Before moving from the wintering grounds to the breeding grounds, pairs form strong seasonal pair bonds that lasting until incubation. The female incubates between 4 and 12 eggs, from late April through to early July, in a shallow depression concealed by reeds, and lined with grass and down, but at this time the male deserts the female. After 25 to 27 days the eggs hatch, and the hatchlings are cared for by the female until they fledge 55 days later. Outside the breeding season, marbled ducks form small groups and sometimes larger flocks (8).
Marbled ducks feed on small seeds and aquatic invertebrates, dabbling and filtering mud during the early morning and evening, but resting during the day. Population size fluctuates in response to annual differences in rainfall, and individuals will disperse widely to find suitable habitat (2).