Penguins produce contact calls to maintain social relationships and group cohesion. Such
vocalisations have recently been demonstrated to encode individual identity information in
the African penguin. Using a source-filter theory approach, we investigated whether acoustic
cues of individuality can also be found in other Spheniscus penguins and the acoustic
features of contact calls have diverged within this genus. We recorded vocalisations from
two ex-situ colonies of Humboldt penguin and Magellanic penguin (sympatric and …