The preferred prey item would be frogs.
What is optimal foraging theory?
It is a theory in ecology that proposes that predating animals that get the most energy from minimal efforts are favored by natural selection.
In order words, selection forces prefer investing minimum energy in order to extract maximally available energy.
In this case, the heron needs to use the lowest time to harvest the maximum energy possible. Since all the preys offer the same amount of energy, the one that requires the lowest time would be preferable for the heron.
In other words, frogs would be the most preferable prey.
More on foraging theory can be found here: brainly.com/question/16970714
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