Abstract:
Assessment of the similarity of sound spectrograms of the loud advertising vocalizations of bitterns (booms) by observers using subjective, qualitative criteria shows that the booms of bitterns are individually distinctive. Multivariate quantitative measures also showed booms to be individually distinctive. Both qualitative and quantitative assessments showed that booms from the same individual are consistent within and between years. The usefulness of individual distinctiveness in vocalizations for collecting data on within and between year survival is discussed, as are the factors limiting the technique.