Before exploring the differences between dolphins and whales, it is essential to understand how the two are categorized. Dolphins are, perhaps surprisingly, all whales. Whales are divided into two suborders, baleen whales and toothed whales. Dolphins are part of the latter group. This group includes orcas, also known as killer whales.  

Whale swimming in dark waterDolphin
[Humpback] Whale (left) vs [Bottlenose] Dolphin (right) Visual Comparison


Main Differences Between a Whale and a Dolphin 

  • Appearance: Dolphins and whales have different body shapes. Dolphins are leaner with longer beaks, while whales are bulkier-looking. Additionally, all dolphins have relatively pronounced dorsal fins, while most whale species have small or no dorsal fins. 
  • Size: Whales are far larger than dolphins. The latter ranges from around six feet to thirty-one feet, while whales can reach nearly 100 feet in length. 
  • Habitat: Whales can be found worldwide, in all oceans regardless of temperate. Often, they spend the summer months at higher latitudes and then spend the next months traveling and breeding. Dolphins prefer to live in open oceans and warm, temperate waters. Some species even live in reverse. 
  • Diet: Dolphins are opportunistic feeders. This means that they choose prey that is easily available rather than being too selective in their diet. They usually eat fish, shrimp, small octopuses, and jellyfish, while whales are generally filter feeders. This means that they feed on plankton and krill. But, some species, like sperm whales, feed on larger prey and have diets more similar to dolphins. 

Whales

Whales are a diverse group of marine mammals. They can be found worldwide, in warm and cold oceans. There are eight living families of whales, including the right whales, grey whales, belugas and narwhales, and sperm whales. They are open-ocean mammals meaning that they spend the entirety of their lives in the open ocean (breeding, feeding, and raising their young). 

Humpback whale breaching
Humpback whale breaching


Whale Species 

Worldwide, there are two types of whales—baleen and toothed. There are seventy-seven species of toothed whale and only fifteen species of baleen whale. Some of the incredible whale species found in the earth’s oceans include: 

Baleen Whales:

  • Blue Whale 
  • Bowhead Whale
  • Right Whale
  • Humpback Whale 
  • Fin Whale
  • Grey Whale
The blue whale is a type of baleen whale
The blue whale is a type of baleen whale

Toothed Whales:

(As noted above, all dolphin species, including the orca, belong to the toothed whale group.)

Whale's fluke above water
Whale’s fluke above water


Appearance

Whales are large, powerful marine mammals that have long, heavy bodies. They have flippers on either side of their body, (sometimes) a small dorsal fin, a fluke or tail fin of varying size, and small eyes and ears. 

Whales are also known for their blowholes which allow them to breathe at the water’s surface. Like dolphins, whale species vary in size and appearance. For example, the smallest whale species reach less than ten feet in length, while the largest species can be up to or more than 100 feet long. The blue whale is famously the largest mammal to ever live on earth. Blue whale calves are around three tons and 25 feet long when they’re born.

Habitat 

Whales live around the world. Various species can be found in both warm and cold water. Some species, like the humpback whale, will migrate to and from their food supply in order to breed and raise their young, while others stay in the same region year-round. Unlike dolphins, whales only live in salt-water environments. 

Sperm whale diving with calf
Sperm whale diving with calf

Credit: Gabriel Barathieu


Communication and Intelligence 

Like dolphins, whales have a unique way of communicating. They speak through what is known as “whale song.” They create whistles and clicks that can travel for miles. These can generate an incredible 20,000 watts of sound. Scientists have noted some instances in which whales have attempted to mimic human speech. 

Whales are also regarded as one of the most intelligent species on earth. They can grieve, teach and learn, cooperate in groups, and understand human behavior. 

Whale's fluke above the water
Whale’s fluke above the water


Threats 

Historically, whales are one of the most threatened species on earth. Throughout the 18th and 19th centuries, whale hunting was a widespread and incredibly detrimental practice that was responsible for the near-extinction of various whale species. Some countries, like Norway, Iceland, and Japan, still engage in varying degrees of whale-hunting. But, throughout much of the world, bans are in effect in an attempt to allow populations to recover. 

Whales are also threatened by human-caused climate change, pollution, trawling, and habitat destruction.

Dolphins

As described above, dolphins are whales. All species of dolphin and porpoise are part of the toothed whale suborder. This includes the orca or killer whale. Below, you can explore some of the attributes common to these incredibly intelligent animals. 

Dolphin displaying body shape and blowhole
Dolphin displaying its body shape and blowhole


Dolphin Species 

Today, there are forty-nine different species of dolphin and porpoise in the world’s oceans. They can be divided into six families. The largest of these is the oceanic dolphin family. Some of the many species of dolphin include: 

  • Bottlenose Dolphin
  • Short-beaked Common Dolphin
  • Chinese White Dolphin
  • Atlantic Humpbacked Dolphin
  • Indo-Pacific Bottlenose Dolphin
  • Killer Whale (Orca) 
  • Long-finned Pilot Whale
  • Hector’s Dolphin
Characteristic dolphin smile
Characteristic dolphin smile


Habitat 

Dolphins spend most of their lives near the surface of the ocean. As mammals, they need to return to the surface to breathe, and they do so through their blowholes, positioned at the top of their heads. They live in all the world’s seas and oceans, around coastal areas, or even in shallower water. But, unlike whales, most species of dolphins prefer warmer waters. 

Pod of dolphins headed towards the surface to breathe
Pod of dolphins headed towards the surface to breathe


Diet 

Dolphins are opportunistic feeders and often utilize herding to gather together groups of fish. When the fish are herded into a small group, commonly known as a bait ball, individual members can swim through the group of fish, feeding as they please. 

Bottlenose dolphins and orcas have also been known to strand their prey on a beach to feed on it.

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

Dolphins, unlike baleen whales, make use of echolocation while hunting. 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.

Dolphin jumping out of water
Dolphin jumping out of the water after surfacing to breathe


Threats 

Like all species of whale, dolphins are at threat from hunting practices, trawling, entanglement with fishing gear (also known as by-catch), pollution, habitat degradation, and more. 

Trawling hauling in its nets
Trawling hauling in its nets


FAQs 

What is the difference between a whale and a dolphin?

The biggest difference, and the one that likely first comes to mind, is their size. Most whale species are far larger than dolphins. Whales also have very small or nonexistent dorsal fins, while dolphins are well-known for possessing distinctive dorsal fins that are sometimes used to tell the species apart. 

Are dolphins whales, yes or no?

Yes, dolphins are whales. But, not all whales are dolphins. There are two suborders of whales—baleen and toothed. Dolphins and porpoises belong to the toothed whale suborder. 

Do whales eat dolphins?

No, most whales are filter feeders. But killer whales (which are actually a kind of dolphin) have been known to eat dolphins. They are one of the ocean’s most formidable predators. 

Do whales eat humans?

No, whales do not eat humans. Whales usually eat small prey, like krill and shrimp. Only a few species eat anything bigger, like squid or fish. 

Do whales and dolphins get along?

There is some evidence that dolphins and whales get along. Generally, neither species is a threat to the other (besides orcas). They are both highly intelligent species and share many of the same needs when it comes to safe habitats.

Are dolphins smarter than humans?

No, dolphins are not smarter than humans. But, they do display a level of intelligence that far outranks most other non-human species. They can learn, communicate with humans, grieve, display empathy, and form relationships with humans.