Killer whale (Orcinus orca) wave washing

It was the pinnacle of his career. A milestone in human exploration. A journey that would forever link his name to the Antarctic continent: on 17 January 1912, Captain Robert Falcon Scott finally stepped onto the Earth’s south pole.

Unbelievably, already waiting for him there was the tent of the Norwegian explorer Roald Amundsen. Amundsen and his crew had abandoned an attempt to reach the north pole and gone south instead. Despite great hardship and months of travel Scott had been beaten to the prize by just 34 days.

And his troubles were not over. By the end of March that same year Scott and his four companions were dead, unable to complete the return journey to their base and supplies because of intense weather and misfortune. In Scott’s words, as he wrote in his diary in the tent that would become his tomb: ‘These rough notes and our dead bodies must tell the tale’.

Our tale today starts with that same diary, but happily we are not focused on its grim end. Instead, we rewind to just over a year before the Englishman Scott reached the pole, in early January 1911. His notes from that time contain one of the first recorded accounts of another epic struggle on the Antarctic ice, involving creatures even more threatening than a precocious Norwegian: killer whales.

A party of ice-breakers

Scott and his ship Terra Nova landed on the southern continent on 4 January 1911, at a site almost directly south of New Zealand. The landing spot had earlier been called the Skuary after its avian inhabitants, but Scott re-named it after his second in command, Edward ‘Teddy’ Evans. Fortunately, the bird-infested location was perfect for setting up their camp, which included the largest building then constructed in Antarctica. This is it nearing completion on 10 January 1911, attended by Francis Davies the ship’s carpenter, with forage bales for the animals stacked alongside:

On 5 January the scene was a busy one, with equipment, dogs, ponies, supplies and motorised sleds—not to mention the captain’s gramophone—all moving from ship to shore. Amid it all, photographer Herbert Ponting moved about creating a comprehensive record of the expedition. But Ponting was about to find himself at the centre of unsettling attention, as Scott recounts in his entry for that day:

I was a little late on the scene this morning, and thereby witnessed a most extraordinary scene. Some 6 or 7 killer whales, old and young, were skirting the fast floe edge ahead of the ship; they seemed excited and dived rapidly, almost touching the floe. As we watched, they suddenly appeared astern, raising their snouts out of water. I had heard weird stories of these beasts, but had never associated serious danger with them. Close to the water’s edge lay the wire stern rope of the ship, and our two Esquimaux dogs were tethered to this. I did not think of connecting the movements of the whales with this fact, and seeing them so close I shouted to Ponting, who was standing abreast of the ship. He seized his camera and ran towards the floe edge to get a close picture of the beasts, which had momentarily disappeared.

This was not the expedition’s first sighting of these mammals. Ponting photographed them on occasion, including this group seen hunting at sea not long before the Terra Nova made landfall in Antarctica:

Back to Scott’s diary:

The next moment the whole floe under him and the dogs heaved up and split into fragments. One could hear the ‘booming’ noise as the whales rose under the ice and struck it with their backs. Whale after whale rose under the ice, setting it rocking fiercely; luckily Ponting kept his feet and was able to fly to security. By an extraordinary chance also, the splits had been made around and between the dogs, so that neither of them fell into the water. Then it was clear that the whales shared our astonishment, for one after another their huge hideous heads shot vertically into the air through the cracks which they had made. As they reared them to a height of 6 or 8 feet it was possible to see their tawny head markings, their small glistening eyes, and their terrible array of teeth–by far the largest and most terrifying in the world. There cannot be a doubt that they looked up to see what had happened to Ponting and the dogs.

The latter were horribly frightened and strained to their chains, whining; the head of one killer must certainly have been within 5 feet of one of the dogs.

After this, whether they thought the game insignificant, or whether they missed Ponting is uncertain, but the terrifying creatures passed on to other hunting grounds, and we were able to rescue the dogs, and what was even more important, our petrol – 5 or 6 tons of which was waiting on a piece of ice which was not split away from the main mass.

Scott was quick to realise that this was no accident. The killer whales, now more commonly called orca in line with their species designation Orcinus orca, were deliberately targeting and attacking the dogs and cameraman. He realised he had underestimated them, and vowed not to do so again, writing:

Of course, we have known well that killer whales continually skirt the edge of the floes and that they would undoubtedly snap up anyone who was unfortunate enough to fall into the water; but the facts that they could display such deliberate cunning, that they were able to break ice of such thickness (at least 2 1/2 feet), and that they could act in unison, were a revelation to us. It is clear that they are endowed with singular intelligence, and in future we shall treat that intelligence with every respect.

