The breeding season begins in May, nests are constructed within thick grasses and reeds, often on river islands to protect them from predation (4). Swan geese in Mongolia nest in colonies. Females lay a clutch of between three and nine eggs; once hatched, different broods often come together into flocks and float downstream, en mass, to broader lakes and valleys (4). Moulting also occurs on the breeding grounds, usually at the end of July, but dependent on the weather condition that year (5). The swan goose then migrates to China, Taiwan, Japan and South Korea, where it spends the winter (4).
Feeding usually occurs after nightfall, and the diet changes with the seasons and location of populations. In the breeding grounds, sedges (Carex species) constitute the majority of the diet, whilst in autumn a large number of berries are consumed (4).