False Peace in Pride of Lions ?

Powerful yet lithe animals stalking the unsuspecting victim from different sides in the tall grass at dusk as if following a rehearsed choreography and suddenly attacking all at once – a pride of lions on the prowl is, to all appearances, the epitome of smooth cooperation. Quarrels and quarrels seem to be forgotten immediately, when the apparently most social of all big cats strive for only one goal in common effort: to procure the next meal. That this image of unity does not stand up to sober observation, we had to recognize when we tracked down the king of animals in the wild for many years.

A) Lions Pride : a Close Group ?

We have been conducting these studies since 1978, when we took over the observation of the same lion population in the Serengeti National Park in Tanzania, on which the German-American animal researcher George Schaller of the wildlife conservation organization Wildlife Conservation International of the New York Zoological Society had done pioneering work on big cats in the wild since 1966; since then we know that they live partly in prides with defended territories, partly nomadically roaming individually or in groups. After Schaller, others had continued to observe the groups, but much of the life of this species remained difficult to explain – especially the behavior in the group, because most cat species are notorious loners. We wanted to know why lions in particular band together to hunt, defend their territory and raise their young.

The Role of Male Lions in the Pride

Male lions enter into a lifelong alliance with up to eight adult sex mates. However, they do not do this out of pure charity, but ultimately for the purpose of maximizing their own chances of reproduction. In most cases, the partners who form a true fighting alliance are brothers or cousins who have grown up together. But some associations consist of unrelated lions that roamed alone for a time as young males and only later joined together.

As fully grown animals, such coalitions, if they succeed, take over a pride, or more precisely, a female clan along with its territory. For about two to three years, they then sire all the offspring – until another coalition defeats them and henceforth rules over the pack. Thus, the reproductive success of the individual depends directly on how well his team passes the challenge of rival alliances.

It is in situations where the self-interests common to all are most threatened that the team demonstrates its greatest ability to cooperate. We challenged this defensiveness by playing tapes of an alien lion’s voice amid the vast territories where males roam at night, making their claims of ownership known with loud roars.

Organizing a Pride of Lions

Whenever we provoked them with this, they immediately ran and searched for the originator near the source of the sound. If we had also placed a male lion dummy there, they attacked it violently. Our collaborator Jon Grinnell has found in dozens of such experiments that unrelated male lions cooperate as well as brothers in such situations. This was not necessarily to be expected, since, in theory, closely related animals should be more likely to stand by each other. (In fact, as we shall see, the difference does affect behavior in other situations). It is also by no means self-evident that the lions attacked the speaker even when they were alone and their confederates could not register their behavior at all. Not even from a triple outnumbering – normally a life-threatening situation – did our experimental lions shy away.

In general, large coalitions dominate over small ones. Also, strong associations are usually younger when they conquer a territory and can hold it longer. Their packs also include more females on average. Cohesion apparently provides so many advantages for reproduction that even most solitary animals form alliances with others. Such alliances of non-relatives, however, never have more than three members; in a team of four or more comrades-in-arms, all are always closely related and have known each other from an early age.

The Competition for a Pride of Lions

Not every male Rude Lion will be able to produce offspring without further ado, especially if many compete with each other for the coveted resource. It is true that large coalitions do best when one calculates how many young there are on average for one male. But the real distribution, at least in the Serengeti population, can be very uneven: Whoever is the first to spot a female willing to mate will guard her at every turn from then on, copulate with her many times during the duration of estrus – often for around four days – and chase away any other male that even dares to come near. Therefore, a litter usually comes from a single male. This was the result of the genetic comparison of hundreds of blood samples collected by Dennis Gilbert in Steven O’Brien’s laboratory at the U.S. National Cancer Institute in Bethesda, Maryland. It also showed that paternity is fairly distributed only in alliances of two males. In larger groups, only very few lions ever achieve the main reproductive success.

Now, from the genetic point of view, it is not too serious for the individual to remain childless, as long as this is compensated by offspring of, for example, brothers, because after all they also carry genes of their closest relatives. Paternity of family members can thus have a value that is worth standing up for. But this is not the case with groups of unrelated lions, so that a larger group of more than two or three males is obviously not worthwhile.

B) Female Lions Leading Lions Pride !

In a pride, lionesses hunt the most. It was once thought that the advantage of cooperative hunting was the main reason for their close cohesion, but we have been able to show that this is not true. The pride often separates into smaller groups for long periods of time, and these do not feed any better than females roaming individually. In quite large hunting groups, the single cat may even fare worse, because the conspecifics often simply do not participate and rely on the luck and skill of the most active among them.

Obviously it plays only a limited role that the assistance could increase the chances of success – at least with the usually hunted large animals, of which all would become full. In the case of defensible prey, after all, there is considerable danger of injury and thus the dilemma of risking wounding, while it would be possible to obtain food without any effort on one’s part.

Apparently, in individual cases, the decisive factor is how skillful and experienced the lioness huntress is who first takes the initiative. If it can be estimated that she manages the matter well alone, then for the others the advantages connected with cooperation never make up for the risk. For a less experienced hunter, the effort may be more worthwhile despite the danger involved.

