Introduce yourself at the beginning – possible identification function of the initial part of the song in the Great Reed Warbler Acrocephalus arundinaceus

Abstract

We analyzed a set of frequency and temporal characteristics of the introductory syllables in the song of the Great Reed Warbler (Acrocephalus arundinaceus) to assess their poten-tial for individual recognition. We also tested if the initial syllables maintained their indi-vidual characteristics over a longer period by comparing their characteristics within a breeding season and over years for individually marked males. We found that within-male seasonal differences in introductory syllables were smaller than differences between males, which enabled correct classification of the majority of individuals within a season. However, the parameters of the introductory syllables of particular males tended to change over years, which diminishes the chances for correctly classifying males across seasons. Our results suggest that the introductory syllables of the Great Reed Warbler song contain sufficient information for male identification, but only within a particular season. As the studied syllables are found in nearly all songs of the Great Reed Warbler, including both long songs attracting females and short songs used during aggressive en-counters with rival males or after pair formation, they may play an important function in both mate and rival recognition.