'Incredible and rare' sight as endangered whale attacked by 60 orcas in brutal hunt

A gang of more than 60 orcas brutally attacked and killed a 59-foot-long (18 meters) pygmy blue whale, leaving a nearby whalewatching tour shocked, new video footage shows.

The dramatic incident occurred in Bremer Canyon, a marine park off the coast of Bremer Bay in Western Australia, on Monday April 7

The enormous group of orcas (Orcinus orca) can be seen hunting together and circling the endangered pygmy blue whale (Balaenoptera musculus brevicauda) in footage posted on Instagram by the tour company Naturaliste Charters. Eventually, the whale is seen floating dead at the ocean surface, the blood pouring from its mouth as the orcas tuck into their hard-earned meal.

"We witnessed an incredible and rare event yesterday as multiple pods of orcas successfully hunted a blue whale in Bremer Canyon," Naturaliste Charters representatives said in the caption of a Facebook post, sharing pictures of the unique event. "The intense ordeal lasted less than 40 minutes from when we first saw the blue at the surface to when the battle was over."

As the blue whale's fate was sealed, the orcas "celebrated with breaches and tail slaps," the representatives added.

This incident marks one of only a handful of times that orcas have been observed attacking a blue whale species, Naturaliste Charters representatives said.

Related: Orcas: Facts about killer whales

Orcas are highly intelligent and hunt in coordinated groups, often using complex communication and teamwork to take down prey far larger than themselves. They often use brutal tactics, having previously been seen creating big waves to wash seals off floating ice, working together to separate whale calves from their mothers and drown them, and even ripping out the livers of sharks.

"We're all still pretty shell shocked," marine biologist Jennah Tucker, who works for Naturaliste Charters and witnessed the recent incident, told ABC. "It was all over pretty quickly for such a big animal."

The whale was seen to be covered in bite marks and at one point was swarmed by as many as 30 of the orcas at once.

"We estimated about 60 orca involved, likely more than that," Tucker said. "We've confirmed five different family groups were involved. Quite often, many will move in once it's over. But in this case, we saw 20 to 30 animals at a time crowding around the whale to take it down."

Tucker also said that there were several juvenile orcas among the feeding frenzy, including one as young as a month old.

"They are involved from a young age — this calf has no teeth but stuck by mum's side," Tucker said.

Pygmy blue whales are a subspecies of blue whale, which is the largest animal on Earth. Regular blue whales can grow as long as 110 feet (34 m), while pygmy blue whales grow up to around 79 feet (24 m). While smaller than their cousins, pygmy blue whales are still longer than many other whales, including humpbacks and sperm whales. Orcas rarely grow longer than 32 feet (10 m).

Pygmy blue whales are mainly found in the Indian Ocean and the southwestern Pacific Ocean and tend to stay in warmer tropical and temperate waters. They are one of five subspecies of blue whale identified so far. Blue whales in general are listed as endangered by the International Union for Conservation of Nature (IUCN), while pygmy blue whales are listed by the IUCN as Data Deficient, and under the Australian Environment Protection and Biodiversity Conservation (EPBC) Act as endangered.

"We definitely do as much as we can to not be involved and to have no interference, but it's a very difficult thing to watch; it can be very brutal," Tucker said of the event. "Especially an animal we know is struggling to bounce back after whaling. Pygmy blue whales are endangered."

"It was very emotional but that's nature, it was quite a privilege to witness the event," she added.

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