Which factor determines prey2 rejection by a predator?
In the classic optimal diet model, rejection of a lower-ranked prey type depends on how quickly the predator expects to encounter the more profitable prey type. Search time for prey 1 is therefore decisive. If prey 1 is encountered frequently, rejecting prey 2 costs little time and preserves a high long-term intake rate. If prey 1 becomes rare and its expected search time increases, accepting prey 2 can raise average energy gain despite its lower E/h ranking. A notable prediction is that the abundance of prey 2 does not directly control the decision after prey 2 has already been encountered; d
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 14