So far it was only a guess – now researchers have provided proof: Orcas are able to kill the largest animals in the world, blue whales. Scientists at the Cetacean Research Center in Western Australia observed such a hunt for the first time in 2019. Back then, 14 killer whales killed and ate an adult blue whale. The group of female orcas led this hunt. “On arrival we already noticed a significant laceration on the top of the head – the bone was exposed. The dorsal fin was missing—no doubt the killer whales had bitten it off. Tooth marks were visible on the whale’s back and even up to its tail,” says Isabella Reeves, a doctoral student at Flinders University and co-author of the study. John Totterdell, a lead author of the study, continues: “Towards the end, a female shot headfirst into the blue whale’s mouth – presumably wanting to eat its tongue. The whale became weaker and weaker and we no longer saw the carcass. After it sank, about 50 killer whales were in the area feeding and sharing the blue whale’s meat.” In the years that followed, scientists were able to observe two more hunts of blue whales, in which orcas killed the animals. They have now published their results in an article for the “Marine Mammal Science” journal. For the first time, these observations are documented evidence that orcas can kill adult blue whales. With a length of up to 33 meters, the giants are four to five times the size of their hunters. Orcas are known for their clever hunting techniques, such as creating waves to knock penguins off their floes. In Argentina, they drive seals to the shallow shore, where their prey can only move slowly. They hunt large whales, such as blue whales, in groups. Orcas live in so-called matriarchies – the female animals lead the actions. When a whale travels in a group, they first separate it from its companions. Blue whales are mammals and regularly need to surface to breathe. Therefore, the killer whales in pairs or in groups push the animal under water until it drowns. Typically, hunters focus on the juveniles of large whales, but the new study shows that adults aren’t safe from them either.
Swell: Wiley, Innerwest ReviewPress Release Flinders University, Geo