Behavioral Interactions in Fishes: Scaling Up from Individual Processes to Population Dynamics
Fred Scharf, University of North Carolina, Wilmington, Department of Biological Sciences
Foraging by fishes is shaped by many factors operating at several different scales in space and time. Only by examining multiple ecological processes operating simultaneously can we begin to identify the mechanisms critical to the feeding patterns of predators. The research presented in this seminar will illustrate the important role that behavioral abilities of both prey and predator can play in organizing predator diets and the potential impacts that dietary choices may have on patterns of prey mortality and predator growth. Probability of attack and capture were found to be mediated by prey behavior and appeared to be mostly responsible for observed predator feeding choices. The fact that marine fish predators may be exposed to seasonally dynamic prey fields, with changes in prey species as well as prey sizes throughout the year, implies that behavioral interactions among individuals will impact population and community dynamics. Detailed population models were used to evaluate the potential growth consequences of variable prey fish dynamics on annual time scales. Results indicate that piscivore foraging is dependent upon the availability of specific forage species of appropriate size, with potentially strong effects on consumption and growth.