Acoustic correlates of body size and individual identity in banded penguins

Abstract

Animal vocalisations play a role in individual recognition and mate choice. In nesting penguins, acoustic variation in vocalisations originates from distinctiveness in the morphology of the vocal apparatus. Using the source-filter theory approach, we investigated vocal individuality cues and correlates of body size and mass in the ecstatic display songs the Humboldt and Magellanic penguins. We demonstrate that both fundamental frequency (f0) and formants (F1-F4) are essential vocal features to discriminate among individuals. However, we show that only duration and f0 are honest indicators of the body size and mass, respectively. We did not find any effect of body dimension on formants, formant dispersion nor estimated vocal tract length of the emitters. Overall, our findings provide the first evidence that the resonant frequencies of the vocal tract do not correlate with body size in penguins. Our results add important information to a growing body of literature on the role of the different vocal parameters in conveying biologically meaningful information in bird vocalisations.

Habitat explained microgeographic variation in Little Penguin agonistic calls

“…Specifically, larger and heavier individuals (regardless of sex) produced calls at higher frequencies (maximum frequencies and bandwidths) than smaller ones, similar to what was found by Miyazaki and Waas (2003b). In many species, the frequency of vocalizations is correlated negatively with body size (Reby and McComb 2003, Hall et al 2013, Linhart and Fuchs 2015, Favaro et al 2017. However, such a relationship is not…”

Bioacoustic monitoring of animal vocal behavior for conservation

“…An example of this is the elongated nose of the male saiga antelope, Saiga tatarica, which effectively extends the vocal tract during roaring, thereby lowering formant frequencies (Frey, Volodin, & Volodina, 2007). A recent study on banded penguins, Spheniscus sp., found that the ecstatic display song given by males during the breeding season encodes body size in the fundamental frequency (Favaro, Gamba, Gili, & Pessani, 2017). A recent study on banded penguins, Spheniscus sp., found that the ecstatic display song given by males during the breeding season encodes body size in the fundamental frequency (Favaro, Gamba, Gili, & Pessani, 2017).…”

Sex identification in King Penguins Aptenodytes patagonicus through morphological and acoustic cues

“…Here, we also study the relationship between morphological and acoustic features as investigated in previous studies (Badyaev & Leaf 1997, Tubaro & Mahler 1998, Bertelli & Tubaro 2002, Martin et al 2011). Favaro et al (2017 showed that duration and fundamental frequency indicate body size in Humboldt Spheniscus humboldti and Magellanic Penguins Spheniscus magellanicus.…”

“…Favaro et al . () showed that duration and fundamental frequency indicate body size in Humboldt Spheniscus humboldti and Magellanic Penguins Spheniscus magellanicus . As the source‐filter theory predicts, acoustic signals can provide reliable information about the signaller (indexical signals), such as the sex or the body size (Taylor & Reby ).…”