in

Social environment affects vocal individuality in a non-learning species


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.

Similar content being viewed by others

Species-independent analysis and identification of emotional animal vocalizations

Density-dependent network structuring within and across wild animal systems

Identifying unknown Indian wolves by their distinctive howls: its potential as a non-invasive survey method

Data availability

Data available on figshare: [doi.org/10.6084/m9.figshare.29958992](http:/doi.org/10.6084/m9.figshare.29958992).

References

  1. Judge, P. G. & de Waal, F. B. Rhesus monkey behaviour under diverse population densities: coping with long-term crowding. Anim. Behav. 54, 643–662 (1997).

    Google Scholar 

  2. Jirotkul, M. Population density influences male-male competition in guppies. Anim. Behav. 58, 1169–1175 (1999).

    Google Scholar 

  3. Knell, R. J. Population density and the evolution of male aggression. J. Zool. 278, 83–90 (2009).

    Google Scholar 

  4. Cooper, W. E., Dimopoulos, I., Pafilis, P. & Sex Age, and population density affect aggressive behaviors in island lizards promoting cannibalism. Ethology 121, 260–269 (2015).

    Google Scholar 

  5. Luna, Á., Palma, A., Sanz-Aguilar, A., Tella, J. L. & Carrete, M. Personality-dependent breeding dispersal in rural but not urban Burrowing owls. Sci. Rep. 9, 2886 (2019).

    Google Scholar 

  6. Fedy, B. C. & Stutchbury, B. J. Territory switching and floating in White-bellied antbird (Myrmeciza longipes), a resident tropical passerine in Panama. Auk 121, 486–496 (2004).

    Google Scholar 

  7. Schoepf, I., Schmohl, G., König, B., Pillay, N. & Schradin, C. Manipulation of population density and food availability affects home range sizes of African striped mouse females. Anim. Behav. 99, 53–60 (2015).

    Google Scholar 

  8. Arcese, P. & Smith, J. N. Effects of population density and supplemental food on reproduction in Song sparrows. J. Anim. Ecol. 57, 119–136 (1988).

    Google Scholar 

  9. Sofaer, H. R., Sillett, T. S., Langin, K. M., Morrison, S. A. & Ghalambor, C. K. Partitioning the sources of demographic variation reveals density-dependent nest predation in an Island bird population. Ecol. Evol. 4, 2738–2748 (2014).

    Google Scholar 

  10. Emlen, S. T. & Oring, L. W. Ecology, sexual selection, and the evolution of mating systems. Science 197, 215–223 (1977).

    Google Scholar 

  11. Lukas, D. & Clutton-Brock, T. H. The evolution of social monogamy in mammals. Science 341, 526–530 (2013).

    Google Scholar 

  12. Morales, M. B. et al. Density dependence and habitat quality modulate the intensity of display territory defence in an exploded lekking species. Behav. Ecol. Sociobiol. 68, 1493–1504 (2014).

    Google Scholar 

  13. Beecher, M. D. Signalling systems for individual recognition: an information theory approach. Anim. Behav. 38, 248–261 (1989).

    Google Scholar 

  14. Pollard, K. A., Blumstein, D. T. & Griffin, S. C. Pre-screening acoustic and other natural signatures for use in noninvasive individual identification. J. Appl. Ecol. 47, 1103–1109 (2010).

    Google Scholar 

  15. Freeberg, T. M. Social complexity can drive vocal complexity: group size influences vocal information in Carolina chickadees. Psychol. Sci. 17, 557–561 (2006).

    Google Scholar 

  16. Freeberg, T. M., Dunbar, R. I. & Ord, T. J. Social complexity as a proximate and ultimate factor in communicative complexity. Philosophical Trans. Royal Soc. B: Biol. Sci. 367, 1785–1801 (2012).

    Google Scholar 

  17. Peckre, L., Kappeler, P. M. & Fichtel, C. Clarifying and expanding the social complexity hypothesis for communicative complexity. Behav. Ecol. Sociobiol. 73, 1–19 (2019).