We know now that Scott never had a chance to put his new-found respect into action. He is still in Antarctica as you read this, still in the tent where he wrote his final diary entries. When his crewmates finally found his camp in November 1912, they collapsed the tent with Scott and his remaining team members Edward Wilson and Henry Bowers inside, and over it built a snow cairn. At the top they placed two skis, tied in a cross.

Waving away

For a long time it seemed Scott’s killer whale observations would remain a curio. In fact, most of the twentieth century passed by before the orca behaviour he witnessed returned to scientific attention.

In 1981 a report appeared in the Canadian Journal of Zoology, written by arctic scientist Thomas Smith and his colleagues at the university of Minnesota. Far from their home institutions, in November 1979 the researchers were sailing in Paradise Bay, about a third of the way clockwise around Antarctica from where Scott had landed. They were scouting for seals, and found a pod of seven orca doing the same thing. The apes and marine mammals joined forces, searching together.

Success came when they spotted a solitary crabeater seal resting on an isolated ice floe. The orca spent the next five minutes sizing up the challenge, rising vertically one by one to peer onto the ice—a behaviour called as ‘spy-hopping’—just as Scott had seen that January morning in 1911. Then, simultaneously the pod quit their deliberations and swam about 100 metres away.

They returned in formation, and at speed. As they approached they twice they rose above the surface to eye their target, then about ten metres from the ice they collectively dove. Their wake formed a wave that continued forward and wiped the seal off its perch. The seal vanished beneath the water, although it wasn’t clear to the watchers whether the whales had managed to capture it or it had somehow escaped.

The accompanying diagram from Smith et al.’s report is the first detailed depiction of orca wave washing behaviour, from (A) spy-hopping, through (C) wave washing, to (E) departure as a group:

You might think that such a clear record would jumpstart research into the behaviour. Yet at this point orca manufacture and use of waves once again drops out of scientific sight. The scarcity of verifiable reports is frustrating but understandable, thanks to the limits of camera technology and fewer research and tourist vessels on the lookout for the behaviour in Antarctic waters. Underwater commando teams are hard to spot from the surface, and as always with animal behaviour luck played a part in who was watching what and when.

Almost three decades after the Paradise Bay incident, in 2008, a review led by New Zealand marine biologist Ingrid Visser with a global team (including Thomas Smith) was only able to come up with six recorded sightings since the 1979 attack. These included a further two wave-based hunts of crabeater seals (in 2004 and 2006), two attacks on leopard seals (in 1998 and 2000), and one assault each on a Weddell seal and an Adelie penguin (in 2000 and 2004 respectively).

This is the video of the 2006 crabeater seal attack, featuring both Visser and Smith, that prompted their review:

A new lens

Herbert Ponting came close to capturing the first photograph of orca wave-formation in 1911, only to have his favourite Zeiss lens—worth £25!—slip off the camera and drop over the ship’s poop rail to the bottom of McMurdo Sound just as the beasts approached. (Don’t worry, he wrote to the manufacturers and got a free replacement.) But killer whale wave-washing piqued the attention of photographers and scientists following the 2008 report, and they have spent the last decade and a half making up for lost time. Finally, we have detailed images of the orcas assembling and using their liquid battering rams.

For instance, here’s a sequence of killer whales wave-washing a Weddell seal captured by Kathryn Jeffs in 2009, during the filming of the first series of Frozen Planet from the BBC:

Along with the Frozen Planet footage, that same 2009 expedition gave us the first detailed, repeated observations on orca wave-washing. It was published by expert orca-watchers Robert Pitman and John Durban in 2012, a full century having passed since Scott’s diary notes. Pitman and Durban, both at the US National Oceanic and Atmospheric Administration or NOAA, spent more than two weeks alongside the BBC film crew and six different groups of B1 orca. Their field site was Laubeuf Fjord, on the west coast of the Antarctic Peninsula that projects northwards towards South America.

They saw 22 different bouts of killer whales seal-hunting using waves. Most of those sessions involved a group targeting a seal by making 1-5 waves over half an hour or less, although an extended bout that lasted more than two hours included 26 different waves—and the targeted Weddell seal got away. The researchers also gave us a precise description of the nature of these attacks:

Typically, after a couple of false starts, the whales swam off together, side-by-side at the surface, to a distance 5–50 m away before turning abruptly back toward the floe. As they charged underwater toward the floe, the whales converged, bodies parallel and almost touching, with their flukes beating rapidly and synchronously.

