Corn Crake - Status

Status

Until 2010, despite a breeding range estimated at 12,400,000 km2 (4,800,000 mi2), 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. 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 farms. 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.