South Africa. North of this area, it is mainly seen on migration, but occasionally winters in North Africa
and to the west and north of its core area in southeast Africa. Most of the South African population of about 2,000 birds occurs in KwaZulu-Natal
and the former Transvaal Province
, and numbers elsewhere in Africa are uncertain. There are several nineteenth-century records, when populations were much higher than now, of birds being seen in western Europe, mainly Britain and Ireland, between December and February.
This crake migrates to Africa along two main routes: a western route through Morocco and Algeria, and a more important flyway
through Egypt. On passage, it has been recorded in most countries between its breeding and wintering ranges, including much of West Africa, and those parts of southern Asia that lie between the east of the breeding range and Africa. Further afield, it has been recorded as a vagrant
to Sri Lanka, Vietnam and Australia, the Seychelles, Bermuda, Canada, the US, Greenland, Iceland, the Faroes
, the Azores
, Madeira
, and the Canary Islands
.
The Corn Crake is mainly a lowland species, but breeds up to 1,400 m (4,600 ft) altitude in the Alps
, 2,700 m (8,600 ft) in China and 3,000 m (9,800 ft) in Russia. When breeding in Eurasia, the Corn Crake's habitats would originally have included river meadows with tall grass and meadow plants including sedges
and irises
. It is now mainly found in cool moist grassland used for the production of hay, particularly moist traditional farmland with limited cutting or fertiliser use. It also utilises other treeless grasslands in mountains or taiga
, on coasts, or where created by fire. Moister areas like wetland edges may be used, but very wet habitats are avoided, as are open areas and those with vegetation more than 50 cm (20 in) tall, or too dense to walk through. The odd bush or hedge may be used as a calling post. Grassland which is not mown or grazed becomes too matted to be suitable for nesting, but locally crops such as cereal
s, peas, rape, clover
or potatoes may be used. After breeding, adults move to taller vegetation such as common reed
, iris, or nettle
s to moult, returning to the to hay and silage
meadows for the second brood. In China, flax
is also used for nest sites. Although males often sing in intensively managed grass or cereal crops, successful breeding is uncommon, and nests in the field margins or nearby fallow ground are more likely to succeed.
When wintering in Africa, the Corn Crake occupies dry grassland and savanna
habitats, occurring in vegetation 30–200 cm (1–6 ft) tall, including seasonally burnt areas and occasionally sedges or reed bed
s. It is also found on fallow and abandoned fields, uncut grass on airfields, and the edges of crops. It occurs at up to at least 1,750 m (5,700 ft) altitude in South Africa. Although it sometimes occurs with the African Crake, that species normally prefers moister and shorter grassland habitats than does the Corn Crake. On migration, the Corn Crake may also occur in wheatfields and around golf course
s.
The Corn Crake is a difficult bird to see in its breeding sites, usually being hidden by vegetation, but will sometimes emerge into the open. Occasionally, individuals may become very trusting; for five consecutive summers, an individual crake on the Scottish island of Tiree
entered a kitchen to feed on scraps, and, in 1999, a wintering Barra
bird would come for poultry feed once the chickens had finished. In Africa, it is more secretive than the African Crake, and, unlike its relative, it is rarely seen in the open, although it occasionally feeds on tracks or road sides. The Corn Crake is most active early and late in the day, after heavy rain and during light rain. Its typical flight is weak and fluttering, although less so than that of the African Crake. For longer flights, such as migration, it has a steadier, stronger action with legs drawn up. It walks with a high-stepping action, and can run swiftly through grass with its body held horizontal and laterally flattened. It will swim if essential. When flushed by a dog, it will fly less than 50 m (150 ft), frequently landing behind a bush or thicket, and then crouch on landing. If disturbed in the open, this crake will often run in a crouch for a short distance, with its neck stretched forward, then stand upright to watch the intruder. When captured it may feign death, recovering at once if it sees a way out.
The Corn Crake is solitary on the wintering grounds, where each bird occupies 4.2–4.9 ha (10.4–11.6 acres) at one time, although the total area used may be double that, since an individual may move locally due to flooding, plant growth, or grass cutting. Flocks of up to 40 birds may form on migration, sometimes associating with Common Quail
s. Migration takes place at night, and flocks resting during the day may aggregate to hundreds of birds at favoured sites. The ability to migrate is innate, not learned from adults. Chicks raised from birds kept in captivity for ten generations were able to migrate to Africa and return with similar success to wild-bred young.
, but it transpires that a male may have a shifting home range, and mate with two or more females, moving on when laying is almost complete. The male's territory can vary from 3 to 51 ha (7.5–126 acres), but averages 15.7 ha (39 acres). The female has a much smaller range, averaging only 5.5 ha (13.5 acres). A male will challenge an intruder by calling with his wings drooped and his head pointing forward. Usually the stranger moves off; if it stays, the two birds square up with heads and necks raised and the wings touching the ground. They then run around giving the growling call and lunging at each other. A real fight may ensue, with the birds leaping at each other and pecking, and sometimes kicking. Females play no part in defending the territory.
The female may be offered food by the male during courtship. He has a brief courtship display in which the neck is extended and the head held down, the tail is fanned, and the wings are spread with the tips touching the ground. He will then attempt to approach the female from behind, and then leap on her back to copulate. The nest is typically in grassland, sometimes in safer sites along a hedge, or near an isolated tree or bush, or in overgrown vegetation. Where grass is not tall enough at the start of the season, the first nest may be constructed in herby or marsh vegetation, with the second brood in hay. The second nest may also be at a higher altitude that the first, to take advantage of the later-developing grasses further up a hill. The nest, well hidden in the grass, is built in a scrape or hollow in the ground. It is made of woven coarse dry grass and other plants, and lined with finer grasses. Although nest construction is usually described as undertaken by the female, a recent aviary study found that in the captive population the male always built the nest.
The nest is 12–15 cm (5–6 in) in diameter and 3–4 cm (1–1.5 in) deep. The clutch is 6–14, usually 8–12 eggs; these are oval, slightly glossy, creamy or tinted with green, blue or grey, and blotched red-brown. They average 37 × 26 mm, (1.5 × 1.0 in) and weigh about 13–16 g, (0.46–0.56 oz), of which 7% is shell. The eggs are laid at daily intervals, but second clutches may sometimes have two eggs added per day. Incubation is by the female only; her tendency to sit tight when disturbed, or wait until the last moment to flee, leads to many deaths during hay-cutting and harvesting. The eggs hatch together after 19–20 days, and the precocial
chicks leave the nest within a day or two. They are fed by the female for three or four days, but can find their own food thereafter. The juveniles fledge after 34–38 days. The second brood is started about 42 days after the first, and the incubation period is slightly shorter at 16–18 days. The grown young may stay with the female until departure for Africa.
Nest success in undisturbed sites is high, at 80–90%, but much lower in fertilised meadows and on arable land. The method and timing of mowing is crucial; mechanized mowing can kill 38–95% of chicks in a given site, and losses average 50% of first brood chicks and somewhat less than 40% of second brood chicks. The influence of weather on chick survival is limited; although chick growth is faster in dry or warm weather, the effects are relatively small. Unlike many precocial species, chicks are fed by their mother to a greater or lesser extent until they become independent, and this may cushion them from adverse conditions. The number of live chicks hatched is more important than the weather, with lower survival in large broods. The annual adult survival rate is under 30%, although some individuals may live for 5–7 years.
