Below, readers can explore some of the various attributes that orcas and dolphins share, as well as the ways in which they differ. They are both highly intelligent marine animals that are known to travel in social groups, exhibit playful and friendly behavior, and utilize hunting techniques like echolocation.

Orca jumping out of the waterBottlenose dolphin breaching
Orca (left) vs Bottlenose dolphin (right) Visual Comparison


The Main Differences Between an Orca and a Dolphin

Here are the top five main differences between the orca and the dolphin: 

  • Appearance: Orcas are black and white with a large dorsal fin, whilst dolphins are grey and sleek, with a longer beaked mouth.
  • Size: Orcas are much larger, at 6-8 metres long and up to 6 tons, compared to dolphins that range from 2-4m and 100-200kg.
  • Habitat: Orcas can be found nearly anywhere, but appear mostly around costal waters, just like dolphins.
  • Diet: Orcas eat fish and larger animals, such as seals and even dolphins. Dolphins feed on schools of fish, squid and jellyfish.
  • Lifespan: Orcas can live up to 90-100 years old, whereas dolphins can reach 50-60 years old.

We’ll explore these differences and interesting facts about the marine animal more below.

Orcas

What is an Orca? 

Orcas are black and white toothed whales and part of the oceanic dolphin family. They are considered to be one of the most powerful predators in the world and have few natural enemies.

Orcas have the second-heaviest brain among marine animals, second only to the sperm whale. They are considered to be highly intelligent, like dolphins, and even trainable. They are known to imitate others, teach skills to their young, and be incredibly curious and playful. They also have the ability to problem-solve. 

Despite their status as “killers,” they are not a threat to human beings. There has never been a fatal attack on a human being recorded. Nevertheless, some people still fear these large mammals. There are believed to be three to five subspecies, or species, of orcas. The main three are described below. 

Orcas swimming above the water
Orcas swimming above the water


Three Types of Orcas 

  • Resident: the most common type of orca. They live in the Pacific northeast and eat fish and squid. They live in complex pods, or groups, and the females have a rounded dorsal fin with a sharp corner. These orcas travel along the coast of British Columbia and Washington.
    Transient: these orcas feed on marine mammals and travel in smaller groups than offshore orcas, usually only between two and six per pod. Transient orcas live along the coast, with sightings in Alaska and California.
  • Offshore: the offshore population of orcas lives in the Pacific northeast and was identified in the late 1980s. They are differentiated due to their large scarred dorsal fins and have been encouraged along Vancouver Island.

Appearance 

Orcas are black and white animals known for their large dorsal fin that sticks straight into the air. (Interestingly, captive orcas’ dorsal fins tend to droop.)  Orcas have a patch of grey behind the dorsal fin, known as a saddle, and are mostly black on the top and white on the bottom, something known as countershading. They have blunt snouts, sharp teeth, and good eyesight above and below the water. 

Orca underwater
Orca underwater

They are capable of swimming quickly through the water due to their tapered bodies, something that makes them even more skilled and fearsome hunters. Most orcas are between six and eight meters or twenty and twenty-six feet in length. They can weigh up to six tonnes. The females are usually a bit smaller, weighing around three to four tonnes. At birth, juvenile orcas are around eight feet long and weigh around 400 pounds. 

There have been documented sightings of albino and melanistic orcas within the world’s oceans (or entirely white or entirely black orcas). 

Habitat 

Orcas are widely distributed, more so than any other mammal. They live in the coastal areas surrounding most countries and are capable of adapting to any climate. They can be found around the equator as well as in the waters of the North and South pole.

The highest density of whales, scientists believe, is located around the Norwegian coast, along with the Aleutian Islands, the Gulf of Alaska, and off the coast of Antarctica. Other common areas where the whales are spotted around off the coast of British Columbia, Washington, Oregon, Iceland, and the Faroe Islands.

Less frequently, these whales are spotted in areas around the Arabian Sea, the Mediterranean, the Gulf of Mexico, and the Persian Gulf. 

Diet

Orcas have a diverse diet. Some orcas only eat fish while others hunt larger prey, something that led to their name “killer whale.” They prey on mammals, like seals, as well as other dolphins. Orcas have even been known to attack larger whales, like baleen whales. This is not an easy task, though. It can take hours for a group of orcas to hunt and attack a larger animal. Usually, they’ll seek out weak members of a group or the young. They may drown a calf that they’ve separated from the mother and consume only parts of it. 

Orcas sometimes beach themselves to catch seals on land. Meaning they jump out of the water, land on the ice or shore, latch onto their prey, and drag it back into the water.

Amazingly, there was a documented case of a pod of orcas attacking a blue whale in 2018. 

Orca dorsal fin
View of an orca’s tall dorsal fin

Orcas are also known for their incredible echolocation abilities. They can detect the location and the characteristics of their prey, as other members of the dolphin family do. 

