population is a measure of the amount of a certain species of animal in an evironment & if something is eliminated then the amount of that something decreases ->  if an animal is eliminated then the population of that animal will decrease  if an animal eats other animals for food , then the animal will be the predator & predators eat prey ->  if an animal eats another animal then the animal will be the predator and the other animal will be the prey  if an animal eats another animal then the animal will be the predator and the other animal will be the prey & hawks eat snakes / rats / rabbits ->  hawks are predators to snakes / rats / rabbits and snakes / rats / rabbits are prey to hawks  hawks are predators to snakes / rats / rabbits and snakes / rats / rabbits are prey to hawks & as population of prey decreases , the population of predators will decrease ->  as the population of snakes / rats / rabbits decreases the population of hawks will decrease  if an animal is eliminated then the population of that animal will decrease & as the population of snakes / rats / rabbits decreases the population of hawks will decrease ->  if snakes / rats / rabbits are eliminated then the population of hawks will decrease  if snakes / rats / rabbits are eliminated then the population of hawks will decrease & to decrease can mean to decline -> if snakes / rats / rabbits are eliminated then the population of hawks will decline