Answer:
Available food
Explanation:
From the given example, it is called the available food
Predators searches for a prey to eat, but first it's sit and wait for it. and when a prey is located, the predator thinks whether to attack and kill it.
Once a predator has been removed from that environment, the prey itself whether of lower class animal or different classes of animals becomes available and vulnerable to other higher class of animals who are in search of food for survival.
