Competition typically increases with the density of nearby individuals. However, Hoare and colleagues (2004) found that killifish in some circumstances prefer to associate with more rather than fewer fish. What can explain this observation?

Question

Quizplus · Accepted Answer

The dilution effect explains this observation because it suggests that by associating with a larger number of individuals, each killifish reduces its individual risk of predation. This is because predators are less likely to single out any one fish when they attack a larger group, thus the risk of being eaten is spread out or "diluted" among all the members of the group.

Competition Typically Increases with the Density of Nearby Individuals