What completes this statement: Optimal foraging theory predicts animals maximize net energy gain per unit time by balancing energy intake with which costs?

• A. Predation risk
• B. Energy spent on reproduction
• C. Time spent resting
• D. Search and handling costs

Answer: (D)

Foraging decisions are about maximizing the speed at which an animal can gain usable energy. Optimal foraging theory frames this as balancing energy gained from food with the costs of getting it. The direct costs in this balance are the time and energy spent searching for prey (search costs) and the time and energy required to capture or handle the prey once found (handling costs). If these costs are high, they erode the net energy gain per unit time, so the animal should choose patches or prey that reduce search and handling effort relative to the energy they provide. While factors like predation risk or taking time to rest can influence foraging choices, the specific costs used in the typical energy-budget balance are search and handling costs.