Practice question

In the optimal diet model, prey are ranked by expected energetic return per unit handling time, E/h. If E1/h1 exceeds E2/h2, prey 1 is the higher-ranked item and should be accepted whenever encountered. This profitability difference explains a persistent preference, but the phrase “regardless of prey2 abundance” reflects an additional prediction: acceptance of a lower-ranked prey generally depends on encounter rates with the more profitable prey, not on how abundant the lower-ranked prey itself is. When prey 1 is sufficiently common, a predator can reject prey 2 and spend search time seeking prey 1; when prey 1 becomes rare, including prey 2 may increase average gain. A long handling time for prey 2 could contribute to its lower ratio but is not the complete criterion because energy content also matters. Equal profitability would not predict a consistent ranking. Thus, the inequality correctly identifies prey 1 as more profitable, while prey 1 encounter rate determines whether strict specialization remains advantageous.