Geographical variation in the vocalisation of the corncrake Crex crex

Geographic variation in the structure of corncrake calls was examined by the analysis of recordings collected in four areas of the species' range. On a large geographic scale (> 100 km), discriminant function analysis correctly attributed 54-88% of individuals to the population from which they were recorded based upon temporal measures of call structure. On a smaller geographic scale (< 1 km), neighbouring individuals shared significantly more similar call structures than more distant individuals. Mantel tests showed a high level of clustering of similar call structures at three sites within the areas studied. The implications of these results for conservation efforts are discussed.