Published online by Cambridge University Press: 11 May 2010
The Corncrake Crex crex is a rail which inhabits tall grass and herbage and migrates between breeding grounds in northern Eurasia and wintering areas in south-east Africa. Corncrake populations are known to have been declining for more than 100 years in some countries and declines have now been reported for almost all of the European part of the species's world range. It appears that mechanized mowing early in the breeding season reduces the production of young to a point below that needed to maintain the population. It might therefore be expected that Corncrakes would be least abundant in countries where the management of agricultural grassland is most mechanized and intensive. To test this hypothesis, an analysis of available statistics for agricultural intensity and Corncrake population density in different European countries was undertaken. Milk yield per dairy cow and measures of the use of fertilizers and tractors were used as indices of the intensity of management of agricultural grassland. Corncrakes were least abundant in European countries with high levels of milk yield, fertilizer and tractor use. Countries with low indices of agricultural intensity and high Corncrake abundance are in eastern Europe where continuing political change makes the future course of agricultural development difficult to foresee. The persistence of the Corncrake in this region depends on the adoption of agricultural policies which do not encourage further intensification of grassland management in those areas which support important populations.