Prey Appraisal—An investigation at Norris Reservoir, Tennessee, revealed how much black bass species crop their own numbers. Researchers checked stomach contents of larger predators and collected age-0 (hatchling) bass to estimate the densities of largemouth, smallmouth, and spotted bass.*

Shad were the dominant prey of all predators, although sunfish, crayfish, and other fish were important, as well. Small black bass were frequently eaten by large bass but not by crappie, flathead catfish, or striped bass. Over their first year of life, 85 percent of hatchling smallmouths were eaten by other bass, along with 97 percent of spotted bass and 71 percent of all largemouths.

Despite these losses, survival of the three species remained density-dependent: The more young bass present, the lower their survival. This level of predation did not reduce overall annual survival but is a natural means of controlling abundance and utilizing food resources.

*Raborn, S. W., L. E. Miranda, and M. T. Driscoll. 2003. Modeling predation as a source of mortality for piscivorous fishes in a southeastern reservoir. Trans. Am. Fish. Soc. 132:560-575.