INDIVIDUAL VARIATION IN FORAGING MOVEMENTS IN A LAKE POPULATION OF YOUNG-OF-THE-YEAR BROOK CHARR (SALVELINUS-FONTINALIS)

We examined the variation in foraging movements in a population of you ng-of-the-year (YOY) brook charr living in the near-shore littoral zon e of a lake. By repeating the methodology of an earlier stream study, we made direct comparisons between data from lake and stream populatio ns. In general, the pattern of variation in foraging movements was sim ilar between the two sites with greater variability and activity obser ved in the lake population. The dichotomous nature of the proportion o f time spent moving in the stream was also observed in the lake popula tion but in a reversal of the stream pattern. Charr that moved constan tly while foraging represented the largest movement category in the la ke. In general, variation in foraging movements were more strongly rel ated to the rate of prey rejection, whereas environmental factors, suc h as distance from shore, submerged objects, and the amount of overhea d riparian cover, were more strongly related to prey ingestion. This l ast finding directly contrasts with that found in the stream literatur e for YOY charr in still water where ingestion rate, as estimated usin g feeding attempt rate, increases with the mobility of YOY charr.