Predation
No predators hunt lions to eat them; however, they do have a few natural enemies, such as hyenas and cheetahs. Hyenas compete with lions for food and often try to steal their kills.
Sexual competition
There is little competition amongst pride males during mating. Instead of fighting to be the first to mate with a fertile female, a male will follow her around very closely at the first signs of fertility onset.
Disease
CDV and babesiosis aren't the only diseases Serengeti lions contract. They're also at risk of feline herpesvirus, feline immunodeficiency virus (FIV), feline calicivirus, feline parvovirus, and feline coronavirus. Of these, feline herpesvirus and FIV are prevalent and very likely endemic in the lions.
Other causes of death
In certain parts of Africa, lions are killed by local people during rites of passage ceremonies to demonstrate manhood or bravery. Other threats. A range of other threats affect lions and their prey in some places, including: mining in wildlife areas, illegal logging, poorly regulated trophy hunting, and disease.