Corncrake, Corn Crake

Upon reaching the breeding territory after migration, males begin to call repeatedly for many hours in order to attract a female. After selecting a male, females then choose a nest site (2). Nests are constructed on the ground from dead stems and leaves amongst patches of nettles (Urtica) or other tall vegetation. The female lays one to two eggs per day and the typical clutch size is eight to twelve eggs. The male leaves the female before egg laying is complete, and attempts to attract another female. Females generally produce a second brood by the beginning of July. During the breeding season corncrakes feed on invertebrates taken from plants or from the ground (3).

The latest corncrake survey in 1998 estimated that there were 589 calling males in the UK. This indicates that the population is beginning to increase in response to conservation measures. These measures include agri-environment schemes that pay farmers to manage their fields in ways that benefit the corncrake, such as cutting the meadows later to prevent losses, and maintaining crop rotation systems that create a mosaic of habitat types. It has been suggested that cutting should proceed from the centre of a field outwards as this minimises losses; in addition, leaving uncut patches at the field margins provides shelter for juveniles during the harvest. Over ten percent of the British corncrake population is located within RSPB managed land, and ten of these sites have been managed specifically for the species. In addition, nine corncrake Special Protection Areas (SPAs) were established in 1998 (3). The corncrake is a UK Biodiversity Action Plan (UK BAP) species; the Species Action Plan aims to maintain the population, increase its range and in the long-term, restore the species to parts of its former UK range (5).

Male and female corncrakes are very similar in appearance; both have light yellowish-brown plumage, and the face and upper parts of the breast are pale grey. In flight their long dangling legs, chestnut wings and buff coloured underparts are visible. The corncrake is easier to hear than to see, the call is a repeated rasping 'crrek crrek' similar to a nail scraping along a comb (2). The scientific name of this species, crex crex refers to this call (4).

Most corncrakes are found in traditionally managed agricultural grasslands. They require tall grasses or herbs of at least 20 centimetres in height so that they can be concealed at all times. Occasionally crops such as barley or oats will be used later in summer (2).

A globally threatened summer visitor, the corncrake was once widespread throughout the UK and much of northern and central Europe, extending to Siberia. Within this former range the corncrake is now restricted, and occurs in fragmented populations. In the UK it is currently found mainly in the Northern and Western islands of Scotland. The species winters in south-eastern Africa and migrates to Europe in spring (3).

Classified as Near Threatened (NT) on the IUCN Red List 2007. Listed under Annex 1 of the EC Birds Directive and Appendix II of the Bern Convention. Included in the Birds of Conservation Concern Red List, and protected under Schedule 1 of the Wildlife and Countryside Act 1981 in the UK (3).

The decline in the UK was first noticed in the south and east of England during the late 19th century; it continued into the 20th century and became more severe. After the 1930s corncrakes were lost from most of England, southern Wales and from large areas of Scotland. They are currently fairly common only in the northern and western islands of Scotland. This decline coincided with the increased use of farm machinery to cut hay meadows. Meadows were also cut earlier, which caused massive losses of adults, juveniles and nests. Other causes of the decline include loss of habitat due to conversion of grassland to arable and sheep pasture, or unsuitable management such as over-grazing. Disturbance and predation by domestic and feral cats and mink may also cause significant losses (3). Between 1978 and 1979 there were just 730 to 750 calling males in the UK; by 1993 this had fallen to 478, but by 2001 there were around 630 (2).