Only the Male Lion resided at the zoo permanently. Three lionesses were shipped over from other zoos as part of a breeding program. Early on in the September phase of the outbreak, they became infected with the t-Virus, causing them to mutate, gaining more stamina and causing their feral instincts to grow.
Despite the infection, they maintained their pack instinct and prowled the zoo for prey. The entire pride was killed by a group of survivors traveling through the zoo in the first days of the outbreak.