    Google Scholar 

  18. Arnold, B. D. & Wilkinson, G. S. Individual specific contact calls of Pallid bats (Antrozous pallidus) attract conspecifics at roosting sites. Behav. Ecol. Sociobiol. 65, 1581–1593 (2011).

    Google Scholar 

  19. Charrier, I., Aubin, T. & Mathevon, N. Mother-calf vocal communication in Atlantic walrus: a first field experimental study. Anim. Cogn. 13, 471–482 (2010).

    Google Scholar 

  20. Pitcher, B. J., Harcourt, R. G. & Charrier, I. Rapid onset of maternal vocal recognition in a colonially breeding mammal, the Australian sea lion. PLoS One 5(8), e12195 (2010).

    Google Scholar 

  21. Sheehan, M. J. et al. Selection on coding and regulatory variation maintains individuality in major urinary protein scent marks in wild mice. PLoS Genet. 12(1), e1005891 (2016).

    Google Scholar 

  22. Tibbetts, E. A. Complex social behaviour can select for variability in visual features: a case study in Polistes wasps. Proc. R Soc. Lond. B Biol. Sci. 271, 1955–1960 (2004).

    Google Scholar 

  23. Beecher, M. D., Medvin, M. B., Stoddard, P. K. & Loesche, P. Acoustic adaptations for parent-offspring recognition in swallows. Exp. Biol. 45, 179–193 (1986).

    Google Scholar 

  24. Loesche, P., Stoddard, P. K., Higgins, B. J. & Beecher, M. D. Signature versus perceptual adaptations for individual vocal recognition in swallows. Behaviour 118, 15–25 (1991).

    Google Scholar 

  25. Medvin, M. B., Stoddard, P. K. & Beecher, M. D. Signals for parent-offspring recognition: a comparative analysis of the begging calls of Cliff swallows and Barn swallows. Anim. Behav. 45, 841–850 (1993).

    Google Scholar 

  26. Martin, M., Gridley, T., Elwen, S. H. & Charrier, I. Extreme ecological constraints lead to high degree of individual stereotypy in the vocal repertoire of the Cape fur seal (Arctocephalus pusillus pusillus). Behav. Ecol. Sociobiol. 75, 1–16 (2021).

    Google Scholar 

  27. Pollard, K. A. & Blumstein, D. T. Social group size predicts the evolution of individuality. Curr. Biol. 21, 413–417 (2011).

    Google Scholar 

  28. Wilkinson, G. S. Social and vocal complexity in bats. In Animal Social Complexity: Intelligence, Culture, and Individualized Societies (Harvard University Press, 2003). 

    Google Scholar 

  29. Brooks, R. J. & Falls, J. B. Individual recognition by song in White-throated sparrows. I. Discrimination of songs of neighbors and strangers. Can. J. Zool. 53, 879–888 (1975).

    Google Scholar 

  30. Godard, R. Long-term memory of individual neighbours in a migratory songbird. Nature 350, 228–229 (1991).

    Google Scholar 

  31. Hyman, J. & Hughes, M. Territory owners discriminate between aggressive and nonaggressive neighbours. Anim. Behav. 72, 209–215 (2006).

    Google Scholar 

  32. Jaška, P., Linhart, P. & Fuchs, R. Neighbour recognition in two sister songbird species with a simple and complex repertoire-a playback study. J. Avian Biol. 46, 151–158 (2015).

    Google Scholar 

  33. Temeles, E. J. The role of neighbours in territorial systems: when are they ‘dear enemies’? Anim. Behav. 47, 339–350 (1994).

    Google Scholar 

  34. Fisher, J. B. Evolution and bird sociality. Evol. As Process., 71–83. (1954).

  35. Blumstein, D. T., Mcclain, D. R. & Jesus, C. Alarcón-Nieto, G. Breeding bird density does not drive vocal individuality. Curr. Zool. 58, 765–772 (2012).

    Google Scholar 

  36. Delgado, M. D. M. et al. Population characteristics may reduce the levels of individual call identity. PLoS One 8(10), e77557 (2013).

