Census of adelie penguins (Pygoscelis adeliae) at the Cape Royds rookery, 22 January, 1985

A penguin census (adults and chicks) was conducted in January on the Cape Royds rookery. The number of chicks and adults were counted three times (by two observers for the chicks and one observer for the adults) and the counts for each observer were averaged (the mean of the two averages for the chicks was taken as the number present in the colony). A degree of error was calculated for the observations.