Canthaxanthin is one of the major carotenoids associated with flamingo coloration. Astaxanthin and other carotenoid derivatives can also contribute to their red, pink and orange hues.

At first, it seems almost pointless. The flamingo bends its head into the murky water, shoves its beak into the air, and glides through the mud at a leisurely pace. There is no chase, no obvious prey, ...