Optimal foraging or surplus killing: selective consumption and discarding of salmon by brown bears

Abstract

Predators do not always eat what they kill. Eating only the most energy-rich tissues may be most efficient for predators with limited stomach space, but why predators leave entire carcasses uneaten is unclear. We found that grizzly bears feeding on salmon routinely discarded completely uneaten and partially eaten fish while seeking the best available prey. When salmon were very abundant, bears discarded whole carcasses of low quality or ate only choice pieces.