Incubation time depends on temperature and can be between about 50 and almost 100 days.

Hatchlings use their strong feet to break out of the egg, then lie on their backs and scratch their way to the surface, struggling hard for 5 to 10 minutes to gain 3 to 15 cm at a time, and then resting for an hour or so before starting again. Reaching the surface takes between 2 and 15 hours. Chicks pop out of the nesting material with little or no warning, with eyes and beaks tightly closed, then immediately take a deep breath and open their eyes,