The Bizarre Friendship Between Dolphins and the Animals That Could Kill Them

In the icy waters off the coast of British Columbia, a peculiar pattern has emerged. Pacific white-sided dolphins, known for their agility and smarts, are voluntarily placing themselves in the company of killer whales.

These apex predators, after all, are no strangers to devouring marine mammals—including dolphins. But the orcas these dolphins seek out belong to a more specific kind: the fish-eating northern and southern resident killer whales.

Researchers using drone footage have documented this unlikely companionship, where dolphins swim alongside orcas for minutes, hours, and sometimes even weeks. At first glance, it looks like interspecies play. Orca calves dart after porpoises in excitement, while adult whales occasionally exhibit irritation, flicking their tails in warning. Yet, according to National Geographic, the dolphins don’t seem deterred. They hang close, weaving between the giants with what appears to be complete confidence.

Dolphins are choosing to swim with killer whales.

Friends or Strategists?

This behavior may not be purely social. Scientists believe these dolphins might be leveraging a strategic advantage. By associating with resident orcas—who feed exclusively on salmon—they avoid the risk of encountering Bigg’s killer whales, also known as transients. Bigg’s orcas hunt marine mammals, including dolphins, and tend to steer clear of the more vocal resident pods. This distinct behavior difference gives the dolphins a clue—and a potential shield.

Drone footage shows that dolphins often initiate these encounters, racing over from a distance as soon as they detect the fish-eating whales. This eagerness, captured by researchers from the Coastal Ocean Research Institute, suggests the dolphins know exactly what they’re doing. As CBC News maintains, it’s a bold move, but likely one rooted in survival instincts.

These killer whales normally eat salmon, not dolphins.

A Taxonomic Surprise

What complicates the story is that orcas aren’t just predators of dolphins—they’re family. Scientifically speaking, orcas belong to the same family as dolphins: Delphinidae. This makes them the largest of all oceanic dolphins.

Despite their formidable presence, orcas share core traits with their smaller cousins—echolocation, complex social networks, and vocal communication, Next Level Sailing reports.

This shared lineage may help explain why some interactions, while risky, still show signs of recognition and even affection. Orcas have been observed forming deep social bonds within their pods, rivaling the tactile interactions of primates. New drone studies recorded more than 800 instances of physical contact between orcas, including synchronized diving and “flipper slaps,” behaviors typically reserved for close social partners, Science reports.

Dolphins may tell orca types apart by sound.

One-Sided Relationships

But the benefit of these interactions seems skewed. While dolphins appear to gain safety and possibly food opportunities, the resident orcas don’t show clear signs of deriving value. Adults often seem indifferent, and sometimes annoyed. Still, they tolerate the presence of their smaller relatives, perhaps recognizing them as non-threats—or simply too persistent to chase off.

The dynamic becomes even more curious when comparing interactions across orca types. In contrast to the relatively peaceful exchanges with northern residents, interactions with southern residents sometimes turn violent. Orcas have been seen flipping porpoises into the air or playing a grim game of toss, with fatal consequences. According to National Geographic, these incidents suggest that not all cetacean interactions are friendly—even among the so-called "resident" groups.

Orcas and dolphins are both in the dolphin family.

Not Just a One-Off

What’s more, dolphins aren’t the only cetaceans to forge interspecies connections. In New Zealand, false killer whales and bottlenose dolphins have been seen swimming together for years, Scientific American reports, forming long-term associations that span hundreds of kilometers. Using photographic ID techniques, researchers confirmed pairings that lasted over five years.

These findings hint at a broader, more nuanced social web among cetaceans. These aren’t random encounters. They are relationships shaped by instinct, intelligence, and the need to navigate a perilous ocean filled with both opportunity and threat.

Learning by Proximity

Some researchers believe dolphins may also be studying the whales—an effort to learn more about their behavior, agility, and movement, which could help them evade danger later. By swimming alongside these top predators, dolphins might better understand how to survive encounters with their more dangerous cousins, such as Bigg’s killer whales. The theory, reported by Vancouver Sun, reflects a survival strategy rooted in observation and adaptation.

It’s a quiet reminder that the marine world isn’t just a battleground. It’s also a place of calculated choices, social nuance, and unexpected friendships.