Blue-billed Duck

1. Breeding males feature a cobalt-blue bill paired with rich chestnut plumage.

2. Females and juveniles have mottled brownish-grey plumage with light barring.

3. Stiff tail feathers held upright during courtship or alert behaviour.

Blue-billed Ducks are expert divers, feeding underwater on aquatic insect larvae, mollusks, seeds, and plant material during dives lasting up to 30 seconds. Breeding occurs primarily in spring and summer when males perform elaborate courtship displays involving tail-slapping movements that create rippling sounds audible over long distances. Females construct domed nests hidden among dense vegetation over water, laying 5–6 pale green eggs and raising ducklings independently.

Blue-billed Ducks inhabit deep freshwater wetlands across southeastern and southwestern Australia, favouring areas with dense aquatic vegetation such as cumbungi (bullrush) beds. They are most commonly found in secluded swamps during breeding season but may form flocks on larger lakes or artificial wetlands like sewage ponds in winter. These secretive birds prefer open water far from shore and are best spotted early morning or late afternoon when actively feeding.