A number of orcas, also called killer whales, are held in captivity by humans for breeding or performance purposes. The practice of capturing and displaying orcas in exhibitions began in the 1960s, and they soon became popular attractions at public aquariums and aquatic theme parks due to their intelligence, trainability, striking appearance, playfulness, and sheer size. As of August 19, 2021, there were 57 orcas in captivity worldwide, 30 of which were captive-born. At that time, there were 19 orcas in the SeaWorld parks.