    Google Scholar 

  37. Chen, Z. & Wiens, J. J. The origins of acoustic communication in vertebrates. Nat. Commun. 11, 1–8 (2020).

    Google Scholar 

  38. Ramanankirahina, R., Joly, M., Scheumann, M. & Zimmermann, E. The role of acoustic signaling for spacing and group coordination in a nocturnal, pair-living primate, the Western woolly Lemur (Avahi occidentalis. Am. J. Phys. Anthropol. 159, 466–477 (2016).

    Google Scholar 

  39. Zhang, C. M., Sun, C. N. & Lucas, F. Acoustic signal dominance in the multimodal communication of a nocturnal mammal. Curr. Zool. (2021).

    Google Scholar 

  40. Linhart, P. & Šálek, M. The assessment of biases in the acoustic discrimination of individuals. PLoS One 12(5), e0177206 (2017).

    Google Scholar 

  41. Odom, K. J., Slaght, J. C. & Gutiérrez, R. J. Distinctiveness in the territorial calls of Great horned owls within and among years. J. Raptor Res. 47, 21–30 (2013).

    Google Scholar 

  42. Yee, S. A., Puan, C. L., Chang, P. K. & Azhar, B. Vocal individuality of Sunda scops-owl (Otus lempiji) in Peninsular Malaysia. J. Raptor Res. 50, 379–390 (2016).

    Google Scholar 

  43. Madhavan, M. & Linhart, P. Vocal individuality in owls: a taxon-wide review in the context of Tinbergen’s four questions. J. Ornithol. 166, 307–319 (2025).

    Google Scholar 

  44. Cavanagh, P. M. & Ritchison, G. Variation in the bounce and whinny songs of the Eastern Screech-Owl. Wilson Bull. 99, 620–627 (1987).

    Google Scholar 

  45. Grieco, F. Aggregation of Eurasian scops owls Otus scops breeding in Magpie Pica pica nests. Ardea 106, 177–191 (2018).

    Google Scholar 

  46. Nagy, C. M. & Rockwell, R. F. Identification of individual Eastern Screech-Owls megascops Asio via vocalization analysis. Bioacoustics 21, 127–140 (2012).

    Google Scholar 

  47. Dreiss, A. N., Ruppli, C. A. & Roulin, A. Individual vocal signatures in barn Owl nestlings: does individual recognition have an adaptive role in sibling vocal competition? J. Evol. Biol. 27, 63–75 (2014).

    Google Scholar 

  48. Van Nieuwenhuyse, D., Van Harxen, R., Johnson, D. H. & De Raedt, J. The Little Owl: Population Dynamics, Behavior and Management of Athene noctua (Cambridge University Press, 2023). 

    Google Scholar 

  49. Chrenková, M., Dobrý, M. & Šálek, M. Further evidence of large-scale population decline and range contraction of the Little Owl Athene noctua in central Europe. Folia Zool. 66, 106–116 (2017).

    Google Scholar 

  50. Šálek, M. et al. Scale-dependent habitat associations of a rapidly declining farmland predator, the Little Owl Athene noctua, in contrasting agricultural landscapes. Agric. Ecosyst. Environ. 224, 56–66 (2016).

    Google Scholar 

  51. Le Gouar, P. J. et al. Long-term trends in survival of a declining population: the case of the Little Owl (Athene noctua) in the Netherlands. Oecologia 166, 369–379 (2011).

    Google Scholar 

  52. Żmihorski, M., Altenburg, D., Romanowski, J., Kowalski, M. & Osojca, G. Long term decline of the Little Owl (Athene noctua Scop., 1769) in central Poland. Pol. J. Ecol. 54, 321–324 (2006).

    Google Scholar 

  53. Mayer, M. et al. Fine-scale movement patterns and habitat selection of Little owls (Athene noctua) from two declining populations. PLoS One 16(9), e0256608 (2021).

