Three separate attacks are the first confirmed blue whale deaths by killer whales
Australian researchers report the first documented killing of an adult blue whale by orcas.
For the first time, researchers have watched killer whales hunt and kill the largest animal on earth – an adult blue whale.
In late March 2019, annual whale and dolphin research surveys led by WA’S Cetacean Research Centre (CETREC
WA), along with Project ORCA, stumbled across the first-ever documented attack and eventual killing of a healthy adult blue whale (Balaenoptera musculus) by killer whales (Orcinus orca).
Reported in a paper recently published in Marine Mammal
Science, there were also two subsequent attacks: one on a blue whale calf two weeks later, and one on a juvenile in 2021. Killer whales are known to prey on a large variety of species – including whales – but had previously only been known to kill and feed on large whale calves, such as grey and humpback whales. They have been seen attacking and harassing blue whales, but these events are the first confirmed kills.
“When we arrived, about 14 killer whales were attacking the blue in 70m waters, with the female killer whales leading the attack,” says co-author Isabella Reeves, a Flinders University PHD candidate who witnesssed the first event. “We already noticed a substantial flesh wound on the top of its head with bone exposed. The dorsal fin was missing, no doubt bitten off by the killer whales.”
Lead author and CETREC researcher John Totterdell adds: “Soon after, there was large chunks of skin and blubber stripped off the sides of the whale, the blue was bleeding profusely and was weakening, evident by its slow speed.”
A female killer whale then lunged into the whale’s mouth to feed on the tongue.
“After the whale carcass sunk, about 50 killer whales were in the area feasting and sharing around the blue’s flesh,” Totterdell concludes.