As they approached the floe below the surface, a small wave formed at the surface in front of their heads, followed by a deep trough above their tailstocks, and a second, larger wave above their pumping flukes. As they reached the ice edge, they lifted their tails in one last power stroke, and the whole group dove under the ice, just barely avoiding contact with it. As they passed under the floe, the whales rolled a quarter turn on their sides, which prevented their dorsal fins from hitting the ice. Sometimes the entire group leaned in the same direction; at other times the group split down the middle with the animals on the right side leaning to the right, and those on the left leaning left.

Pitman and Durban distinguish between two main types of waves, over which the orcas seem to have full control. There is the dramatic washing wave, reaching up to a metre across the top of a targeted seal-infested ice floe, and a lower but more extensive and extended wave that the animals continue to generate as they swim under larger ice sheets. The lower wave bends and fragments the sheet—this is the kind of wave that Herbert Ponting encountered in 1911 (luckily for him it wasn’t the other kind). Once a seal was wiped off its perch, the orca regularly released a stream of bubbles and churned the water with their flukes in a seeming attempt to disorient the prey, as they tried to grab its hind flippers and avoid its toothy end.

But that’s not all. The scientists found that captured seal meat was shared among the hunting group, but they weren’t eaten straight away. No shark-feeding-frenzy for these genteel giants. Rather, one or two of the orcas spent time processing the seal while the rest of the group swam on, spy-hopping for new targets. Once the seal was ready, the group returned and immediately started feeding together.

What kind of processing can a massive mammal do without hands or a good butcher’s knife, you ask? Quite a lot (note: skip the next paragraph if you’re squeamish).

Pitman and Durban retrieved one seal carcass that showed a systematic dismembering technique. The orcas slit the seal’s skin completely around its belly and at the back of its skull. The slit at the skull base allowed an orca to cleanly separate the skull from its backbone, without damaging the head itself. One whale had then held the front part of the seal while another pulled out the back end and middle parts of the prey, neatly disarticulating the seal at its shoulders without breaking any bones. The bits left behind and collected by the scientists were essentially a partial skin tube with the head, front flippers and the top half of the skin still intact with its blubber, and the rest of the animal carefully slid out from inside and eaten. The work was methodical each time, the killer whales using only their teeth, and took about 5-10 minutes before the meal was ready to eat. Culinary skills at their finest.

Moving pictures

It is not just more time with the animals that is giving us new insights, but novel forms of camera that would have made Ponting clap with joy. Drone images of orca hunts have given us whole new angles on the activity, like this one by Bertie Gregory of a Weddell seal hunt, winner of the mammal behaviour category in the 2023 World Wildlife Photographer of the Year competition:

Gregory spent months looking for this specific group hunting behaviour, joining forces with another documentary film crew. There is still a lot to learn, but the orcas are now getting the kind of dedicated time needed to go beyond incidental or accidental sightings, to start understanding the process driving the killer whales.

One result of film crews paying attention (and paying a lot of money that scientists don’t often have) is videos like the one below from Frozen Planet II. It shows the same ice-breaking action that almost caught Scott’s dogs, followed by the orcas deliberately moving their trapped prey to an open space for the final wipeout, along with some bubbly distractions:

The extended whale-watching time has allowed scientists to realise that wave-making is not a general feature of orca behaviour, or even of Antarctic orcas as a whole. It seems to be restricted to a specific group referred to as B1—the videos above and Gregory’s award-winning shot were both captured by following B1 pods through their hunting grounds.

By comparing almost 10,000 photos taken across a decade, researchers in 2021 led by Holly Fearnbach estimated that there were around 100 B1 orcas in and around the Antarctic peninsula (which includes Paradise Bay, location of the 1979 sighting). The different groups—A, B1, B2, C and the lesser-known D—are recognised by their different bodily patterns such as eye markings, as well as size, range and dietary differences. Individuals are also recognised by distinctive fin shapes or damage and body colouring. Like all social mammals, they mainly associate with their own close relatives, helping us track the evolution of their pods.

Of the two B-types, B2 orcas seem to be doing better, holding steady at over 700 individuals. On the other hand B1 whales declined by around a fifth during the study period (2008-2018). The reasons aren’t clear, but the likelihood that wave-washing is a cultural behaviour learned by young B1 group members means that this unusual activity is itself at risk.

(Con)sequential tool use

So, let’s get down to it: is this tool use? We can be certain it’s not coincidental that the orcas cooperate to form the waves, given the planning, repetition and spy-hop monitoring that go into each event. The animals may not have an overt mathematical grasp of the mechanics of their wave formation, but they have a solid, reliable understanding built on trial, error, learning and immediate feedback.

