National Geographic: "The Serengeti Lion" project

The Killers, a male coalition of four, earned their name with lethal attacks on females. They almost killed their rival C-Boy too. Because good territory is a precious resource, fighting and displacing competitors are part of the natural struggle. (© Michael Nichols/National Geographic).

Cubs of the Simba East pride: too young to kill but old enough to crave meat. Adult females, and sometimes males, do the hunting. Zebras and wildebeests rank high as chosen prey in the rainy season. (© Michael Nichols/National Geographic)

Large cubs of the Vumbi pride and a grown female (fifth from left) feast on a wildebeest. The darkest, moonless hours are prime hunting time because the cats can see better than their prey. These black-and-white photographs were made with infrared light to minimize disruption to the lions. (© Michael Nichols/National Geographic).

C-Boy mates with a Kibumbu pride female. After fathering cubs, a resident male can be displaced by other males. His young offspring will then be killed by the new males or left to die. (© Michael Nichols/National Geographic).

C-Boy and a Vumbi female relax between matings. During estrus a female may be monopolized for days by a single male consort. Dark manes correlate with robustness, and dark-maned studs like C-Boy are preferred. (© Michael Nichols/National Geographic).

Older cubs like these Vumbi youngsters are raised together as a creche, or nursery group. Pride females, united in the cause of rearing a generation, nurse and groom their own and othersâ offspring. (© Michael Nichols/National Geographic).

A female wrangles her infant cubs. During the first few weeks, when they're too young for the competitive jumble among older cubs in the pride and so vulnerable to predators, she keeps them hidden away in a den. But these will soon join the group. (© Michael Nichols/National Geographic).

Hildur, C-Boy's partner, frequently makes a long run to visit the Simba East pride. A coalition that controls two prides must maintain vigilance over both. (© Michael Nichols/National Geographic).

Dry season is hard on everyone. Vumbi females, stressed and fiercely protective of their young, get cross with C-Boy, though heâs one of the resident fathers. (© Michael Nichols/National Geographic).

A male often asserts his prerogatives. C-Boy feasts on a zebra while the Vumbi females and cubs wait nearby, warned off by his low growls. Their turn will come. (© Michael Nichols/National Geographic).

The August 2013 issue of NATIONAL GEOGRAPHIC MAGAZINE © National Geographic.