Why a Pod of Pacific White-Sided Dolphins is Teaming Up with Orcas?
23rd Dec. 2025
Researchers working off Vancouver Island recorded scenes that would have been hard to imagine a decade ago. Northern resident orcas and Pacific white-sided dolphins were seen diving and foraging in close coordination. In several cases, the whales followed dolphins down as they hunted. Then after orcas caught large Chinook salmon, Dolphins were seen feeding on the scraps.
Scientists used multiple tools in this study. They deployed drones for aerial videos. They attached suction-cup tags to animals to log movement. They also gathered underwater footage and acoustic recordings. Together, these methods let researchers track who led, who followed, and how these animals behaved above and below the surface.
What the footage shows and why it matters?
The recorded footage reveals repeated patterns. Dolphins often forage near the surface and use echolocation to find and locate fish. Orcas, which can dive deeper for large salmon, were observed changing course after encountering these dolphins. Researchers interpret this as whales “eavesdropping” on dolphin echolocation to dive deeper, and locate larger prey. In return, dolphins gets the oppurtinity to scavenged pieces of salmon that the orcas broke apart.
The behavior appears more than accidental. The study documents dozens of such encounters and multiple coordinated hunting events. In some of those, orcas captured Chinook and shared prey within their group while dolphins were present and then they fed on the leftovers. Scientists describe the pattern as possible cooperative foraging between two species that historically have been treated as competitors or simple co-occurring predators.
How cooperation between Dolphins and Orcas pay off?
In this study researchers have proposed a simple cost-benefit logic. Dolphins act as acoustic scouts. They are fast and produce echolocation clicks that reveal location of fish schools. Orcas save energy by trailing the dolphins and using those cues to hunt larger salmon that dolphins cannot swallow whole. In return, Dolphins gain access to nutritious scraps and receive protection from other orca groups while near the larger predators. Both sides may therefore increase their net food intake.
This arrangement also matter ecologically. Chinook salmon are a prized and patchy resource. Any strategy that increases their detection or capture efficiency will change how top predators interact. More broadly, the find challenges assumptions about fixed predator roles. It shows that intelligent marine mammals can adapt their behaviour quickly. That adaptability became more visible as researchers deploy drones and high-resolution tags
Not everyone is convinced that it’s true cooperation
Some experts have urged caution. They note the difference between deliberate partnership and opportunistic scavenging. Dolphins might simply follow where food is available, and orcas might tolerate their presence because the dolphins do not threaten the whales’ catch. The observers themselves acknowledge the need for further data to rule out alternative explanations. In short: the interaction is compelling, but its interpretation need further investigation.
What comes next for researchers : A small discovery with big questions
The footage breaks new ground because the two species were not previously known to coordinate hunts in this way. Yet it raises larger questions about how marine predators respond to shifting prey patterns, human impacts on salmon stocks, and changing ocean conditions. For now, researchers describe a tentative win-win: dolphins acting as living sonar, and orcas doing the heavy lifting. Future work will test how stable and widespread that arrangement truly is.
Note on the Researchers:
The study was led by Sarah M. E. Fortune (Dalhousie University; also affiliated with UBC’s Marine Mammal Research Unit). Co-authors are Xi Cheng (Leibniz Institute for Zoo and Wildlife Research, Berlin), Keith Holmes (Hakai Institute, Victoria, BC) and Andrew W. Trites (Marine Mammal Research Unit, University of British Columbia). Sarah Fortune is listed as the corresponding author.
Web Resources on Dolphins and Orcas hunting together:
1. UBC Science: Orcas and dolphins seen hunting together.
2. Livescience.com: Killer whales are teaming up with dolphins on salmon hunts.
3. Nationalgeographic.com: Watch orcas and dolphins team up to hunt.
4. Smithsonian magazine: Watch These Orcas Follow Dolphins to Snag a Salmon Feast.