An aspect of defence designed to avoid predation. Much of this avoidance behaviour is neither wholly innate nor wholly learned. Many animals have species-specific defence reactions. For example, some may struggle to escape when caught by a predator, while other feign death. New avoidance behaviour is more quickly learned if it is similar to the species-specific defence behaviour of the animal concerned.
Defence against predators may be primary or secondary. Primary defences operate regardless of whether or not there is a predator in the vicinity. They reduce the probability that a predator will encounter an animal. They include camouflage and mimicry, group living and some forms of social interactions, and symbiosis.
Secondary defences operate only after an animal has detected a predator. They increase the chances that the animal will escape from the encounter. They include withdrawal, flight (escape), bluff, death feigning, deflection of attack, and retaliation. Bluff takes the form of deimatic display designed to scare off a predator. For example, the caterpillar of the hawkmoth (Leucorampha sp.) normally rests upside down beneath a branch or leaf. When disturbed it raises and inflates its head, the ventral surface of which has conspicuous eye-like marks, and the general patterning of which resembles the head of a snake. Many moths and butterflies have eye-spots on their wings, which they reveal suddenly when disturbed, with the possible effect of frightening the predator.
Subjects: Zoology and Animal Sciences.