Facts about the animal kingdom

Types of Orcas - Killer Whale Species

 
María Luz Thurman
By María Luz Thurman, Biologist/ornithologist. November 25, 2024
Types of Orcas - Killer Whale Species

Also known as killer whales, orcas (Orcinus orca) are one of the world's most effective and versatile predators. Although they are marine mammals and cannot walk on land, they are even known to manipulate animals from terrestrial areas into the sea for hunting. Their great intelligence and hunting prowess means they are apex predators, having no natural predators of their own. This has led to successful populations in waters all over the world. Despite there being only one killer whale species, there are different types of orcas we can find in nature. These types are determined by location and other factors.

To learn more about the differences, AnimalWised shares the different types of orcas. We look at how individuals of the the killer whale species are categorized and share photos of what they look like.

You may also be interested in: Is a Killer Whale a Whale?
Contents
  1. Classification and taxonomy of orcas
  2. Northern resident orcas
  3. Northern transient orca
  4. Offshore orca
  5. Type A orca
  6. Type B1 orca
  7. Type B2 orca
  8. Type C orca
  9. Type D orcas
  10. North Atlantic orcas
See more >>

Classification and taxonomy of orcas

Despite having the common name of killer whale, the orca belongs to the family Delphinidae. Rather than being a relatively small whale, they are the largest type of dolphin in the world. As we stated in the introduction, there is only one actual species of orca (Orcinus orca). Despite this, there is much debate among cetologists about whether the different types of killer whale represent variations in race or subspecies, potentially even distinct species.

Living across the world's oceans, orcas have a cosmopolitan distribution. This has led to different populations emerging over the years, resulting in differentiation between ecotypes dependent on where the killer whale lives. Ecotypes are groups of organisms differentiated by ecological and geographic adaptations. These differences are seen in adaptations such as diet, behavior, vocalization and distribution range.

In the Northern Hemisphere, three main ecotypes of killer whales have been identified. They are present in the North Pacific and are:

  • Resident orcas
  • Transient orcas
  • Offshore orcas

In the Southern Hemisphere, other ecotypes have been classified in the Antarctic and sub-Antarctic region based mainly on their dietary preferences and physical characteristics. This classification is not definitive, as genetic and behavioral research continues to reveal more details about the differences between these groups.

Despite being similar in size to whales, we can see from their taxonomic ranking that they are actually types of dolphin. Below is the detailed taxonomic classification of orcas:

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Mammalia
  • Order: Cetacea
  • Suborder: Odontoceti
  • Family: Delphinidae
  • Genus: Orcinus
  • Species: Orcinus orca

The taxonomic classification highlights their close relationship to other dolphins, although their behavior, diet and distribution are much more varied. The ecotypes of killer whales show ecological adaptations that could justify future revisions in their scientific categorization. This is a cause of great debate among cetologists, especially since the orca is such an interesting specimen to study.

Discover all you need to know about dolphin mating and reproduction with our related guide.

With this in mind, we look at some of the proposed types of orcas, some of which are more generally accepted than others.

Northern resident orcas

We start with the North Pacific type of killer whale. Resident killer whales are highly social, living in family groups known as ‘pods’ which are usually matriarchal, i.e. led by a female. This ecotype of killer whale is especially dependent on fish, with salmon as its main prey. They can consume up to 550 lb (250 kg) of fish or other prey per day.

Northern resident orcas are extremely vocal. They use complex sounds to communicate and hunt, demonstrating an advanced level of group coordination.

These types of killer whales have a curved dorsal fin and clearly defined white spots. They are found in coastal waters of the North Pacific, mainly near Canada and the northwestern United States. Their trajectories are usually based on following the movements of schools of fish.

Types of Orcas - Killer Whale Species - Northern resident orcas
Image: Springtide Whale Watching

Northern transient orca

Also known as Bigg's killer whale, the transient orcas of the North Pacific specialize in hunting marine mammals such as seals, porpoises and sea lions. They use highly adapted stealth techniques such as minimizing the sounds they emit so as not to alert their potential prey. They hunt in small groups and display a more or less stable social hierarchy compared to resident orcas.

The resident dorsal fin is more pointed and their coloration less defined than those of transient orcas. These types of orcas are found in the North Pacific, generally ranging from Alaska to California, but they travel over great distances.

Types of Orcas - Killer Whale Species - Northern transient orca

Offshore orca

This ecotype of orcas inhabits deep waters far from the coast. While they are known to eat all types of fish, their diet is likely based on large fish and sharks. Feeding on sharks wears down their teeth due to the abrasiveness of the skin of their prey. They are characterized by forming large groups, often of up to 75 individuals and are less vocal than the residents.

They are a type of killer whale that have an appearance similar to resident killer whales, but with slight variations in size and the shape of the dorsal fin. These killer whales are difficult to observe due to their preference for habitats far from the coast. A photo of a pod of these types of killer whales can be seen below.

