“Strategic alliance”. Orcas and dolphins seen hunting together for the first time

The orcas were seen orienting themselves towards the dolphins and following them at depth, which suggests that they were “listening” and using the dolphins’ echolocation cues. Dolphins gain protection from predators and access to the remains of one of the most coveted fish in the Ocean.

In a new study, a team of researchers observed, for the first time, two different species of large marine predators — orcas and white-flanked dolphins — at sea. join forces to locate and attack salmon schools off British Columbia.

According to the study authors, the images collected suggest that they have established a cooperation relationship that can bring mutual benefits, and that these interactions These are not random encounters.

On the contrary, everything indicates that the species work together to hunt salmon chinook in waters off British Columbia, where they are often seen within a few meters of each other.

The study, conducted by researchers from the University of British Columbia (UBC), Dalhousie University (DU), the Leibniz Institute and the Hakai Institute, was presented in a published this Thursday in Scientific Reports.

“We have long known that resident orcas interact with Pacific white-flanked dolphins, but seeing them dive and hunt in sync with the dolphins completely changes our understanding of what these meetings mean”, explains Sarah Fortuneresearcher at DU and first author of the article, in one from UBC.

“Our images show that orcas and dolphins may actually be cooperating to locate and share prey — something never before documented in this population”, adds the researcher.

Using drones launched by the Hakai Institute and biotelemetry devices with suction cups that later detach, researchers collected remarkable images, both aerial and underwater, of these coordinated interactions between the two species.

Observations showed that orcas and dolphins often fed very close to each other, and often synchronized their movements.

Orcas have been seen orient yourself in the direction of the dolphins and to follow them in depth, which suggests that would be “listening” and using the cues dolphins use echolocation to locate large salmon — prey that dolphins dolphins cannot capture and swallow whole.

“A strategic alliance that we observed among dolphins and orcas is extraordinary”, highlights Andrew Tritesprofessor at UBC and lead author of the study.

The images reveal that, after capturing the salmon and breaking it into smaller pieces to share with other orcas, the dolphins they quickly used up the leftovers.

“Working together, Orcas can save energy and use dolphins as a kind of scouts with radarincreasing the chances of finding large chinook salmon at greater depths. In return, the dolphins gain protection from predators and access to the remains of one of the most prized fish in the ocean. It is a situation in which everyone wins”, details Trites.

Keith Holmesa drone pilot at the Hakai Institute, was the first to detect this behavior, just in case, during fieldwork on a UBC project. “View from above, there was incredible activity. It was clear that there was some kind of communication and that they were actively feeding together.”

The researchers recorded 258 distinct episodes of dolphins moving close to the heads of tagged orcas. All orcas that interacted with dolphins exhibited behaviors associated with searching for foodhow to catch, eat and search for salmon. It is important to note that none of the species showed signs of aggression or avoidance of each other.

“By combining aerial and underwater information, we are revealing a hidden layer of coordination between species“, said Sarah Fortune. “It’s a stunning example of how new technologies are leading us to rethink the relationship between the oceans’ top predators.”