When animals are fenced, and especially in the case of predators where there is not an abundance of them, it is important to manage their numbers and genetics.
The predators in the Park are monitored and information is kept on which Lions are mating with which Lionesses. If not managed the males could breed with their offspring.
Therefore, Park Management will make decision, a call depending on the info, as to whether they need new blood and if so, which Lions should move to a new home. In order to keep the predator / prey base in balance it is essential that this is managed correctly.