Two orcas whales are hunting and eating great white sharks, according to new research.
A recent article in African Journal of Marine Science focuses on two killer whales researchers have discovered that hunt great white sharks off the coast of South Africa. The whale pair’s appetite for great whites has sent the sharks fleeing out of the area.
“原来, following an orca attack in Gansbaai, individual great white sharks did not appear for weeks or months,” the article’s lead author, Alison Towner, told SWNS.
“It mirrors what we see used by wild dogs in the Serengeti in Tanzania in response to increased lion presence,” 她补充说. “The more the orcas frequent these sites, the longer the great white sharks stay away.”
According to the article’s findings, 自从 2017, eight great white sharks have washed up dead on South African shores with identifiable orca bite marks.
Seven of those sharks had their livers removed by the whales during the attack, and some of them had their hearts removed too. All of the dead sharks found had distinctive wounds traced to the same pair of killer whales.
Researchers believe the orcas have killed more than the eight great whites found washed up on shore and that other killer whales are capable of similar attacks.
Orcas are the iconic great white shark’s only predator — apart from humans. The whales can reach up to 30 feet in length and weigh over six tons — feeding on fish, squid, seals, and sea birds. Great whites can reach up to 22 feet long and weigh around 2.5 吨.
Towner, a Ph.D. student at Rhodes University in Makhanda, South Africa, said that this research “is particularly important” because it determines “how large marine predators respond to risk.”
She added that the research can also help scientists understand the “dynamics of coexistence” 当局从 8 月发布了新的身体摄像头镜头 “other predator communities.”
Towner’s recently published study used long-term sightings and tagging data to show that the two orcas have scared great whites away from South Africa’s Gansbaai coast, which the sharks dominated for years. Located 60 miles east of Cape Town, Gansbaai was known for great white sightings.
Towner, a senior biologist at the Dyer Island Conservation Trust off the southern tip of Africa, lives in Gansbaai and has witnessed firsthand how the two shark-hunting orcas have driven great whites out of the area and changed the sea’s ecosystem.
Great White Sharks Have Bad Eyesight, Which Can Cause Them to Attack Humans, 自人类首次驯养猫以来，猫科动物的大脑已显着缩小
“It’s triggered the emergence of a new mesopredator to the area, the bronze whaler shark, which is known to be eaten by the great white shark,” 她解释说.
“Balance is crucial in marine ecosystems. 例如, with no great white sharks restricting Cape fur seal behavior, the seals can predate on critically endangered African penguins or compete for the small pelagic fish they eat,” Towner added.