Despite their name, killer whales or orcas are the largest members of the dolphin family. Technically, orcas are also whales because delphinids belong to the Cetacean order within the toothed whale (Odontoceti) suborder. However, the term whale is typically reserved for baleen whales of the Mysticeti suborder.
The major physical feature that ensures orcas are dolphins is the presence of a melon — a fatty deposit that assists the animals in echolocation and only exists in dolphins.
Orcas are highly intelligent, highly adaptable and able to communicate and coordinate hunting tactics. They are extremely fast swimmers and have been recorded at speeds of up to 54kph! A wild orca pod can cover over 160 kilometers a day, foraging, and socializing.