Handling time and the evolution of caching behavior

Food caching is widespread among several animal species. Few studies have proposed that handling time should affect the evolution of caching behavior, especially under foraging time constraints. Nevertheless, to date, there has been no analytical support to the "handling time hypothesis." In the present article, we use an analytical model to show that caching behavior may evolve as the result of shorter handling time caching relative to eating. We evaluate caching behavior under 3 fitness objectives (or environmental scenarios): maximizing energy consumed, maximizing and balancing energy consumed, and maximizing energy consumed under risk of predation. Our analyses reveal that under all 3 fitness objectives, caching behavior can evolve when caching time is shorter than eating time, to allow the animal to free up search time during the period when food is plentiful and postpone time spent handling to the period when food is scarce and search time is less valuable. That effect may be called "search time reallocation," and it is still prevalent even if food decays. Our model provides predictions that can be field tested, adds to the debate of handling time and perishability hypotheses, and invites researchers to direct their focus toward understanding the evolutionary motives of caching behavior.