Repeatability of Foraging Tactics in Young Brook Trout, Salvelinus fontinalis

Abstract

In this study, we repeatedly observed individually marked Brook Trout in a field setting to determine if the bimodal variation in foraging tactics previously observed in young salmonid populations (without distinct morphological differences) is generated by individuals specializing at different foraging tactics. We found significant but low repeatability in several foraging movement parameters. This indicated that while individuals did have tendencies to be sedentary versus highly active, there was considerable variation in foraging activity within individuals. These results suggest that relatively consistent differences among individuals may facilitate selection for specialized morphology and that there may be a heritable component to activity. Erratum included.