Horrific Observations Confirm That Orcas Feed on Blue Whales

As apex predators, orcas can principally feed on whichever marine animal they need, however biologists weren’t fully positive if these aquatic killers feast on the most important of all of them: blue whales. New proof suggests they very a lot do, and it ain’t fairly.

Warning: This article accommodates photographs that may be disturbing.

“Here we provide the first documentation of killer whales killing and eating blue whales,” declare the authors of the brand new study, printed in Marine Mammal Science. The staff, which included Robert Pitman from Oregon State University, detailed three totally different killing incidents, two in 2019 and one other in 2021. Importantly, “the first whale taken appeared to be a healthy adult,” the marine biologists write.

The paper describes coordinated assaults, by which packs of largely females labored collectively to subdue their prey. Each incident came about in Bremer Bay of Australia, some 40 miles (60 km) from shore, and all observations had been made aboard a business whale-watching vessel.

“We suggest that the reason attacks on blue whales have been so rarely witnessed—and none fatal—is because commercial whaling in the 1900s nearly exterminated blue whales from the planet,” defined Pitman in an electronic mail. “Killer whales that preyed upon them would have had to find other prey or maybe died out also. Either way, the skills and teamwork to take down large whales may have disappeared also.”

That orcas, also referred to as killer whales, would feed on blue whales will not be an enormous shock, as accounts exist of orcas chasing after these majestic giants. These are the primary confirmations of profitable assaults on Balaenoptera musculus—the biggest animal to have ever appeared on Earth. Accordingly, blue whales can now be added to the orca food regimen, a prolonged checklist that features grey whales, bowhead whales, dolphins, squid, octopuses, fish, seals, rays, and even sharks.

The first of the noticed assaults occurred on March 16, 2019. An apparently wholesome grownup blue whale measuring between 18 and 22 meters lengthy was attacked by a dozen orcas consisting of eight grownup females, one grownup male, and a few youthful members who watched from the sidelines. The scientists’ account of the assault is nothing wanting a horror present (warning: a graphic description follows):

After roughly 20 min of steady assaults by the killer whales, the blue whale slowed and started swimming in a circle with a radius of about 200 m [656 feet]. By 09:20, massive chunks of pores and skin and blubber had been stripped off the whale’s flanks behind the dorsal fin; it was bleeding profusely and seemed to be weakening because it continued to scale back its swim velocity. A couple of minutes later, three grownup feminine killer whales lined up, side-by-side, perpendicular to the blue whale, and rammed headlong in its flank, pushing it via the water after which forcing it below. At the identical time, two different killer whales had been attacking the blue whale’s head, and its ahead motion stopped. Moments later, at roughly 09:30, whereas it was nonetheless alive, an grownup feminine killer whale put its head contained in the blue whale’s mouth and started feeding on its tongue.

Over 50 orcas would finally participate within the feeding, as did a whole bunch of scavenging birds, together with shearwaters, petrels, and albatrosses.

“They pick up the scraps during the attack and after the kill. These birds all have a keen sense of smell, and as soon as the killer whales leave the first tooth rake marks on their intended victim, whale oil seeps into the ocean, and the birds start to show up,” stated Pitman. “Although a lot less visible, sharks start to collect underwater—I suspect that after all is said and done, the sharks probably consume more of the blue whale than the killer whales will.”

These animals consumed the carcass for days till it lastly sank. The scientists returned to the scene six days later, the place they noticed a big slick on the floor brought on by oil trickling up from the carcass beneath, the place undoubtedly different marine animals had been now profiting from the whale fall.

The second noticed assault occurred only a few weeks later, when a pack of 25 orcas, 22 of them females, feasted upon a blue whale calf. A blue whale round one yr of age was the topic of the third assault, by which the orcas as soon as once more lined-up in coordinated trend in the course of the account. Pitman says orcas are “intelligent, social creatures” and nothing they do surprises him anymore.

In all three circumstances, the orcas ate the tongue, which is excessive in dietary worth. Females, who must feed their younger, had been predominantly concerned within the assaults as they probably should feed extra regularly, the scientists say.

Speaking to The Guardian, Erich Hoyt, a analysis fellow at Whale and Dolphin Conservation, said the research confirmed prior suspicions about orca conduct, together with the consuming of the tongue, which they’re identified to do on different whale species. The “excellent photographs in the paper and the extraordinary detail provided by the scientists give us a real insight into how it happens,” he stated.

Fascinatingly, wholesome humpback whales are “the only baleen whale that appears to be impervious to killer whale attack,” the scientists write, and “it is the only species known to deliberately approach and drive off mammal-eating killer whales, including those attacking other prey.”

The marine biologists will now monitor for related assaults to find out the extent to which orcas are shaping whale communities now that business whaling is, fortunately, nowhere as prevalent because it was.

“Now, with the recovery of some blue whale populations, what we may be seeing is killer whales rediscovering a prey base that has largely been absent for the past 50 to 100 years,” stated Pitman. “We may also be getting a glimpse of what the ocean looked like before we emptied out most of the large creatures.”

More: Watch deep sea creatures feast on a whale carcass.