    Google Scholar 

  54. Šálek, M. & Lövy, M. Spatial ecology and habitat selection of Little Owl Athene noctua during the breeding season in central European farmland. Bird. Conserv. Int. 22, 328–338 (2012).

    Google Scholar 

  55. Šálek, M. & Mayer, M. Farmstead modernization adversely affects farmland birds. J. Appl. Ecol. 60, 101–110 (2023).

    Google Scholar 

  56. Šálek, M. & Schröpfer, L. Population decline of the Little Owl (Athene noctua Scop.) in the Czech Republic. Pol. J. Ecol. 56, 527–534 (2008).

    Google Scholar 

  57. Šálek, M., Chrenkova, M. & Kipson, M. High population density of Little Owl (Athene noctua) in hortobagy National park, Hungary, central Europe. Pol. J. Ecol. 61, 165–169 (2013).

    Google Scholar 

  58. Šálek, M. et al. In Owl’s Paradise: Little Owl Population Densities in Traditional Human Settlements Represent One of the Highest Densities Reported among Owls. J. Raptor Res. 59(1), 1–11 (2025).

    Google Scholar 

  59. Jacobsen, L. B., Sunde, P., Rahbek, C., Dablesteen, T. & Thorup, K. Territorial calls in the Little Owl (Athene noctua): spatial dispersion and social interplay of mates and neighbours. Ornis Fenn. 90(1), 41–49 (2013).

    Google Scholar 

  60. Orlando, G., Varesio, A. & Chamberlain, D. Field evaluation for playback surveys: species-specific detection probabilities and distance estimation errors in a nocturnal bird community. Bird. Study. 68, 78–87 (2021).

    Google Scholar 

  61. Hardouin, L. A., Tabel, P. & Bretagnolle, V. Neighbour-stranger discrimination in the Little owl, Athene noctua. Anim. Behav. 72, 105–112 (2006).

    Google Scholar 

  62. Siracusa, E. R. et al. Familiar Neighbors, but not relatives, enhance fitness in a territorial mammal. Curr. Biol. 31, 438–445 (2021).

    Google Scholar 

  63. Falls, J. B. Individual recognition by sounds in birds. In Acoustic Communication in Birds Vol. 2 (eds Kroodsma, D. E. & Miller, E. H.) 237–278 (Academic, 1982).

    Google Scholar 

  64. Exo, K. M. Annual cycle and ecological adaptions in the Little Owl (Athene noctua). J. Ornithol. 129, 393–415 (1988).

    Google Scholar 

  65. Fick, S. E. & Hijmans, R. J. WorldClim 2: new 1-km Spatial resolution climate surfaces for global land areas. Intl J. Climatology. 37, 4302–4315 (2017).

    Google Scholar 

  66. Průchová, A., Šálek, M. & Linhart, P. Social factors affect vocal activity patterns of two common call types in Little Owl males. J. Ornithol. 166, 235–246 (2025).

    Google Scholar 

  67. Šálek, M. Dlouhodobý pokles početnosti sýčka obecného (Athene noctua) v jádrové oblasti Jeho rozšíření v Čechách. Sylvia 50, 2–12 (2014).

    Google Scholar 

  68. Exo. Population ecology of Little Owls Athene noctua in Central Europe: a review. The ecology and conservation of European owls, 64–75. (1992).

  69. Charif, R. A., Waack, A. M. & Strickman, L. M. Raven Pro 1.4 User’s Manual (Cornell Lab of Ornithology, 2010).

  70. Araya-Salas, M. Rraven: connecting R and Raven bioacoustic software. R package version 1.0.9. (2020).

  71. Linhart, P. et al. Measuring individual identity information in animal signals: overview and performance of available identity metrics. Methods Ecol. Evol. 10, 1558–1570 (2019).

    Google Scholar 

  72. Blumstein, D. T. & Munos, O. Individual, age and sex-specific information is contained in Yellow-bellied marmot alarm calls. Anim. Behav. 69, 353–361 (2005).

