With its 3-inch-long teeth and phenomenal hunting skills, the killer whale, or orca, is one of the ocean’s apex predators.
They’re so terrifying that even great white sharks stay well out of their way, abandoning their hunting grounds the moment a killer whale appears.
This predatory behavior aligns them with the shark, while their name suggests they belong to the same family as whales.
Although they have much in common with the whale, the reality is, killer whales belong to the dolphin family and bear little relation to the shark. Confused? Don’t worry, we’ll clear that up in no time.
Why Killer Whales Are Dolphins And Not Sharks?
Killer whales may behave a little like sharks, but that’s where the similarities end.
Sharks are cold-blooded fish with a skeleton made of cartilage rather than bone. Killer whales, on the other hand, are warm-blooded mammals with bony skeletons similar to our own.
Killer whales and sharks are both top predators that pursue similar prey species, including fish, sea lions, and other sharks, although their hunting techniques are very different.
While sharks are generally solitary creatures that hunt alone, killer whales work together, performing coordinated attacks similar to those orchestrated by wild dogs.
In these respects, they’re much more like dolphins than sharks. Like dolphins, killer whales also give birth to live young, but so do some sharks, so this isn’t a useful distinguishing feature.
There are a couple of characteristics that set the killer whale apart from sharks, and they are its teeth and breathing apparatus.
A shark goes through thousands of teeth in its lifetime, having up to 3,000 in its mouth at any one time. However, orca whales have just one set of teeth and, if they lose one, it’s not replaced.
Sharks never have to surface to breathe. Instead, like fish, they have gills that extract oxygen from the surrounding water.
Killer whales are more like other whales and have a blowhole on the top of their heads, which works similarly to a human’s nostrils.
Killer whales breathe oxygen into their lungs and then hold their breaths while underwater. They usually surface every 15 minutes for another gulp of air, but when traveling at speed, they may surface as often as every minute.
What Makes an Orca a Dolphin?
The killer whale’s official name is Orcinus orca, which roughly translates as a whale “of the kingdom of the dead.”
Although they belong to the same order as the whale, the Cetacea order, their teeth place them in the suborder Odontoceti, which makes them toothed whales. Other whales that belong to the same order include beaked and sperm whales.
Dolphins also belong to this order, which means they’re also technically whales, but have certain distinctions that separate them into a different family groups.
Killer whales, dolphins, and porpoises belong to the Delphinidae family, distinguished from other members of the Odontoceti suborder by their cone-shaped teeth, pronounced beak, single blowhole, and complex social organization.
The Delphinidae family has been referred to as a “taxonomic trash basket,” because it contains such a large and diverse number of species.
Nevertheless, there are similarities between the dolphin and killer whale that make it easier to understand why they’re both members of the dolphin family.
Like dolphins, killer whales are highly intelligent marine mammals that can adapt their hunting techniques according to their prey.
Killer whales have been observed storming the beach to catch sea lions, flipping great white sharks onto their backs to induce tonic immobility, and effectively drowning blue whales by preventing them from surfacing.
This wide array of hunting strategies is indicative of the killer whale’s intelligence.
Both dolphins and killer whales use echolocation to detect prey and communicate with one another. This enables them to coordinate their hunting strategies even when visibility is poor.
The ability to echolocate is related to a distinguishing feature that all members of the dolphin family share. They have a bulbous formation known as the melon on the top of their heads.
The melon is composed of “fat and connective tissue,” It focuses on high-frequency sound waves and projects them into the water in front of the orca.
This enables them to pinpoint the location of their prey and communicate that information to others in the pod.
Key Differences Between Orcas and Sharks
Orcas Are Bigger
Orcas are the largest member of the dolphin family, with the male orca reaching up to 32 feet in length and weighing as much as six tons.
Female orcas are a little smaller but they’re still larger than almost every type of shark, including the great white shark, or Carcharodon carcharias.
Great whites can reach 20 feet, but most average between 11 to 16 feet. They’re also lighter than the orca, weighing around 1,500 to 4,000 lb.
The great white shark appears to have cottoned onto its inferiority. A new study shows that white sharks near Southeast Farallon Island abandon their hunting grounds for up to a year whenever an orca appears in the area.
They have good reason to fear these black and white predators. Killer whales off the coast of South Africa have been seen targeting great white sharks and ripping out their livers with almost surgical precision.
Two killer whales named Port and Starboard have perfected the art of hunting sharks to such an extent that great whites seem almost absent from the area’s orcas frequent.
The pair have subsequently turned their attention to the bronze whaler shark which has capitalized on the great white’s absence and moved in.
Orcas Are More Intelligent
Not only are killer whales bigger than most shark species, but they’re also a lot smarter.
Orcas have the second largest brain of all marine mammals, second only to the sperm whale. With brains that weigh around 15 lb, the killer whale has a brain-to-bodyweight ratio similar to that of chimpanzees.
They can learn local dialects and teach one another specialized hunting techniques.
In comparison, a shark’s brain makes up just 0.008% of its total body weight, suggesting that it isn’t very intelligent at all.
That’s not entirely true, and there’s evidence to suggest that sharks can learn new skills by observing the behavior of others. However, even with this level of intelligence, the shark can’t begin to compete with the killer whale.
Its intelligence enables it to orchestrate complex hunting strategies that place it at the top of the food chain.
Orcas Eat More
In captivity, the average-sized orca eats between 150 and 300 lb of food a day.
In the wild, it’s suspected that it increases to around 500 lb due to them being more active. Sharks eat between 1% and 10% of their body weight each week.
That means the average great white with a weight of 2,750 lb would consume between 27.5 and 275lb of food per week, averaging just 3.9 to 39 lb per day.
The reason the orca needs so much more food than the shark is that warm-blooded mammals require a lot more energy in order to maintain a constant body temperature. Indeed, “mammals and birds require much more food and energy than do cold-blooded animals of the same weight.”
Conclusion
Killer whales and sharks are both natural predators that can be found throughout the world’s oceans. They are both at the top of the food chain and share similar prey populations.
Despite these similarities, the two species belong to two completely distinct family groups.
Sharks are cold-blooded creatures that extract oxygen from water, whereas killer whales are warm-blooded animals that breathe through a blowhole.
The killer whale’s status as an apex predator, along with its distinctive dorsal fin, means it’s sometimes confused with the great white shark, even though it’s a type of dolphin.
These amazing creatures share many of the dolphin’s distinguishing features, including its highly complex social structure and the ability to adapt hunting strategies according to the prey.
Although some marine scientists are now beginning to suspect that killer whales are the top predators in most ocean ecosystems, there’s been no known orca attack on a human in the wild.
They may terrify great white sharks, but there’s no reason for you to fear them.
Nicky is a British adventurer and animal lover who spends her time exploring the natural world and writing about her experiences. Whether on horseback, underwater, running, hiking or just standing with a fishing rod in hand, she embraces everything her adopted home of South Africa has to offer.