A viral video showed two whales killing great white sharks by ripping out their livers.
The whales, called Port and Starboard, are well known among scientists, one expert said.
They and other killer whales have long been hunting sharks for their organs, he said.
Footage of killer whales killing a great white shark by snapping its liver has recently captivated the internet.
But while the video, released prior to a Discovery + documentary, showed such a hunt in detail, one expert told Insider it wasn’t unusual.
In fact, in the waters off South Africa, the strategy is so common that two particular killer whales have earned a reputation for organizing teams of killer whales to unite and hunt great whites.
Two male killer whales, named Port and Starboard, are likely to blame, said Michael Weiss, director of research at the Center for Whale Research.
Evidence of their efforts is a series of shark carcasses that are washed without livers, after being attacked by killer whales with surgical precision.
Surgical strokes to target adipose organs
For Weiss, livers are a prime target for killer whales because they are fat and give a good amount of energy in exchange for the effort needed to hunt them.
“Shark livers are extremely fat, so there are a lot of calories,” he said.
There have been several reports documenting this behavior, for example near the Farallon Islands in Northern California. There, too, the killer whales attacked the livers of the sharks.
Previous footage had shown that killer whales could tear apart sharks by pulling their fins around their stomachs, according to an article in the African Journal of Marine Science, which focused on sightings in South Africa.
“Their tongues and mouths are pretty skilled, despite how big they are. They can do pretty wild things,” Weiss said.
Port and Starboard, the famous shark hunters
Two of the killer whales in the film are known to scientists as Port and Starboard, due to the tilt of their dorsal fins.
“They were kind of minor celebrities,” Weiss said.
The couple have their own Wikipedia page. Since they began hunting in South African bays off the coast of South Africa, sightings of great white sharks have gone from around 200 per year to around zero, according to the Guardian in 2020.
Weiss said this wasn’t because they killed every single shark, but because the sharks started avoiding the area.
It is unclear how sharks learned to avoid killer whales. Sharks have limited social interaction and it’s unlikely they would have learned from each other, Weiss said.
“My thought would be that it would probably be a matter of smell. You smell the dead shark in the water,” he said.
What is clear is that this has had a ripple effect on the environment. The academic paper showed that another species, the bronze whaling shark, had instead taken over.
“The ability of two animals to reshape an ecosystem is absolutely fascinating,” Weiss said.
On the hunt for delicacies
Weiss explains that it’s not uncommon for killer whales to focus on one organ and leave the rest.
The footage showed them eating the lips and tongues of other whales they just killed and leaving the rest. Weiss says he also saw whales “extracting whole fetuses from pregnant porpoises.”
“This is where the best value for money is in terms of soft, easily accessible fabric,” he said.
“You have a limited time to eat this thing. It will start to sink, the scavengers will start to appear,” he said.
Weiss said the sharks may be able to locate the most attractive organs using their sonar.
“The killer whales that I study, we think are able to use echolocation to distinguish between different salmon species by detecting the size and location of the swim bladder,” he said.
“I wouldn’t be surprised if that was something that was happening” with the sharks, he said.
Killer males with peculiar abilities
Port and Starboard are both male. They like to hunt together, a rare occurrence in the world of killer whales.
“Killer whales in most populations are quite matrilineal. The offspring hang out with the mother for most or all of their lives,” Weiss said.
Weiss says it’s unclear where they might have picked up the behavior. Some whales specialize in shark hunting, but other killer whales in the area don’t seem to have mastered this behavior.
“Most of the foraging strategies are passed down from mother to offspring,” he said.
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