Killer Whales Appear to Have Massacred 4 Bowheads in an Arctic Bay

Four bowhead whales that washed up on the shores of a Canadian bay in the Arctic Circle appear to have been attacked by killer whales. A scientist analyzing images of the carcasses said the killer whales appear to have torn at the bowhead tongues—a hunting behavior that has previously been observed among orcas.

The four carcasses were found by Rene Kukkuvak around 40 miles from Kugaaruk, a hamlet in Canada's northern Nunavut territory, off the Gulf of Boothia. Kukkuvak was with his son and wife when they came across the bowhead whales. He posted the pictures to Facebook and the images were sent to Steve Ferguson, a research scientist with Fisheries and Oceans Canada who studies killer whales.

Ferguson told Nunatsiaq News the images suggested killer whales had attacked the whales, with two of the carcasses showing injuries consistent with their known hunting techniques. Two of the animals were also younger, which fits with the type of bowhead that orcas would normally target.

Ferguson said killer whales—hunting in pods—will pull down on a bowhead's lip to open its mouth, allowing other members to attack its fatty tongue. He also said the photos suggest these injuries were sustained while the bowheads were still alive.

The Gulf of Boothia is known as a spot where bowheads congregate in the summer months for feeding. This also results in the arrival of killer whales, which prey on bowheads.

The Gulf is an area where summer sea ice persists and it is thought this offers protection from killer whales. A report by the Committee on the Status of Endangered Wildlife in Canada published in 2009 notes that bowheads "often exhibit a fright reaction" to killer whales and tend to move into areas of broken sea ice and shallow near-shore waters, where they can hide from the predators.

Research published in PNAS earlier this year looked at how the presence of the predator impacts bowhead behavior in the Gulf of Boothia. Tracking the bowheads and the killer whales, researchers found that bowheads had moved into the Gulf of Boothia by July and remained there until October. Analysis of both species' movements appeared to confirm the idea that bowheads fear killer whales and will navigate to these areas, even though they are poor for food sources.

"Bowhead movement into heavy sea ice and shallow water, coupled with greatly reduced activity, when under predation threat, therefore, suggests predator avoidance occurred at the expense of foraging," the study said.

In an email to Newsweek, Ferguson, who was one of the authors of the PNAS study, said it is unusual for bowheads to wash up in the eastern Canadian Arctic generally, but that attacks by killer whales are more common in this area compared with the west of the country. He said estimates suggest around 50 bowheads are killed each year by killer whales.

"This is the first sighting of washed up bowhead in the Prince Regent Inlet and Gulf of Boothia region that I have heard of—however, this may be partly due to the lack of people living and using this area—really it is only Kugaaruk in the entire region," he said.

Ferguson said the bowheads may have stranded themselves to escape the attack, but thinks in this case it is unlikely. "Bowhead whales will retreat into sea ice or close to shallow shorelines in order to escape killer whales. Speculation is that they may beach themselves trying to escape orcas. This has been speculated for smaller whales like beluga and narwhal. My guess is that in this case they were killed by killer whales in one small area and then the carcasses floated into the shoreline because they are so fatty (versus sinking.)"

In September, the U.S. National Ocean and Atmospheric Administration said Arctic sea ice had reached its annual minimum, covering 1.44 million square miles. This is the second-lowest minimum ever recorded, and experts said it may drop even further because of a "late-season surge of summer warmth."

Mark Serreze, director of National Snow and Ice Data Center, said summer sea ice in the Arctic is declining year-on-year. "The ice is shrinking in the summer, but it's also getting thinner. You're losing extent, and you're losing the thick ice as well. It's a double whammy," he said in a statement.

Speaking to Nunatsiaq News, Kukkuvak said there had been "no ice, not even icebergs" in the waters around Nunavut over the summer. This may have left the bowheads exposed to killer whale attacks. He also said this was the first time killer whales had been in this part of the Bay: "This is something new," he told the newspaper.

Ferguson said he believes the loss of sea ice has led the bowheads and their young to move into the Gulf of Boothia to find sea ice for protection from the killer whales. "In the past decades we found washed up dead bowhead in the Foxe Basin area that were attributed to killer whales," he said. "Now this may be the new normal with killer whale predation happening in the Gulf of Boothia as shown by our paper.

"We don't have strong evidence that the numbers of killer whales have increased in the Arctic but this is likely. However, we do know that with the loss of sea ice, killer whales have expanded their summer range farther into the Canadian Arctic and that they spend more time in the region now that sea ice does not impede their movements."

This article has been updated to include additional quotes from Steve Ferguson.

killer whale
Stock image of a pod of killer whales in waters off Canada. Four bowhead whales found on the shores of a Canadian Arctic bay are believed to have been killed by orcas. iStock
Killer Whales Appear to Have Massacred 4 Bowheads in an Arctic Bay | Tech & Science