A surprising new study has found that orcas and Pacific white-sided dolphins are teaming up to hunt salmon off the coast of British Columbia — the first documented case of such cooperation between the two predators.
Researchers from the University of British Columbia and international partners used drone footage, underwater cameras and acoustic tags to track northern resident killer whales, a salmon-specialist ecotype. They discovered the whales were closely following dolphins that appeared to act as “scouts,” leading them toward large Chinook salmon.
“Seeing these highly skilled predators following dolphins as if they were leaders was really counterintuitive — and thrilling,” said lead author Sarah Fortune.
A Cooperative Strategy
Dolphins cannot catch big salmon on their own, but by chasing the fish ahead of the orcas, they gain access to the scraps when the whales tear their prey apart at the surface. Surprisingly, the whales show no aggression toward the dolphins, even though they typically guard fresh kills carefully.
Researchers considered other explanations — such as dolphins seeking protection, bow-riding, or stealing leftovers — but none matched the observed behavior. Instead, the whales consistently oriented themselves behind the dolphins, suggesting true cooperation.
Listening to Each Other Underwater
Tags attached to the whales captured alternating echolocation clicks from both species during deep dives. Scientists believe the two predators may even be eavesdropping on each other’s sonar, expanding their ability to detect fish in the dark waters.
What Comes Next?
Researchers want to determine whether hunting with dolphins actually improves the whales’ success rate, and whether both species benefit equally from the partnership.
Regardless of the outcome, the findings broaden the understanding of whale and dolphin intelligence.
“Killer whales are incredibly social and culturally sophisticated,” Fortune said. “Seeing them refine their strategy by cooperating with another species shows just how adaptable they truly are.”
