Large terminal phase males will defend breeding sites to which females migrate on a daily basis. A study was done to estimate the relative roles of each sex in choosing the location of such sites. All terminal phase males or all females were replaced in local isolated populations, and the resulting site use was monitored. After males were replaced, the mating system was not affected. On the other hand, after the females were replaced, half of the old sites were lost and the same number of new sites came into use, and continued to be occupied for over a year after these manipulations. This occurred although large males originally continued to defend and display at the original sites. Therefore, this shows the importance of female choice in the feeding system of the blue-headed wrasse, and that males will respond to the females' site preferences.
