Detectable but unseen: imperfect crypsis protects crab spiders from predators

Some crab spiders can change their colour to match the flower they use as a hunting platform and, in choice trials, they select same-colour flowers over contrasting flowers. Colour change is a costly physiological process that could help spiders capture more prey or avoid predators. There is no evidence, however, that crypsis increases the hunting success of spiders, and its effect on predator avoidance has not been studied. To evaluate the...