Original title: Does intra-sexual selection drive the evolution of individual identity in animal signals?
Authors: MADHAVAN, Malavika
Document type: Doctoral theses
Year: 2026
Language: eng
Abstract: This thesis investigates whether population density, as a proxy for intrasexual competition, influences vocal individuality in a territorial species, the little owl (Athene noctua), and more broadly in owls as a comparative system. It combines literature synthesis, population-level, individual-level, and comparative analyses across five chapters. Chapter 1 reviews vocal individuality in owls, summarising methods, identifying gaps, and outlining directions for future work. Chapter 2 shows that little owls living in dense aggregations exhibit higher vocal individuality, with local population structure playing a stronger role than overall population density. Chapter 3 confirms one of our study populations as the highest-density little owl population recorded, highlighting its value as a system with high natural intrasexual competition. Chapter 4 demonstrates that neighbouring males diverge more in their calls than distant individuals independent of genetic relatedness, suggesting that repeated interactions may promote signal divergence. And finally, Chapter 5 uses phylogenetic analyses to demonstrate that body size strongly constrains vocal frequency across owls, with additional selective pressures further driving low frequency calls. Further, habitat density had no effect on call frequency, and population density showed mixed associations in different directions with acoustic traits. Overall, this thesis supports the idea that intrasexual selection regulates vocal individuality in owls, with conspecific interaction at the local scale suggested as one of the main factors responsible for this. Moreover, it highlights that acoustic signals in owls are governed by multiple selective pressures, which should be considered together to further understand the evolution of their vocalisations.
Keywords: Individuality; Intrasexual selection; Owl; Population density; Signal evolution; Vocalizations
Citation: MADHAVAN, Malavika. Does intra-sexual selection drive the evolution of individual identity in animal signals?. České Budějovice, 2026. disertační práce (Ph.D.). JIHOČESKÁ UNIVERZITA V ČESKÝCH BUDĚJOVICÍCH. Přírodovědecká fakulta

Institution: University of South Bohemia in České Budějovice (web)
Document availability information: Fulltext is available in the Digital Repository of University of South Bohemia.
Original record: http://www.jcu.cz/vskp/67181

Permalink: http://www.nusl.cz/ntk/nusl-775098


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Universities and colleges > Public universities > University of South Bohemia in České Budějovice
Academic theses (ETDs) > Doctoral theses