By the way, if the forces underlying orcas waves are your thing, I recommend a paper from Hojung You et al. in 2019, which goes into great detail on that point—see the sources list below for the full reference—as you can tell from their figure:

Orca-built waves are solid enough objects to forcibly push a seal from its resting place, and flexible enough to snap solid ice floes. But they are not completely detached from the surrounding ocean. This makes them fixels instead of tools in the scheme recently created by Abby Desmond and me, more akin to using a flexible branch still attached to a tree to scratch your back than a detached stick used for the same purpose. The difference is subtle, but it helps us talk more easily about what the behaviour actually involves.

For one, orca waves are exceedingly temporary, much more so than sticks or stones (or leaves or webs or any of the other materials used by animals on land). They are made, used and irretrievably returned to the environment in a matter of seconds. They vanish back into the matrix. A Thai macaque might also use a stone for a few seconds to open oysters and then drop it again, but that stone remains visible and re-useable by the same or another monkey. Drop enough stones at suitable places for their use and you have a training ground for younger animals, even if that wasn’t part of any plan. Young orcas don’t get the benefit of having used wave tools lying around to practice with.

What they do have is a super-abundance of raw material. They breathe, travel, feed and sleep at the surface, so the interface of sea and air is familiar and explorable from the moment of birth. The trick is recognising that the interface can be controlled, that teamwork of a certain shape can produce effects beyond their bodies that have a predictable and delicious outcome. Unlike a woodpecker finch needing a cactus spine to probe for larvae, or a wrasse looking for the right coral outcrop against which it can bash a shellfish, the materials for wave-washing are always there when needed, right to hand/fin/fluke.

Another tool noted by the orca researchers is also ever-present. In Pitman and Durban’s report, and the Frozen Planet II video narrated by David Attenborough above, killer whales released streams of bubbles around washed-off seals. The same tactic is used by humpback whales to corral their own prey, spiralling in on a trapped meal. These bubbles are tools, discrete objects used to enable new actions. The orcas are combining initial fixel use with subsequent tool use as part of a hunting strategy, a sequential use of objects that has parallels in wild chimpanzees that access underground insect nests using first puncturing then probing tools. If you want to go further, we could even consider killer whales pushing floating ice into clear waters as a kin of tray tool use: these animals deeply understand ice and how to manipulate it.

Fixel use has been sometimes considered lesser to ‘true’ tool use. It gets the label ‘proto’ or ‘borderline’ tool use in many scholarly works, with an implication that using fixed objects is less cognitively demanding or skilful. But the killer whales show us the error of this thinking. Bubbles are great tools when your prey is surrounded by water, and the orcas use them then. But bubbles are less helpful at the interface of water, ice and air. The logical thing to do is to build objects that work effectively in that environment, and waves are the ideal low-cost option. In theory the orcas could instead break off chucks of nearby ice and individually throw them at a resting seal, but the solution they have invented is a far more elegant use of their natural abilities and resources. Tools and fixels both have their time and place, and one is not inherently more sophisticated than the other.

It is not necessary to wave-wash seals (or dogs brought to Antarctica by doomed explorers) to survive as an Antarctic killer whale. Only a small population routinely hunt this way, and it is possible that the behaviour will die out at some point. It is also possible that another orca group will reinvent it or something similar—all the ingredients are there waiting. Killer whales are behaviourally impressive creatures, but we should not be fooled into thinking that animal tool use is the pinnacle of a struggle for existence, brought to fruition by intelligence. It is a behaviour that comes and goes, and historical records and modern drones both have a role in working out how that fluctuation happens. We will learn much more about how tool use drives interactions between animals and their natural worlds by treating it less as a special gift, and more as a reflection of how life always, everywhere, finds a way.

Further reading

Herbert Ponting, Scott’s photographer, gave his own thrilling account of his killer whale encounter of 5 January 1911 in his book The Great White South. Published in 1921, it also includes this illustration of Ponting fleeing the jaws of the ‘savage monsters’ and ‘devils of the sea’ as he calls them, which he insists was drawn faithfully to the incident. Read his tale in his own words, if you dare…

I had noted some fine icebergs frozen into the sea ice about a mile distant. The morning after our arrival, I was just about to start across the ice to visit these bergs, with a sledge well loaded with photographic apparatus, when eight Killer whales appeared, heading towards the ice, blowing loudly. Since first seeing some of these wolves of the sea off Cape Crozier I had been anxious to secure photographs of them. Captain Scott, who also saw the approaching school, called out to me to try and obtain a picture of them, just as I was snatching up my reflex camera for that purpose. The whales dived under the ice, so, hastily estimating where they would be likely to rise again, I ran to the spot — adjusting the camera as I did so. I had got to within six feet of the edge of the ice — which was about a yard thick — when, to my consternation, it suddenly heaved up under my feet and split into fragments around me; whilst the eight whales, lined up side by side and almost touching each other, burst from under the ice and ‘spouted.’

