Scientists studying marine mammals off the Pacific coast of North America have observed an unusual interaction between two highly intelligent predators: killer whales and dolphins apparently hunting together.

The observations were recorded in British Columbia waters, where researchers documented groups of fish-eating resident orcas moving alongside Pacific white-sided dolphins during salmon hunts.

Researchers studying killer whales in the North Pacific have uncovered evidence suggesting that orcas may occasionally prey on other orcas, a behaviour rarely documented among the ocean’s top predators.

The clues come from two severed dorsal fins discovered on Bering Island in Russia’s Commander Islands. The fins bore clear tooth marks and other signs of feeding damage, indicating they may have been torn from killer whales and partially consumed.

Scientists have discovered evidence that orcas may eavesdrop on dolphins, potentially using the sounds produced during dolphin echolocation to help locate prey. The finding adds a new dimension to how marine predators may exploit the acoustic landscape of the ocean.

Reports of orcas ramming and damaging leisure boats off Spain and Portugal have sparked global fascination and alarm. While some incidents have led to vessels being towed back to port, researchers increasingly believe the behaviour is not aggression but a form of play or social learning within a small group of Iberian orcas.

Over the past twenty years, researchers have documented nearly 34 cases of wild orcas offering food to humans—dropping fish, birds, stingrays, and even turtles—before lingering as if waiting for a response. These curious encounters, recorded from California to Norway, suggest deep social awareness and possibly a desire to connect across species boundaries.  

In a surprising new study, scientists have observed killer whales using marine plants—mostly kelp—as tools for social grooming. The findings, published in Current Biology, mark one of the clearest examples yet of non-human animals using natural objects for mutual care and bonding.

Wikie and Keijo represent the tragic fate of marine mammals held in parks for human entertainment. Their lives in captivity were limited and isolated, far from the expansive oceans they once could have roamed freely with their families. Known for their complex social structures and strong family bonds, orcas are highly intelligent creatures that typically live in pods, passing down knowledge and forming deep, lifelong connections. But for these orcas, their natural behaviours were denied, replaced by confined pools, restricted social interactions and repetitive performance routines.

The study, which was led by Francesca Pancaldi, used photographic and video evidence to show how a pod of killer whales (Orcinus orca) employed a collaborative approach to target the whale sharks' pelvic area, including the claspers and pelvic fins. This strategy caused significant blood loss and allowed the killer whales access to the sharks’ lipid-rich livers, which is a highly nutritious part of the prey.

The Salish Sea is home to two unique populations of orcas: the northern and southern residents. While the northern population has slowly rebounded to over 300 individuals, the southern residents remain critically endangered, with their numbers stuck at around seventy-five.

The reasons behind the southern orcas' struggle to recover have been well-documented—reduced salmon runs, pollution, and past capture for entertainment purposes. Now, new research suggests another key culprit: human-made underwater noise.