An experimental study of foraging site selection in young-of-the-year yellow perch, Perca flavescens

Synopsis

We performed a series of laboratory experiments to identify and evaluate preferences of young-of-the-year yellow perch for using six foraging sites, and to relate these preferences to the observed diet of perch in nature. The six foraging sites, the water surface, floating vegetation, open water column, submerged macrophytes, open substrate, and benthic cover, were simulated by artificial devices in 56.81 aquaria. The distribution of the number of food items removed from the six foraging sites did not differ significantly from random. The order of removals, however, revealed significant preferences. The water column site was selected before all others, while the surface and the floating vegetation sites were used last. Handling time efficiencies showed nearly opposite patterns: the midwater site required a longer handling time than all other sites while the surface and floating vegetation were among those sites with the shortest handling times. The selection of foraging sites was essentially independent of the order of encountering the feeding devices, and was not affected by experimental experience. The foraging site selection by the fish in our experiments corresponds to naturally important foraging sites for perch of the same size. Our results suggest that preference for a foraging site, whether genetic or due to early experience, can override immediate profitability.