Orcas ( orcinus orca) are aquatic mammals that can grow up to 8 metres in length, with a dorsal fin that stands up to 1.8 metres tall. But despite being commonly known as killer whales, these intelligent apex predators are actually the largest member of the dolphin family. Highly intelligent, orcas can live in a variety of marine environments all over the world, adapting their diet and hunting habits to better suit their surroundings. It’s not just their appetite that changes, either, they communicate in distinct ‘dialects’, and animals from different populations don’t often interbreed. This makes them the only known non-human species whose culture shapes evolution.