If a predator prefers prey1 regardless of prey2 abundance, it is due to:
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 p
Ref: Ecology: Concepts and Applications, Molles, 9th Ed., Ch. 14