If you were whale-obsessed as a kid you probably know that "killer whale" is just a dramatic name for an orca and that they're actually dolphins, not whales. But, did you know that there are more types of orcas than you ever thought?
Scientists are actually discovering new orcas all the time.
According to LiveScience there are four types of orca in the waters of Antarctica: Type A, B, C and D. And, there are three types of orca in the North Pacific: resident, transient and offshore.
But, the National Oceanic and Atmospheric Administration says those types can be separated into smaller populations. The organization notes, for instance, that there are four populations of resident whales each with "its own unique diet, behaviors, social structure and habitat."
And, NOAA's killer whale chart also seems to show four types per hemisphere with even those breaking down into smaller categories. (Small and large Type B in the southern hemisphere, and Type 1 and Type 2 Eastern North Atlantic orca in the northern hemisphere.)
There seem to be a total of 10 recognized forms under the single orca species.
Some of these new types were not even discovered that long ago.
According to Wired, when Type D orcas were first seen in the 1950s, scientists thought their bulbous heads, tiny white eye patches and curved dorsal fins were genetic abnormalities. Eventually other sightings were recorded to confirm their Type D status.
Per NatGeo, some scientists believe the preliminary genetic testing may even classify Type D as its own species.
NOAA reports that what essentially separates types of ocas comes down to how they look, what they eat, where their habitat is and what their behavior is like. And no types interbreed, despite some sharing waters, which makes them all pretty distinct.
You can read the WDC's (Whale and Dolphin Conservation) full list of what makes each type different here.
But here's a rough breakdown of the 10 forms:Resident
- Eat fish, especially salmon, and are called resident orcas because they establish living situations around fish populations
- They eat large mammals like seals and whale and travel large distances.
- These are not quite as well-studied but have been found eating fish and sharks. They're the smallest of the northern hemisphere types.
- Found around Norway, they can be seen hunting by slapping their tail into bait balls to stun fish. They have also been seen eating seals.
- These orcas eat whales and other dolphins and have downward-sloping white eye patches.
- These hunt minke whales and are the largest of the southern hemisphere.
- These whales hunt seals on the pack ice. You probably have seen their wave technique which washes seals off the ice and into the water. They also have a more yellow tint to their skin.
- These orcas are known to hunt penguins and are, of course, smaller than large Type B whales.
- These are the smallest southern orcas and have an upward-slanting eye patch. They eat fish, but more studies need to be done to determine more about them.
- The most distinctive of the ecotypes, these whales have blunt heads, small eye patches and short dorsal fins.
The WDC notes that other suspected ecotypes may exist and further research needs to be done to establish if the orca populations divide even further.
This is all cool and everything — who doesn't love a good orca — but having so many different types can actually be really important.
On the surface, it may seem as if the killer whale is thriving and living in all kinds of climates and eating all kinds of things.
But, now knowing there are different types and populations, LiveScience notes that scientists can better track how individual types of orcas are doing. Maybe one ecotype isn't faring as well as another, or one is doing super well.
Knowing how many kinds of killer whales there are can help researchers build a bigger picture of overall ocean health for this species and others.