Flamingos aren’t born pink.

The phrase “you are what you eat” may hold most true when talking about flamingos. These striking pink birds initially lack any sort of flamboyant coloration, as their feathers are more of a dull gray for the first year or two of their lives. Over time, flamingos develop their signature pink color due to their diet.

These birds mainly dine on algae, brine shrimp, fly larvae, and other foods containing carotenoids — a type of organic pigment associated with shades of red, orange, and yellow. One carotenoid that’s typically found in the aforementioned food sources is the red-orange beta-carotene, which is broken down in the flamingo’s digestive tract and then absorbed into the fats of its liver. Those pigments are then deposited into the bird’s feathers and skin, resulting in its bright pink hue.