If form follows function, often so does color, it's so important as camouflage. Blending in is key like this yellow warbler pictured munching on American beautyberries. Where's Waldo?
Each and every day, small passerines have two overriding imperatives: 1) find enough food to survive another day, 2) stay hidden enough not to be eaten themselves, it's do or die as this wonderful photo so illustrates.
Thank you, Jason Dykes for sending it to me.