The killer whale, also known as the orca, is actually the largest member of the dolphin family. While they are massive sea mammals, they share more physical traits with a bottlenose dolphin than with a blue whale. Scientists classify them in the family Delphinidae (oceanic dolphins). Therefore, all killer whales are dolphins, and all dolphins are technically toothed whales.

Teeth and Blowholes

One of the main differences between orcas and other large whales is how they eat. True giants of the ocean, like humpback whales, have baleen plates in their mouths to filter tiny food from the water. Killer whales are “toothed whales.” They have rows of large, interlocking teeth used to grab prey, such as seals, fish, and squid.

Another clue is on top of their heads. Baleen whales have two blowholes side-by-side for breathing. Killer whales, like other dolphins, possess only a single blowhole.

A Misunderstood Name

If they are dolphins, why are they called killer whales? The name originated with ancient sailors who observed pods of orcas hunting larger whale species. They originally called them “whale killers.” Over time, the words were flipped to “killer whale.” Despite their fierce reputation as top predators, there are no records of wild orcas hunting humans.

Social Structure

Like other dolphins, orcas are extremely social. They live in tight-knit family groups called pods. These pods work together to hunt and protect their young. They communicate using a complex system of clicks, whistles, and pulsed calls (echolocation) to navigate and find food in murky water.