    Google Scholar 

  73. Tumulty, J. P., Lange, Z. K. & Bee, M. A. Identity signaling, identity reception, and the evolution of social recognition in a Neotropical frog. Evolution 76, 158–170 (2022).

    Google Scholar 

  74. Favaro, L., Gamba, M., Alfieri, C., Pessani, D. & McElligott, A. G. Vocal individuality cues in the African penguin (Spheniscus demersus): a source-filter theory approach. Sci. Rep. 5(1), 17255 (2015).

    Google Scholar 

  75. Galeotti, P., Paladin, M. & Pavan, G. Individually distinct hooting in male Pygmy owls Glaucidium passerinum: a multivariate approach. Ornis Scand. 1993, 15–20 (1993).

    Google Scholar 

  76. Li, Y., Xia, C., Lloyd, H., Li, D. & Zhang, Y. Identification of vocal individuality in male cuckoos using different analytical techniques. Avian Res. 8, 1–7 (2017).

    Google Scholar 

  77. Hutchinson, G. E. Concluding remarks. Cold Spring Harb Symp. Quant. Biol. 22, 415–427 (1957).

    Google Scholar 

  78. Alvarado-Serrano, D. F. & Knowles, L. L. Ecological niche models in phylogeographic studies: applications, advances and precautions. Mol. Ecol. Resour. 14, 233–248 (2014).

    Google Scholar 

  79. Bearhop, S., Adams, C. E., Waldron, S., Fuller, R. A. & MacLeod, H. Determining trophic niche width: a novel approach using stable isotope analysis. J. Anim. Ecol. 73, 1007–1012 (2004).

    Google Scholar 

  80. Raxworthy, C. J., Ingram, C. M., Rabibisoa, N. & Pearson, R. G. Applications of ecological niche modeling for species delimitation: a review and empirical evaluation using day geckos (Phelsuma) from Madagascar. Syst. Biol. 56, 907–923 (2007).

    Google Scholar 

  81. Hart, P. J., Ibanez, T., Paxton, K., Tredinnick, G., Sebastián-González, E., & Tanimoto-Johnson, A. Timing is everything: acoustic niche partitioning in two tropical wet forest bird communities. Front. Ecol. Evol. 9, 753363 (2021).

  82. Henry, C. S. & Wells, M. M. Acoustic niche partitioning in two cryptic sibling species of Chrysoperla green lacewings that must duet before mating. Anim. Behav. 80, 991–1003 (2010).

    Google Scholar 

  83. Sinsch, U., Lümkemann, K., Rosar, K., Schwarz, C. & Dehling, M. Acoustic niche partitioning in an Anuran community inhabiting an Afromontane wetland (Butare, Rwanda). Afr. Zool. 47, 60–73 (2012).

    Google Scholar 

  84. Swanson, H. K. et al. A new probabilistic method for quantifying n-dimensional ecological niches and niche overlap. Ecology 96, 318–324 (2015).

    Google Scholar 

  85. Core Team, R. R. C. R: A language and environment for statistical computing. (2022).

  86. Budka, M., Matyjasiak, P., Typiak, J., Okołowski, M. & Zagalska-Neubauer, M. Experienced males modify their behaviour during playback: the case of the Chaffinch. J. Ornithol. 160, 673–684 (2019).

    Google Scholar 

  87. Linhart, P., Fuchs, R., Poláková, S. & Slabbekoorn, H. Once bitten twice shy: long-term behavioural changes caused by trapping experience in Willow warblers Phylloscopus trochilus. J. Avian Biol. 43, 186–192 (2012).

    Google Scholar 

  88. Oñate-Casado, J., Porteš, M., Beran, V., Petrusek, A. & Petrusková, T. An experience to remember: lifelong effects of playback-based trapping on behaviour of a migratory passerine bird. Anim. Behav. 182, 19–29 (2021).

    Google Scholar 

  89. Sexton, K., Redmond, L., Murphy, M. & Dolan, A. Dawn song of Eastern kingbirds: intrapopulation variability and sociobiological correlates. Behav 144, 1273–1295 (2007).

