title: Individually specific call feature is not used to neighbour-stranger discrimination: the corncrake case.
abstract: In various contexts, animals rely on acoustic signals to differentiate between conspecifics. Currently, studies examining vocal signatures use two main approaches. In the first approach, researchers search for acoustic characteristics that have the potential to be individual specific. This approach yields information on variation in signal parameters both within and between individuals and generates practical tools that can be used in population monitoring. In the second approach, playback experiments with natural calls are conducted to discern whether animals are capable of discriminating among the vocal signatures of different individuals. However, both approaches do not reveal the exact signal characteristics that are being used in the discrimination process. In this study, we tested whether an individual-specific call characteristic--namely the length of the intervals between successive maximal amplitude peaks within syllables (PPD)--is crucial in neighbour-stranger discrimination by males of the nocturnal and highly secretive bird species, the corncrake (Crex crex). We conducted paired playback experiments in which corncrakes (n = 47) were exposed to artificial calls with PPD characteristics of neighbour and stranger birds. These artificial calls differed only in PPD structure. The calls were broadcast from a speaker, and we recorded the birds' behavioural responses. Although corncrakes have previously been experimentally shown to discriminate between neighbours and strangers, we found no difference in the responses to the artificial calls representing neighbours versus strangers. This finding demonstrates that even if vocal signatures are individual specific within a species, it does not automatically mean that said signatures are being crucial in discrimination among individuals. At the same time, the birds' aggressive responses to the artificial calls indicated that the information transmitted by PPDs is important in species-specific call recognition and may be used by males and/or females to evaluate sender quality, similarly like sound frequency in some insect species.
authors.affiliation: Department of Behavioural Ecology, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland.
authors.forename: Michał
authors.initials: M
authors.lastname: Budka
authors.affiliation: Department of Behavioural Ecology, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland.
authors.forename: Tomasz S
authors.initials: TS
authors.lastname: Osiejuk
mesh_terms: D000161:Acoustic Stimulation; D000162:Acoustics; D000374:Aggression / Q000523:psychology; D000818:Animals; D001717:Birds / Q000502:physiology*; D005260:Female; D008297:Male; D046709:Pattern Recognition, Physiological / Q000502:physiology*; D013016:Sound; D013637:Tape Recording; D014828:Vocalization, Animal / Q000502:physiology*
references.citation: Anim Behav. 1999 Jun;57(6):1175-1183
references.pmid: 10373249
references.citation: PLoS One. 2009 Nov 30;4(11):e7824
references.pmid: 19956596
references.citation: J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2004 Oct;190(10):823-9
references.pmid: 15278399
references.citation: J Exp Biol. 2008 Feb;211(Pt 3):317-26
references.pmid: 18203986
references.citation: Behav Processes. 2011 Mar;86(3):323-8
references.pmid: 21295119
references.citation: Proc Biol Sci. 2012 Sep 22;279(1743):3749-55
references.pmid: 22719031
references.citation: PLoS Biol. 2007 May;5(5):e139
references.pmid: 17503965
references.citation: Proc Biol Sci. 2000 Jun 7;267(1448):1081-7
references.pmid: 10885512
references.citation: Anim Behav. 1998 Sep;56(3):579-594
references.pmid: 9784206
references.citation: J Exp Biol. 2001 Feb;204(Pt 4):663-72
references.pmid: 11171348
references.citation: Brain Lang. 2010 Oct;115(1):59-68
references.pmid: 20471673
references.citation: Behav Processes. 2008 Feb;77(2):191-8
references.pmid: 17980974
references.citation: Front Zool. 2005 Jun 16;2(1):10
references.pmid: 15960848
references.citation: Nature. 2001 Aug 30;412(6850):873
references.pmid: 11528465
references.citation: PLoS One. 2012;7(8):e42528
references.pmid: 22880018
references.citation: Am J Primatol. 2009 Apr;71(4):324-32
references.pmid: 19090554