Distribution and Variability of Song Types in the Wood Thrush

Abstract

Abstract Compared to the song of other oscine species, wood thrush song shows little macro-geographical variation: 1) Most song types defined for a local population are widespread over the geographical range, 2) the relative abundances of different song types are similar in samples taken from different locations, and 3) a given song type is no more variable in structure over the geographical range than within a local population. Wood thrush song also shows little microgeographical variation. The degree of song type sharing does not vary as a function of the distance between males in a local population. Song remains stable over time in a local population, as indicated by a similarity in the relative abundances of song types in samples taken 14 years apart. Regarding the distribution of song types among repertoires, 1) Different combinations of song types within repertoires occur no more or less often than expected by chance, 2) different versions of a single song type are distributed at random among repertoires, 3) large repertoires do not contain a greater proportion of rare (unclassified) songs than small repertoires, and 4) rare songs are not clustered in the repertoires of certain individuals.