Mysterious pod of killer whales found near Chile, revealing newly discovered hunting skills

Off the coast of Chile, in waters filled with krill and anchovies fed by the Humboldt Current, lives an elusive and little-known group of killer whales. Thanks to citizen science and years of diligent observation, a team of scientists led by Dr. Ana García Segarra of the University of Antofagasta is uncovering the group’s secrets—starting with dinner.

Garcia-Segarra’s team, which had previously observed killer whales using fishing boats to help them hunt sea lions, has now observed them successfully hunting dusky dolphins for the first time and sharing food with the group. This new evidence of their eating habits could help experts understand how killer whale populations in the Southern Hemisphere are connected, potentially boosting conservation efforts.

“Studying killer whales in their natural environment is a major challenge because they are marine predators, travel long distances and live at sea, making monitoring difficult,” said Garcia-Segarra, lead author of the study. Frontiers in Marine Science“But understanding its role in the marine environment is crucial to the conservation of this little-known species in the Humboldt Current.”

You are what you eat

Killer whales are predators with an impressively diverse diet, but not all killer whales eat the same things. Populations can be grouped into different ecotypes based on their food preferences, acoustics, and genetics, so understanding what Humboldt Current killer whales eat is a big step toward understanding their place among the world’s other killer whales.

Five different ecotypes have been reported in the Southern Hemisphere: some, such as Type A and Type B killer whales, focus on marine mammals, while others prefer fish. Understanding the niche of Humboldt Current animals will help us understand how these groups are related to each other on a broader scale and conserve them for the future.

Garcia-Segarra and her colleagues used a combination of their own surveys and citizen science data collected from whale-watching trips and fishing vessels to monitor the population and track their fishing choices. The observers recorded the presence of killer whales, the group’s composition, and its location, and took photos and videos that the scientists could compare to a catalog of known individuals.

By combining this data with their own systematic surveys and drone footage, the scientists built a map of killer whale presence in the area and tracked group behavior and prey choices.

This allowed researchers to capture evidence that Menacho’s pod of killer whales was hunting dusky dolphins – a species that no killer whales in this area have ever successfully hunted. Dramatic images show Ms. Dakota tossing a dusky dolphin into the air.

These sightings may suggest that these killer whales may belong to the mammalian hunting ecotype Type A. Their prey and small size are consistent with this hypothesis, although their white eye patches are smaller than usual in Type A killer whales. They have never been recorded in Patagonia with other Type A killer whales.

“We hope to be able to obtain skin biopsy samples to analyze their genetic data, as there is no genetic information on killer whales in this area of ​​the southeast Pacific,” Garcia-Segarra said. “However, they are very elusive and intelligent, which makes it difficult to approach them in a boat to take samples.”

sharing the spoils

Observations of dolphins hunting in the dark also revealed that Menacho’s pod shared its food. Food sharing has been documented among many killer whale groups, sometimes to help feed relatives, and other times because the pod hunts cooperatively and everyone gets a share.

In this case, García-Segarra and colleagues suggest that Menacho’s group was sharing food with its relatives, similar to Type A killer whales that hunt sea lions by deliberately leaving them out: Female killer whales have been observed sharing meat with group members, allowing closer relatives to eat first.

Garcia Segarra stressed that more information and systematic studies are needed to fully understand and protect this secretive group of killer whales.

“The fact that we observed newborn whale calves is important because it suggests that they will give birth to calves, but we don’t know their survival rate,” she added. “Thanks to citizen science, we can track the presence of killer whales along thousands of kilometers of the northern Chilean coast — but most killer whale sightings have been opportunistic.”