, but mainly feeds on invertebrate
s, including earthworm
s, slug
s and snail
s, spiders, beetles, dragonflies
, grasshopper
s and other insects. In the breeding areas, it is a predator of Sitona
weevil
s, which infest legume crops. and in the past consumed large amounts of the former grassland pests, leatherjacket
s and wireworm
s. This crake will also eat small frogs and mammals, and plant material including grass seed and cereal grain. Its diet on the wintering grounds is generally similar, but includes locally available items such as termite
s, cockroach
es and dung beetle
s. Food is taken from the ground, low-growing plants and from inside grass tussocks; the crake may search leaf litter with its bill, and run in pursuit of active prey. Hunting is normally in cover, but, particularly in the wintering areas, it will occasionally feed on grassy tracks or dirt roads. Indigestible material is regurgitated as 1 cm (0.5 in) pellets
. Chicks are fed mainly on animal food, and when fully grown they may fly with the parents up to 6.4 km (4 mi) to visit supplementary feeding areas. As with other rails, grit is swallowed to help break up food in the stomach.
and domestic cat
s, introduced
American mink
, feral ferret
s, otters
and red fox
es, and birds including the Common Buzzard
and Hooded Crow
. In Lithuania, the introduced Raccoon Dog
has also been recorded as taking Corn Crakes. When chicks are exposed by rapid mowing, they may be taken by large birds including the White Stork
, harriers
and other birds of prey
, gull
s and corvids
. At undisturbed sites nests and broods are rarely attacked, as reflected in a high breeding success. There is a record of a Corn Crake on migration through Gabon
being killed by a Black Sparrowhawk.
The widespread fluke
Prosthogonimus ovatus, which lives in the oviduct
s of birds, has been recorded in the Corn Crake, as have the parasitic worm
Plagiorchis elegans, the larvae of parasitic flies, and hard ticks
of the genera Haemaphysalis
and Ixodes
.
During the reintroduction of Corn Crakes to England in the 2003 breeding season, enteritis
and ill heath in pre-release birds was due to bacteria
of a pathogen
ic Campylobacter
species. Subsequently, microbiology
tests were done to detect infected individuals and to find the source of the bacteria in their environment.
on the IUCN Red List
because of serious declines in Europe, but improved monitoring in Russia indicates that anticipated losses there have not occurred and numbers have remained stable or possibly increased. It is therefore now classed as Least Concern
, since the major populations in Russia and Kazakhstan are not expected to change much in the short term. There are an estimated 1.3–2.0 million breeding pairs in Europe, three-quarters of which are in European Russia, and a further 515,000–1,240,000 pairs in Asiatic Russia; the total Eurasian population has been estimated at between 5.45 and 9.72 million individuals. In much of the western half of its range, there have been long-term declines that are expected to continue, although conservation measures have enabled numbers to grow in several countries, including a five-fold increase in Finland, and a doubling in the UK. In the Netherlands, there were 33 breeding territories in 1996, but this number had increased to at least 500 by 1998.
The breeding Corn Crake population had begun to decline in the 19th century, but the process gained pace after World War II. The main cause of the steep declines in much of Europe is the loss of nests and chicks from early mowing. Haymaking dates have moved forward in the past century due to faster crop growth, made possible by land drainage and the use of fertilisers, and the move from manual grass-cutting using scythe
s to mechanical mower
s, at first horse-drawn and later pulled by tractor
s. Mechanisation also means that large areas can be cut quickly, leaving the crake with no alternative sites to raise either a first brood if suitable habitat has gone, or a replacement brood if the first nest is destroyed. The pattern of mowing, typically in a circular pattern from the outside of a field to its centre, gives little chance of escape for the chicks, which are also exposed to potential animal predators. Adults can often escape the mowers, although some incubating females sit tight on the nest, with fatal results.
Loss of habitat
is the other major threat to the Corn Crake. Apart from the reduced suitability of drained and fertilised silage fields compared to traditional hay meadows, in western Europe the conversion of grassland to arable has been aided by subsidies, and further east the collapse of collective farming
has led to the abandonment and lack of management of much land in this important breeding area. More localised threats include floods in spring, and disturbance by roads or wind farm
s. This bird is good eating; when they were common in England, Mrs Beeton
recommended roasting four on a skewer. More significant than direct hunting is the loss of many birds, up to 14,000 a year, in Egypt, where migrating birds are captured in nets set for the quail with which they often migrate. Although this may account for 0.5–2.7% of the European population, the losses to this form of hunting are less than when the targeted species were more numerous and predictable.
Most European countries have taken steps to conserve the Corn Crake and produce national management policies; there is also an overall European action plan. The focus of conservation effort is to monitor populations and ecology
and to improve survival, principally through changing the timing and method of hay harvesting. Later cutting gives time for breeding to be completed, and leaving uncut strips at the edges of fields and cutting from the centre outwards reduces the casualties from mowing. Implementing these changes is predicted to stop the population decline if the measures are applied on a sufficiently large scale. Reduction of illegal hunting, and protection in countries where hunting is still allowed, are also conservation aims. Reintroduction of the Corn Crake is being attempted in England, and breeding sites are scheduled for protection in many other countries. Where breeding sites impinge on urban areas, there are cost implications, estimated in one German study at several million euros per Corn Crake. The Corn Crake does not appear to be seriously threatened on its wintering grounds and may benefit from deforestration, which creates more open habitats.
"Corne Crake" was popularised by Thomas Bewick
, who used this term in his 1797 A History of British Birds. Other Scottish names include "Corn Scrack" and "Quailzie"; the latter term, like "King of the Quail", "Grass Quail", and the French "roi de caille" refer to the association with the small gamebird. Another name, "Daker", has been variously interpreted as onomatopoeic, or derived from the Old Norse
Ager-hoene, meaning "Cock of the field"; variants include "Drake", "Drake Hen" and "Gorse Drake".
"Upon Appleton House
", written in 1651 about the North Yorkshire
country estate of Thomas Fairfax
. The narrator depicts the scene of a mower cutting the grass, before his "whistling Sithe" unknowingly carves the Rail. The farmhand draws out the scythe "all bloody from its breast" and "does the stroke detest". It continues with a stanza that demonstrates the problematic nature of the Corn Crake's nesting habits:
Unhappy Birds! What does it boot
To build below the Grass' Root;
When Lowness is unsafe as Hight,
And Chance o'ertakes, what scapeth spight?
John Clare
, the nineteenth-century English poet based in Northamptonshire
, wrote "The Landrail", a semi-comic piece which is primarily about the difficulty of seeing Corn Crakes – as opposed to hearing them. In the fourth verse he exclaims: "Tis like a fancy everywhere/A sort of living doubt". Clare wrote about Corn Crakes in his prose works too, and his writings help to clarify the distribution of this rail when it was far more widespread than now.
The proverbial use of the Corn Crake's call to describe someone with a grating or unmelodious voice is illustrated in the quotation "thanks to a wee woman with a voice like a corncrake who believed she was an apprentice angel". This usage dates from at least the first half of the nineteenth century, and continues through to the present.
Rallidae
The rails, or Rallidae, are a large cosmopolitan family of small to medium-sized birds. The family exhibits considerable diversity and the family also includes the crakes, coots, and gallinules...