While we are discussing the types of killer whale in the wild, you can learn about why orca fins bend in captivity with our related article.

Types of Orcas - Killer Whale Species - Offshore orca

Type A orca

So far we have looked at the different types of orcas from the Pacific Ocean, but now we can look at some from southern waters. The type A ecotype of killer whales is the largest in the Antarctic region, with a size that can exceed 30 ft (9 m) in length. It is known as the Antarctic orca.

They prefer open waters and hunt common minke whales (Balaenoptera acutorostrata), working together in groups to herd them. This behavior shows their ability to hunt prey significantly larger than themselves. They have a prominent dorsal fin and a classic black and white coloration common to orcas. They inhabit open waters in the Southern Ocean and migrate by following the movements of their prey.

Type B1 orca

The type B1 killer whale is also known as the pack ice orca. It is smaller than the type A. Their common name is derived from the fact they live near sea ice and primarily hunt the seals that live on and around it. They use innovative techniques to catch their prey such as flipping ice floes to knock seals into the water. This orca ecotype is highly social and relies on teamwork to hunt in a challenging environment.

They are slightly smaller than type A killer whales and have a yellowish tint to their skin due to the accumulation of diatoms. These types of killer whales are found in cold waters close to ice floes.

Find out more about what orcas hunt with our article explaining what do killer whales eat?

Type B2 orca

This type of orca is known as the Gerlache orca because it is known to be found in the Gerlache Strait of the Antarctic Peninsula. While they are similar to the B2 type, they are smaller in size and tend to feed mainly on penguins and fish. They also use cooperative techniques such as tipping ice floes to capture their prey.

Additionally, these types of orcas also have a similar coloration with a yellowish tone. They prefer areas near glaciers and areas with high penguin activity.

Type C orca

The type C ecotype is the smallest in Antarctica and specializes in feeding on fish, particularly Antarctic hake. They live in large social groups and have unique vocalizations that they use for communication and hunting. They are also known as Rossa Sea orcas, named after the deep bay on the southern coast of Antarctica.

Among the different types of orcas that exist, these are distinguished by a slanted eye patch and live in remote areas covered in sea ice. Due to living in such remote and inhospitable conditions for humans, they are particularly difficult to study, even for orcas.

Learn about how other aquatic mammals are categorized with our article asking are whales mammals or fish?

Type D orcas

Type D orcas are the most enigmatic and least studied of all killer whale types. They prefer subantarctic waters, sometimes being referred to as Sub-Antarctic orcas. They have a diet that includes fish and squid. These orcas form small pods and seem to be less social than other ecotypes.

They are distinguished by a more rounded head and a small eye patch. They live in subantarctic waters and occasionally in the open sea.

North Atlantic orcas

Finally, we come to the North Atlantic killer whales. They are not as diverse as Antarctic orcas, with only two types suggested at this point. Type 1 is considered a herring-eating orca as this fish constitutes the main part of their diet. Type 2 North Atlantic orcas are thought to feed mainly on baleen whales. Both types of killer whale congregate in moderate groups and are highly vocal, using specific sounds to hunt and communicate.

Despite differences in diet, both types of North Atlantic orcas have a prominent dorsal fin and a well-defined black and white color. They inhabit temperate waters of the North Atlantic, ranging from Europe to Greenland.

There is also a very small population of about 50 killer whales in the North Indian Ocean. They have been sighted in the Persian Gulf and other areas, but not much is known about them yet.

If you want to know about similar animals that live in the world's oceans, take a look at our article providing a list of aquatic animals.

If you want to read similar articles to Types of Orcas - Killer Whale Species, we recommend you visit our Facts about the animal kingdom category.

Bibliography
  • de Bruyn, P. N., Tosh, C. A., & Terauds, A. (2013). Killer whale ecotypes: Is there a global model? Biological Reviews, 88(1), 62–80. https://doi.org/10.1111/j.1469-185X.2012.00239.x
  • Krahn, M. M., Wade, P. R., Kalinowski, S. T., Dahlheim, M. E., Taylor, B. L., Hanson, M. B., ... & Waples, R. S. (2002). Status review of southern resident killer whales (Orcinus orca) under the Endangered Species Act. '
  • Morin, P. A., Archer, F. I., Foote, A. D., Vilstrup, J., Allen, E. E., Wade, P., ... & Harkins, T. (2010). Complete mitochondrial genome phylogeographic analysis of killer whales (Orcinus orca) indicates multiple species. Genome Research, 20(7), 908–916. https://doi.org/10.1101/gr.102954.109
  • Pitman, R. L., & Ensor, P. (2003). Three forms of killer whales (Orcinus orca) in Antarctic waters. Journal of Cetacean Research and Management, 5(2), 131–139.
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Types of Orcas - Killer Whale Species