Dolphin Facts and Information

Dolphins are marine mammals and are a part of the cetacean species which also includes whales and porpoises.

Dolphins can vary greatly in terms of their size and can range from 4 ft. (Maui’s dolphin) to 30 feet (the killer whale) in length and weigh anywhere from less than 100 pounds to as much as 22, 000 pounds.

Currently there are about 40 known species of dolphin in existence today, however some of the earliest known species of dolphin can be traced back as far as 10 million years.

Dolphins are known for being extremely intelligent and playful animals.

They are also known to be some of the most agile and athletic species known to inhabit the ocean.

In fact some species of dolphin have been known to swim as deep as 1000 ft, jump as high as 30 feet out of the water and travel as fast as 25 miles per hour.

Diet

Dolphins are known to eat a variety of food including, herring, cod, squid, plankton, and fish.

Most dolphins generally eat smaller aquatic lifeforms such as those named above, however a few dolphin species are known to attack and eat other marine mammals and larger prey.

For instance the killer whale (which is the largest of the dolphin species) will attack and consume seabirds, seals, sea lions and even whales.

Although dolphins have teeth many species tend to swallow their food whole, using their teeth mainly to catch and grasp their prey.

Physical Characteristics

Dolphins can vary greatly in size from the smallest dolphin (Maui’s dolphin) measuring in at around 4 feet and weighing around 88 pounds to the massive killer whale which can measure in at 30 ft and weigh more than 22,000 pounds.

Most dolphins have streamlined bodies which are designed for agility and fast swimming.

In order to swim dolphin’s use their tail is for propulsion while their fins help them stabilize, turn, roll and navigate through the water.

Dolphins are also born with a single blowhole used for breathing compared to baleen whales which are born with two blowholes.

Migration

Unlike whales most dolphins do not make huge migrations trips.

Some dolphins will migrate due to seasonal changes, but they usually don’t travel nearly as far as some whale species.

Dolphins typically prefer tropical climates, however they can be found swimming in colder waters as well, such as the killer whale.

Most dolphins belong to one of two ecosystems.

Coastal dolphins are typically smaller in size and prefer to stay near the coastline in shallow waters.

These dolphins make up the majority of dolphins.

The other type of dolphins are known as off shore dolphins which prefer to live further out at sea and away from the coastline.

While coastal dolphins prefer to stay closer to the coastline they are often limited in their travel rang while the larger off shore dolphins are more likely to migrate during seasonal changes or when their food migrates to a new area.

Social Structure

Dolphins are extremely sociable creatures, often traveling together in pods composed of 2 - 30 dolphins, however pod sizes can grow to be much larger during certain types of activities such as feeding or during certain social events.

Aside from communication and hunting for food large pods are also used as way to protect themselves against larger predators.

Dolphins communicate using a series of  clicking and whistling sounds, and through the use of body language such as leaping out of the water, slapping their fins against the water and bumping into one another.

These sounds and body language signals are used to communicate affection, warn other dolphins of danger and communicate a number of other important things.

Each dolphin has a unique frequency that allows other dolphins to distinguish which one in the groups is communicating and allows the mother dolphin keep track of her children, even when in large pods.

Another technique dolphins use to locate each other, find food and navigate the ocean is to use echolocation.

By using echolocation dolphins can tell how far the object is, if it is above or below them, how fast it is moving, if it is dense or hollow and how small or large it is.

Echolocation becomes extremely useful during times of low visibility such as during the night-time or when diving in areas where light is low or non-existent.

Breeding

The average gestation period (the time from inception to birth) for a female dolphin can range from 11 – 17 months.

Unlike whales that have a mating season and feeding season many species of dolphin can bear offspring year-long, although it is more likely that they will mate during the warmer months.

Dolphins have also been known to have intercourse during periods where they are not in their estrous cycle.

During mating season male dolphins can become increasingly aggressive and competitive and may even fight other males or herd off the female dolphin to limit her chances of becoming impregnated by other males.

Some male dolphins will even create factions where they’ll fight and fend off competing factions trying to mate with their females.

For dolphins that do begin mating and bear offspring female dolphins usually mature between the ages of 5 - 14, while males usually mature between the ages of 9 – 14, however as with their gestation period sexually maturity can range from 5 – 21 years depending on the species.

Female dolphins typically produce a single offspring every 2 – 6 years and will often raise their young for several years after they are born.

10 dolphin facts you may not have known about

  1. There are around 40 known species of dolphin in existence today.
  2. Despite being called a “killer whale” this marine mammal is actually part of the dolphin family.
  3. Because dolphins are marine mammals they are warm-blooded, produce milk, breathe air and bear offspring.
  4. Dolphins are part of the cetacean family which includes all species of whale, dolphin and porpoise.
  5. The average gestation period for a cetacean can vary from 10 – 17 months depending on the species.
  6. The killer whale is the largest of the dolphin species reaching lengths of up to 30 ft. and weighing up to 6 tons.
  7. Dolphins are capable of using echolocation to find food, navigate the ocean and avoid predators.
  8. Although dolphins are part of the toothed whale suborder not all dolphins use their teeth for chewing.
  9. All dolphin are born with one blowhole while baleen whales possess two blowholes.
  10.  Dolphins can vary greatly in terms of colors such as, black, brown, gray, yellow, pink and white.