Breeding season: April to June. Clutch size is 5-15. Nesting takes place in winter. The male and female remain together for about five months, which includes courtship, nest building and egg-laying. The nest consists of a platform of grass on the ground. The large eggs (dark bluish-green) are laid at intervals of two to four days. The shells are thick, with paler green and white layers under the dark outer layer. The female dominates the male during pair formation but once incubation begins, the male becomes aggressive to other Emus, including his mate.