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The corn crake, corncrake or landrail ( Crex crex) is a bird in the Rallidae. It breeds in Europe and Asia as far east as western China, and bird migration to Africa for the Northern Hemisphere's 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 beak is flesh-toned, the iris is pale brown, and the legs and feet are pale grey. Juveniles are similar in plumage to adults, and down feather 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 , 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 which 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 completed. The corn crake is omnivorous but mainly feeds on , the occasional small frog or mammal, and plant material including grass seed and cereal grain. Threats include dogs, cats, other introduced and feral mammals, large birds, various Parasitism and .
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 increased population in some countries which had suffered the greatest losses. Despite its elusive nature, the loud call has ensured the corn crake has been noted in literature, and garnered a range of local and dialect names.
Corn crakes were first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae 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 onomatopoeia, 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 species' habit of nesting in dry hay or cereal fields, rather than marshes used by most members of this family.
The corn crake is sympatry 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.
The female corn crake may give a call that is similar to that of the male; it also has a distinctive barking sound, similar in rhythm to the main call but without the grating quality. The female also has a high-pitched cheep call, and a sound to call the chick. The chicks make a quiet contact call, and a chirp used to beg for food. Because of the difficulty in seeing this species, it is usually by counting males calling between 11 pm and 3 am; the birds do not move much at night, whereas they may wander up to 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 Ireland and Britain, 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. Birds from Coll following the western route paused in West Africa on their way further south, and again on the return flight, when they also rested in Spain or North Africa. Eastern migrants have been recorded in those parts of southern Asia that lie between the east of the breeding range and Africa. Further afield, the corn crake has been recorded as a vagrant to Sri Lanka, Vietnam and Australia, New Zealand, the Seychelles, Bermuda, Canada, the US, Greenland, Iceland, Brazil, the Faroe islands, the Azores, Madeira, and the Canary Islands.
The corn crake is mainly a lowland species, but breeds up to altitude in the Alps, in China and in Russia. When breeding in Eurasia, the corn crake's habitats would originally have included river meadows with tall grass and meadow plants including Carex 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 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-grown crops such as , peas, Brassica napus, clover or potatoes may be used. After breeding, adults move to taller vegetation such as Phragmites, iris, or Urtica dioica to moult, returning to the 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 tall, including seasonally burnt areas and occasionally sedges or . 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 altitude in South Africa. Each bird stays within a fairly small area. 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 .
The corn crake is solitary on the wintering grounds, where each bird occupies 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 . 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.
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 in diameter and 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 and weigh about , 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.
The widespread Trematoda Prosthogonimus ovatus, which lives in the of birds, has been recorded in the corn crake, as have the parasitic worm Plagiorchis elegans, the larvae of parasitic flies, and Ixodidae of the genera Haemaphysalis and Ixodes.
During the reintroduction of corn crakes to England in the 2003 breeding season, enteritis and ill health in pre-release birds was due to bacteria of a Campylobacter species. Subsequently, microbiology tests were done to detect infected individuals and to find the source of the bacteria in their environment.
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 to mechanical , at first horse-drawn and later pulled by . 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 . This bird is edible; 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 deforestation, which creates more open habitats.
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 Finnish poet Eino Leino also wrote about the bird in his poem "Nocturne".
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.
In The Decemberists "The Hazards of Love 2 (Wager All)" Colin Meloy references the corn crake's call, singing: "And we'll lie until the corn crake crows."
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