Whistling Ducks
Birds of Panama - large bird photo gallery
The whistling ducks or tree ducks are a subfamily, Dendrocygninae of the duck, goose and swan family of birds, Anatidae. They are not true ducks. In other taxonomic schemes, they are either considered a separate family Dendrocygnidae, or a tribe Dendrocygnini in the goose subfamily Anserinae. For more details from Wikipedia about the Whistling Duck please see this page here.
This image was taken near the Panama Rainforest Discovery Center in the Soberania National Park in Panama.