Complex sentence: For example, a certain forager gains energy from food, but incurs the cost of searching for the food: the time and energy spent searching could have been used instead on other endeavors, such as finding mates or protecting young.
Split into simpler sentences: For example, a certain forager gains energy from food, but incurs the cost of searching for the food. The time and energy spent searching could be used instead on other endeavors, such as finding mates or protecting young.