On prey grouping and predator confusion in artifical fish schools

摘要

In two simulation models the benefit of schooling under predatory pressure is investigated. It appears that if a predator cannot become confused by prey, grouping is seldom beneficial. If prey, however, can confuse a predator, schooling appears to protect prey under a whole range of parameters. Using an evolutionary approach we found that, in the case of a confusable predator, cohesive groups with a consistent forward movement evolve most frequently, but that milling stationary groups also prove to be effective. We suggest that the predator protection in moving and stationary groups rely on different mechanisms, among other things, on a kind of altruistic behaviour.