Group living

A typical pride of lions consists of about six related females, their dependent offspring, and a “coalition” of 2–3 resident males that joined the pride from elsewhere. The pride is a “fission-fusion” society and pridemates are seldom found together, except for mothers that have pooled their offspring into a “crèche.”

Most daughters are recruited into their mothers’ pride although about a third disperse to form new prides; pride size ranges from 1–21 females, and mid-sized prides enjoy the highest reproductive rates, and females in the same pride breed at similar rates. Young males always leave home in search of unrelated mates. Coalition size varies from 1–10 males, and coalitions of 4–10 males consist entirely of males born in the same pride, whereas pairs and trios often include unrelated individuals. Although larger male coalitions enjoy higher per capita reproductive success, reproduction is only equally shared in small coalitions.

Lions are most affectionate to their like-sexed companions. Females spend their lives in their mothers’ pride or with their sisters in a new pride; males may only spend a few years in a given pride but remain with their coalition partners throughout their lives. Read more about group living.

Infanticide

When a new male coalition first takes over a pride, the cubs represent a major impediment to their reproduction. Mothers of surviving cubs will not mate again until their offspring are at least 18 months of age but will mate within days if their cubs are lost. Thus, incoming males are unwilling to be stepfathers and kill all the young cubs in their new pride; infanticide accounts for a quarter of all cub deaths. Although subadults often escape from infanticidal males, they become outcasts and must fend for themselves and suffer the risks of starvation and attacks from neighboring prides. Mothers will occasionally accompany evicted subadults until they reach independence.

Mothers directly defend their offspring against attacks by outside males, and females also reduce the risks of infanticide by inciting competition between rival males such that they only conceive again after the largest available coalition has become resident in their pride.

Female lions will kill the cubs of rival prides, but they never kill the cubs of their pridemates. The “egalitarianism” of female lions is strikingly different from the despotic behavior of wolves, wild dogs and many other species where dominant females prevent subordinates from breeding.

Communal cub rearing

A male takeover resets the reproductive clocks of all the females in a pride such that pridemates often give birth synchronously. Mothers of similarly aged cubs form a “crèche” and remain together for 1–2 years. Crèche-mates often nurse each other’s cubs, though they give priority to their own offspring followed by the offspring of their closest relatives. Mothers of singleton cubs produce the same amount of milk as mothers of large litters, and single-cub mothers are the least discriminating in their nursing.

The primary advantage of forming a crèche is that a group of females is better able to protect their young against infanticide. Males are 1.5 times larger than females, so a male can easily overpower a lone mother, whereas a crèche with at least two mothers can successfully protect at least some of their cubs against an extra-pride male. However, the crèche can only withstand a brief male incursion, so the females must also rely on protection from their resident males, who patrol the pride territory and fiercely repel outside males.

Territoriality

Lions are highly territorial and occupy the same area for generations. Females actively defend their territories against other females, while resident males protect prides from rival coalitions. Territory size depends on prey abundance, as well as access to water and denning sites.

The lion’s roar is a territorial display that can be heard from at least five km away. Lions are able to count the number of individuals in a roaring group and will challenge the invaders if they safely outnumber them.

Although foraging groups of lions often suffer reduced food intake from having to share their kills with pridemates, larger prides have a strong advantage in competition against neighboring groups. Larger prides are able to expand the size and quality of their territories and thereby gain greater reproductive success. The heterogeneity of savanna habitat appears to be the root cause of group territoriality in lions: territory quality largely depends on proximity to river confluences, which serve as funnels that force prey into a small area and also hold persistent waterholes and dense vegetation.