Introduction | Conservation issues

Hunting and prey selection | Behaviour

Like all cats lions have very good acceleration, but little stamina. When hunting it is important for them to get as close to their prey as possible before charging. Concealment and the stalk, therefore, are very important parts of the hunt. Concealment can be gained through the vegetation, physical features of the habitat such as raises and gullies and, most important of all, by cover of darkness. Lions hunt mainly at night especially when the moon is down, or in cloud.

To catch their prey lions have to be smart. If the prey is sighted some distance away the lions may at first move quite rapidly towards them. As they approach they go into the stalking posture with heads and bodies held low, intently watching the prey, freezing should they look in their direction, then moving forward as the prey look away, or down to continue feeding. Eventually, if they are lucky, the lions manage to get within striking distance, which is 20-30 m from the prey.

When they strike the prey still have a better than even chance of escaping. However, a particular individual may not detect the lions in time, or it may stumble or run into an obstacle, or it may be young, sick or old and slow. Should something like this transpire the lions will quickly catch up with the prey and pull it down, usually killing it by strangulation or suffocation, showing incredible strength in doing so.

Some prey species are killed by special techniques. Buffalo herds are usually followed for long distances with no attempt to stalk. Rather it seems that the lions attempt to panic the buffalo into scattering and to break up the formidable phalanx of buffalo making it easier to select a victim. Warthogs are dug out of their burrows.

It is often assumed that the lioness is the active hunter and that adult male lions are virtual parasites living off the females. This is certainly true in open areas like the Serengeti. However, in the more wooded Kruger National Park a rather different situation to this sexist stereotype of the male lion occurs. Kruger male lions in fact acquire most of their food by killing it themselves and there is a separation in the prey killed by males and females. Males kill mainly buffalo, but also impala and warthog, whereas females concentrate on zebra and wildebeest. In wooded areas male lions do not associate with females as much as they do in open habitats, probably because the extra cover gives the females a better chance to hide their cubs from strange, aggressive males. Males do not have to invest as much time and energy protecting their cubs and can look for other females with which to mate.

Behaviour

The core of a lion pride is a group of 2–18 closely related adult females (mothers and daughters, sisters and aunts) that occupy a territory. These females are not together all the time - individuals tend to go off on their own, or more often with one or two of the other females. Why is the lion the only truly social cat? The obvious explanation is that co-operative group hunting gives them a big advantage. Not only does it increase their hunting success, it also enables them to overcome larger prey than they would if they hunted on their own. However, although it is true that large groups are more successful at hunting very large prey like buffalo, and even that hunting success is related to hunting group size, solitary lions have a higher rate of food intake as they do not have to share their food with others. Group hunting even decreases rates of food intake in female lions as the spoils have to be shared. So there must be other reasons for lions being social.

The females of a pride co-operate in raising cubs. They synchronise the births of cubs, which grow up in a crèche in which the females suckle each other’s cubs and co-operatively defend their cubs against strange males. Female cubs usually stay in the natal pride for life, all male cubs born in a pride leave when they are two to four years of age. With no pride or territory commitments to attend to the subadult males concentrate their efforts on feeding and growing big and strong, forming coalitions with usually related males that may exceptionally be as large as seven. When they reach full maturity the males are ready to take over a territory. The territory may coincide with that of a pride of females, or it may be larger encompassing the territories of several prides. If there are other adult males in the territory the new males must firstly displace them, an activity that is often violent.

Once the new coalition of males has taken over a territory and gained tenure of the pride they perform the dastardly act of infanticide – they kill the cubs. The females, being much smaller than the males, are usually unable to prevent this, but they do try to gang up against the males and particularly if their cubs are older than a year, they may be able to escape.

Within days of losing their cubs the females come into oestrus and mate with the cub-killing males. Contrary to popular belief there is no single dominant male lion in a pride, the members of a coalition are of equal status, as are the adult females. It is a case of first come first served. Mating lasts about four days during which time copulation occurs roughly once every 25 minutes. If the female fails to conceive she will come into oestrous again in 16 days. If she does conceive she will produce 1–4 cubs after a gestation of 3.5 months. Compared to single males, pairs, or coalitions of three or more can more easily gain tenure of prides of females, retain tenure for longer, mate with more different females, and produce more surviving offspring.

When the females give birth again the new males give protection to cubs with which they share their genes and not those of other males. If it were not for the infanticide the new males might have to wait two years before they could sire their own cubs. As the period of tenure of a pride by males is not usually more than three or four years, they might not otherwise be able to raise any of their own offspring.

Neither are the male lions the lazy chauvinists they are so often reputed to be. In woodland savannas male lions are active hunters. Moreover, the task of maintaining the territory demands regular patrols through the territory. During these the males announce their presence by roaring and scent marking by spray urinating bushes. Should intruders be encountered they may lay their lives on the line to defend their home turf in a rare display of co-operation and teamwork.

If the reason for lions being the only truly social cats cannot easily be explained through hunting advantages, what are they? The most important one seems to be that by forming co-operative groups lionesses are able to lessen the chances of their cubs being killed by nomadic males and during pride take-overs, particularly when the cubs are larger and more mobile. Long-term studies in the Serengeti have shown that the reproductive success of a lioness is better if she belongs to a pride of three or more females than it would be if she belonged to a pride of one or two females. Furthermore, lionesses are better able to defend their hunting territories against other female groups if they do so in a pride. Large prides dominate smaller ones and females will attack and kill their neighbours. Finally, females in a group are better able to defend their carcasses against spotted hyaenas.

Dr Gus Mills