Pregnant Orca Dies After Beaching Herself While Hunting

A pregnant orca has died after she beached herself while hunting off the coast of Argentina.

The 12-year-old orca, known to research groups as Sheuen or PTN021, had stranded herself along the Valdes Peninsula and been unable to return to the water, the Orca Rescues Foundation said in a Facebook post.

The orca was still alive when rescue teams arrived. Attempts were made to save her life but she died early on Monday.

Rescue teams believe she became stranded while attempting to hunt sea lions that live along the shoreline. A necropsy to determine the exact cause of death is currently underway as "circumstances aren't 100 percent clear."

Marine mammals strand all the time. But this particular pod of orcas—also known as killer whales—are well known for doing it on purpose, as a hunting technique.

Orcas off Argentina are well known for this hunting technique. The orcas wait in the shallows until the opportune moment, and once they have prey in sight, they lunge forward and strand themselves. When ashore, they will grab a sea lion and drag them back into the depths.

According to the Orca Rescues Foundation, this technique requires "years of practice" and "is passed down from generation to generation."

The rescue group said it "always carries the risk of error."

Orca are extremely intelligent. Scientists have observed that each pod of orcas has its own family traditions. Hunting techniques and behaviors will also differ among orcas in different countries.

"Sheuen was known for being a little 'wild and crazy', with a habit of scaring pups off the beach rather than grabbing them. Needless to say, she was a talented hunter and was known to teach the younger orca. Luck just wasn't on her side that day," the Orca Rescues Foundation said on Facebook.

In the Facebook comments, the foundation said that the orca's pregnancy could have altered her ability to maneuver back into the water, once she was ashore.

Orcas need water to survive. The whales have a very thick layer of blubber meaning they can die from becoming too hot if they are stranded for too long.

According to the Peninsula Valdes Orca Research group, Sheuen had been a "proficient hunter" and had taken to teaching younger orcas in her pod how to do so.

Orcas have complex social bonds and family ties. Older orcas, usually a female, will teach younger members traditions and behaviors that are usually unique to their pod.

Differing behaviors have been observed in orca groups all over the world. One group of orcas in the Crozet Islands learned how to use fishing boats as sources for buffet style meals. Another group of orcas off the coast of Portugal have also taken to head butting boat rudders—scientists are still researching why this could be.

Newsweek has contacted the Orca Rescues Foundation.