This brilliant little video by James Kusz, whose work has appeared here several times, demonstrates the evolutionary adaptation of a bird species to its environment. The Black Turnstones forage almost exclusively in terrain like that pictured here: rocks in the intertidal zone. Their topside plumage has evolved to become practically invisible in that habitat. Unless they’re moving, you have a very hard time spotting them.
Other birds, such as the Snowy Egret, stand out sharply when viewed from above. But when viewed from the water below, that whiteness might blend in nicely with the sky and hide the bird better than a dark color would. It all depends on the point of view.
Other images by James Kusz