The emperor goose feeds on grasses, berries and sedge leaves while at its inland breeding grounds, but feeds on algae, seaweeds, clams and mussels while on the coast during winter (2) (6), when it can be seen foraging in shallow water or on mudflats exposed by the retreating tide (6).
During the breeding season, the female emperor goose selects a nest site (4), situated on a small island in a pond or along the shoreline, where there is low, dead vegetation and good visibility (6). One to eight eggs are laid in a shallow depression in the ground lined with down, feathers and dead vegetation (2). While the female builds the nest and lays the eggs the male stays nearby and chases any intruders away (4), and confronts predators with an aggressive posture and threatening cries (2). The female is solely responsible for incubating the eggs, which hatch after 24 to 25 days (2). The chicks are capable of walking and swimming within hours after hatching and usually leave the nest in the first day, and fledge at 50 to 60 days of age (6). The emperor goose reaches sexual maturity at about three years of age (2).