A nested ANOVA design was used to measure the variance component due to differences between individual Adélie penguins in the length of krill eaten, using data from Esperanza Bay. The variance component -0.26 was not significantly different from zero (F = 0.093; P = 0.54).This finding supports the argument for using individual penguins to estimate parameters of the prey population without discriminating by sex, weight or other factors pertaining to the predator.