. It breeds in Europe and Asia as far east as western China, and migrates
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
to Africa for the winter. It is a medium-sized crake with buff
Buff (colour)
Buff is a pale yellow-brown colour that got its name from the colour of buff leather.Displayed on the right is the colour buff.EtymologyAccording to the Oxford English Dictionary, buff as a descriptor of a colour was first used in the London Gazette of 1686, describing a uniform to be "A Red Coat...
- or grey-streaked brownish-black upperparts, chestnut
Chestnut (color)
Chestnut, also known as Indian red, is a color, a medium brownish shade of red, and is named after the nut of the chestnut tree.As Indian red, it is named after the red laterite soil found in India. It is thus an earth tone as well as a red. It is composed of naturally occurring iron oxides. Other...
markings on the wings, and blue-grey underparts with rust-coloured and white bars on the flanks and undertail. The strong bill
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
is flesh-toned, the iris
Iris (anatomy)
The iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupils and thus the amount of light reaching the retina. "Eye color" is the color of the iris, which can be green, blue, or brown. In some cases it can be hazel , grey, violet, or even pink...
is pale brown, and the legs and feet are pale grey. The juvenile is similar in plumage
Plumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
to the adult, and the downy
Down feather
The down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in a few groups of birds. Down is a fine thermal insulator and padding, used in goods such as jackets, bedding,...
chicks are black, as with all rails. There are no subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
, although individuals from the east of the breeding range tend to be slightly paler than their western counterparts. The male's call is a loud krek krek, from which the scientific name is derived. The Corn Crake is larger than its closest relative, the African Crake
African Crake
The African Crake is a bird in the rail family that breeds in most of sub-Saharan Africa away from the arid south and southwest. It is seasonally common in most of its range other than the rainforests and areas that have low annual rainfall...
, which shares its wintering range; that species is also darker-plumaged, and has a plainer face.
The Corn Crake's breeding habitat is grassland, particularly hay
Hay
Hay is grass, legumes or other herbaceous plants that have been cut, dried, and stored for use as animal fodder, particularly for grazing livestock such as cattle, horses, goats, and sheep. Hay is also fed to pets such as rabbits and guinea pigs...
fields, and it uses similar environments on the wintering grounds. This secretive species builds a nest of grass leaves in a hollow in the ground and lays 6–14 cream-coloured eggs that are covered with rufous
Rufous
Rufous is a colour that may be described as reddish-brown or brownish-red, as of rust or oxidised iron.The first recorded use of rufous as a colour name in English was in the year 1782....
blotches. These hatch in 19–20 days, and the black precocial
Precocial
In biology, the term precocial refers to species in which the young are relatively mature and mobile from the moment of birth or hatching. The opposite developmental strategy is called "altricial," where the young are born or hatched helpless. Extremely precocial species may be called...
chicks fledge
Fledge
Fledge is the stage in a young bird's life when the feathers and wing muscles are sufficiently developed for flight. It also describes the act of a chick's parents raising it to a fully grown state...
after about five weeks. This crake is in steep decline across much of its former breeding range because modern farming practices often destroy nests before breeding is finished. The Corn Crake is omnivorous, but mainly feeds on invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s, the occasional small frog or mammal, and plant material including grass seed and cereal grain. Natural threats include introduced
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
and feral mammals, large birds, and various parasite
Parasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
s and diseases.
Although numbers have declined steeply in western Europe, this bird is classed as Least Concern
Least Concern
Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...
on the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
because of its huge range and large, apparently stable, populations in Russia and Kazakhstan. Numbers in western China are more significant than previously thought, and conservation
Conservation biology
Conservation biology is the scientific study of the nature and status of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction...
measures have facilitated an increase in population in some of the countries which had suffered the greatest losses. Despite its elusive nature, the loud call has ensured that the Corn Crake has been noted in literature, and garnered a range of local and dialect names.
Taxonomy
The railsRallidae
The rails, or Rallidae, are a large cosmopolitan family of small to medium-sized birds. The family exhibits considerable diversity and the family also includes the crakes, coots, and gallinules...
are a bird family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
comprising nearly 150 species. Although the origins of the group are lost in antiquity, the largest number of species and the least specialised forms are found in the Old World
Old World
The Old World consists of those parts of the world known to classical antiquity and the European Middle Ages. It is used in the context of, and contrast with, the "New World" ....
, suggesting that this family originated there. The taxonomy
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
of the small crakes is complicated, but the closest relative of the Corn Crake is the African Crake, C. egregia, which has sometimes been given its own genus, Crecopsis, but is now more usually placed in Crex. Both species are short-billed brown birds with a preference for grassland rather the wetland
Wetland
A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....
habitats typical of rails. Porzana
Porzana
Porzana is a genus of birds in the crake or rail family, Rallidae. It has a global distribution, contains 13 living species, and 4-5 recently extinct ones...
crakes, particularly the Ash-throated Crake
Ash-throated Crake
The Ash-throated Crake is a species of bird in the Rallidae family.It is found in Argentina, Bolivia, Brazil, Colombia, French Guiana, Guyana, Paraguay, Peru, Suriname, Trinidad and Tobago, and Venezuela....
(Porzana albicollis) are near relatives of the Crex genus.
The Corn Crake was first described by Linnaeus in his Systema Naturae
Systema Naturae
The book was one of the major works of the Swedish botanist, zoologist and physician Carolus Linnaeus. The first edition was published in 1735...
in 1758 as Rallus crex, but was subsequently moved to the genus Crex
Crex
Crex is a small genus of birds in the rail family. It contains two species, the Corn Crake, C. crex, which breeds across Europe and Asia and winters in southern Africa, and the African Crake, C. egregia, which migrates within Africa. Both are short-billed rails with blackish-brown upperparts,...
, created by German naturalist and ornithologist Johann Matthäus Bechstein
Johann Matthäus Bechstein
Johann Matthäus Bechstein was a German naturalist, forester, ornithologist and entomologist. In Great Britain, he was known for his treatise on singing birds .-Biography:Bechstein was born in Waltershausen in the district of Gotha in Thuringia...
in 1803, and named Crex pratensis. The earlier use of crex gives it priority
Principle of Priority
thumb|270px|Boa manditraIn zoology, the scientific study of animals, the Principle of Priority is one of the guiding principles of the International Code of Zoological Nomenclature, defined by Article 23....
over Bechstein's specific name pratensis, and leads to the current name of Crex crex. The binomial name, Crex crex, from the Ancient Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
"κρεξ", is onomatopoeic, referring to the crake's repetitive grating call. The common name was formerly spelt as a single word, "Corncrake", but the official version is now "Corn Crake". The English names refer to the habit of the species of nesting in dry hay or cereal fields, rather than the marshes used by most members of this family.
Description
The Corn Crake is a medium-sized rail, 27–30 cm (10.6–11.8 in) long with a wingspan of 42–53 cm (16.5–20.9 in). Males weigh 165 g (5.8 oz) on average and females 145 g (5.1 oz). The adult male has the crown of its head and all of its upperparts brown-black in colour, streaked with buff or grey. The wing coverts are a distinctive chestnut colour with some white bars. The face, neck and breast are blue-grey, apart from a pale brown streak from the base of the bill to behind the eye, the belly is white, and the flanks, and undertail are barred with chestnut and white. The strong bill is flesh-coloured, the iris is pale brown, and the legs and feet are pale grey. Compared to the male, the female has warmer-toned upperparts and a narrower duller eye streak. Outside the breeding season, the upperparts of both sexes become darker and the underparts less grey. The juvenile is like the adult in appearance, but has a yellow tone to its upperparts, and the grey of the underparts is replaced with buff-brown. The chicks have black down, as with all rails. While there are no subspeciesSubspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
, all populations show great individual variation in colouring, and the birds gradually become paler and greyer towards the east of the range. Adults undergo a complete moult after breeding, which is normally finished by late by late August or early September, before migration to south eastern Africa. There is a pre-breeding partial moult prior to the return from Africa, mainly involving the plumage of the head, body and tail. Young birds have a head and body moult about five weeks after hatching.