The head of one was within two yards of me. I saw its nostrils open, and at such close quarters the release of its pentup breath was like a blast from an air-compressor. The noise of the eight simultaneous blows sounded terrific, and I was enveloped in the warm vapour of the nearest ‘ spout,’ which liad a strong fishy smell. Fortunately the shock sent me backwards, instead of precipitating me into the sea, or my Antarctic experiences would have ended somewhat prematurely.

As the whales rose from under the ice, there was a loud ‘ booming sound ’ — to use the expression of Captain Scott, who was a witness of the incident — as they struck the ice with their backs. Immediately they had cleared it, with a rapid movement of their flukes (huge tail fins) they made a tremendous commotion, setting the floe on which I was now isolated rocking so furiously tliat it was all I could do to keep from falling into the water. Then they turned about with the deliberate intention of attacking me. The ship was within sixty yards, and I heard wild shouts of ‘Look out!’ ‘ Run!’ ‘Jump, man, jump!’ ‘Run, quick!’ But I could not run; it was all I could do to keep my feet as I leapt from piece to piece of the rocking ice, with the whales a few yards behind me, snorting and blowing among the ice-blocks. I wondered whether I should be able to reach safety before the whales reached me; and I recollect distinctly thinking, if they did get me, how very unpleasant the first bite would feel, but that it would not matter much about the second.

The broken floes had already started to drift away with the current, and as I reached the last fragment I saw that I could not jump to the firm ice, for the lead was too wide. The whales behind me were making a horrible noise amongst the broken ice, and I stood for a moment hesitating what to do. More frantic shouts of ‘Jump, man, jump!’ reached me from my friends. Just then, by great good luck, the floe on which I stood turned slightly in the current and lessened the distance. I was able to leap across, not, however, a moment too soon.

As I reached security and looked back, a huge black and tawny head was pushed out of the water at the spot, and rested on the ice, looking round with its little pig-like eyes to see what had become of me. The brute opened his jaws wide, and I saw the terrible teeth which I had so narrowly escaped.

Sources: Scott Polar Research Institute, University of Cambridge, ‘Scott’s Last Expedition’; https://www.spri.cam.ac.uk/museum/diaries/scottslastexpedition/about/ || Smith, T. et al. (1981) Coordinated behavior of killer whales, Orcinus orca, hunting a crabeater seal, Lobodon carcinophagus. Canadian Journal of Zoology 59:1185-1189. || Visser, I. N. et al. (2008) Antarctic peninsula killer whales (Orcinus orca) hunt seals and a penguin on floating ice. Marine Mammal Science 24:225–234. || Pitman, R. & J. Durban (2012) Cooperative hunting behavior, prey selectivity and prey handling by pack ice killer whales (Orcinus orca), type B, in Antarctic Peninsula waters. Marine Mammal Science 28:16-36. || Fearnbach, H. et al. (2021) A decade of photo-identification reveals contrasting abundance and trends of Type B killer whales in the coastal waters of the Antarctic Peninsula. Marine Mammal Science 38:58–72. || You, H. et al. (2019) Mechanical understanding of hunting waves generated by killer whales. Marine Mammal Science 35:1396-1417. || Ponting, H. (1921) The Great White South. Duckworth & Co, London.

Main image credit: Allison Bone; https://thewest.com.au/news/world/australian-captures-stunning-photographs-of-pod-of-orcas-attacking-seal-ng-b88706355z || Second and third image credits: Antarctic Heritage Trust || Fourth image credit: Smith et al. (1981) || First video credit: National Geographic; https://www.youtube.com/watch?v=3__L0oAa2T8 || Fifth image credit: Kathryn Jeffs; https://www.naturepl.com/search?s=kathryn+jeffs || Sixth image credit: Bertie Gregory; https://www.nationalgeographic.com/animals/article/animals-up-close-wave-washing-killer-whales || Second video credit: BBC Earth; https://www.youtube.com/watch?v=fs8ZveNZQ8g || Seventh image credit: You et al. (2019) || Eighth image credit: Ponting (1921)