Ethology 94, 279-290 (1993) @ 1993 Paul Parey Scientific Publishers, Berlin and Hamburg ISSN0179-1613 Centred'Etwdes Biologiques de Chizé,Beauaoir sur Niort, and,Laboratoire d' Etho làgie Exp éritne ntale, N ogentJe- Roi Individuality in the Voice of the Emperor Penguin Aptenodytes forsteri: Adaptation to a Noisy Environment P.c,truce RoussoN, TnrnnRv AustNEr JraN-CI-euor lnnuoNo ROBrsSoN, P., AUBIN, T. Ec BnruoNo,J,-Q. 1993: Individuality in the voice of-the emperor penguin Àpi"oayit forsteri: Adaptation to a noisy environment'Ethology 94' 279-290' Abstract The exrreme coloniality in emperorpen guins (Aptenodytes forste.i) demands that (1) individual .... o*nirion by the murual display caii ,n,r$ bJrupt.tttely adapted to the total absence of nestsites - iili;;ffi;r;;rrJ f".itioè pârtner reunion, .nd (z) uitat must transmit a precise message through "n obrt^.tud and noisy en niÂrrrnent. A computerizedsound analysis and subsequent data were submitted to univariareand multivariate statistics to determineindividual-specific cuesof the call. i;;;;;î ;;r;riing of syllabies, variables of the power sPectmm (f199ue1,cr, andtimbre features) and ,rJr'Ui., "iîU.", g!r.r"la by two acoustic ro.rri., *.t. analyzed (58 calls from Tanimals). Number .iJf,-u;;rt";;i ryl'l"bl.r, fu'i"menml frequencies and period of the beat were highly individual,with inier- significanriy gr"^r", then intra-individual variaiion, enablingcorrect classification of the 58 ;ii;. Thi;;;;.;;l;.1.1.u.n.. of temporaland spectral cues for individualrecognition is discussed' In ;h;;;;ri;;fuy hostile and noisy "niironm.n,, b..t was peculiarly emphasized, as it allowed great ;;;";ri"" l;-;Ée production of an amplitude modulation that was unlikely to be degraded by the environment. Corresponding author: Patrice RoBIssoN, CentreNational de la Recherche Scientifique, Centre a'Et"d., Oi"iaiq,rei de Chizé,Villiers en bois, F-71J6O Beauvoir sur Niort' Introduction An ideal signal for individual recognitionwould be highly stere,otyPed within each indi;dual but would differ noticeably among individuals (Hurcnt- soNet al. 1968).Natural selection would appear to acton sigttat,tte traitsofvocal ,i*i"fr in birdswherethe signaller benefits in beingrecognizedby its partner and ;-f?qp;ù,; thar it breeds iuccessfully, especially in colonial species suchasthe u.5. copyright clearance cenrer code sntement: ol79-161.3/g3/g404-0279$02.50/o