It’s a whale! No, it’s a dolphin! Wait… Perhaps this question has never occurred to you. We tend to picture two very different looking animals when we think of a dolphin vs a whale, and the majority of you would probably say that you can decipher the difference. But there’s more than meets the eye…Spoiler alert, dolphins are in fact whales, or part of the whale family. Stay with us, this gets a little confusing. Scientifically, all whales, dolphins and porpoises are classified as Cetacea. And within Cetacea are two suborders: baleen whales and toothed whales. Baleen whales include the really big ones, such as blue whales and humpbacks. Toothed whales include dolphins and orcas, or killer whales, as they’re often known. In fact, orcas are the largest dolphins, growing to be about 32 feet (10 meters) long. Many dolphins only average eight to nine feet (2-3 meters) in length. So yes, orcas are dolphins, and dolphins are whales! This might blow you awayBecause they’re mammals, both dolphins and baleen whales need to surface to breathe, doing this through their blowholes. They’re also incredibly intelligent. Both animals can produce vocalizations to communicate, but since whales communicate mostly underwater, you might not be as familiar with their sounds as compared to those distinct clicks or whistles more commonly heard from dolphins. Dolphins also have the ability to echolocate, where baleen whales do not.
Despite their size, the interesting thing about baleen whales is they eat smaller food at a larger volume. In other words, they consume tons (literally tons) of krill or small fish, instead of a few larger fish. Dolphins, on the other hand, eat a variety of fish and crustaceans, like shrimp. The types of fish they eat depends on where the dolphins live and what’s available to them. Both dolphins and baleen whales often travel in groups. This is for safety, as well as to hunt for food. On average, dolphin pods can range from a few individuals to hundreds or thousands because of their very social nature. In contrast, humpback whales tend to be more solitary and travel with only one or two other individuals. Both species procreate less than other smaller animal—resembling humans in that regard. Dolphins and baleen whales only have one baby at a time, but dolphins give birth every two to three years, while baleen whales might go two to five years or more. In terms of gestation, most dolphins are pregnant for 10-12 months depending on the species, while orcas carry their calves for 18 months!
Family Ties and Physiology
First thing’s first: all dolphins are whales, but not all whales are dolphins. That’s because the Cetacean order of sea animals encompasses dolphins, porpoises and what we think of as whales. And Cetacean is derived from the Greek word for whale, ketos. It may sound confusing, but all dolphins are simply smaller types of whales. The whale order (Cetacea) is divided into several different families, one of them being Delphinidae (this includes all oceanic dolphin species). For example, Killer whales are the largest member of this dolphin family, so they are both a whale and a dolphin at the same time. Because they belong to the Cetacean order, dolphins and whales share mammalian traits like warm blood, hair, and lung-based breathing. Other physical similarities include fins on their tails called flukes, streamlined bodies adapted for swimming and, in some cases, dorsal fins on their backs.
Let’s Talk Teeth
There are two types of whales out there, baleen, or Mysticeti, and toothed, also known as Odontoceti. In mysticeti whales, stiff plates of baleen grow down from the gums of the upper jaw. These plates are perfect for filtering vast quantities of water and trapping all the plankton and other small creatures inside their mouths. When it comes to breathing, whales and humans alike are limited by their lung capacities. However whales’ lungs can hold much more oxygen than land-walkers, meaning they can stay under water for much longer before they have to come up for air. Whales also use blowholes to breathe—some even have two! The plankton-eating baleen whale has two blowholes, whereas whales with teeth have just one.
Whales and Wails
Toothed whales have the ability to echolocate. This means they emit various clicking sounds through the water and wait for the rebounding sound waves to indicate where their prey is. Echolocation also enhances their communication abilities. Baleen whales such as humpbacks and blue whales communicate through a series of “songs,” but not echolocation. When it comes to the loudness between whales and dolphins, the competition is tight. Dolphins’ clicks, whistles and pulsed sounds can reach up to 220 decibels. For reference, 150 decibels is loud enough to burst a human’s eardrum. However, the sperm whale’s echolocation clicks have been measured upwards around 230 decibels.
Sea of Smarts
Whales and dolphins share social patterns of communication such as teaching each other various hunting techniques, learning, cooperating with one another and even exhibiting ‘grief’ over lost members of their pod. Dolphins’ advanced communication abilities forge strong bonds within their pods, and dolphins have even been witnessed assisting injured or sick whales. One of the most impressive characteristics is the dolphins’ ability to call to each other using signature whistles. Dolphins use these unique whistles to communicate identity, location, and to address other individuals. We often use nicknames; perhaps dolphins use click-names.
What are the main differences between dolphins and porpoises?
The biggest difference is size, with all species of porpoise being that much smaller than their dolphin cousins. Porpoises don’t have the pronounced beak that most, but not all dolphins have and they also have different shaped teeth. Porpoise teeth are spade-shaped whilst dolphins are conical.
Are dolphins and whales endangered?
Like too many animals today, climate change and human encroachment are putting marine mammals in danger. Human-made threats like ship strikes and entanglement in fishing nets are pushing species to the brink of extinction. There are only 9-10 remaining vaquitas left in the world and the Maui dolphin in New Zealand has about 55 individuals remaining. With fewer than 360 individuals left, the North Atlantic right whale is also critically endangered.