    Google Scholar 

  90. Tobias, J. A., Gamarra-Toledo, V., García-Olaechea, D., Pulgarín, P. C. & Seddon, N. Year-round resource defence and the evolution of male and female song in suboscine birds: social armaments are mutual ornaments: evolution of mutual ornaments in birds. J. Evol. Biol. 24, 2118–2138 (2011).

    Google Scholar 

  91. Xia, C. et al. Dawn singing intensity of the male Brownish-Flanked Bush warbler: effects of territorial insertions and number of neighbors. Ethology 120, 324–330 (2014).

    Google Scholar 

  92. Ripmeester, E. A. P., Kok, J. S., Van Rijssel, J. C. & Slabbekoorn, H. Habitat-related birdsong divergence: a multi-level study on the influence of territory density and ambient noise in European Blackbirds. Behav. Ecol. Sociobiol. 64, 409–418 (2010).

    Google Scholar 

  93. Stuart, C. J., Grabarczyk, E. E., Vonhof, M. J. & Gill, S. A. Social factors, not anthropogenic noise or artificial light, influence onset of dawn singing in a common songbird. Auk 136, ukz045 (2019).

    Google Scholar 

  94. Owen, K. C. & Mennill, D. J. Singing in a fragmented landscape: Wrens in a tropical dry forest show sex differences in the effects of neighbours, time of day, and time of year. J. Ornithol. 162, 881–893 (2021).

    Google Scholar 

  95. Sánchez, N. V. & Mennill, D. J. Behavioural consequences of conspecific neighbours: a systematic literature review of the effects of local density on avian vocal communication. J. Ornithol. 165, 847–859 (2024).

    Google Scholar 

  96. Gokcekus, S., Firth, J. A., Regan, C. & Sheldon, B. C. Recognising the key role of individual recognition in social networks. Trends Ecol. Evol. 36, 1024–1035 (2021).

    Google Scholar 

  97. Tibbetts, E. A., Mullen, S. P. & Dale, J. Signal function drives phenotypic and genetic diversity: the effects of signalling individual identity, quality or behavioural strategy. Phil Trans. R Soc. B. 372, 20160347 (2017).

    Google Scholar 

  98. Osiecka, A. N., Briefer, E. F., Kidawa, D. & Wojczulanis-Jakubas, K. Strong individual distinctiveness across the vocal repertoire of a colonial seabird, the Little auk, Alle alle. Anim. Behav. 210, 199–211 (2024).

    Google Scholar 

  99. Charrier, I. Mother-offspring vocal recognition and social system in pinnipeds. Coding strategies in vertebrate acoustic communication 231–246 Cham: Springer International Publishing. (2020).

  100. Elfström, S. T. Responses of territorial Meadow pipits to strange and familiar song phrases in playback experiments. Anim. Behav. 40, 786–788 (1990).

    Google Scholar 

  101. Wegrzyn, E., Leniowski, K. & Osiejuk, T. S. Introduce yourself at the beginning-possible identification function of the initial part of the song in the Great reed warbler Acrocephalus arundinaceus. Ornis 86 (2), 61–70 (2009). (2009).

    Google Scholar 

  102. Mathevon, N. et al. Singing in the rain forest: how a tropical bird song transfers information. PLoS ONE. 3, e1580 (2008).

    Google Scholar 

  103. Wheeldon, A., Kwiatkowska, K., Szymański, P. & Osiejuk, T. S. Male and female songs propagation in a duetting tropical bird species in its preferred and secondary habitat. PLoS ONE. 17, e0275434 (2022).

    Google Scholar 

  104. Lengagne, T. Temporal stability in the individual features in the calls of Eagle owls (Bubo bubo). Behaviour 138, 1407–1419 (2001).

    Google Scholar 

  105. Garland, T. & Adolph, S. C. Why not to do two-Species comparative studies: limitations on inferring adaptation. Physiological Zool. 67, 797–828 (1994).