The Corn Crake is sympatric
Sympatry
In biology, two species or populations are considered sympatric when they exist in the same geographic area and thus regularly encounter one another. An initially-interbreeding population that splits into two or more distinct species sharing a common range exemplifies sympatric speciation...
with the African Crake on the wintering grounds, but can be distinguished by its larger size, paler upperparts, tawny
Tawny (color)
Tawny is a yellowish brown color. The word means "tan-colored," from Anglo-Norman tauné "associated with the brownish-yellow of tanned leather," from Old French tané "to tan hides," from Medieval Latin tannare, from tannum "crushed oak bark," used in tanning leather, probably from a Celtic source...
upperwing and different underparts pattern. In flight, it has longer, less rounded wings, and shallower wingbeats than its African relative, and shows a white leading edge to the inner wing. In both the breeding and wintering ranges it is unlikely to be confused with any other rails, since sympatric species are smaller, with white markings on the upperparts, different underparts patterns and shorter bills. A flying Corn Crake can resemble a gamebird
Game (food)
Game is any animal hunted for food or not normally domesticated. Game animals are also hunted for sport.The type and range of animals hunted for food varies in different parts of the world. This will be influenced by climate, animal diversity, local taste and locally accepted view about what can or...
, but its chestnut wing pattern and dangling legs are diagnostic.
Voice
On the breeding grounds, the male Corn Crake's advertising call is a loud, repetitive, grating krek krek normally delivered from a low perch with the bird's head and neck almost vertical and its bill wide open. The call can be heard from 1.5 km (1 mi) away, and serves to establish the breeding territory, attract females, and challenge intruding males. Slight differences in vocalisations mean that individual males can be distinguished by their calls. Early in the season, the call is given almost continuously at night, and often during the day too. It may be repeated more than 20,000 times a night, with a peak between midnight and 3 am. The call has evolvedSexual selection
Sexual selection, a concept introduced by Charles Darwin in his 1859 book On the Origin of Species, is a significant element of his theory of natural selection...
to make a singing male's location clear, as this species hides in vegetation. The frequency of calling reduces after a few weeks, but may intensify again near the end of the laying period before falling away towards the end of the breeding season. To attract males, mechanical imitations of their call can be produced by rubbing a piece of wood down a notched stick, or by flicking a credit card against a comb or zip-fastener
Zipper
A zipper is a commonly used device for temporarily joining two edges of fabric...
. The male also has a growling call, given with the bill shut and used during aggressive interactions.
The female Corn Crake may give a call similar to that of the male, but additionally has a distinctive barking sound, with a similar rhythm to the main call, but lacking the grating quality. The female also has a high-pitched cheep call, and a oo-oo-oo sound to call the chick. The chicks make a quiet peeick-peeick contact call, and a chirp used to beg for food. Because of the difficulty in seeing this species, it is usually census
Census
A census is the procedure of systematically acquiring and recording information about the members of a given population. It is a regularly occurring and official count of a particular population. The term is used mostly in connection with national population and housing censuses; other common...
ed by counting males calling between 11 pm and 3 am; the birds do not move much at night, whereas they may wander up to 600 m (650 yd) during the day, which could lead to double-counting if monitored then. Identifying individual males suggests that just counting calling birds underestimates the true count by nearly 30%, and the discrepancy is likely to be greater, since only 80% of males may call at all on a given night. The Corn Crake is silent in Africa.
Distribution and habitat
The Corn Crake breeds from Britain and Ireland east through Europe to central Siberia. Although it has vanished from much of its historic range, this bird was once found in suitable habitats in Eurasia everywhere between latitudes 41°N and 62°N. There is also a sizable population in western China, but this species nests only rarely in northern Spain and in Turkey. Old claims of breeding in South Africa are incorrect, and result from misidentification of eggs in a museum collection which are actually those of the African RailAfrican Rail
The African Rail is a small wetland bird of the rail family.Its breeding habitat is marshes and reedbeds across eastern and southern Africa from Ethiopia to South Africa...
.
The Corn Crake winters mainly in Africa, from the Democratic Republic of the Congo
Democratic Republic of the Congo
The Democratic Republic of the Congo is a state located in Central Africa. It is the second largest country in Africa by area and the eleventh largest in the world...
and central Tanzania south to eastern South Africa. North of this area, it is mainly seen on migration, but occasionally winters in North Africa
North Africa
North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...
and to the west and north of its core area in southeast Africa. Most of the South African population of about 2,000 birds occurs in KwaZulu-Natal
KwaZulu-Natal
KwaZulu-Natal is a province of South Africa. Prior to 1994, the territory now known as KwaZulu-Natal was made up of the province of Natal and the homeland of KwaZulu....
and the former Transvaal Province
Transvaal Province
Transvaal Province was a province of the Union of South Africa from 1910 to 1961, and of its successor, the Republic of South Africa, from 1961 until the end of apartheid in 1994 when a new constitution subdivided it.-History:...
, and numbers elsewhere in Africa are uncertain. There are several nineteenth-century records, when populations were much higher than now, of birds being seen in western Europe, mainly Britain and Ireland, between December and February.
Flyway
A flyway is a flight path used in bird migration. Flyways generally span over continents and often oceans.-Flyways of the Americas:*Atlantic Flyway*Central Flyway*Mississippi Flyway*Pacific Flyway*Allegheny Front...
through Egypt. On passage, it has been recorded in most countries between its breeding and wintering ranges, including much of West Africa, and those parts of southern Asia that lie between the east of the breeding range and Africa. Further afield, it has been recorded as a vagrant
Vagrancy (biology)
Vagrancy is a phenomenon in biology whereby individual animals appear well outside their normal range; individual animals which exhibit vagrancy are known as vagrants. The term accidental is sometimes also used...
to Sri Lanka, Vietnam and Australia, the Seychelles, Bermuda, Canada, the US, Greenland, Iceland, the Faroes
Faroe Islands
The Faroe Islands are an island group situated between the Norwegian Sea and the North Atlantic Ocean, approximately halfway between Scotland and Iceland. The Faroe Islands are a self-governing territory within the Kingdom of Denmark, along with Denmark proper and Greenland...
, the Azores
Azores
The Archipelago of the Azores is composed of nine volcanic islands situated in the middle of the North Atlantic Ocean, and is located about west from Lisbon and about east from the east coast of North America. The islands, and their economic exclusion zone, form the Autonomous Region of the...
, Madeira
Madeira
Madeira is a Portuguese archipelago that lies between and , just under 400 km north of Tenerife, Canary Islands, in the north Atlantic Ocean and an outermost region of the European Union...
