A pod of killer whales can be seen chasing sharks during an hour-long chase off Mossel Bay, a port town in the southern province of the Western Cape, in helicopter and drone footage that informed a scientific study released this week. Alison Towner, a shark scientist at the Academy of Marine Dynamics in Gansbaai, South Africa, and lead author of the study, said: “This behavior has never been observed in detail and certainly never from the air.” A clip from the video, taken in May, shows five orcas hunting and killing a great white, and scientists believe three others were killed during the hunt. Simon Elwen, a marine mammal expert and co-author of the study, said: “Killer whales are highly intelligent and social animals. Their group hunting methods make them incredibly efficient predators.” Orcas, the ocean’s top predator, are known to prey on other shark species, but evidence of attacks on great whites was previously limited. The study did not examine the reasons behind this behavior. One of the whales was known to have attacked great white sharks in the past, but the other four had not. The authors said this suggests the practice is spreading, with previous studies having shown that black and white animals can learn from each other through “cultural transmission”. The sharks disappeared from the area after the attack, with only one great white spotted over the next 45 days, according to the paper, which was published in the journal Ecology. The authors say this confirms that sharks have a flight response and could have wider implications. In previous cases observed, the animals ended up abandoning former key habitats, with consequences for the ecosystem and shark-related tourism, said Alison Kock, a marine biologist at South African National Parks.
