Recent work by Dr. Warner has shown, through a series of experimental manipulations, that the interaction of tradition and resource assessment is a potent force in mating system determination in a model species, Thalassoma bifasciatum (a coral reef fish). Mating sites that have been in use for generations change to new locations only when tradition is broken by removing and replacing the entire population. Under normal circumstances, site usage is constrained by tradition. The physical attributes of mating site may change over time, but the population has little opportunity to reset to any new distribution of resources because there is an initial liability in attempting to mate at a nontraditional site. These results are significant because they challenge current thinking in behavioral ecology: mating systems may not be predictable from measurements of the current distribution of resources. This work leads to some predictions about the role of catastrophic disturbance in this mating system. If population traditions are broken by a natural catastrophe, the mating system which is reestablished should be correlated with existing measurable resources. Prior to the occurrence of Hurricane Hugo, Dr. Warner had mapped the distribution of mating sites on 19 patch reefs in Teague Bay, St. Croix. On five of these reefs he had also measured the physical characteristics of these sites as well as other sites that were suitable but were not used. There were many unused sites that had the same physical characteristics as sites that were used. If Dr. Warner's published predictions are correct, a new suite of mating sites will arise after the hurricane, and these will posses physical characteristics that will clearly distinguish them from other structures on the reef. This is an unprecedented opportunity to test a hypothesis that referred specifically to the effects of catastrophic events on mating systems.
