Optimality Foraging essays

Optimality Foraging essays This study was undertaken to experimentally test for evidence of optimal foraging in guppies, Poecilia reticulata. Foraging preferences of guppies feeding on brine shrimp were studied to make predictions about optimal diet breadth. First, the profitabilities (Engery intake/ handling times) were determined by testing the handling time of four size classes of guppies foraging on brine shrimp of sizes 2, 4, 6, and 8 mm. The following week, we tested whether guppies of various sizes prefer prey that return the greatest benefit. This was accomplished by arbitrarily placing brine shrimp of different sizes in various tanks with different size guppies. Our results did not support the optimal diet breadth theory. All species must obtain some sort of nutrition in order to survive and reproduce. To do this, many animals must forage for their own food. Therefore, the energy used to forage could be energy used for other activities, such as mating. Thus, a logical hypothesis has been made that animals will optimize the benefits of obtaining food to survive, yet minimize the energy used to obtain said food. This is the optimal foraging idea. In this experiment, we looked at guppies and see if they favored efficient foraging behaviors according to optimality models. Using optimality models helps predict if an animals behavior has in fact been shaped by natural selection to maximize benefits to costs. Our hypothesis of this experiment was that guppies will favor efficient foraging behaviors. Thus our HA is that the guppies will choose the prey that will give them the highest net energy gain (cal/handling time). The HO is therefore that foraging in guppies occurs due to chance. The reasoning behind this is that if given sufficient prey choices, animals will be selected to choose to maximize the benefits to costs ratio. If the animal is making decisions about the environment, and if food giving a high rate ...