by Great white sharks have been strangely absent from South Africa’s coast in recent years, with suspicions of dwindling numbers falling on that other of the oceans’ most notorious predators, the orca.
Now there is footage of a real hunt in action.
Two new sightings, one from a helicopter and one from a drone, have captured two of the ocean’s fiercest predators facing off in a world first.
“This behavior has never been observed in detail before, and certainly never from the air,” says marine scientist Alison Towner of Rhodes University in South Africa.
In Mossel Bay harbor on the afternoon of May 16, a drifting drone spotted a white-bellied in the blue. A handful of killer whales were swimming close to the surface and the drone pilot – a beach hobbyist – decided to keep an eye on them.
As the drone followed and recorded the group, a pair of orcas separated eastwards towards the mouth of the local river – a known hotspot for shark activity.
Two of the remaining cetaceans began to swim near the surface of the ocean, facing in opposite directions, as if looking out.
Seven seconds later, a fifth orca emerged from the deep right between the two patrols. Its nose was pushing a three-meter white shark, belly up, to the surface. With a quick spin, the orca rolled the shark onto its side and bit its belly behind its pectoral fin, blood spilling into the sea.
With the shark firmly clamped in the orca’s jaws, the fifth individual dove deep once more, releasing the carcass as it went.
One of the patrolling orcas then approached and grabbed the shark’s tail, pulling the once mighty hunter into the abyss, never to be seen again.
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One individual in the group of orcas was later identified as ‘Starboard’, a famous male with a dorsal fin. Starboard was previously involved in a series of washed-up shark carcasses found on South African beaches, four of which were missing their livers.
No one has ever caught Starboard in direct combat with a great white shark, but anecdotal evidence suggests that he and another male orca, named Port, are the potential killers of other local shark species. These two whales often frequent shark dens, and when they visit, the large fish tend to leave the area for days.
“I first saw Starboard in 2015 when it and its close partner ‘Port’ were linked to the killing of seven gill sharks in False Bay,” says David Hurwitz, a boat-based whale watching operator from Simon’s Town Boat Company , who contributed to the study.
“We saw them kill a bronze whaler [copper shark] in 2019 – but this new observation is really something else.”
Orcas are known to occasionally hunt great white sharks, but only three studies have ever formally described such a battle.
An official analysis of the drone footage and footage from a local helicopter are the first to show the hunting strategy in any detail.
Helicopter pictures show at least two other great white sharks were also killed by orcas near Mossel Bay on the same fateful day.
Shortly before the drone footage, the helicopter pilot witnessed two shark kills from the air.
With their phone, the pilot was able to capture a series of images and short video clips of the orca predators.
“Given the overlap in time and area, we assume it is the same group captured by the drone video,” the researchers write.
“Two video sequences at 14:07 and 14:00 on the 27th showed two different killer whales (right in the first clip) closely following great white sharks in
This circling technique is probably the shark’s way of tracking an orca. It is similar to how their own prey avoids them. While sharks occasionally come together to hunt, orcas have been perfected as a fine art, meaning that looking in one direction is no guarantee of safety.
From the helicopter, the pilot took pictures of one of the orcas eating what looked like a huge shark liver, one the size of an orca’s head. This suggests that a great white shark’s liver is buoyant, meaning that the fatty meal could float to the surface after a large bite into a shark’s belly.
Four minutes before the feeding event, observers from the beach and the drone pilot reported seeing sharks leaving the area. Some even reached the shore as shallow as two meters.
That day, ten sharks were spotted by the drone. But for weeks after the killing spree, almost no sharks were seen in the area, based on satellite tags, drone surveys and boat sightings.
The fact that Starboard, an elderly male orca, has now been caught hunting white sharks with a different orca pod suggests the behavior may be spreading.
If more orcas adopt the practice, then it could have a serious impact on the local shark populations, which are valuable and respected in Mossel Bay.
Fewer shark sightings off the coast have led some to blame illegal hunting activities and overfishing for their absence. But that may not be true after all.
The study was published in Ecology.