, and the Canary Islands
Canary Islands
The Canary Islands , also known as the Canaries , is a Spanish archipelago located just off the northwest coast of mainland Africa, 100 km west of the border between Morocco and the Western Sahara. The Canaries are a Spanish autonomous community and an outermost region of the European Union...
.
The Corn Crake is mainly a lowland species, but breeds up to 1,400 m (4,600 ft) altitude in the Alps
Alps
The Alps is one of the great mountain range systems of Europe, stretching from Austria and Slovenia in the east through Italy, Switzerland, Liechtenstein and Germany to France in the west....
, 2,700 m (8,600 ft) in China and 3,000 m (9,800 ft) in Russia. When breeding in Eurasia, the Corn Crake's habitats would originally have included river meadows with tall grass and meadow plants including sedges
Carex
Carex is a genus of plants in the family Cyperaceae, commonly known as sedges. Other members of the Cyperaceae family are also called sedges, however those of genus Carex may be called "true" sedges, and it is the most species-rich genus in the family. The study of Carex is known as...
and irises
Iris (plant)
Iris is a genus of 260-300species of flowering plants with showy flowers. It takes its name from the Greek word for a rainbow, referring to the wide variety of flower colors found among the many species...
. It is now mainly found in cool moist grassland used for the production of hay, particularly moist traditional farmland with limited cutting or fertiliser use. It also utilises other treeless grasslands in mountains or taiga
Taiga
Taiga , also known as the boreal forest, is a biome characterized by coniferous forests.Taiga is the world's largest terrestrial biome. In North America it covers most of inland Canada and Alaska as well as parts of the extreme northern continental United States and is known as the Northwoods...
, on coasts, or where created by fire. Moister areas like wetland edges may be used, but very wet habitats are avoided, as are open areas and those with vegetation more than 50 cm (20 in) tall, or too dense to walk through. The odd bush or hedge may be used as a calling post. Grassland which is not mown or grazed becomes too matted to be suitable for nesting, but locally crops such as cereal
Cereal
Cereals are grasses cultivated for the edible components of their grain , composed of the endosperm, germ, and bran...
s, peas, rape, clover
Clover
Clover , or trefoil, is a genus of about 300 species of plants in the leguminous pea family Fabaceae. The genus has a cosmopolitan distribution; the highest diversity is found in the temperate Northern Hemisphere, but many species also occur in South America and Africa, including at high altitudes...
or potatoes may be used. After breeding, adults move to taller vegetation such as common reed
Phragmites
Phragmites, the Common reed, is a large perennial grass found in wetlands throughout temperate and tropical regions of the world. Phragmites australis is sometimes regarded as the sole species of the genus Phragmites, though some botanists divide Phragmites australis into three or four species...
, iris, or nettle
Nettle
Nettles constitute between 24 and 39 species of flowering plants of the genus Urtica in the family Urticaceae, with a cosmopolitan though mainly temperate distribution. They are mostly herbaceous perennial plants, but some are annual and a few are shrubby...
s to moult, returning to the to hay and silage
Silage
Silage is fermented, high-moisture fodder that can be fed to ruminants or used as a biofuel feedstock for anaerobic digesters. It is fermented and stored in a process called ensiling or silaging, and is usually made from grass crops, including corn , sorghum or other cereals, using the entire...
meadows for the second brood. In China, flax
Flax
Flax is a member of the genus Linum in the family Linaceae. It is native to the region extending from the eastern Mediterranean to India and was probably first domesticated in the Fertile Crescent...
is also used for nest sites. Although males often sing in intensively managed grass or cereal crops, successful breeding is uncommon, and nests in the field margins or nearby fallow ground are more likely to succeed.
When wintering in Africa, the Corn Crake occupies dry grassland and savanna
Savanna
A savanna, or savannah, is a grassland ecosystem characterized by the trees being sufficiently small or widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of C4 grasses.Some...
habitats, occurring in vegetation 30–200 cm (1–6 ft) tall, including seasonally burnt areas and occasionally sedges or reed bed
Reed bed
Reed beds are natural habitats found in floodplains, waterlogged depressions andestuaries. Reed beds are part of a succession from young reed colonising open water or wet ground through a gradation of increasingly dry ground...
s. It is also found on fallow and abandoned fields, uncut grass on airfields, and the edges of crops. It occurs at up to at least 1,750 m (5,700 ft) altitude in South Africa. Although it sometimes occurs with the African Crake, that species normally prefers moister and shorter grassland habitats than does the Corn Crake. On migration, the Corn Crake may also occur in wheatfields and around golf course
Golf course
A golf course comprises a series of holes, each consisting of a teeing ground, fairway, rough and other hazards, and a green with a flagstick and cup, all designed for the game of golf. A standard round of golf consists of playing 18 holes, thus most golf courses have this number of holes...
s.
Behaviour
Tiree
-History:Tiree is known for the 1st century BC Dùn Mòr broch, for the prehistoric carved Ringing Stone and for the birds of the Ceann a' Mhara headland....
entered a kitchen to feed on scraps, and, in 1999, a wintering Barra
Barra
The island of Barra is a predominantly Gaelic-speaking island, and apart from the adjacent island of Vatersay, to which it is connected by a causeway, is the southernmost inhabited island of the Outer Hebrides in Scotland.-Geography:The 2001 census showed that the resident population was 1,078...
bird would come for poultry feed once the chickens had finished. In Africa, it is more secretive than the African Crake, and, unlike its relative, it is rarely seen in the open, although it occasionally feeds on tracks or road sides. The Corn Crake is most active early and late in the day, after heavy rain and during light rain. Its typical flight is weak and fluttering, although less so than that of the African Crake. For longer flights, such as migration, it has a steadier, stronger action with legs drawn up. It walks with a high-stepping action, and can run swiftly through grass with its body held horizontal and laterally flattened. It will swim if essential. When flushed by a dog, it will fly less than 50 m (150 ft), frequently landing behind a bush or thicket, and then crouch on landing. If disturbed in the open, this crake will often run in a crouch for a short distance, with its neck stretched forward, then stand upright to watch the intruder. When captured it may feign death, recovering at once if it sees a way out.
The Corn Crake is solitary on the wintering grounds, where each bird occupies 4.2–4.9 ha (10.4–11.6 acres) at one time, although the total area used may be double that, since an individual may move locally due to flooding, plant growth, or grass cutting. Flocks of up to 40 birds may form on migration, sometimes associating with Common Quail
Common Quail
The Common Quail, Coturnix coturnix, is a small bird in the pheasant family Phasianidae. It is widespread and is found in parts of Europe, .- Description :It is a small rotund bird, essentially streaked brown with...
s. Migration takes place at night, and flocks resting during the day may aggregate to hundreds of birds at favoured sites. The ability to migrate is innate, not learned from adults. Chicks raised from birds kept in captivity for ten generations were able to migrate to Africa and return with similar success to wild-bred young.
Breeding
Until 1995, it was assumed that the Corn Crake is monogamousMonogamy
Monogamy /Gr. μονός+γάμος - one+marriage/ a form of marriage in which an individual has only one spouse at any one time. In current usage monogamy often refers to having one sexual partner irrespective of marriage or reproduction...
