Marine biologists filmed killer whales hunting together for the first time and dolphins

A team of researchers captured an unusual form of interspecies interaction off the coast of Canada. Killer whales and Pacific white-sided dolphins were helping each other hunt fish.

Killer whales and dolphins collaborate to hunt salmon in the North Pacific Ocean—an unexpected discovery that once again reveals the complex social life of marine mammals. Video cameras and sensors attached to nine killer whales captured four of them diving alongside numerous Pacific white-sided dolphins to catch salmon hiding in the depths off Vancouver Island. Three more killer whales were spotted by drone.

The killer whales ate the salmon, and the dolphins scavenged the remains. Chinook salmon, also known as king salmon, can grow over a meter in length, making them often too large for dolphins. However, the whales are messy eaters, simply tearing the fish apart, leaving blood, scales, and bits of meat for the dolphins.

Researchers believe dolphins help whales "scout" salmon. Trackers captured four killer whales diving with dolphins to depths of up to 60 meters, where it's dark and salmon can hide among rocks and crevices. The data showed that the whales frequently reduced their echolocation, apparently to "listen" to the dolphins scanning the water.

Scientists believe the new study convincingly demonstrates cooperation between whales and dolphins, even though these species often fight each other. However, these animals are intelligent and have flexible behavioral responses.