Abstract
Individual recognition is fundamental to the social behaviour of many animals. In the context of territorial behaviour, animals in high-density populations encounter conspecific rivals and potential mates more frequently, which should enhance the individuality of territorial signals to facilitate recognition among conspecifics. We investigated vocal individuality in male territorial calls of two populations of little owls (Athene noctua) with different densities. Further, to explore the potential influence of local population distribution on individuality, we also examined isolated males without neighbours and clumped males with neighbours. Our findings indicate higher individuality at higher densities across both scenarios, measured using two individuality metrics: Beecher’s information statistic and Discrimination score. Clumped males exhibited significantly lower acoustic niche overlaps (i.e. higher vocal individuality) compared to isolated males. However, only a non-significant trend for lower acoustic niche overlaps (i.e. higher vocal individuality) was found for males from high density compared to low density populations. This suggests that the immediate social environment might be more influential than larger-scale population density patterns. This study suggests that vocal individuality in a territorial species is influenced by conspecific density, similar to findings in group-living and colonial species.
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Data availability
Data available on figshare: [doi.org/10.6084/m9.figshare.29958992](http:/doi.org/10.6084/m9.figshare.29958992).
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Acknowledgements
We are grateful to all four anonymous reviewers whose feedback on a previous version of the manuscript helped to improve its quality and clarity.
Funding
This study was supported by the Czech Science Foundation (GACR 21–04023 K). Martin Šálek was partly supported by the Czech Academy of Sciences in the framework of the program Strategy AV 21 and the research aim of the Czech Academy of Sciences (RVO 68081766). Malavika Madhavan was partly supported by the University of South Bohemia (GAJU No. 047/2025/P). Martin Šálek and Malavika Madhavan were also supported by One Nature Project (LIFE17 IPE/CZ/000005, LIFE IP: N2K Revisited), supported by the EU´s Financial Instrument LIFE.
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PL and MŠ conceived the study and acquired funding for the project. MŠ and AP collected the data, and AP, PL, LH, and MM curated the data. MM, LH, and PL investigated the data and performed the analyses. MM and PL drafted the manuscript, and all authors contributed to its editing and final approval.
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Madhavan, M., Hornátová, L., Šálek, M. et al. Social environment affects vocal individuality in a non-learning species.
Sci Rep (2025). https://doi.org/10.1038/s41598-025-29387-3
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DOI: https://doi.org/10.1038/s41598-025-29387-3
Keywords
- Acoustic niche
- Bioacoustics
- Owl
- Population density
- Signal evolution
- Vocal learning
- Vocal plasticity
Source: Ecology - nature.com

