Blue Duck (Hymenolaimus malacorhynchos)

The blue duck is unlike any other duck. It is the only member of its genus and has no close relatives. It is an almost uniform slate blue-grey duck with a characteristic pale bill.

Morphology
Male and female blue ducks have a similar appearance with the following characteristics:

• almost the entire plumage is slate blue-grey
• the head is a little darker and crown and nape washed with brown
• the breast is mottled with chestnut (reddish-brown) spots that are denser and more extensive in the male
• the undertail coverts are also chestnut
• the secondaries are tipped with white, and inner secondaries and tertials have a thin, black outer margin
• the bill is pinkish-white with black tip and flaps of skin at the side towards the tip which assist its feeding technique
• legs and feet are dark grey with black at joints
• eyes yellow

Rights Holder: Natural History Museum, London