Fun Facts

Do dolphins sleep?

Not really. Dolphins (and all whales) are conscious breathers. They have to consciously think about every breath they take, so they are never able to go into a deep sleep like people do.

For example, when we go to sleep, we don’t have to actively think about the breaths we take. That’s because we have a breathing reflex, which allows us to go into a deep sleep.

Since dolphins lack a breathing reflex, they can never go into a full deep sleep. Instead, dolphins shut one half of their brain down (letting it sleep), while the other side concentrates on breathing. So it’s more of a resting state, rather than sleeping. It is thought that they “rest” about 8 hours per day. They either rest at the surface of the water with their blowholes exposed or rest at the bottom in shallow water, surfacing periodically to breath.

Why do dolphins and whales spout water from their heads?

Dolphins and whale are mammals that breathe air with lungs. A whale's spout, or blow, is actually just the whale exhaling through its blowhole. So it is air, not water, being expelled from the lungs. Their nose is on top of their head. It is called a blowhole. With their “nose” on the top of their head, they are able to breathe easier when they come to the surface of the water –they don’t need to raise their entire head out of the water to breathe. When the animals go back under the surface of the water, the blowhole close to prevent water from getting in.

The reason you can see whales’ exhalation is because the whales body temperature is warmer compared to the cool air around them. Just like when you can see your own breath on a cold day, that is why you can see a whales’ breath.

Are dolphins smart?

Yes! Scientists believe that dolphins are extremely intelligent. It’s thought that the dolphin brain is, when compared to body size, second in size only to humans (2). Dolphins have very complex communication skills. For instance, it’s suggested that some dolphins have their own “language.” Bottlenose dolphins make specific whistling sounds to call other individuals in a pod, sounds which are thought to be similar to having a human name. This ability is especially important to moms that get separated from calves while they are off hunting for food. Aside from humans, dolphins are the only other animals known to communicate in this way.

Bottlenose dolphins have even learned sign language and computer-generated language! Not only did the dolphins understand simple language, but they could also understand sentence structure. It seems that dolphins have learned our language, but humans have still not been able to decode dolphin “language” – which species do you think is smarter?

Do all dolphins and whales have a dorsal fin?

Some whales have a dorsal fin. Some do not. For example, killer whales and humpback whales have dorsal fins. Beluga whales, gray whales, and North Atlantic right whales do not. Fins vary in size and shape depending on the kind of whale and individual. Scientists can identify some individual animals just by the color, pattern, shape, and scarring of their dorsal fin.

How does dolphin echolocation work?

All toothed whales (dolphins, porpoises, sperm whales, orcas) have the ability to echolocate, or create a type of sonar, which allows them to explore in an environment with very little light. They produce high frequency pulses and use their melon, a large organ that focuses the sounds, to direct the pulses into the ocean. These sounds hit objects (for example, fish), the sound echoes back. Dolphins can determine distance, size, and material of objects. They basically “see” with sound.

What and how much do dolphins eat?

Bottlenose dolphins eat mostly fish species, such as mackerel, herring, and cod as well as squid. How much a dolphin eats depends on many things: the size of the dolphin, the type of prey it is feeding on, the energy output of the dolphin that day, among many other factors. On average, an adult bottlenose dolphin, for example, will eat 4-5% of its body weight in fish per day. That means a 500 lb dolphin will eat 20-25 lb of fish per day. An adult mackerel weighs about 0.7-0.9 lb so a bottlenose dolphin would eat about 22-35 adult mackerel per day.

How long can dolphins live?

They can live up to 40-50 years, but the average lifespan is often around 20 years.

What is baleen?

Baleen whales, such as humpback whales, gray whales, and blue whales, do not have teeth. They have baleen. Baleen is made of keratin - the same protein that makes up our fingernails and hair. Each baleen plate overlaps the next. Baleen plates hang from the upper jaw of the whale, sort of like vertical blinds. Each plate is frayed on the bottom and sides. (It feels like thick plastic hair!) The fringed edges mat together and help trap food.

Right whales have the longest baleen (measure around 9 feet long). Before we had plastic, whales were hunted for their baleen (in addition to their blubber, which could be turned into oil) to make corsets, combs, and buggy whips.

Why do dolphins strand?

When an animal strands itself, it means that they come up onto the beach (also called beaching itself). There are two types of strandings: single and mass strandings. When a single animal strands, it's usually a sick or injured individual. When a mass stranding occurs, entire pods of dolphins (or other toothed whales) strand themselves. Some species of whales and dolphins occasionally strand in groups. No one really knows why mass strandings occur, but there are many theories. Since no one theory can explain them, it may be a combination of things that cause mass stranding to occur.

Here are just a few theories: 1) animals follow prey close to shore and then get stuck when the tide goes out, 2) dolphins may use the earth's magnetic field to navigate and animals can get disoriented and strand if the magnetic field is disturbed, 3) if one animal gets sick and strands itself, the other follow their sick pod-mate, and 4) underwater sonar technology (often used by the Navy) may cause inner-ear damage, from hearing loss to permanent damage (internal hemorrhages), to these animals that rely primarily on sound as means to communicate and navigate.

How deep can dolphins dive or hold their breath?

It depends on the species. For instance, inshore bottlenose dolphins (Tusiops truncates), on average, dive 23-43 ft (7-13 m) to the ocean bottom. Common dolphins (Delphinus delphis) can reach 853 ft (260 m) into the sea and hold their breath up to 8 minutes. However, on average they dive about 295 ft (90 m) and stay down for about 3 minutes. Pilot whales (Globicephala melas), another species of toothed whale, can dive up to 1,640-1,970 ft (500-600 m) and hold their breath up to 16 minutes.

The sperm whale (Physeter macrocephalus), the largest species of toothed whale, is thought to be the deepest diving mammal in the world! It can reach 1.2-1.9 mi (2-3 km) into the sea. It also can hold its breath for up to 2 hours! However, on average, they dive 1,300 ft (400 m) and hold their breath for about 45 minutes.

How fast are dolphins?

Again, it depends on the species. For example, Bottlenose dolphins can reach bursts of speed up to 30 mph (48 kph), but usually travel at about 3-6 mph (5-10 kph)

Can dolphins live in fresh water?

Yes! There are some species of dolphins, called river dolphins, that are adapted to freshwater. These species are found in Asia and South America. Some examples are the Indus river dolphin, the Amazon river dolphin, and the baiji. The tucuxi dolphin is the only species that can be found in both fresh and salt water.

Do dolphins drink water?

No. Even though dolphins live in water, the ocean water is too salty for them to drink. Instead of drinking water directly, they get all the water in their diet through the food they eat.