Royal Penguins are monogamous (Waas et al. 2000). Reproduction only occurs on Macquarie Island from September to March. The season is marked when males arrive and begin building nests made out of grass and lined with small stones. The nests are easily distinguished from other crested penguin nests (Royal 1998). Females arrive in early October and lay eggs near the end of the month. Eudyptes schlegeli are known to breed in both large and small colonies. The largest colony is estimated to have around 500,000 pairs, while smaller colonies can contain a mere 70 to 200 pairs.
Two eggs are laid in the nest but only the second egg is incubated (Waas et al. 2000). Incubation takes approximately 30 to 40 days. When the chick hatches the male protects and raises it for 10 to 20 days. During this time the female penguin gathers and brings food to the nest daily. At an age of about 70 days, the chick is capable of leaving the nest and subsisting on its own. Royal Penguins reach sexual maturity in approximately one year (Royal 1998).