Rare Drone Footage Captures Orcas Feeding on Dusky Dolphins

For scientists who study orcas, directly observing the apex predator’s hunting behavior in the wild is a rare opportunity. The animals, sometimes called killer whales, range over thousands of miles of open ocean in small pods searching for food, so researchers need to be lucky to get a chance to watch them eat.

“It is a dream come true to study these cetaceans in the wild,” Ana María García Cegarra, a marine scientist at the University of Antofagasta in Chile tells El Pais’ Constanza Cabrera. “It is not common to see orcas so close to the shore.”

But watching orcas eat and learning about their diet and habits is more than just an item on a marine biologist’s bucket list—it’s critical to understanding their complex behaviors and assisting conservation efforts. A new study co-authored by García Cegarra in the journal Frontiers in Marine Science does just that, capturing drone footage of an orca pod near Chile feeding on dusky dolphins.

Orcas live in oceans all around the world, but they’re not all the same. Groups, called ecotypes, living in different locations can have unique diets, communication styles and even cultures, Sarah Teman, a marine biologist at the University of Washington who wasn’t involved in the study tells CNN’s Mindy Weisberger.

“We’re still learning just how diverse killer whale populations are,” Teman says. “The more we learn about whales, the better equipped we are to protect the seas they live in.”

Scientists have spotted at least five ecotypes of orca in the area off South America’s west coast, including type A, who tend to eat marine mammals, and type B1, who like to feast on fish. But the ecotype of the pod being studied by García Cegarra has thus far remained a mystery.

The pod appears to hunt in the Humboldt Current, where cold, nutrient-rich water upwells from the deep ocean. These nutrients feed creatures like krill and anchovies at the bottom of the food chain, which in turn get eaten by seals and dolphins.

In the new study, scientists trawled through citizen science data from whale-watching trips and fishing boats to track the mysterious pod. They also conducted their own surveys and captured drone footage to track the group. This effort let them capture dramatic footage of the pod’s matriarch, an individual called Dakota, tossing a deceased dusky dolphin into the air. This was the first time scientists have ever documented an orca successfully hunting the species.

Based on this prey preference and their small pod size, researchers think the Humboldt Current pod might be from the type A ecotype. But their white eye patch is smaller than is typical of type A. DNA testing would provide conclusive evidence, but samples for such an analysis are hard to retrieve.

“We wish we could obtain skin biopsy samples to analyze their genetic data, as there is no genetic information for orcas in this region of the south-east Pacific,” García Cegarra says in a statement. “However, they are very elusive and intelligent, which makes it difficult to approach them in the boat for biopsies.”

ORCAS | Imágenes inéditas de una manada alimentándose en Chile | EL PAÍS

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Bruno Díaz, scientific director of the Bottlenose Dolphin Research Institute, tells El Pais that the new study is a starting point. “It is a foundation stone for future studies,” he says. “It would be interesting to see how regularly they visit that area and how they catch their favorite prey in that case.”

Another question remaining for scientists is how successfully the group is reproducing. In two recorded incidences of feeding on dusky dolphins, a female orca held onto the unlucky prey as her calves and other orcas ate. This evidence of successful offspring is encouraging, but risks such as pollution from nearby ports could be harmful to the survival of the population.

“The fact that we have observed newborn calves is important,” García Cegarra says in the statement, “because it indicates that they are having offspring, but we don’t know their survival rate.”

Rudy Molinek | READ MORE

Rudy Molinek is Smithsonian magazine's 2024 AAAS Mass Media Fellow.