Song structure and repertoire sharing in the Tawny Pipit Anthus campestris in Poland

The present study characterizes the song of Tawny Pipit males (n = 55) recorded in May 2005 in the Wielkopolska region of Poland. Tawny Pipits sang with a very variable rate of 4-28 songs per minute (mean +/- SE 16.0 +/- 1.35). Songs were thus short, with an average duration of under 0.5 sec. At the same time, songs were relatively complex in structure and consisted of 2-3 (max. 5) units of frequency between 2.7 and 5.3 kHz. Based on visual inspection of sonograms and further cross-correlation analysis, 20 different song types were distinguished. Each male had only a single song type in his repertoire and the rendition of strophes produced by a male were very stereotypical. The songs of different males exhibited varying levels of similarity, from completely different, through sharing some within-song units, to strongly similar on sonograms. However, even the strongly similar songs of different males demonstrated some individuality in frequency parameters or fine note structure. On average, there were only 0.38 different song types per male within the population studied, and 83% of males sang song types shared with at least one other male. Nine of the 20 song types described were unique, i.e. sung by single males. The results of this study suggest that a highly variable song rate may be a signal of male motivation, whereas individual differences in song structure probably enable individual recognition.