African White-backed Duck Thalassornis leuconotus

This species of duck is the only one in its genus; it is not closely related to any other species of duck. It's found in Subsharan Africa and Madagascar, where it lives on fresh water, diving for water lily bulbs and other vegetation.

In their exhibit in Bird's World you can see below the water line. I haven't seen them diving yet. When I've watched them they spend their time swimming near the front of the exhibit (where you can get a great view of their beautiful cryptic plumage) or preening themselves.

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