Behaviour 2019
Neighbors matter: spatial vocal plasticity in Gentoo penguin ecstatic display calls  
Helen Rößler1, Maureen Lynch2, Michaël Beaulieu1. 1Stiftung Deutsches Meeresmuseum/ German Oceanographic Museum Foundation, Science Department , Stralsund, MV, Germany; 2Vermont Fish and Wildlife Department, Fish Division, Fish & Wildlife Lab, Roxbury, VT, United States

The social structure of animal groups may affect the way animals communicate with each other. Colonies of Gentoo penguins (Pygoscelis papua ellsworthi) are interesting to examine such social influence at the interspecific scale, as these brushed-tailed penguins may breed (or not) in the same colony as other closely-related penguins (Adélie (P. adeliae), chinstrap (P. antarcticus) penguins). We therefore examined here whether the presence of congeneric penguins breeding within colonies of Gentoo penguins affected their vocal characteristics. We found that the frequency of the ecstatic display calls of Gentoo penguins was consistently lower when they bred in contact with Adélie penguins than when they bred alone, while no effect was found in relation to the presence of chinstrap penguins. These results suggest that the vocalizations of Gentoo penguins are plastic and support the acoustic adaptation hypothesis. The adaptiveness of this vocal plasticity remains, however, to be clarified.