If a new male lion takes over a pride, the fate of the cubs in that pride is often grim. Typically, the incoming male will kill all the cubs that are less than a year old. This behavior ensures that the future cubs born in the pride will carry the genes of the new dominant male, as the females will come into estrus sooner after losing their cubs

. Male cubs, when they reach sub-adulthood around 3 years of age, are usually forced to leave or are kicked out of their natal pride. These young males then attempt to take over another pride, often forming coalitions with other males to challenge the dominant males of that pride. If successful, they may repeat the cycle of killing existing cubs to assert their genetic dominance

. In summary:

• New dominant males often kill existing cubs to promote their own lineage.
• Male cubs leave their birth pride at about 3 years old to find or take over another pride.
• Cubs are cared for communally by lionesses in the pride, but their survival depends heavily on the stability of the pride's male leadership