A description of the vocal behaviour of Gentoo penguins in the open ocean and the functional role of these calls, recorded using animal-borne video cameras, is discussed in Scientific Reports this week.
Gentoo penguins (Pygoscelis papua) are found on sub-Antarctic islands and in the Antarctic region, and primarily prey in groups on krill and fish. However, the inaccessibility of the open-ocean foraging sites of penguins to researchers has precluded the study of the vocal repertoires used during foraging trips.
Won Young Lee and colleagues recorded the foraging behaviour of Gentoo penguins from King George Island in Antarctica over two breeding seasons (2014-2015 and 2015-2016), using animal-borne video cameras. The authors collected 598 offshore calls from 10 individuals and analysed the acoustic characteristics and behavioural contexts of these calls. The authors found that in almost half of the calls, individuals formed groups within one minute following an offshore call. The penguins did not show any significant difference in the proportion of foraging dives or prey rate capture before and after producing an offshore call, which may suggest that the call was involved in group contact rather than relating to food. However, the authors observed that after producing offshore calls, the penguins undertook shallower, shorter dives and that they travelled to a new area instead of lingering in a particular spot. The authors hypothesize that the penguins may use vocal communications for grouping purposes during foraging trips.
The authors note that further investigations are required to better understand the aquatic life of these penguins.