Researchers have confirmed that an orca, or killer whale, has been seen independently killing a great white shark – and then taking off with its liver.
The dramatic event was written up in a study published in the African Journal of Marine Science, which documented what the authors say are “new predation tactics of orcas.”
Orcas (Orcinus orca) are generally known to hunt in groups to catch prey. There have been accounts of orcas hunting large animals individually, but never great white sharks (Carcharodon carcharias). The authors say the hunting tactics have the potential to create an imbalance in marine ecosystems.
“What we witnessed was an orca, nicknamed Starboard – due to his collapsed dorsal fin – performing alone to incapacitate and consume a white shark within an astounding two-minute timeframe,” says Dr. Alison Towner, the lead author of this study from Rhodes University in South Africa.
The researchers watched from two vessels and saw Starboard preying on a 2.5-metre juvenile great white shark, and later watched it swim past the boat carrying the shark’s lipid-rich liver in its mouth.
“This sighting revealed evidence of solitary hunting by at least one killer whale, challenging conventional cooperative hunting behaviors known in the region,” says Towner.
What’s going on with orca’s?
“These are groundbreaking insights into the predatory behavior of this species, and our findings significantly contribute to the global understanding of killer whale predation dynamics, enhancing knowledge of marine ecosystems and predator-prey relationships”.
Dr. Primo Micarelli, co-author of the article from the University of Siena, witnessed Starboard’s attack from one of the vessels.
“Over two decades of annual visits to South Africa, I’ve observed the profound impact these killer whales have on the local white shark population. Seeing Starboard carry a white shark’s liver past our vessel is unforgettable,” says Micarelli.
“Despite my awe for these predators, I’m increasingly concerned about the coastal marine ecology balance.”
In the last decade various shark species, including great white sharks, have faced displacement off the coast of South Africa, and researchers think orcas may be to blame.
“The displacement of various shark species due to killer whale presence may have implications for mesopredator [a mid-ranking trophic level predator] release and potential trophic changes in the marine ecosystem.”
