02360nas a2200205   4500008004100000245010700041210006900148260001600217300001400233490000800247520169800255653002301953653002001976653001401996653002402010100002702034700002402061700001502085856005402100       2018                        eng d00aSoft songs in male ortolan buntings are used in an aggressive context but are not an aggressive signal0 aSoft songs in male ortolan buntings are used in an aggressive co  cJan-08-2018  a549 - 5580 v1243 a<p>Many bird species produce low‐amplitude acoustic signals that have been poorly studied in comparison with loud, broadcast songs used for mate attraction and repelling rivals. In some birds, these soft signals were found to be emitted in an antagonistic context and were the most reliable predictor of a subsequent physical attack. The function of this signal is poorly understood, and several hypotheses have been proposed to explain the mechanisms and possible functions of such low‐amplitude signals. The subject of this study is the ortolan bunting, a small passerine species that produces soft songs during territorial defence. In this study, we aim to study whether the soft songs of the ortolan bunting are a signal of increased aggressiveness by testing if they meet the context, prediction and response criteria of aggressive signals. We simulated stranger male intrusion into a focal male territory with three different playback experiments. We found no significant differences in the male responses to the taxidermic model regardless of whether they were or were not producing soft songs in response. The males responded more strongly to loud songs than to soft songs during the simulated intrusions, and the males did not treat soft songs as a predictor of conflict escalation. Although soft songs clearly appeared during territorial encounters and were not present during spontaneous singing before the intrusions, our results did not support the hypothesis that soft songs indicate aggressive character. We suggest that soft songs in the ortolan bunting are intentionally used by birds to modify their intentions or target‐specific individuals within a close range.</p>
10aAggressive signals10aortolan bunting10asoft song10aterritorial defence1 aJakubowska, Aleksandra1 aOsiejuk, Tomasz, S.1 aFusani, L.  uhttp://doi.wiley.com/10.1111/eth.2018.124.issue-8