, but it transpires that a male may have a shifting home range, and mate with two or more females, moving on when laying is almost complete. The male's territory can vary from 3 to 51 ha (7.5–126 acres), but averages 15.7 ha (39 acres). The female has a much smaller range, averaging only 5.5 ha (13.5 acres). A male will challenge an intruder by calling with his wings drooped and his head pointing forward. Usually the stranger moves off; if it stays, the two birds square up with heads and necks raised and the wings touching the ground. They then run around giving the growling call and lunging at each other. A real fight may ensue, with the birds leaping at each other and pecking, and sometimes kicking. Females play no part in defending the territory.
The female may be offered food by the male during courtship. He has a brief courtship display in which the neck is extended and the head held down, the tail is fanned, and the wings are spread with the tips touching the ground. He will then attempt to approach the female from behind, and then leap on her back to copulate. The nest is typically in grassland, sometimes in safer sites along a hedge, or near an isolated tree or bush, or in overgrown vegetation. Where grass is not tall enough at the start of the season, the first nest may be constructed in herby or marsh vegetation, with the second brood in hay. The second nest may also be at a higher altitude that the first, to take advantage of the later-developing grasses further up a hill. The nest, well hidden in the grass, is built in a scrape or hollow in the ground. It is made of woven coarse dry grass and other plants, and lined with finer grasses. Although nest construction is usually described as undertaken by the female, a recent aviary study found that in the captive population the male always built the nest.
The nest is 12–15 cm (5–6 in) in diameter and 3–4 cm (1–1.5 in) deep. The clutch is 6–14, usually 8–12 eggs; these are oval, slightly glossy, creamy or tinted with green, blue or grey, and blotched red-brown. They average 37 × 26 mm, (1.5 × 1.0 in) and weigh about 13–16 g, (0.46–0.56 oz), of which 7% is shell. The eggs are laid at daily intervals, but second clutches may sometimes have two eggs added per day. Incubation is by the female only; her tendency to sit tight when disturbed, or wait until the last moment to flee, leads to many deaths during hay-cutting and harvesting. The eggs hatch together after 19–20 days, and the precocial
Precocial
In biology, the term precocial refers to species in which the young are relatively mature and mobile from the moment of birth or hatching. The opposite developmental strategy is called "altricial," where the young are born or hatched helpless. Extremely precocial species may be called...
chicks leave the nest within a day or two. They are fed by the female for three or four days, but can find their own food thereafter. The juveniles fledge after 34–38 days. The second brood is started about 42 days after the first, and the incubation period is slightly shorter at 16–18 days. The grown young may stay with the female until departure for Africa.
Nest success in undisturbed sites is high, at 80–90%, but much lower in fertilised meadows and on arable land. The method and timing of mowing is crucial; mechanized mowing can kill 38–95% of chicks in a given site, and losses average 50% of first brood chicks and somewhat less than 40% of second brood chicks. The influence of weather on chick survival is limited; although chick growth is faster in dry or warm weather, the effects are relatively small. Unlike many precocial species, chicks are fed by their mother to a greater or lesser extent until they become independent, and this may cushion them from adverse conditions. The number of live chicks hatched is more important than the weather, with lower survival in large broods. The annual adult survival rate is under 30%, although some individuals may live for 5–7 years.
Feeding
The Corn Crake is omnivorousOmnivore
Omnivores are species that eat both plants and animals as their primary food source...
, but mainly feeds on invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s, including earthworm
Earthworm
Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female...
s, slug
Slug
Slug is a common name that is normally applied to any gastropod mollusc that lacks a shell, has a very reduced shell, or has a small internal shell...
s and snail
Snail
Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
s, spiders, beetles, dragonflies
Dragonfly
A dragonfly is a winged insect belonging to the order Odonata, the suborder Epiprocta or, in the strict sense, the infraorder Anisoptera . It is characterized by large multifaceted eyes, two pairs of strong transparent wings, and an elongated body...
, grasshopper
Grasshopper
The grasshopper is an insect of the suborder Caelifera in the order Orthoptera. To distinguish it from bush crickets or katydids, it is sometimes referred to as the short-horned grasshopper...
s and other insects. In the breeding areas, it is a predator of Sitona
Sitona
Sitona is a large genus of weevils in the family Curculionidae, native to the Nearctic and Palaearctic regions. More than 100 species have been described...
weevil
Weevil
A weevil is any beetle from the Curculionoidea superfamily. They are usually small, less than , and herbivorous. There are over 60,000 species in several families, mostly in the family Curculionidae...
s, which infest legume crops. and in the past consumed large amounts of the former grassland pests, leatherjacket
Crane fly
A crane fly is an insect in the family Tipulidae. Adults are very slender, long-legged flies that may vary in length from though tropical species may exceed to ....
s and wireworm
Click beetle
The family Elateridae is commonly called click beetles , elaters, snapping beetles, spring beetles or "skipjacks". They are a cosmopolitan beetle family characterized by the unusual click mechanism they possess...
s. This crake will also eat small frogs and mammals, and plant material including grass seed and cereal grain. Its diet on the wintering grounds is generally similar, but includes locally available items such as termite
Termite
Termites are a group of eusocial insects that, until recently, were classified at the taxonomic rank of order Isoptera , but are now accepted as the epifamily Termitoidae, of the cockroach order Blattodea...
s, cockroach
Cockroach
Cockroaches are insects of the order Blattaria or Blattodea, of which about 30 species out of 4,500 total are associated with human habitations...
es and dung beetle
Dung beetle
Dung beetles are beetles that feed partly or exclusively on feces. All of these species belong to the superfamily Scarabaeoidea; most of them to the subfamilies Scarabaeinae and Aphodiinae of the family Scarabaeidae. This beetle can also be referred to as the scarab beetle. As most species of...
s. Food is taken from the ground, low-growing plants and from inside grass tussocks; the crake may search leaf litter with its bill, and run in pursuit of active prey. Hunting is normally in cover, but, particularly in the wintering areas, it will occasionally feed on grassy tracks or dirt roads. Indigestible material is regurgitated as 1 cm (0.5 in) pellets
Pellet (ornithology)
A pellet, in ornithology, is the mass of undigested parts of a bird's food that some bird species occasionally regurgitate. The contents of a bird's pellet depend on its diet, but can include the exoskeletons of insects, indigestible plant matter, bones, fur, feathers, bills, claws, and teeth...
. Chicks are fed mainly on animal food, and when fully grown they may fly with the parents up to 6.4 km (4 mi) to visit supplementary feeding areas. As with other rails, grit is swallowed to help break up food in the stomach.
Predators and parasites
Predators on the breeding grounds include feralFeral
A feral organism is one that has changed from being domesticated to being wild or untamed. In the case of plants it is a movement from cultivated to uncultivated or controlled to volunteer. The introduction of feral animals or plants to their non-native regions, like any introduced species, may...
and domestic cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
s, introduced
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
American mink
American Mink
The American mink is a semi-aquatic species of Mustelid native to North America, though human intervention has expanded its range to many parts of Europe and South America. Because of this, it is classed as Least Concern by the IUCN. Since the extinction of the sea mink, the American mink is the...
