Corn Crake

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 (160 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 (10–12 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 quails. 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 corn crake breeds from 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 rail. 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. 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, 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 (8,900 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-grown crops such as cereals, peas, rape, clover or potatoes may be used. After breeding, adults move to taller vegetation such as common reed, iris, or nettles 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 30–200 cm (0.98–6.56 ft) tall, including seasonally burnt areas and occasionally sedges or reed beds. 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 (5,740 ft) 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 golf courses.

Until 2010, despite a breeding range estimated at 12,400,000 km (4,800,000 sq mi), the corn crake was classified as near threatened 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 scythes to mechanical mowers, at first horse-drawn and later pulled by tractors. 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.