Lone Orca Starboard Kills White Shark in Two Minutes

Orca pack hunting and white shark livers

Orca pack hunting is the stuff of legend. Operating in highly coordinated groups, these formidable predators can overcome prey that would be far too challenging for a single orca to tackle.

Yet even white sharks (Carcharodon carcharias), feared throughout the ocean, are no match for an orca (Orcinus orca). Scientists working off South Africa have now recorded a lone orca killing a white shark with remarkable ease before swimming away with the animal's rich, nourishing liver.

"As previously in South Africa, the orcas are exhibiting a strong preference for extracting and consuming the lipid-rich livers of white sharks – a specialized feeding behavior," says marine biologist Alison Towner of Rhodes University in South Africa.

"But what we witnessed was an orca, nicknamed Starboard – due to his collapsed dorsal fin – performing alone to incapacitate and consume a white shark within an astounding two-minute timeframe. Starboard was observed preying on a 2.5-meter (8.2-foot) juvenile white shark, later carrying the shark's liver in its mouth past a boat."

Across the world, orcas concentrate on different prey according to what is locally available. However, the targeting of one particular prey species came as a major surprise to researchers several years ago. As shown in the 2022 video below, orcas have been recorded killing white sharks off South Africa with exceptional efficiency for several years.

Their interest is focused on a single body part, which they remove with surgical accuracy. White shark livers are exceptionally large and nutrient-dense, storing the fats and oils that support sharks during their vast migrations. Orcas have apparently worked this out and are enthusiastically exploiting the resource.

Starboard's lone white shark kill

Recorded observations of these hunts remain fairly uncommon. Only a small number of groups containing two or more orcas have been caught 'red-finned' while attacking sharks, and repeated sightings often involve the same animals. Since 2015, Starboard has been observed hunting several shark species alongside another male, known as Port because his dorsal fin bends to the left.

On 18 June 2023, Port and Starboard were reported off Mossel Bay on South Africa's southern coast. Researchers quickly launched a boat in the hope of watching the pair hunt. They located the orcas at Seal Island, an established hunting site for the species. Port then headed north of the island, while Starboard stayed on its southern side.

When a juvenile white shark appeared near Starboard, the orca immediately attacked. In less than two minutes, the shark had been disembowelled and Starboard had claimed his hepatic reward.

Researchers also discovered a second shark carcass nearby, measuring 3.55 metres (11.6 feet). Because nobody witnessed that kill, however, it remains uncertain whether it was made by one or both orcas.

Concerns for South Africa's coastal ecosystem

Although uncovering the sophisticated behaviour of these striking predators is both captivating and astonishing, scientists are worried about the consequences for the local ecosystem. Fewer sharks have been documented since the orcas began hunting them, which in turn has led to fewer elephant seals being killed by sharks.

Whether this could trigger more severe effects is still unknown. One possibility is greater competition for food among seals, potentially harming younger and more vulnerable animals and creating population difficulties in the future.

"Over two decades of annual visits to South Africa, I've observed the profound impact these killer whales have on the local white shark population. Seeing Starboard carry a white shark's liver past our vessel is unforgettable," says shark biologist Primo Micarelli of the University of Siena in Italy.

"Despite my awe for these predators, I'm increasingly concerned about the coastal marine ecology balance."

Orcas are extremely intelligent and rapid social learners. Should more individuals enter the area and begin dividing their efforts to conquer prey, their presence could accelerate the ecological consequences of this indiscriminate feeding.

"The presence of these shark-hunting killer whales possibly ties into broader ecosystem dynamics," Towner says. "Rapid developments in this phenomenon make it challenging for science to keep pace, prompting us to publish these timely short communications."

The research was published in the African Journal of Marine Science.