Species: Orca (Orcinus orca)
Family: Delphinidae
FACT #1 What’s In A Name?
The Orca is a member of the dolphin family. Historically, Orcas were called ‘killer whales’. This was due to a mistranslation of the Spanish phrase ‘asesino de ballenas,’ which means ‘whale killer.’ Since the 1960s, scientists have been gradually replacing the name ‘Killer Whale’ with the name ‘Orca’.
FACT #2 Orcas Inhabit All Oceans
We tend to associate Orcas with cold waters, such as the Pacific Northwest, and it is certainly true that they occur in their highest densities in colder waters. However, Orcas inhabit all of the oceans around the planet. It is thought that the Orca is the second most widespread mammal on the planet, second only to humans.
FACT #3 Orca Isn’t A Single Species
We associate the Orca as a single species, but scientists think there are at least 3 to 5 subspecies or species. There may be more! The International Union For The Conservation of Nature has listed the Orca as data-deficient from a conservation viewpoint, pending confirmation of the number of species that exist. It’s important for us to understand this information as it will help protect them.
FACT #4 They Control Blood Flow To Their Organs
Orcas can control the flow of blood to their heart and brain. When they are diving, this capability is invaluable, as it prevents them from suffering from a lack of oxygen and maximizes their dive time.
FACT #5 They Have Large Brains
The Orca has the second-largest brain by mass, second only to the sperm whale. What’s fascinating, though, is the Orca’s cerebral cortex. The cerebral cortex handles higher-level brain functions like reasoning, thought, memory, language, and consciousness. The Orca’s cerebral cortex is thought to be more developed than a chimpanzee.
FACT #6 Orcas Have Baby Calves
When they are born, a baby Orca is an incredible 2.6m in length and 160kg in weight. A baby Orca is called a calf.
FACT #7 Grandmothers Are The Pod Leaders
A group of Orcas is called a pod, led by the grandmother. Unusually amongst animals, orcas stick together as families. Neither males nor females disperse from the family group. The leader of the group shares food amongst the pod and also takes responsibility for passing on knowledge about hunting techniques.
FACT #8 Orcas Live For A Long Time
The oldest documented Orca was a female named ‘Granny’. Original estimates put her at 105 years old, but more conservative estimates say between 65 and 80 years is more realistic. Scientists estimate that a lifespan of 50 to 80 years is typical for the Orca.
FACT #9 Orcas Echolocate To Hunt
Orcas use a process called echolocation to hunt for their food. They produce pulses of sound in the form of clicks. The sound waves reflect, sending a pulse back to them, which they interpret using specialized auditory nerves in their ear canals.
Using this technique, they can determine the size, shape, and location of objects in their environment. They can use this information not only to hunt but also to navigate.
FACT #10 Orcas Are Formidable Predators
Orcas are apex predators with a generalist diet that includes fish, squid, dolphins, sea lions, seals, rays, and whales. They are such formidable predators that they will even target other predators such as sharks!
Fact #11 Orcas Are Pretty Fast
When it comes to speed, the Orca is one of the fastest marine mammals in the ocean. Their top speed is a sprightly 30 mph, although they typically travel at a more leisurely speed of up to 6 mph.
FACT #12 Orcas Aren’t Persecuted By Mankind
The Orcas’ speed and the fact that their bodies are pretty streamlined have meant that they historically haven’t been targeted by mankind for their oil in the same way whales are. It takes 21 Orcas to yield the same amount of oil as one sperm whale. So Orcas are one of the few large mammals in the sea that haven’t been persecuted by us.
FACT #13 Orcas Evolved From Land Mammals
This might sound strange, but Orcas evolved from even-toed ungulates like hippos and deer. Over millions of years, they adapted to an aquatic-based lifestyle.
FACT #14 Orcas Have Formidable Teeth
Orcas have between 40 and 56 interlocking teeth, which they use to rip and tear prey into smaller pieces. Having said that, a lot of their prey is just gulped down whole, including sea lions and seals.
FACT #15 Orcas Are Pretty Big
An Orca can grow up to an impressive 9.8 meters in length and weigh a massive 5,500 kg. Their dorsal fin can grow up to 1.8 meters, which means just their fin alone is bigger than the average human!
REFERENCES
- Perrin, W.F., Wursig, B.G. and Thewissen, J.G.M. (eds) (2009) Encyclopedia of marine mammals. 2nd ed. London: Academic. [Accessed 24/05/2025]
