IMPROVING ESTIMATES OF ADÉLIE PENGUIN BREEDING POPULATION SIZE: DEVELOPING FACTORS TO ADJUST ONE-OFF POPULATION COUNTS FOR AVAILABILITY BIAS

It is widely recognised that the interpretation of counts of penguin populations at their breeding sites during the breeding period are strongly dependent on the timing within a breeding season at which they are undertaken. While the need to adjust raw penguin count data obtained at varying times within a breeding season to minimise bias in estimates of the breeding population has long been recognised, the considerable work in obtaining one-off counts for population surveys have not been matched by the collection of adjustment data. This was recognised at the recent Predator Survey workshop, where the collection of adjustment data to improve estimation of penguin abundance was identified as a priority for future work. This paper reports on the collection and development of adjustment factor data for Adélie penguins in east Antarctica.