How do groups of male lions take over and defend a pride?

Male lions typically become nomads after being expelled from their birth pride at about three years of age. They remain in this state until they are old enough—usually after age five—to attempt to take over a new pride.1

Competition for pride control is fierce, and success often depends on forming cooperative partnerships. Coalitions of two to four males are significantly more effective at maintaining tenure over a pride than individual males, with larger coalitions often fathering more surviving offspring. While small coalitions frequently consist of related males, larger groups may include unrelated individuals.1

Once a new cohort of males successfully takes over a pride, they defend their territory and assert dominance through vocalizations, such as their distinctive roar, and by scent marking areas with urine or by rubbing against vegetation. To secure their own reproductive success, incoming males often engage in infanticide, killing young cubs sired by their predecessors to bring the lionesses back into reproductive condition more quickly. Lionesses may attempt to defend their cubs, though they are generally more successful at protecting older offspring.231