Nonindependent mating in a coral reef damselfish: evidence of mate choice copying in the wild

Theoretical and experimental studies have shown that mate choice copying is a viable mating strategy under certain conditions. Copying experiments in fish have been conducted primarily in the laboratory, except for one study conducted in the field under artificial conditions. We investigated whether in a wild population of the coral reef whitebelly damselfish (Amblyglyphidodon leucogaster) females copy the choice of other females. Females preferentially spawn with males that have recently mated. To determine if the presence of new eggs in the nest was the reason females chose mates or whether females were mate choice copying, we conducted egg-switching experiments. Eggs from males that recently mated were donated to males that had no eggs. If females are mate choice copying, then donor males with no eggs in the nest should continue to receive additional eggs. If females are using the presence of new eggs as the criterion for mate choice, then foster males with new eggs should receive additional eggs. We found that donor males received new eggs significantly more often than expected. More females mated with donor males than foster males. Furthermore, females preferentially chose to mate with males whom they had seen mating with another female. Females appear to remember the mate choice of other females and choose to mate with those same males even after 1 day. These results suggest that females may be copying the mating decision of other females rather than choosing males based on the presence of new eggs in the nest.