• A study from Australia is the first to scientifically document the killings of blue whales by orcas.

• Orcas were observed devouring the nutrient-rich tongues of the giant blue whales.

• "This is the biggest predation event on this planet," said a marine scientist.

For the first time, a pack of orcas — also known as killer whales — have been observed hunting and killing blue whales, the largest animal on the planet.

According to a report published in Marine Mammal Science, the scientific community has long debated if orcas can hunt the massive blue whales.

But this question has now been answered after three instances of packs of orcas attacking blue whales off the coast of Western Australia were recorded by marine scientists from Cetrec WA (Cetacean Research). It includes details of how the killer whales swam inside the mouth of the enormous whales to eat their nutritionally rich tongue just before they died.

"Here we provide the first documentation of killer whales killing and eating blue whales: two individuals killed, 16 days apart in 2019, and a third in 2021," researchers wrote in the paper. "Notably, the first whale taken appeared to be a healthy adult."

Researchers arrived at the first killing of a 72 foot-long blue whale to see large chunks of skin and blubber having been gouged its body and with most of the dorsal fin having been bitten off.

It was followed by relentless attacks by the orcas, where three lined up against the blue whale and pushed it underwater, while two attacked its head.

The study explains that 50 orcas joined the pack for six hours to feed on the carcass.

A few weeks later, the next attack occurred when a blue whale calf was targeted. Twenty-five orcas attacked the 40-foot long animal.

The final attack recorded by the study was on a 45-foot long blue whale, chased for 15 miles in a 90 minutes hunt. Again, the orcas hunting strategy was to push and ram the whale under the water while others attacked its head and tongue. A 50-strong pack devoured the remains of the kill.

(editor：)