American Flamingo - Phoenicopterus ruber
Flamingos aren’t naturally pink! They get their coloration from beta carotene found in the blue-green algae they consume. The flamingos that consume blue-green algae directly are much pinker than flamingos that primarily consume the blue-green algae secondhand (via zooplankton/brine shrimp).
Flamingos are also unique in their method of eating - their bills are designed to scoop the bottom sediment and then filter out the mud and silt, leaving only the blue-green algae or the brine shrimp in their mouth. They shake their head back and forth under the water after scooping up the sediment. The big, fleshy tongue of the flamingo pushes water back and forth in the mouth and facilitates the filtering of all that mud. They also swallow their food while their head is upside-down! The meaty tongue used to be considered a delicacy among the Roman elite.
Nature Neighbors: Embracing Birds, Plants, and Minerals. Nathanial Moore Banta for the American Audubon Association, 1914.
Osteologia Avium; or, A sketch of the osteology of birds. T.C. Eyton, 1867.