Vergleich des Strophenaufbaus und der Strophenabfolge an Gesängen von Sprosser (Luscinia luscinia) und Blaukehlchen (Luscinia svecica)

Songs of three Thrush Nightingales and three Blue Throats were recorded in the field and analyzed by visual inspection of frequency spectrograms. An analysis of the succession of elements within a song as well as the succession of songs in a song bout revealed the following results in both species: a) the succession of elements within songs was organized as a hierarchical branching structure, b) three structurally different sections could be found in all songs, c) songs were initialized by specific element types. A termination of songs by specific element types was only found in the thrush nightingale. Songs ot the Thrush Nightingale were organized as series of songs which corresponded in their first two element types (same song class). These series consisted of different song types, which succeeded with a high constancy. Different song types were sung in close sequential association and recurred preferably after intervals of 8-10 songs. In song bouts of the Blue Throat however songs which corresponded in all sections were rarely found. Those songs corresponding in the first two element types were often repeated immediately, but in comparison to the Thrush Nightingale series of these songs were rare. Besides many similarities in the song organization in both species the song of the Thrush Nightingale was more similar to the closely related Nightingale (Luscinia megarhynchos) - with regard to the syntactical organization of song and the organization of consecutive songs. The song organization of the Blue Throat showed more similarities to the European Redstart (Phoenicurus phoenicurus). These results indicate a relation between the syntactical organization of song and the sequential organisation of consecutive songs.