DIET OVERLAP IN A PISCIVORE COMMUNITY

We examined prey selection of largemouth bass (Micropterus salmoides), smallmouth bass (M. dolomieu), and yellow perch (Perca flavescens) by comparing diet overlap in a small, unexploited lake in Michigan, USA from 1988 to 1990. Niche hypervolume principles were applied to diet d ata as a means of assessing diet space for each species and the commun ity as a whole. Largemouth bass occupied the largest proportion of com munity diet space (70.2%), followed by smallmouth bass (44.2%), and ye llow perch (21.7%). The majority of community diet space (58.8%) was o ccupied by a single species, and 41.2% was shared by greater than or e qual to 2 species. Diet overlap was assessed by measuring the amount o f diet space of one species occupied by the other species. Our analyse s demonstrated that diet partitioning in a three species piscivore com munity is reflected in different use of the prey resource by co-occurr ing species. Niche overlap of largemouth bass with smallmouth bass and yellow perch is strongly asymmetric, largely due to the ability of la rgemouth bass to effectively consume prey of terrestrial origin.