Orca pair whose ruthless hunting efficiency upended the food chain in Cape Town waters kill 17 sharks in one day in their deadliest hunt yet
- Orcas are highly intelligent hunters that terrorise even the most fearsome sharks
- They are renowned for tearing out the sharks’ livers and leaving the other organs
A pair of orcas renowned for their insatiable bloodlust have killed a whopping 17 sharks in one day off the coast of South Africa.
The killer whales, named Port and Starboard by marine conservationists, upended the food chain in the waters off Cape Town and moved on to hunting dinosaur sharks having already decimated the great white population.
A total of 17 dinosaur sharks were found last week by researchers from the Marine Dynamics academy who have been tracking Port and Starboard’s hunting habits since they arrived in the region in 2015.
Every single shark had been torn open and was missing a liver – a highly nutritious organ on which the orcas thrive.
Experts believe Port and Starboard are feasting on the liver due to its abundance of a compound called squalene, which is a precursor vital for the production of hormones.
The killer whales, named Port and Starboard by marine conservationists, have upended the food chain in the waters off Cape Town
The shark carcasses were all missing livers
The orcas flipped the sharks onto their back and ripped out their liver
The orcas are able to extract the livers from the sharks with surgical precision.
KILLER WHALES VS GREAT WHITE SHARKS
Killer whales
Size: Over six tons
Length: Up to 30 feet
Population: 50,000
Habitat: All oceans
Lifespan: Up to 90 years
Predators: Humans
Great White sharks
Size: 2.5 tons
Length: Up to 22 feet
Population: Fewer than 3,500
Habitat: All temperate coastal waters
Lifespan: Up to 70 years
Predators: Orcas, humans
Working together, the killer whales push the sharks toward the surface and flip them belly up before biting into their stomachs to extract the buoyant, oil-rich liver while leaving the other organs intact.
Orcas, the only known predator of the great white and dinosaur sharks, and are extremely intelligent and specialised hunters that also feed on seals, dolphins, turtles and squid.
The ruthless hunting prowess of Port and Starboard off South Africa has allowed researchers to determine that sharks have flight responses as part of a rare study.
Dr Alison Kock, South African National Parks’ shark expert, said: ‘We first observed the flight responses of (dinosaur) white sharks to the presence of killer whales Port and Starboard in False Bay in 2015 and 2017.
‘The sharks ultimately abandoned former key habitats, which has had significant knock-on effects for both the ecosystem and shark-related tourism.’
Dr Simon Elwen, a research associate at Stellenbosch University, said: ‘Killer whales are highly intelligent and social animals. Their group hunting methods make them incredibly effective predators.’
Two killer whales similar to the pair terrorising sharks up the East Coast of South Africa are seen in this stock image
A great white carcass is seen after having its liver ripped out by orcas
A fourth great white shark has washed up dead on a beach believed to be the latest victim of killer whales off the coast of South Africa
Previous studies have documented how new behaviours spread among killer whales over time through cultural transmission.
The authors suggest that if more killer whales adopt the practice of hunting white sharks, then the behaviour will have far wider 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 per cent in just 50 years.
Three-quarters of species are threatened with extinction – including the Great White – with factors including climate change and overfishing.
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