Reproduction 

A female orca gives birth to one offspring every three to ten years. It is partly due to this slow period of reproduction that the species is having trouble repopulating. Their gestation period is around seventeen months, and once born, the calf nurses for several times an hour for days until the child is weaned. Female orcas mature around ten years old and reach the height of their fertility around twenty. 

Orcas are one of the only animals that undergo menopause and still live for a period after they’re no longer able to have children. Also of interest is the fact that males are mature at the age of fifteen but don’t reproduce for several more years. They live shorter lives than females do, around 30-60 in comparison to 50-100. 

Orca jumping of water
Orca jumping of water

They are unique among marine animals for the complexity of their social structure. They have social bonds that are only part of the reason that keeping these animals in captivity is considered to be inhumane. They usually travel with as many as four generations. These groups are highly stable and matrilineal. 

Dolphin

What is a Dolphin? 

Dolphins are mammals. They are grouped into five families, the largest of which is the ocean dolphin, to which thirty-eight species belong. The remaining four are all river dolphin families with only one species per family. 

Dolphins jumping out of water
Dolphins jumping out of water

Often categorized as a whale, the orca is, in fact, a dolphin. It is one of the largest, along with the pilot whale and the false killer whale. According to Whale and Dolphin Conservation, the smallest is the New Zealand dolphin and tucuxi.

Dolphins are among the most intelligent non-human animals on the planet. Studies regarding their aptitude suggest that they are capable of mimicking, have self-awareness, solving problems, have empathy, and can feel grief, playfulness, and more. 

Appearance

Dolphins are slimmer and sleeker than orcas are. They can move at higher speeds through the ocean while hunting with longer beaked mouths. They also have a more pronounced smile or grin in comparison to orcas. Their teeth are shaped differently, and dolphins also have a curved or hooked fin on their backs, according to Live Science

Dolphin close up
Dolphin close up – notice how its head differs from that of an orcas

Dolphins also have a variable number of teeth, ranging from 14 up to 240 in the mouth of the spinner dolphin. The size of their teeth, as well as the position and shape, depends on their species. The majority of ocean dolphins have cone-shaped teeth used for catching fish. 

Diet 

Dolphins other feed by herding. This means that a pod surrounds a school of fish herding them into a small group, commonly known as a bait ball. Individual members swim through the group of fish, feeding as they please. Bottlenose dolphins, like orcas, have also been known to strand their prey on a beach to feed on it.

Common prey includes fish, squid, and jellyfish. Since dolphins are found around the world, they typically eat whatever fish they come upon. This may depend on the time of year as well.

Dolphins also make use of echolocation. This allows them to hunt via reflected sound or echoes. They can use this to find prey and learn important information about the size and other characteristics. 

Reproduction

Dolphins give birth to one calf at a time. Their pregnancies last between nine and sixteen months. The babies then stay with their mothers for several years, a time period in which the mother teaches the child everything he or she needs to know to survive. Dolphins can live between twenty and eighty years. 

Dolphins swimming underwater
Dolphins swimming underwater

Dolphins are highly social creatures, as orcas are. They spend time in large groups, sometimes between the hundreds to thousands, (but mostly smaller), and communicate through a series of whistles and squeals.

Threats to Orcas and Dolphins

Orcas and dolphins, like all marine animals, are at threat from industrial fishing, nets, pollution, chemical spills, sound pollution, and changes in ocean temperature. As large animals at a high trophic level, the orca and dolphin are at particular threat from toxins in the ocean. This is even more true for orcas that are sensitive to one particular toxin–polychlorinated biphenyls. It can accumulate in their blubber, something that is highly dangerous, especially when food is scarce and the whale metabolizes its blubber for energy. 

Dolphins underwater
Dolphins underwater

Estimates put the worldwide orca population at around 50,000 individuals. This is based on a 2006 study, according to Worldwide Distribution and Abundance of Killer Whales. 

Out of the forty-one species of dolphins, five are considered endangered by the IUCN. These are the Atlantic humpback dolphin, the Amazon River dolphin, the Baiji dolphin, the Maui dolphin, and the South Asian River dolphin. Hunting and bycatch are mostly to blame. 

FAQs 

Can a dolphin beat a killer whale?

Dolphins are one of the orca’s notable food sources. Orcas are one of the most powerful marine predators and are not a threat from any of the many species of dolphins.

What are orcas’ predators?

Orcas have very few natural threats. There are examples of sharks praying on these large predators, but it’s more common to see sharks fleeing from the sight of a pod of orcas. Orcas are far more threatened by human-caused oceanic changes.

Would an orca eat a human?

Orcas are incredibly peaceful animals. There are no recorded instances of an orca killing a human being in the wild. In captivity, it’s a different story. Various studies have focused on the inhumane and incredibly detrimental effects of keeping these highly intelligent and social animals in captivity.

Are orcas friendly?

Yes, there are numerous recorded instances of orcas exhibiting playful and friendly behavior around humans in the wild. They are peaceful animals that are considered to be highly intelligent.