Do Female Fish Prefer to Spawn in Nests with Eggs for Reasons of Mate Choice Copying or Egg Survival?

Abstract

When a female is more likely to mate with a male because other females have mated with him, the female is said to be "copying" the mate choice of others. Much of the discussion of copying has centered around lekking birds. However, reviews on the subject have also pointed to experimental studies of fish and female preferences for males with eggs in their nest as evidence for the existence of copying. I question this claim by arguing that these studies may indicate that females prefer to spawn in nests with eggs because the presence of eggs increases the quality of a spawning site through increased egg survival, not because eggs signify a previous female's mate choice. The two hypotheses may not always be mutually exclusive, but data on female preference for nests with an intermediate number of eggs or eggs in the earlier stages of development are more in line with the egg survival hypothesis than the mate choice copying hypothesis.