Observations of intraspecific aggressive behaviour in the adelie penguin (Pygoscelis adeliae)

The cause, function, effect and patterns of behaviour in penguin fighting on the colony was determined from long periods of direct observations of banded penguins and on set-period recordings of all movement in a number of other colonies. The incidence of fighting through the season was determined by counts made through the day of all incidents among the 1500 or so penguins in H Block. The behaviour postures associated with fighting have been determined and described and by factor analysis the common sequences of behaviour occurring with increasing and decreasing aggressive drive established. Detailed observations on daily activities were made on randomly selected nest sites with each watched for 10 minutes. Recordings were made of format and occurrence of displays, percentage time spent in various activities, orientation of birds with respect to neighbours and contacts with neighbours and strangers. Position within the colony was compared with respect to numbers of birds passing by, the amount of contact and fighting and the mortality of eggs and chicks. The colony size and structure was mapped through the season and inter-nest distances were measured. Several experiments were conducted to measure differences between among individual penguins.