Male Wood Duck in a Forest Pool, study for book Concealing Coloration in the Animal Kingdom

In 1909, Abbott Handerson Thayer and his son, Gerald, published a controversial book titled Concealing Coloration in the Animal Kingdom, offering their theory of animal camouflage. Thayer believed that the coloration of animals, no matter how eye-catching, was meant to disguise them in nature through what he called "countershading." Even bright pink flamingoes would vanish against a similar colored sky at sunset or sunrise. No matter that at times their brilliant feathers were highly visible, their coloration would protect them from predators at crucial moments so that "the spectator seems to see right through the space occupied by an opaque animal."