Mystery as Orca Swallows Six Sea Otters Whole

An orca has been found dead with a very strange meal inside its stomach: Six whole sea otters, fully intact, with a seventh stuck in its throat.

The orca's carcass was found off the coast of the Russian Commander Islands in the Bering Sea in 2020. Investigating scientists then discovered the sea otters, weighing a combined 258 pounds, a new study in the journal Aquatic Mammals revealed.

The orca's stomach was also found to contain 256 cephalopod beak parts. The otter that was lodged between the whale's oral cavity and its esophagus may have been the cause of its death.

Orcas usually have specific diets within their populations, and they are rarely seen to eat sea otters, preferring seals, whales, sharks, sea lions and salmon.

"There are different populations which have different diets," Alex Ford, a professor of biology at the University of Portsmouth in the U.K., told Newsweek. "Some are fish eaters, while others eat marine mammals such as seals. Those that eat marine mammals typically accumulate more pollutants in their bodies."

One other strange aspect of this finding is that when orcas eat their prey, they tend to tear chunks off, rather than eat something whole, as with the otters.

"Killer whales don't really chew their food, but instead usually break up their prey before swallowing it by thrashing it or tearing between several animals," Joseph K. Gaydos, a wildlife veterinarian and science director of the SeaDoc Society at the University of California, Davis, told Newsweek.

Orcas snacking on sea otters isn't completely unheard of, however.

"It sounds like the whale that died with the seven sea otters in its stomach was of the mammal-eating ecotype," Gaydos said. "In the NE Pacific Ocean (AK, BC, WA, OR, CA) there are multiple killer whale populations that each can be one of three distinct types of killer whales - what scientists call ecotypes. They differ by diet (some mammal eaters, some fish eating that are salmon specialists, and some fish eating shark specialists). This whale was of the mammal eating ecotype so it would have grown up eating seals, sea lions, whales, and yes, maybe otters."

"It is not common, but killer whales have been known to eat sea otters and have even been suggested as having played a role in their decline in Alaska in the 1990s," Gaydos said. "This adult female may have been hunting alone or the otters may have been just small enough for her to swallow them whole ... all except the last, which it sounds like could have caused her demise."

Sea otters like the ones found inside the orca can grow up to five feet long, making them an uncommonly large and unpalatable meal The exact reason for the orca's death is unknown, but the size and bulk of its final meal may have contributed.

"If there was a whole otter lodged in the esophagus and there was necrosis or tissue death in that area suggesting the otter was stuck there, the last otter may have been like the last straw for this one," Gaydos said.

Alternatively, the orca may have just been desperate for food, and ate the only things available to it.

"Their traditional diets may have dwindled, this individual was starving or it became savvy at picking out otters as easy prey from a coastal gulley," Ford suggested.

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