Living with failure: the prey capture success of young brook charr in streams

We examined the prey capture success of recently emerged brook charr (Salve linus fontinalis) foraging in shallow, clear, still-water pools along the e dges of streams. Fewer than 42% of attacks ended with ingestion either beca use of difficulty distinguishing suitable prey from unsuitable items or bec ause of difficulty capturing evasive prey. Probabilities of capture upon at tack and ingestion upon capture depended upon where attacks were directed i n the water column, the fish's level of activity at the time of attack and its fork length, and the sampling date. In general, success was higher for larger, sedentary fish attacking prey in the lower portion of the water col umn than for smaller, active fish attacking prey at the water surface. The frequency of items attacked was only a moderate predictor of the frequency of prey ingested. Poor capture success is an important aspect of the early life history of brook charr in particular and probably of young salmonines in general.