Crested auklets are monogamous seabirds breeding in dense seashore colonies and using all possible communicative channels. Their well-developed olfactory behaviour was investigated in details, however vocal performances are poorly studied. We investigated individual specificity and caller quality encoded in trumpetings – complex vocalizations, performed as advertising displays by males and very rarely by females. In 2008 we recorded 185 calls, 4-20 per individual, from 18 individually colour-banded DNA-sexed male crested auklets on Talan Island (Okhotsk Sea, Russia). Trumpetings included two parts: the high-frequency introduction and the main part with 2-7 low-frequency bark-like calls alternated with 1-4 high-frequency calls. Discriminant analysis with 8 time and frequency parameters included into analysis, showed 98.7% correct assignment to individual. Parameters of introduction were more individually-specific than parameters of the main part. We found a positive correlation between body mass of a caller' and the duration of the main part and a negative correlation between body mass and frequencies of the high-frequency calls of the main part (Pearson correlation, r=0.898, p=0.000 and r=-0.719; p=0.013). Video and audio analysis showed that the high-ranked males, advertising on the stone tops produced the high-frequency calls of the main part lower in frequency relative those of males advertising on the stone bottoms (MANOVA, F1,139=64.7, p=0.000). We conclude that trumpetings of crested auklets provides information about individuality and quality of a caller and together with specific odor appears to be an important component of complex social behaviour of this species.
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