Review of historical population information of emperor penguins

In 1902, the first breeding colony of emperor penguins was discovered. Over the following decades, the number of known emperor penguin colonies increased steadily and new ones are still being discovered. However, rigorous census work has been carried out at only a few colonies and accurate information on trends in breeding populations is limited to a small number of locations. Thus, the total number of breeding pairs is still unknown as is the size of the global population (breeders, non-breeders, juveniles). The International Union for the Conservation of Nature (IUCN) lists the species’ status as ‘least concern’ and states that although the population trend for emperor penguins has not been quantified, the global population appears to be stable. This review summarises the currently available information on the populations of emperor penguins at known colonies in terms of survey methods, count units used and survey frequency. It examines what is known about the state of various colonies and demonstrates that currently available data are inadequate for a trend assessment of the global population.