CLOSED: Strange looking wader in Lake Peten

We saw this bird at extreme range in a remote part of Lake Peten, Guatemala.
It is not in my bird book.
Any ideas?

Black-bellied Whistling Duck

Resin

Thank you Resin. A very interesting bird. Next time we will get closer to take better photos. They survive here in the Lake because their habitat is very remote.

John here is a picture of my pets ones. I have the Black-bellied, White-faced, and Fulvous Whistling Ducks