In celebration of World Orca Day (which to us is every day!), here are 10 questions about killer whales that we often get asked on our tours.
Do we call them orcas or killer whales?
Most scientists, educators and policymakers prefer to call them killer whales because that’s what they are—the ocean’s top predator. Other people choose instead to use orca, which is derived from the whale’s Latin name, Orcinus orca . The irony of this choice is that Orcinus means “belonging to the kingdom of the dead.” And orca translates into “large-bellied jar or cask,” probably referring to their body shape!
How many killer whales are there in the world?
There are an estimated 50,000 or more killer whales around the world. Next to humans, they’re one of the most widespread mammals on the planet! Killer whales around the world are divided into separate ecotypes, each with its own geographical range, diet, language, social structure and slight physical variations. The Bigg’s killer whales we see on our tours are one of three killer whale ecotypes found off the BC coast!
How big are killer whales?
Sizes vary slightly among the different ecotypes. Off BC, the largest are the mammal-eating Bigg’s killer whales. Bigg’s females can be as long as 7 metres and weigh 5 tons. Males can be more than 8 metres long and tip the scales at more than 7 tons—the weight of about four cars! For all you dinosaur fans, that’s close to the estimated weight of a T. rex!
How long do killer whales live?
The average lifespan for a male killer whale is around 30, but he may live to 60 or more. Females can live to 50 and possibly 80 years or more. Why the difference? Female killer whales have menopause just like us! They stop having calves at around age 40 but may live for decades longer. One reason for this is the vital “elder” role that killer whale mothers and grandmothers play within their family group. Sound familiar?
How deep can killer whales dive?
They have many different dive patterns ranging from shallow dives of less than one minute to deeper dives of three to five minutes. They can hold their breath for up to 15 minutes. They typically dive no deeper than 300 metres, but they’re physiologically able to go much deeper and longer. One tagged killer whale in the southern Atlantic dove to an astonishing 1,087 metres, a world record for her species!
What do killer whales eat?
Globally, their diet includes almost 150 species of marine animals, including fish, seals and sea lions, dolphins and porpoise, sharks and rays, octopus and squid, seabirds, and other types of whales. But local populations tend to have strong cultural preferences. The Bigg’s killer whales we see off BC are marine mammal hunters. Seal, porpoise, sea lion, dolphin, elephant seal and small whales are all on the menu!
Do killer whales sleep?
Just like us, killer whales need their rest. But while we breathe automatically when we enter our “unconscious” sleep, killer whales are “conscious breathers.” They must think about each breath they take. How do they rest without drowning? They have a superpower! Half of their brain “shuts down,” while the other half remains active to regulate breathing and stay aware of their surroundings!
Do killer whales migrate?
Not in the classic north-south sense. In some parts of the world, they alter their regional travel patterns as their food supply shifts with the seasons. Here in the Salish Sea, the endangered southern resident killer whales are seasonal migrants. They follow the salmon! The mammal-eating Bigg’s killer whales enjoy abundant food all year along the coast. Which is why they can be seen anywhere, anytime of year!
How smart are killer whales?
They have the second largest brain of all marine mammals, after sperm whales. They also have more folds and wrinkles in their brains than any other animal on the planet—including us! That makes them very fast thinkers. And they have some highly developed brain features associated with emotional learning, long-term memory and self-awareness. That’s a lot of brain power. It suggests that they experience deeper thought and emotional intelligence that we can’t even comprehend!
Why do killer whales breach?
Only the breaching whale knows for sure. It may be sending a message to other whales nearby because the splash landing makes a lot of noise underwater. It could be taking a quick look around or playing. Or in the case of Bigg’s killer whales, celebrating a successful hunt. Or maybe—and this is our favourite answer—it’s breaching because it can and it’s fun!
Blog written by Eagle Wing naturalist Valerie Shore
Republished July 13, 2022