    Google Scholar 

  106. Goymann, W. & Schwabl, H. The tyranny of phylogeny—A plea for a less dogmatic stance on two-species comparisons: Funding bodies, journals and referees discourage two‐ or few‐species comparisons, but such studies provide essential insights complementary to phylogenetic comparative studies. BioEssays 43(8), 2100071 (2021).

    Google Scholar 

  107. Kidawa, D., Wojczulanis-Jakubas, K., Jakubas, D., Palme, R. & Barcikowski, M. Mine or my neighbours’ offspring: an experimental study on parental discrimination of offspring in a colonial seabird, the Little auk Alle alle. Sci. Rep. 13, 15088 (2023).

    Google Scholar 

  108. Klenova, A. V., Volodin, I. A. & Volodina, E. V. The variation in reliability of individual vocal signature throughout ontogenesis in the Red-crowned crane Grus japonensis. Acta ethol. 12, 29–36 (2009).

    Google Scholar 

  109. Lefevre, K., Montgomerie, R. & Gaston, A. J. Parent–offspring recognition in Thick-billed murres (Aves: Alcidae). Anim. Behav. 55, 925–938 (1998).

    Google Scholar 

  110. Osiecka, A. N., Oliva, M. Q., Kouřil, J., Petrusková, T. & Burchardt, L. S. Yellowhammer (Emberiza citrinella) males sing using individual isochronous rhythms and maximise rhythmic dissimilarity with neighbours. bioRxiv. Preprint at. https://doi.org/10.1101/2025.06.17.660106 (2025).

    Google Scholar 

  111. Geberzahn, N. & Aubin, T. How a songbird with a continuous singing style modulates its song when territorially challenged. Behav. Ecol. Sociobiol. 68, 1–12 (2014).

    Google Scholar 

  112. Hardouin, L. A., Reby, D., Bavoux, C., Burneleau, G. & Bretagnolle, V. Communication of male quality in owl hoots. Am. Nat. 169, 552–562 (2007).

    Google Scholar 

  113. Linhart, P., Jaška, P., Petrusková, T., Petrusek, A. & Fuchs, R. Being angry, singing fast? Signalling of aggressive motivation by syllable rate in a songbird with slow song. Behav. Processes. 100, 139–145 (2013).

    Google Scholar 

  114. McGregor, P. K., Dabelsteen, T., Shepherd, M. & Pedersen, S. B. The signal value of matched singing in Great tits: evidence from interactive playback experiments. Anim. Behav. 43, 987–998 (1992).

    Google Scholar 

  115. Thomsen, H. M., Balsby, T. J. & Dabelsteen, T. The imitation dilemma: can parrots maintain their vocal individuality when imitating conspecifics? Behaviour 156, 787–814 (2019).

    Google Scholar 

  116. Delport, W., Kemp, A. C. & Ferguson, J. W. H. Vocal identification of individual African wood owls Strix woodfordii: A technique to monitor long-term adult turnover and residency. Ibis 144, 30–39 (2002).

    Google Scholar 

  117. Rognan, C. B., Szewczak, J. M. & Morrison, M. L. Vocal individuality of Great gray owls in the Sierra Nevada. J. Wildl. Manage. 73, 755–760 (2009).

    Google Scholar 

  118. Takagi, M. Vocalizations of the Ryukyu scops owl Otus elegans: individually recognizable and stable. Bioacoustics 29, 28–44 (2020).

    Google Scholar 

  119. Tripp, T. M. & Otter, K. A. Vocal individuality as a potential long-term monitoring tool for Western screech-owls, Megascops kennicottii. Can. J. Zool. 84, 744–753 (2006).

    Google Scholar 

  120. Rivera-Gutierrez, H. F., Pinxten, R. & Eens, M. Songs differing in consistency elicit differential aggressive response in territorial birds. Biol. Lett. 7, 339–342 (2011).

    Google Scholar 

  121. Sierro, J., de Kort, S.R., Hartley, I.R. Sexual selection for both diversity and repetition in birdsong. Nat. Commun. 14(1), 3600 (2023).

