Development of foraging behaviour and evidence of extended parental care in the gentoo penguin (Pygoscelis papua)

We used radio telemetry and observations to study the activity patterns and behaviour of gentoo penguin chicks during their “fledging period”; defined as the time between a chick’s first trip to sea and its final dispersal from the breeding colony. Our study was conducted at a colony of approximately 2500 breeding pairs of gentoo penguins in Admiralty Bay, King George Island, South Shetland Islands during the 2004-05 austral summer. Gentoo penguins exhibited delayed dispersal of young coupled with extended parental provisioning, behaviours not observed in other Pygoscelis species. Chicks took their first trip to sea at a mean age of 70 days of age, before finally departing the colony at an average age of 82 days. During this fledging period, individual chicks made an average of five trips to sea. Trip duration increased significantly with chick age as trips to sea becoming more similar to adult foraging trips in both timing and duration. Behavioural observations confirmed that many chicks were still being fed during this fledging period, with parental feeding behaviours most often observed in the late afternoon to evening hours. We hypothesize that these behaviours not only provide the opportunity for chicks to gain experience at sea prior to dispersal, but also allow them to develop foraging behaviours and skills at this time. These results have implications to differences in life history traits and population trends among gentoo penguins and their congeners, the Adélie and chinstrap penguins.