A viral video showed two whales killing great white sharks by ripping out their livers.
The whales, called port and starboard, are well known to scientists, one expert said.
They and other killer whales have a long history of hunting sharks for their organs, he said.
Footage of orcas killing a great white shark by snapping at its liver recently enchanted the internet.
But while video, released ahead of a Discovery+ documentary, showed one such hunt in detail, an expert told Insider that it’s not uncommon.
In fact, this strategy is so widespread in the waters off South Africa that two particular killer whales have gained a reputation for organizing teams of orcas to band together and hunt great whites.
Two male orcas named port and starboard are likely to blame, said Michael Weiss, research director for the Center for Whale Research.
Evidence of their efforts is a series of liverless shark carcasses washing up after being attacked by orcas with surgical precision.
Surgical interventions to attack fatty organs
According to Weiss, livers are a prime target for orcas because they are fatty and provide a good amount of energy in exchange for the effort required to hunt them.
“Shark livers are extremely fatty, so there are a lot of calories in them,” he said.
There are several reports documenting this behavior, such as near the Farallon Islands in Northern California. There, too, the killer whales attacked the livers of the sharks.
Previous footage had shown that the orca could tear the sharks apart by yanking at the fins around their belly, according to an article in the African Journal of Marine Science, which focused on sightings in South Africa.
“Their tongues and mouth are quite dexterous despite being so large. They can do some pretty wild things,” Weiss said.
Port and starboard, the famous shark hunters
Two of the killer whales in the footage are known to scientists as port and starboard, reflecting the tilt of their dorsal fins.
“They were kind of a minor celebrity,” Weiss said.
The couple have their own Wikipedia page. Great white shark sightings have dropped from about 200 a year to about zero since they began hunting in the bays of South Africa off the coast of South Africa, The Guardian reported in 2020.
Weiss said it wasn’t because they were killing every single shark, but because the sharks started avoiding the area.
It’s not clear how the sharks learned to avoid the orcas. Sharks have limited social interaction and are unlikely to have learned from each other, Weiss said.
“My thought would be that it would probably be a smell thing. You smell dead shark in the water,” he said.
It is clear that this had an impact on the environment. The scientific work showed that another species, the bronze whaler, had taken over instead.
“The ability of two animals to remodel an ecosystem is absolutely fascinating,” Weiss said.
Hunt for delicacies
Weiss explains that it’s not uncommon for killer whales to concentrate on one organ and abandon the rest.
Footage shows them eating the lips and tongues of other whales they just killed, leaving the rest behind. Weiss says he’s also seen whales “take entire fetuses from pregnant bottlenose dolphins.”
“This is in some ways the biggest bang for the buck in terms of the soft, accessible fabric,” he said.
“You only have a limited amount of time to eat this thing. It will start to sink, scavengers will start to appear,” he said.
Weiss said the sharks may be able to spot the most attractive organs using their sonar.
“We think the killer whales I study are able to use echolocation to distinguish between different species of salmon by detecting the size and position of the swim bladder,” he said.
“I wouldn’t be surprised if that happens in sharks,” he said.
Killer males with special abilities
Port and starboard are both males. They enjoy hunting together, which is rare in the orca world.
“Killer whales are fairly matrilineal in most populations. The offspring spend most or all of their lives with their mother,” Weiss said.
Weiss says it’s unclear where they might have picked up the behavior. Some whales specialize in shark hunting, but the other orcas in the area don’t seem to have learned this behavior.
“Most foraging strategies are passed from mother to offspring,” he said.
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