    Google Scholar 

  122. Miles, L. S., Rivkin, L. R., Johnson, M. T., Munshi-South, J. & Verrelli, B. C. Gene flow and genetic drift in urban environments. Mol. Ecol. 28, 4138–4151 (2019).

    Google Scholar 

  123. Evans, K. L. Individual species and urbanisation. Urban ecology, 53-87 (2010).

  124. Hill, S. D., Aryal, A., Pawley, M. D. M. & Ji, W. So much for the city: Urban-rural song variation in a widespread Asiatic songbird. Integr. Zool. 13, 194–205 (2018).

    Google Scholar 

  125. Narango, D. L. & Rodewald, A. D. Urban-associated drivers of song variation along a rural–urban gradient. Behav. Ecol. 27, 608–616 (2016).

    Google Scholar 

  126. Halfwerk, W. et al. Adaptive changes in sexual signalling in response to urbanization. Nat. Ecol. Evol. 3, 374–380 (2018).

    Google Scholar 

  127. Brenowitz, E. A. Evolution of the vocal control system in the avian brain. Semin Neurosci. 3, 399–407 (1991).

    Google Scholar 

  128. Ten Cate, C. Re-evaluating vocal production learning in non-oscine birds. Phil Trans. R Soc. B 376(1836), 20200249 (2021).

    Google Scholar 

  129. Brumm, H. & Zollinger, S. A. The evolution of the Lombard effect: 100 years of psychoacoustic research. Behaviour 148, 1173–1198 (2011).

    Google Scholar 

  130. Dunlop, R. A., Cato, D. H. & Noad, M. J. Evidence of a Lombard response in migrating Humpback whales (Megaptera novaeangliae). J. Acoust. Soc. Am. 136, 430–437 (2014).

    Google Scholar 

  131. Halfwerk, W., Lea, A. M., Guerra, M. A., Page, R. A. & Ryan, M. J. Vocal responses to noise reveal the presence of the Lombard effect in a frog. Behav. Ecol. 27, 669–676 (2016).

    Google Scholar 

  132. Janik, V. M. & Slater, P. J. The different roles of social learning in vocal communication. Anim. Behav. 60, 1–11 (2000).

    Google Scholar 

  133. Arellano, C. M., Canelón, N. V., Delgado, S. & Berg, K. S. Allo-preening is linked to vocal signature development in a wild parrot. Behav. Ecol. 33, 202–212 (2022).

    Google Scholar 

  134. Beecher, M. & Brenowitz, E. Functional aspects of song learning in songbirds. Trends Ecol. Evol. 20, 143–149 (2005).

    Google Scholar 

  135. Palmero, A. M., Illera, J. C. & Laiolo, P. Song characterization in the Spectacled warbler (Sylvia conspicillata): a circum-Mediterranean species with a complex song structure. Bioacoustics 21, 175–191 (2012).

    Google Scholar 

  136. Slater, P. J. B. & Lachlan, R. F. Is Innovation in Bird Song Adaptive? In Animal Innovation (eds Reader, S. M. & Laland, K. N.) 117–136 (Oxford University Press, 2003).

    Google Scholar 

  137. Walcott, C., Mager, J. N. & Piper, W. Changing territories, changing tunes: male loons, Gavia immer, change their vocalizations when they change territories. Anim. Behav. 71, 673–683 (2006).

    Google Scholar 

  138. Groothuis, T. The influence of social experience on the development and fixation of the form of displays in the Black-headed gull. Anim. Behav. 43, 1–14 (1992).

    Google Scholar 

Download references

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.

Author information

Authors and Affiliations

Authors

Contributions

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.

Corresponding author

Correspondence to
Malavika Madhavan.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary Material 1

Supplementary Material 2

Supplementary Material 3

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.

Reprints and permissions

About this article

Cite this article

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

Download citation

  • Received:

  • Accepted:

  • Published:

  • 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

Advancing an adaptable and practical framework to address water quality challenges in a changing world

Gender dynamics and remittances in the adoption of sustainable agricultural practices in Nepal

Back to Top