Behavior of the Pride of Lions

If the pride has prey nearby, the mother leads her cubs there to feed. If the distance is too great, she lets her children participate indirectly – through her milk – in the meal. Then even not only the own cubs drink from her; also this observation might have nourished the fairy tale of the selfless community of the lions.

But on closer inspection, the relationships turn out to be more complicated. The females of a manger tend to feed at the same catch and return together. After long excursions, they are so exhausted that they doze off soon after returning – and that gives them access to the milk source. Since we have observed more than a dozen nurseries, we know that any young can actually drink from any female.

Such behavior, in turn, can be explained in sober terms, much like that of team-building males. Indeed, in contrast to their brothers, many young lionesses remain in the rearing unit later; therefore, the female nucleus of a pride consists of mothers and daughters, sisters and cousins. Litters vary in size: usually two or three cubs, sometimes only one, occasionally four. When we measured the amount of milk in almost a dozen individual females, it was revealed to our surprise that it does not depend on the number of young, but on the portion of meat eaten.

Females Define the Territory of Pride

Lionesses that don’t have cubs usually like to be alone, away from the commotion of shared hunting expeditions and defining the territory of the pride. They visit their sisters and cousins only now and then, but usually hunt for themselves and can fill their bellies without envy. That the nursery is the heart of the lion pride, as it were, does not mean that its main purpose is to feed the offspring particularly well. Females do behave most sociably while their cubs are still dependent, but even then they may eat less than a lioness who has to care for her litter alone – and as we have seen, the amount of milk depends on this. Indeed, lions do not have a babysitting system that would allow, say, mothers in the clan to eat more regularly.

What else could be the purpose of cohesion? It takes young lions two years to become independent. Only when they die does the mother become ready to mate again prematurely – within days – and have her next litter up to a year earlier than normal. The male lions, on the other hand, hardly care for their offspring, but protect them by their regular territorial patrols. Because if they lose the territory to a new ruling team, the cubs are in mortal danger. The new owners will do everything they can to produce offspring themselves – the sooner, the better; often they only have about two years to do so. Young animals are only in their way, because their mothers do not immediately come into question as partners. Simply killing the foreign children therefore increases the chances of reproduction.

C) Conflict Over Cubs

In the meantime many observations prove this connection. More than a quarter of all lion cubs fall victim to new territory owners. In the end the mothers are the ones who have to face the consequences of a pride takeover every few years and often lose many cubs. That is why they defend their offspring to the best of their ability. But alone they have practically no chance even against a single male, because he is almost 50 percent larger. Only when they are united can they protect their young.

But lionesses not only have to fend off attacks by the opposite sex. They are also territorial themselves; that is, as a pride they defend preferred hunting grounds, resting places and watering places against foreign females as well as against territorial claims by female sexes from neighboring territories. In this, large clans outnumber smaller ones; females are often killed in boundary conflicts. In contrast to the males, they have the opportunity to reproduce for up to eleven years. This may be the reason that such territorial disputes drag on much longer than conflicts between male teams aimed at replacing dominance.

Lionesses are remarkably cautious in confronting unfamiliar females. When Karen McComb, now at the University of Sussex (England), played tape recordings of other lionesses to groups of females, they did not attack in every case, as male lions do, but only when their own troop had at least two more animals than the supposed one from the tape.

As these experiments show, lionesses can actually count and keep a certain safe distance if possible. In general, the number of animals in the pride decides over life and death: With only one or two lionesses, it is doomed in the long run; connection to another is not possible, it cannot defend its territory, because it is only rushed around, and it is no longer able to raise cubs.

Male Lions Come and Go

The lion pride, the lifelong association of females, is the only reasonably safe haven in an environment full of enemies that can never be definitively defeated: the male and female conspecifics. Over the years, we have observed many times how pack owners had to make way for new male alliances. The various rulers, hundreds of lions in all, left the same unmistakable mark each time: first of conquest and murder, then of paternity, and in the end of decay and fall. We have also seen a few dozen times how new prides arose and left their mark. Male lions comes and go each time. Other lion prides had to perish for it. As great as the king of animals in community may appear, when he conquers land from neighboring groups and fights off dangerous strangers – above all he testifies to the evolutionary forces, from whose contradictions a cooperating animal society emerges as a precarious compromise.

D) Members of a Pride of Lions

Male Lions

The head of the family is the pride’s male. He is the king of the pride and it is his job to protect the female lions, called lionesses, and their cubs. Sometimes three or four kings share this responsibility. Unlike females, male lions have a mane, which is long, thick hair around their head, neck and shoulders. No one really knows why, but it may be to help them look bigger and fiercer and also to serve as protection in a fight.

Lionesses

Lionesses have a lot of work to do. Not only do they care for their cubs, but they also have to go hunting for food to feed the rest of the pride. They are smaller and faster than the males and do not have a mane that would make them easy to spot. When a lioness has to leave her cubs to go hunting, another lioness in the pride will look after them while she is away. This is called a crib, like the one you may have gone to as a child.

Cubs

Life as a cub is much easier if you’re a girl. Female cubs normally stay with their family pride forever, but life for their brothers is much harder. At the age of about two, male cubs are forced to leave their pride when their family members chase them away. Many of them end up living alone for the rest of their lives, but some gather in groups, again forming a pride of lions.