A killer whale, Orcinus Orca, is not actually a whale, but the largest member of the dolphin family. These black and white mammals are the only known predator of great white sharks, and are frequently used as show animals in marine-themed parks. Research conducted since the late 20th century has determined that the killer whale is divided into at least three groups so dissimilar that they may qualify as different species.
The killer whale is instantly recognizable by its characteristic black and white body. Although some variations have been recorded, most killer whales feature a black back and sides, with a large white patch behind each eye and a white belly. Some may have yellow or orange coloration on the borders of the two primary colors. Full grown, they range in size from 16-26 feet (5-8 meters) in length and weigh between 5,500 and 16,000 lbs (2,495-7,257 kg). Males are generally somewhat larger than females.
Orcas are divided into three groups based on behavior. Resident orcas live in matriarchal pods, with calves of both genders remaining with their mothers permanently. Residents eat only fish, and can often be found in the company of other dolphins, seals and sea lions. Studies have shown that when the songs of resident killer whales are played to seals and sea lions, the animals do not react as they do to predators. Orcas residing in theme parks are always residents, as their diet is entirely fish based.
Transient killer whales live in small groups, usually of between two and six animals. They subsist entirely off of other marine mammals, and do not eat fish. Transients may also not stay together in a permanent pod. They differ from residents in terms of physical characteristics, including a more triangular and pointed dorsal fin, and an entirely grey saddle-patch area surrounding the dorsal.
The third variety of killer whale is called an offshore killar whale, and has proved an elusive research subject for experts. Offshore pods are believed to be genetically distinct from residents and transients, and have been seen traveling in groups of up to 60 animals. These orcas are believed to spend their entire lives traveling, living on a diet of sharks and sea turtles.
The killer whale has a complex history of interaction with humans. Although there have been only a few recorded attacks of wild orcas on humans, the species has long been feared for its coordinated hunting abilities. The Latin name of the genus, orca translates to English as “from hell,” while the common name of killer whale also can imply fear. Yet humans have long been fascinated by this giant dolphin, and have kept orcas in captivity since 1964.
Orca captivity is a controversial topic, with some experts believing that the stresses of tank life are damaging to the animals. 60-90% of captive male orcas experience dorsal fin collapse which may indicate excessive stress on the animal. In the wild, killer whales live 60-80 years, while in captivity most die between 20-40 years of age. Wild orcas travel over great distances in search of food, and some experts suggest that tanks, however large, cannot compare to the open spaces of their natural habitat. Proponents of captivity claim that allowing the public to interact with whales instills compassion toward the species and may lead to increased worldwide conservation efforts.
Orcas exist in every ocean in the world, but they are not protected from the harm caused by pollution and environmental changes. Some communities of orcas are considered by experts to be endangered, including the Southern Resident community native to Washington state and British Colombia. Studies of this population have shown that their numbers have shrunk from 200 animals to 90 in a short time. Reasons for the decline are believed to be pollution and the dramatic decline in the salmon population, a main source of food for the community. The killer whale remains a fascinating apex predator, but without conservation help, its natural abilities and intelligence may not be enough to protect it from permanent population harm.