, feral ferret
Ferret
The ferret is a domesticated mammal of the type Mustela putorius furo. Ferrets are sexually dimorphic predators with males being substantially larger than females. They typically have brown, black, white, or mixed fur...
s, otters
European Otter
The European Otter , also known as the Eurasian otter, Eurasian river otter, common otter and Old World otter, is a European and Asian member of the Lutrinae or otter subfamily, and is typical of freshwater otters....
and red fox
Red Fox
The red fox is the largest of the true foxes, as well as being the most geographically spread member of the Carnivora, being distributed across the entire northern hemisphere from the Arctic Circle to North Africa, Central America, and the steppes of Asia...
es, and birds including the Common Buzzard
Common Buzzard
The Common Buzzard is a medium to large bird of prey, whose range covers most of Europe and extends into Asia. It is usually resident all year, except in the coldest parts of its range, and in the case of one subspecies.-Description:...
and Hooded Crow
Hooded Crow
The Hooded Crow is a Eurasian bird species in the crow genus. Widely distributed, it is also known locally as Scotch Crow, Danish Crow, and Corbie or Grey Crow in Ireland, which is what its Welsh name, Brân Lwyd, translates as...
. In Lithuania, the introduced Raccoon Dog
Raccoon Dog
The raccoon dog , also known as the magnut or tanuki, is a canid indigenous to east Asia. It is the only extant species in the genus Nyctereutes...
has also been recorded as taking Corn Crakes. When chicks are exposed by rapid mowing, they may be taken by large birds including the White Stork
White Stork
The White Stork is a large bird in the stork family Ciconiidae. Its plumage is mainly white, with black on its wings. Adults have long red legs and long pointed red beaks, and measure on average from beak tip to end of tail, with a wingspan...
, harriers
Harrier (bird)
A harrier is any of the several species of diurnal hawks forming the Circinae sub-family of the Accipitridae family of birds of prey. Harriers characteristically hunt by flying low over open ground, feeding on small mammals, reptiles, or birds....
and other birds of prey
Bird of prey
Birds of prey are birds that hunt for food primarily on the wing, using their keen senses, especially vision. They are defined as birds that primarily hunt vertebrates, including other birds. Their talons and beaks tend to be relatively large, powerful and adapted for tearing and/or piercing flesh....
, gull
Gull
Gulls are birds in the family Laridae. They are most closely related to the terns and only distantly related to auks, skimmers, and more distantly to the waders...
s and corvids
Corvidae
Corvidae is a cosmopolitan family of oscine passerine birds that contains the crows, ravens, rooks, jackdaws, jays, magpies, treepies, choughs and nutcrackers. The common English names used are corvids or the crow family , and there are over 120 species...
. At undisturbed sites nests and broods are rarely attacked, as reflected in a high breeding success. There is a record of a Corn Crake on migration through Gabon
Gabon
Gabon , officially the Gabonese Republic is a state in west central Africa sharing borders with Equatorial Guinea to the northwest, Cameroon to the north, and with the Republic of the Congo curving around the east and south. The Gulf of Guinea, an arm of the Atlantic Ocean is to the west...
being killed by a Black Sparrowhawk.
The widespread fluke
Trematoda
Trematoda is a class within the phylum Platyhelminthes that contains two groups of parasitic flatworms, commonly referred to as "flukes".-Taxonomy and biodiversity:...
Prosthogonimus ovatus, which lives in the oviduct
Oviduct
In non-mammalian vertebrates, the passageway from the ovaries to the outside of the body is known as the oviduct. The eggs travel along the oviduct. These eggs will either be fertilized by sperm to become a zygote, or will degenerate in the body...
s of birds, has been recorded in the Corn Crake, as have the parasitic worm
Parasitic worm
Parasitic worms or helminths are a division of eukaryoticparasites that, unlike external parasites such as lice and fleas, live inside their host. They are worm-like organisms that live and feed off living hosts, receiving nourishment and protection while disrupting their hosts' nutrient...
Plagiorchis elegans, the larvae of parasitic flies, and hard ticks
Ixodidae
Ixodidae is a family of ticks containing the hard ticks.-Description:They are distinguished from the other main family of ticks, the soft ticks by the presence of a scutum or hard shield...
of the genera Haemaphysalis
Haemaphysalis
Haemaphysalis is a genus of tick.-Species:* Haemaphysalis aborensis Warburton, 1913* Haemaphysalis aciculifer Warburton 1913* Haemaphysalis aculeata Lavarra, 1904* Haemaphysalis adleri Feldman-Muhsam, 1951...
and Ixodes
Ixodes
Ixodes is a genus of hard-bodied ticks . It includes important disease vectors of animals and humans . Some ticks in this genus may transmit the pathogenic bacterium Borrelia burgdorferi responsible for causing Lyme disease...
.
During the reintroduction of Corn Crakes to England in the 2003 breeding season, enteritis
Enteritis
In medicine, enteritis, from Greek words enteron and suffix -itis , refers to inflammation of the small intestine. It is most commonly caused by the ingestion of substances contaminated with pathogenic microorganisms. Symptoms include abdominal pain, cramping, diarrhea, dehydration and fever...
and ill heath in pre-release birds was due to bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
of a pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
ic Campylobacter
Campylobacter
Campylobacter is a genus of bacteria that are Gram-negative, spiral, and microaerophilic. Motile, with either unipolar or bipolar flagella, the organisms have a characteristic spiral/corkscrew appearance and are oxidase-positive. Campylobacter jejuni is now recognized as one of the main causes...
species. Subsequently, microbiology
Microbiology
Microbiology is the study of microorganisms, which are defined as any microscopic organism that comprises either a single cell , cell clusters or no cell at all . This includes eukaryotes, such as fungi and protists, and prokaryotes...
tests were done to detect infected individuals and to find the source of the bacteria in their environment.
Status
Until 2010, despite a breeding range estimated at 12,400,000 km2 (4,800,000 mi2), the Corn Crake was classified as Near ThreatenedNear Threatened
Near Threatened is a conservation status assigned to species or lower taxa that may be considered threatened with extinction in the near future, although it does not currently qualify for the threatened status...
on the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
because of serious declines in Europe, but improved monitoring in Russia indicates that anticipated losses there have not occurred and numbers have remained stable or possibly increased. It is therefore now classed as Least Concern
Least Concern
Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...
, since the major populations in Russia and Kazakhstan are not expected to change much in the short term. There are an estimated 1.3–2.0 million breeding pairs in Europe, three-quarters of which are in European Russia, and a further 515,000–1,240,000 pairs in Asiatic Russia; the total Eurasian population has been estimated at between 5.45 and 9.72 million individuals. In much of the western half of its range, there have been long-term declines that are expected to continue, although conservation measures have enabled numbers to grow in several countries, including a five-fold increase in Finland, and a doubling in the UK. In the Netherlands, there were 33 breeding territories in 1996, but this number had increased to at least 500 by 1998.
The breeding Corn Crake population had begun to decline in the 19th century, but the process gained pace after World War II. The main cause of the steep declines in much of Europe is the loss of nests and chicks from early mowing. Haymaking dates have moved forward in the past century due to faster crop growth, made possible by land drainage and the use of fertilisers, and the move from manual grass-cutting using scythe
Scythe
A scythe is an agricultural hand tool for mowing grass, or reaping crops. It was largely replaced by horse-drawn and then tractor machinery, but is still used in some areas of Europe and Asia. The Grim Reaper is often depicted carrying or wielding a scythe...
s to mechanical mower
Mower
A mower is a machine for cutting grass or other plants that grow on the ground. Usually mowing is distinguished from reaping, which uses similar implements, but is the traditional term for harvesting grain crops, e.g...
s, at first horse-drawn and later pulled by tractor
Tractor
A tractor is a vehicle specifically designed to deliver a high tractive effort at slow speeds, for the purposes of hauling a trailer or machinery used in agriculture or construction...
s. Mechanisation also means that large areas can be cut quickly, leaving the crake with no alternative sites to raise either a first brood if suitable habitat has gone, or a replacement brood if the first nest is destroyed. The pattern of mowing, typically in a circular pattern from the outside of a field to its centre, gives little chance of escape for the chicks, which are also exposed to potential animal predators. Adults can often escape the mowers, although some incubating females sit tight on the nest, with fatal results.
