Orca (Killer Whale)
Species: O. orca
Common Names: Orca, Killer Whale, Blackfish, Grampus
Orca behavior varies widely depending on population. Some live together in large pods of over 75 whales, while others live in smaller groups. While their diet varies between groups, all orcas are apex predators at the top of the food chain. Some even prey on great white sharks! It is known that when an orca enters waters occupied by white sharks, most of the sharks in the area will abandon that territory.
Some killer whales eat exclusively fish, while others prefer sea mammals like seals, sea lions and porpoises. Others eat larger whales like sperm whales or humpbacks. These larger prey animals are difficult to takedown, and hunting them involves significant cooperative behavior by the orca pod. Pods have very complex social structures and strong societal bonds.
Though often called “killer whales”, they are not technically whales but dolphins, and they pose little danger to humans in the wild. Their “killer” name refers to the orca’s status as an apex predator and skilled hunter, but no recorded orca attacks in the wild have been fatal to humans.
Female killer whales reach maturity around age 10, and can often breed until age 40. Mothers usually give birth to a single calf, and all members of a pod both male and female will usually care for calves.
Orcas are the largest member of the oceanic dolphin family. They can grow over 25 feet in length and weight as much as 6 tonnes (6.6 short tons).They are heavy bodied with large, paddle-shaped fins. Males typically have a straight, tall dorsal fin that can measure nearly six feet high.
Their unique coloration makes them quite easy to recognize. They are usually black above and white below, with a large white “eye” patch located just behind the eye and a gray “saddle” marking behind the dorsal fin. The “eye” patch can vary greatly in size and shape among different populations, as can the saddle.
Orcas are found in all of the world’s oceans. Across their broad range, there are many different populations which vary in how they look, what they eat, and their general behavior. In the North Pacific, for example, there are three main types: Residents, Transients, and Offshore. Meanwhile, in the North Atlantic, there are Type 1 and Type 2 orcas.
The cold waters of the Antarctic are home to four unique types of orca, all of which look quite different from each other. Type A orcas resemble a “typical” orca. Type B orcas are mostly gray instead of black, have very large eye patches, and a prominent saddle. Type C are the smallest, and are also mostly gray, with a very slanted eye patch. Both B and C types are often stained yellow in their white areas, which is thought to be due to algae called diatoms in the water. Type D are the most mysterious of the Antarctic orcas. They are rarely seen and have a very bulbous forehead, with a very small eye patch. Some scientists believe they may even be a completely different species of orca.
Orcas have a long history in the spirituality and religions of indigenous cultures in the Pacific Northwest of North America. Orcas are regarded as powerful beings and rulers of the sea.
The first known written record of the orca is found around the year 70 AD, where Pliny the Elder described them as “an enormous mass of savage flesh with teeth”.
Though they were initially not targeted by the whaling industry, orcas were hunted once the populations of larger baleen whales began to dwindle from overhunting. However, there are also documented cases of orcas cooperating with humans to hunt larger whales, including an orca named Old Tom in Australia. Today, commercial whaling of killer whales has largely ceased.