The status of the Corncrake Crex crex in Britain in 1998

A census of Corncrakes throughout Britain was carried out in 1998. National Grid squares of 10 km in the Hebrides, Northern Isles and the mainland of Highland Scotland known to have held the species during the breeding season since 1988 were searched systematically by night for singing males. A sample of such squares elsewhere in Scotland was also searched. In addition, bird-watchers and the general public were encouraged by press publicity to contribute records of singing birds, which were checked for accuracy. A total of 589 singing males was counted in 93 10-km squares. Ninety percent of the population was in the Hebridean Islands. The total count was 23% larger than in the previous census in 1993 and 3% larger than in 1988. All surveys of distribution and censuses between the late 19th century and 1993 recorded a progressive decline in the national population and range. The average rate of population decline between 1988 and 1993 was 3.5% per year, but between 1993 and 1998 the population increased by an average of 4.2% per year. However, annual counts from 1993 to 1998 in core areas that held more than 90% of the population, showed that this overall increase resulted from four successive annual increases of 4-16% followed by a decline of 15% between 1997 and 1998. There was considerable variation among islands and areas in the rate of change of their Corncrake numbers.