02504nas a2200253   4500008004100000245010500041210006900146520167700215653002401892653002501916653002101941653001801962653002001980653002302000100001802023700002202041700002902063700002202092700002102114700002002135700001602155700002402171856005502195       2019                        eng d00aSinging behind the stage: thrush nightingales produce more variable songs on their wintering grounds0 aSinging behind the stage thrush nightingales produce more variab3 a<p>The songs of migratory passerine birds have a key role in mate attraction and territory defence during the breeding season. Many species also sing on their wintering grounds, but the function of this behaviour remains unclear. One possible explanation, proposed by the song improvement hypothesis, is that the birds take advantage of this period to develop their singing skills for the next breeding season. If so, non-breeding songs should reflect features of an early phase in song development, characterized by high vocal plasticity. In our study, we tested this prediction by comparing songs of thrush nightingales (Luscinia luscinia) recorded at two different breeding areas in Europe and one wintering area in Africa. While all songs from European localities had a typical structure characteristic of the study species, 89% of the songs recorded from Africa were highly variable, lacking such typical structure. We conducted further detailed analysis of breeding and winter songs that exhibited species-specific structure. First, we explored plasticity at the syllable level using a cross-correlation analysis, to obtain similarity scores as a measure of consistency. Second, we asked multiple human observers to quantify element variability. Our results showed significant differences in syllable consistency between breeding and wintering grounds, with more consistent delivery of syllables in the breeding areas. Likewise, element variability was substantially lower in the breeding populations. While both results fit the predictions of the song improvement hypothesis, more research is needed to elucidate the roles of singing on the wintering grounds.</p>
10aElement variability10aNon-breeding singing10aSong consistency10aSong function10aSong plasticity10aThrush nightingale1 aSouriau, Abel1 aGeberzahn, Nicole1 aIvanitskii, Vladimir, V.1 aMarova, Irina, M.1 aVokurková, Jana1 aReifová, Radka1 aReif, Jiři1 aPetrusková, Tereza  uhttp://link.springer.com/10.1007/s00265-019-2765-x02647nas a2200145   4500008004100000245016500041210006900206520203900275100002902314700002302343700002002366700001902386700002402405856007202429       2019                        eng d00aExtraordinary variation in a simple song: No geographical patterns in initial phrase variation of the Yellowhammer, a passerine with pronounced dialectsAbstract0 aExtraordinary variation in a simple song No geographical pattern3 a<p>Geographical variation of birdsong is used to study various topics from cultural evolution to mechanisms responsible for reproductive barriers or song acquisition. In species with pronounced dialects, however, patterns of variation in non-dialect parts of the song are usually overlooked. We focused on the individually variable initial phrase of the song of the Yellowhammer (Emberiza citrinella), a common Palearctic passerine which became a model species for dialect research. We used a quantitative method to compare the similarity of initial phrases from the repertoires of 237 males recorded at different spatial scales in a central European country covering all main dialect types. We hypothesized that patterns of initial phrase sharing and/or phrase similarity are affected by dialect boundaries and geographical proximity (i.e. that birds from the same dialect regions use more similar phrases or share them more often). Contrary to our expectations, initial phrase variation seems unrelated to dialects, as we did not find higher similarity either among recordings from the same dialect areas or among those from the same locality. Interestingly, despite the immense variability of phrase types detected (only 16% of 368 detected initial phrase types were shared between at least 2 males), a relatively high proportion of males (45%) was involved in sharing, and males using the same initial phrase were located anywhere from tens of meters to hundreds of kilometers apart. The patterns of variation suggest that precise copying during song learning as well as improvisation play important roles in forming individual repertoires in the Yellowhammer. Our data also confirm previous indications that the repertoires of Yellowhammer males (i.e. the composition of initial phrases) are individually unique and temporally stable. This makes the species a good candidate for individual acoustic monitoring, useful for detailed population or behavioral studies without the need for physical capture and marking of males.</p>
1 avan Boheemen, Sharina, J1 aDiblíková, Lucie1 aBílková, Jana1 aPetrusek, Adam1 aPetrusková, Tereza  uhttps://academic.oup.com/auk/article/doi/10.1093/auk/ukz055/5601449