Chestnut Teals form monogamous pairs that stay together outside the breeding season. Both parents choose and defend a nest site and the males stay with the female while she incubates the eggs. The nest is usually located over water, in a down-lined tree hollow about 6 m to 10 m high. Sometimes nests are placed on the ground, among clumps of grass near water, and are little more than a scrape, lined with down. Artificial nest boxes of the right size and located in suitable habitat will also be readily used. Males do not assist with incubation but do look after the young when hatched. Sometimes 'dump-laying' occurs, where females leave their eggs in the nest of another female, which accounts for some large clutch sizes (up to 17 eggs in a nest). The young hatch ready to swim and walk within a day, and will move out with their mother onto the water straight away. Both parents defend their brood and will chase off other teal with pecks. If threatened by a predator, parents will feign injury, splash and quack in an attempt to distract it while the young dive or swim off. Predators include: Little Ravens, which eat eggs and young; Blue-tongued Lizards, which eat eggs; Purple Swamphens and Musk Ducks, which take ducklings; Swamp Harriers and Peregrine Falcons, which take adults; and Foxes, which take eggs, young and adults.