Loss of habitat
Habitat destruction
Habitat destruction is the process in which natural habitat is rendered functionally unable to support the species present. In this process, the organisms that previously used the site are displaced or destroyed, reducing biodiversity. Habitat destruction by human activity mainly for the purpose of...
is the other major threat to the Corn Crake. Apart from the reduced suitability of drained and fertilised silage fields compared to traditional hay meadows, in western Europe the conversion of grassland to arable has been aided by subsidies, and further east the collapse of collective farming
Collective farming
Collective farming and communal farming are types of agricultural production in which the holdings of several farmers are run as a joint enterprise...
has led to the abandonment and lack of management of much land in this important breeding area. More localised threats include floods in spring, and disturbance by roads or wind farm
Wind farm
A wind farm is a group of wind turbines in the same location used to produce electric power. A large wind farm may consist of several hundred individual wind turbines, and cover an extended area of hundreds of square miles, but the land between the turbines may be used for agricultural or other...
s. This bird is good eating; when they were common in England, Mrs Beeton
Mrs Beeton
Isabella Mary Beeton , universally known as Mrs Beeton, was the English author of Mrs Beeton's Book of Household Management, and is one of the most famous cookery writers.-Background:...
recommended roasting four on a skewer. More significant than direct hunting is the loss of many birds, up to 14,000 a year, in Egypt, where migrating birds are captured in nets set for the quail with which they often migrate. Although this may account for 0.5–2.7% of the European population, the losses to this form of hunting are less than when the targeted species were more numerous and predictable.
Most European countries have taken steps to conserve the Corn Crake and produce national management policies; there is also an overall European action plan. The focus of conservation effort is to monitor populations and ecology
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
and to improve survival, principally through changing the timing and method of hay harvesting. Later cutting gives time for breeding to be completed, and leaving uncut strips at the edges of fields and cutting from the centre outwards reduces the casualties from mowing. Implementing these changes is predicted to stop the population decline if the measures are applied on a sufficiently large scale. Reduction of illegal hunting, and protection in countries where hunting is still allowed, are also conservation aims. Reintroduction of the Corn Crake is being attempted in England, and breeding sites are scheduled for protection in many other countries. Where breeding sites impinge on urban areas, there are cost implications, estimated in one German study at several million euros per Corn Crake. The Corn Crake does not appear to be seriously threatened on its wintering grounds and may benefit from deforestration, which creates more open habitats.
In culture
Most rails are secretive wetland birds that have made little cultural impression, but as a formerly common farmland bird with a loud nocturnal call that sometimes led to disturbed sleep for rural dwellers, the Corn Crake has acquired a variety of folk names and some commemoration in literature.Names
The favoured name for this species among naturalists has changed over the years, with "Landrail" and variants of "Corncrake" being preferred at various times. "Crake Gallinule" also had a period of popularity between 1768 and 1813. The originally ScottishScottish English
Scottish English refers to the varieties of English spoken in Scotland. It may or may not be considered distinct from the Scots language. It is always considered distinct from Scottish Gaelic, a Celtic language....
"Corne Crake" was popularised by Thomas Bewick
Thomas Bewick
Thomas Bewick was an English wood engraver and ornithologist.- Early life and apprenticeship :Bewick was born at Cherryburn House in the village of Mickley, in the parish of Ovingham, Northumberland, England, near Newcastle upon Tyne on 12 August 1753...
, who used this term in his 1797 A History of British Birds. Other Scottish names include "Corn Scrack" and "Quailzie"; the latter term, like "King of the Quail", "Grass Quail", and the French "roi de caille" refer to the association with the small gamebird. Another name, "Daker", has been variously interpreted as onomatopoeic, or derived from the Old Norse
Old Norse
Old Norse is a North Germanic language that was spoken by inhabitants of Scandinavia and inhabitants of their overseas settlements during the Viking Age, until about 1300....
Ager-hoene, meaning "Cock of the field"; variants include "Drake", "Drake Hen" and "Gorse Drake".
In literature
Corn Crakes are the subject of three stanzas of the seventeenth century poet Andrew Marvell'sAndrew Marvell
Andrew Marvell was an English metaphysical poet, Parliamentarian, and the son of a Church of England clergyman . As a metaphysical poet, he is associated with John Donne and George Herbert...
"Upon Appleton House
Upon Appleton House
Upon Appleton House is a poem written by Andrew Marvell for Thomas Fairfax, 3rd Lord Fairfax of Cameron. It was written in 1651, when Marvell was working as a tutor for Fairfax's daughter, Mary...
", written in 1651 about the North Yorkshire
North Yorkshire
North Yorkshire is a non-metropolitan or shire county located in the Yorkshire and the Humber region of England, and a ceremonial county primarily in that region but partly in North East England. Created in 1974 by the Local Government Act 1972 it covers an area of , making it the largest...
country estate of Thomas Fairfax
Thomas Fairfax, 3rd Lord Fairfax of Cameron
Thomas Fairfax, 3rd Lord Fairfax of Cameron was a general and parliamentary commander-in-chief during the English Civil War...
. The narrator depicts the scene of a mower cutting the grass, before his "whistling Sithe" unknowingly carves the Rail. The farmhand draws out the scythe "all bloody from its breast" and "does the stroke detest". It continues with a stanza that demonstrates the problematic nature of the Corn Crake's nesting habits:
Unhappy Birds! What does it boot
To build below the Grass' Root;
When Lowness is unsafe as Hight,
And Chance o'ertakes, what scapeth spight?
John Clare
John Clare
John Clare was an English poet, born the son of a farm labourer who came to be known for his celebratory representations of the English countryside and his lamentation of its disruption. His poetry underwent a major re-evaluation in the late 20th century and he is often now considered to be among...
, the nineteenth-century English poet based in Northamptonshire
Northamptonshire
Northamptonshire is a landlocked county in the English East Midlands, with a population of 629,676 as at the 2001 census. It has boundaries with the ceremonial counties of Warwickshire to the west, Leicestershire and Rutland to the north, Cambridgeshire to the east, Bedfordshire to the south-east,...
, wrote "The Landrail", a semi-comic piece which is primarily about the difficulty of seeing Corn Crakes – as opposed to hearing them. In the fourth verse he exclaims: "Tis like a fancy everywhere/A sort of living doubt". Clare wrote about Corn Crakes in his prose works too, and his writings help to clarify the distribution of this rail when it was far more widespread than now.
The proverbial use of the Corn Crake's call to describe someone with a grating or unmelodious voice is illustrated in the quotation "thanks to a wee woman with a voice like a corncrake who believed she was an apprentice angel". This usage dates from at least the first half of the nineteenth century, and continues through to the present.
External links
- Corn Crake on the Internet Bird Collection
- Flickr Field Guide Birds of the World photographs
- Upon Appleton House, to my Lord Fairfax by Andrew Marvell
- The Landrail by John Clare