31 July 2014

What does the penguin say? Vocal variety in African penguins

An African penguin vocalising.
Photo credit: Favaro et al
ITALY - African penguins are highly social and vocal seabirds; they vocalise to communicate with their parents, mates and colony members. They are even known as jackass penguins because of their donkey-like bray. But, until now, descriptions of their vocal repertoire have been mostly limited to basic descriptions of calls.

A study published on 30 July in PLoS ONE provides the first detailed description of African penguin vocalisations: four different ones for adults and two for chicks and juveniles. The study was carried out by Livio Favaro and colleagues from University of Turin, Italy, on captive penguins at Zoom Torino.

The authors of the study collected, categorised and acoustically analysed hundreds of audio and video vocal recordings from the large captive colony. They also identified the behavioral contexts in which calls were made.

Results showed that an adult African penguin's auditory repertoire has four basic vocalisations: a contact call emitted by isolated birds, an agonistic call used in aggressive interactions, an ecstatic display song uttered by single birds during the breeding season, and a mutual display song vocalised by pairs at their nests. The authors also identified two distinct vocalisations interpreted as begging calls by nesting chicks (begging peep) and unweaned juveniles (begging moan).

The colony is captive, so the authors say they can't be sure they have identified all of an African penguin's possible vocalizations. But they suggest this analysis will help to standardise known vocalisations that can be used in further study of these endangered seabirds.

Source
Vocal variety in African penguins [press release], 30 July 2014, PLOS

PLoS One citation
Favaro L, Ozella L, Pessani D (2014) The vocal repertoire of the African penguin (Spheniscus demersus): Structure and Function of Calls. PLoS ONE 9(7): e103460. doi:10.1371/journal.pone.0103460

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