Giant killers: macropredation in lions

By now you have probably heard that episode 2 (‘Great Plains’) of the BBC’s series Planet Earth (currently in its second series) included amazing footage of the elephant-killing lions of Savuti in Chobe National Park, northern Botswana. While most people ‘know’ that elephants are immune to predation thanks to their size, nobody has told this to the Savuti lions. Hunting at night, when the elephant’s poor night vision puts them at a major disadvantage, the lions co-operate as a pride of about 30 individuals to bring down and dispatch elephant prey. It is amazing. But, as usual, the media is leading us all horribly astray.

We should make clear to begin with that these are not just any old lions, behaving spontaneously or opportunistically: they are a specialised, highly experienced population that have, uniquely, become elephant killers. While there are some major questions as to how the Savuti lions learnt to do this, Planet Earth didn’t, unfortunately, touch on how old this culture is, or how it originated. It is thought that the Savuti lions have learnt over time to kill bigger and bigger prey, each time winning success by the virtue of their large pride size. Lions elsewhere can – opportunistically – kill Cape buffalo Syncerus caffer* (weighing c. 1000 kg) and sometimes hippo Hippopotamus amphibious (c. 1500-3500 kg), and it has been speculated that, after learning to successful tackle and kill hippo, the lions became bold enough to begin regularly taking juvenile elephants, eventually moving up to adults. And if you’re wondering: YES, the Savuti lions have been recorded attacking and killing adult elephants.

* Though note that some lion populations are specialist buffalo-killers. In Tanzania’s Lake Manyara National Park, George Schaller (1972) reported that an amazing 62% of all lion prey was made up of Cape buffalo, with 81% of this 62% being adult male buffalo. Buffalo-killing is also important to the lions of Kruger National Park, and studies here have shown, significantly, that male lions are not just frequent and successful hunters: they are also the lions that are best at killing buffalo (Funston et al. 1998).

A few opportunistically recorded events may have encouraged the lions to view elephants as potential prey. In their National Geographic film Ultimate Enemies, wildlife film-makers Dereck and Beverly Joubert recorded a case where, after a fight with another bull, a defeated elephant lay, wounded, on the ground. Understandably, the elephant’s misfortune became the hungry lion pride’s gain. Wildlife photographer and travel writer Leigh Kemp recorded a case where an old, weakened bull that collapsed and became unable to stand was discovered and eaten (while still alive) by opportunistic lions. It is tempting to suggest that these events and others like them might have been catalysts in encouraging the development of elephant-killing in the Savuti lions. Numerous other instances of elephant-killing have been filmed and documented by the Jouberts, and in 1997 they published a book covering this behaviour in depth (The Lions of Savuti: Hunting with the Moon, published by National Geographic).

The Lions of Savuti: Hunting with the Moon records something like 15 years of observations, and even in 1990 the Jouberts were estimating that about 20% of the Savuti lion’s diet was made up of elephant. I would love to know if the behaviour goes back further than this, as personally I find it highly unlikely that this behaviour really is something that the lions have ‘just learnt’. Historically, Africa was filled with a lot more lions than it is now, not to mention elephants, and given the extraordinary behavioural flexibility of lions* I suspect that elephant-killing is something that lions have practiced many many times in the near and distant past.

* If you’re read Bruce D. Patterson’s outstanding The Lions of Tsavo (Patterson 2004) you’ll know that studies of the Serengeti-type lion that we’re all so familiar with (e.g. Schaller 1972) have ‘created an orthodoxy around lion biology that applies poorly to the species elsewhere’ (p. 138).

The fact that the Jouberts were photographing and filming this behaviour negates one of the claims that have appeared as a result of Planet Earth’s coverage: this being that the BBC were the first to film this behaviour (not that anyone working for the BBC has said this, so far as I can tell). In fact Ultimate Enemies, showing scenes of night-time elephant predation by Savuti lions, was broadcast in North America in 2004. This is not to downplay the BBC’s commendable efforts, however, and it is clear that obtaining the sort of footage they did is tremendously time-consuming, dangerous, and requires a monumental amount of effort. With panicked elephants lumbering around in the dark, and surrounded by hungry and aggressive lions that routinely kill animals weighing many hundreds of kilos, the camera teams were in the middle of the bush, in the middle of the night, in small jeeps with open sides and windows.

What did we actually get to see? The answer to this is both positive and negative. To begin with, it seems that the lions used psychological warfare to intimidate and confuse the elephants: loud roaring in the dark. This behaviour has been recorded in other lion populations and also in leopards, and it seems that the idea is to scare prey into making an ill-thought dash for ‘safety’. Paying particular attention to juvenile and adolescent elephants, especially those that were separated from the rest of the herd, the lions were then shown attacking the hind legs and haunches of fleeing elephants, biting and clawing and hanging on to the pursued animal. And that… is about it. Here’s where we come to the negative, particularly problematic, part of this whole story.

We empathise with elephants. And, somehow, seeing them being killed and eaten by big cats is, for many people, just wrong. That may or may not be a justifiable point of view, but what is undeniable is that elephant-killing is protracted, unpleasant, and gory. Consequently almost none of the actual killing was shown. By clawing and biting at the elephant’s legs, the lions hamstring a chosen elephant, and also use the combined weight of multiple individuals to bring it down. This apparently happens surprisingly quickly. From spotting an elephant, to pursuing it, to getting it to collapse: all can take as little as 30 seconds. Once an elephant is down, some of the lions work on clamping its trunk shut, and I presume that they might also attack the throat and mouth. Like it or not, we can assume that lions at the other end of the animal will now begin feeding. The elephant might take about 30 minutes to die. It does not sound nice, or look nice.

I empathise with elephants, and do not enjoy the thought of them being killed. But the fascination that I have for animals makes me want to know more about what actually happens. This is a natural act of predation: sure, it’s not pleasant, or pretty, but I want to know what happens. For me, the footage was ultimately disappointing, then, in showing bugger all (worth noting here is that views on the screening of acts of predation are starting to change. See Finally: big cat kills uncensored and uncut).

What makes this all the more frustrating is the implication from some that the lions are downright nasty, committing an evil, murderous act that is heinous and unjust. An article – titled ‘The killing fields’ – that appeared in Times2 (a supplement to the British newspaper The Times) described the footage as ‘possibly the most shocking natural history footage you will have seen’. It went on to state that ‘If you have any sentimental feelings about lions, prepare to lose them’. I’m sorry, but that’s crap. The appreciation I have of lions and their amazing behavioural flexibility and unique social system is increased by the knowledge that they have learnt to kill elephants. Yes it’s gory, and – no doubt about it from our point of view – upsetting and even horrific, but it is an amazing thing that we should wonder at.

Coming eventually: agamas, tupuxuarids, fake Chinese turtles, temnospondyls for beginners, kinglets and the passerine supertree, more on sea snakes, anguids, giant eagles and plethodontids, those lost tree frogs, storks and (one day) rhinogradentians. For many of these posts you'll have out check Tetrapod Zoology at its new location here.

Refs - -

Funston, P. J., Mills, M. G. L., Biggs, H. C. & Richardson, P. R. K. 1998. Hunting by male lions: ecological influences and socioecological implications. Animal Behaviour 56, 1333-1345.

Patterson, B. D. 2004. The Lions of Tsavo: Exploring the Legacy of Africa’s Notorious Man-Eaters. McGraw-Hill, New York.

Schaller, G. 1972. The Serengeti Lion. University of Chicago Press, Chicago.