The animal kingdom is a world of color. Animals produce colors in numerous, intricate ways. Many fish, reptiles, amphibians, crustaceans, and cephalopods produce color and reflect light from their skin using cells called chromatophores.
Chromatophores are also responsible for the rapid changes in color we observe in many types of animal camouflage, like with chameleons. Other animals display color effects, which occur when randomly spaced skin materials, like scales, form parallel thin layers and refract waves of light that hit the surface of the skin.
You Are What You Eat
But perhaps, the most complex animal coloration happens through the synthesis of organic pigments. Pigments, such as melanin, are the colored chemicals in animal tissues that give many animals an earth-tone.
Though, while animals can produce melanin at the cellular level, they can't make many other pigments. So, despite its appearance, the male cardinal at your feeder doesn't even produce the pigments that create his dazzling red plumage.
The cardinal acquires these carotenoid pigments that range from yellows to reds from its food. They ingest enough of these carotenoids to essentially mask the melanin they actually produce.
Berries And Shrimp
Flowering dogwood produces carotenoids in its fruits, which are a staple of the cardinal's diet. By eating dogwood berries, cardinals absorb red carotenoids, which are then displayed in their feathers.
Something similar happens with flamingoes. Flamingoes are born grey but develop their tufted pink feathers from a diet of brine shrimp. These shrimps can't synthesize carotenoids either: the blush-colored crustaceans derive their own pigments from their diet of microscopic red algae.
Animals naturally use many mechanisms to produce their colors throughout their lives.
Thank you to Ted Stankowich of Cal State Long Beach for reviewing this episode's script.
Sources And Further Reading:
- Koren, Maria. "For Some Species, You Really Are What You Eat." Smithsonian Magazine. april 24, 2013. Accessed July 24, 2018.
- Hilton Jr., B. 1996. Animal colors. South Carolina Wildlife 43(4):10-15