Original photo by sethakan/ iStock
There are a few common misconceptions about killer whales, such as how they’re often seen as bloodthirsty creatures that hunt humans. (They don’t — killer whale attacks are incredibly rare.) But the biggest confusion about these black-and-white ocean dwellers is right in their name: They aren’t really whales. The Orcinus orca is actually the largest species in the Delphinidae (aka dolphin) family, weighing as much as 350 pounds at birth and growing up to 32 feet long during its 30- to 50-year lifespan. But in comparison to most whales — like the 100-foot blue whale, the largest animal on our planet — orcas are relatively small. Biologists also group killer whales with dolphins because of their aerodynamic body shape, which helps them reach speeds of up to 34 miles per hour, and their use of echolocation for hunting and navigation.
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It's a factGetting a good night’s rest is a necessity for most animals, but dolphins have a tricky way of sleeping since they must remain conscious to breathe. By sleeping with only half their brain at a time, dolphins can stay somewhat alert, which helps protect them from predators and obstacles.
So why do we call them killer “whales”? The name stems from sailors of old, who witnessed the massive dolphins hunting whales (and other large marine mammals) together, and originally called them “whale killers.” Over time, the name was reordered, giving orcas a reputation as fierce and dangerous predators. These oceanic dolphins are clever hunters, known for beaching themselves to feast on seals and sea birds, and for working in pods to take down larger prey like great white sharks. But they’re also extremely social marine animals that spend their lives in matriarchal groups with as many as 40 members. Killer whales are so focused on community building that pods often host “greeting ceremonies” to meet members of other groups or welcome new babies, and hold aquatic funerals to mourn podmates. And the most reputation-busting research shows they might just like belly rubs.
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Whales and dolphins are ______, not fish.
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Whales and dolphins are mammals, not fish.
The U.S. military trains dolphins for special underwater missions.
Dolphins are known for their intelligence and use of echolocation, which is why the U.S. military has been training them as underwater operatives since 1959. Naval scientists first began researching bottlenose dolphins and how they swim in part to create better torpedoes, but quickly expanded to training, sending the first skilled dolphins to guard ships and perform surveillance in Vietnamese waters in 1965. By the early 1990s, the dolphin program — initially kept secret — was so successful that the U.S. Navy relied on more than 100 of the animals to transport tools to underwater crews and patrol naval bases in the Persian Gulf and elsewhere. The Navy’s Marine Mammal Program was officially declassified in 1992, but dolphins are still important military members. Their use of sonar (echolocation) makes them especially adept at mine-clearing tasks, in which they’re trained to distinguish (from a safe distance) between naturally occurring ocean features and human-made items that could be bombs, and then tag the locations for human divers to examine.
Interesting Facts writers have been seen in Popular Mechanics, Mental Floss, A+E Networks, and more. They’re fascinated by history, science, food, culture, and the world around them.
