Why are distasteful prey not cryptic?

Abstract

Bright coloration among unpalatable prey is common1. Turner2 has suggested that, as with Fisher's explanation for the evolution of distastefulness itself3, such aposematic coloration has been favoured by kin selection. Distasteful aposematic prey tend to live in kin groups and predators sampling from such groups will learn to avoid conspicuous prey more readily than cryptic prey and, as a consequence, fewer members of conspicuous kin groups are preyed upon2,4–6. We know of no clear evidence that vertebrate predators take fewer trials when learning to avoid conspicuous rather than cryptic distasteful prey6,7. Here we report results from a series of experiments that provide such evidence.