The Caribbean beaugregory damsel fish (Stegastes leucostictus) maintains permanent territories and breeds throughout the year. Previous studies found that the reproductive success of most males dramatically improved with the addition of new artificial breeding sites. This finding
suggests that most natural sites were of relatively poor quality and may explain why many previously occupied territories became vacant after several months. Randomly removing defenders verified that little competition existed for most previously occupied territories, although high-quality
artificial sites were quickly occupied. However, similar to the natural sites, artificial sites also had vacancies after several months. Those males remaining on old artificial sites had a significantly lower reproductive success than those males whose old sites were replaced with new ones.
The new sites that replaced old ones were also less likely to become vacant. The decline in male reproductive success was related to changes in the quality of the territory and appeared independent of any male quality changes. Our observations and experiments suggest that males can not, or
do not, oust other males from high-quality territories. Instead, they probably remain with their sites until they find “new” uninhabited high quality territories.
The Bulletin of Marine Science is dedicated to the dissemination of high quality research from the world's oceans. All aspects of marine science are treated by the Bulletin of Marine Science, including papers in marine biology, biological oceanography, fisheries, marine affairs, applied marine physics, marine geology and geophysics, marine and atmospheric chemistry, and meteorology and physical oceanography.