Corncrake Crex crex census estimates: a conservation application of vocal individuality

Vocal individuality could be used to estimate numbers of individuals in species otherwise difficult to monitor. However, the usefulness of this technique in providing conservation information is little studied. The vocalisations of the Corncrake show a high level of individual distinctiveness. This fact was used to examine current counting methods and estimate movement patterns within one breeding season. Information on individual identity gained from vocalisations increased census estimates by 20–30% and showed that male Corncrakes called less frequently than previous studies had suggested. Males moved greater distances in areas with lower availability of suitable habitat. The conservation implications of these results are discussed.