An area around South Africa known to harbor great white sharks was absent from the apex predators for about seven weeks after a pack was viciously attacked by a pack of killer whales — and this behavior suggests sharks possess a flight response.
Only three studies have ever discussed a flight response among sharks, but the new paper published this month suggests the apex predators didn’t return to their natural hunting grounds because they had been deterred by the horrific event that had happened earlier.
The discovery builds on astonishing footage released in June showing the first intense tones of an orca ripping out and feeding on the great white dog’s liver, but never-before-seen clips captured by a helicopter overhead gave more details of the massacre.
A pilot operating tourist flights saw five orcas swimming together, but quickly separated to ambush four great whites in nearby waters — and at least two, maybe three, sharks were killed in one hour.
Footage taken by a helicopter flying off the coast of South Africa shows five orcas attacking at least four great white sharks. The top middle photo probably shows a shark’s liver floating on the surface before being eaten by the killer whale
dr. Alison Kock, South African National Parks shark expert, said: ‘We first observed the flight responses of seven gills and white sharks to the port and starboard orcas presence in False Bay in 2015 and 2017.
“The sharks eventually left the formerly important habitats, which has had significant impacts on both the ecosystem and shark-related tourism.”
Although the clips show four sharks, beach observers reported several sharks in the area about four minutes before the attack.
The study builds on images released in June showing the first time an orca whale feeding on a great white shark. The whale rips into the shark’s belly and removes the liver before swallowing the organ
The helicopter footage (pictured) reveals what was believed to be an attack on one shark, was in reality on a group and it lasted an hour
KILLER WHALES VS GREAT WHITE SHARKS
Mate: More than six tons
Length: Up to 30 feet
Habitat: All oceans
Lifespan: Up to 90 years
Great White Sharks
Mate: 2.5 tons
Length: Up to 22 feet
Population: Less than 3,500
Habitat: All temperate coastal waters
Lifespan: Up to 70 years
Predators: Orcas, humans
They said the great whites started swimming randomly in all different directions, moving even in shallow waters as low as six feet deep.
Scientists at the Marine Dynamics Academy, who studied the videos and wrote the paper, determined that a total of 10 sharks were sighted on May 16 when the killer whales attacked the sharks.
According to the study published in ESA magazines, drones released eight days after the predation event saw only a lone great white.
Cage operators who typically see at least three sharks per trip didn’t see a single shark swimming in the waters 45 days later — and the operators didn’t see a single one until July.
“Given the well-documented, predictable year-round presence of white sharks in Mossel Bay, the sudden absence of white sharks for several weeks immediately after the predation event supports a flight response due to the survival of great white sharks in the area,” the study reads.
The combined images also gave scientists insight into how orcas hunt and kill white sharks.
On two occasions, killer whales approached sharks closely and slowly, while instead of fleeing, the shark stayed close to the predator and kept it in plain sight.
This is a common strategy used by seals and turtles to avoid sharks. Because killer whales hunt in groups, the researchers think it may not be effective in this situation.
Co-author Dr Simon Elwen, a research associate at Stellenbosch University, said: ‘Orcas are highly intelligent and social animals. Their group hunting methods make them incredibly effective predators.’
Researchers collected data on the area days after the attack took place and found that great white sharks had been absent for at least seven weeks. This suggests that sharks have a flight response
Previous studies have documented how new behaviors spread among killer whales over time through cultural transmission.
The authors suggest that if more orcas adopt the practice of white shark hunting, the behavior will have much greater impacts on shark populations.
It is hoped that their findings will lead to the development of better conservation strategies for great white sharks.
The number of sharks in open oceans has fallen by more than 70 percent in just 50 years.
Three quarters of the species are threatened with extinction – including the Great White – due to climate change and overfishing, among other things.
Pair of killer whales have killed at least EIGHT great white sharks off the coast of South Africa since 2017
Two killer whales are believed to have killed at least eight great white sharks off the coast of South Africa since 2017 and deterred many more.
Researchers found that the Great Whites avoided certain regions of the Gansbaai coast for fear of being hunted by orcas.
At least seven great white shark carcasses have washed up in False Bay, South Africa, since 2017, with teeth marks indicating they were destroyed by orcas. Great whites encountering orcas immediately leave their usual hunting grounds for up to a year
Many of the shark carcasses washed ashore without their livers and hearts, or with other injuries typical of the killer whale.
The study used long-term observations and tagging data. For five and a half years, 14 sharks were tracked that fled the areas when the whales were present.
Shark experts from the Dyer Island Conservation Trust argue that this suggests the marine predators trigger the ‘flight’ response in sharks when they’re nearby.
This, in turn, results in their rapid, prolonged emigration from the area, creating an opportunity for an influx of new predators to deplete other species.
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