Bottlenose Dolphin
Tursiops truncatus

These well-known marine mammals must surface to breathe air through the blowhole on top of their heads. Sleek, strong bodies allow them to swim great distances in search of food, and their social behaviors help them avoid predators, and improve their ability to catch prey and raise their young.

What They Eat
Dolphins primarily eat fish, and occasionally squid and shellfish. They use clicking sounds (echolocation) to track their prey. The sounds travel underwater until hitting an object, then bounce back revealing the object’s size, location, and speed. Employing many different feeding strategies, dolphins may hunt alone or in groups-often herding fish into a tight ball for easy feeding.

Where They Live
Bottlenose dolphins can be found in warm and temperate waters around the world. Many live near coasts where they may enter harbors, bays, lagoons, estuaries, and river mouths. Others live in large areas of open water offshore.

What They Do
Bottlenose dolphins live in groups of 2-15 animals called “pods.” Highly social, they often work together to capture food and raise their young. They can often be seen tail-slapping, surfing waves, playing chase, or leaping into the air.

How They’re Doing
Although their numbers have declined in some areas, bottlenose dolphins are generally considered common throughout the world's oceans. They are protected in U.S. waters by the Marine Mammal Protection Act of 1972.

Bottlenose Dolphin

Dolphins are actually small whales, belonging to the group known as 'toothed whales'. They have between 86 to 100 coned shaped teeth to catch and hold onto their prey.

Dolphins have 20/20 vision both above and below the water. They are able to see well in both environments due to specialized muscles that control how light bends as it enters the eyes.

Dolphins don’t sleep like other animals, because they must constantly rise to the surface to breathe. Instead, they rest one half of their brain at a time. This allows them to stay awake to surface and breathe, and to stay alert to approaching danger.

All dolphins breathe through the single blowhole located on top of their head. On average they breathe 1–3 times per minute, and can dive around 8 minutes before needing to resurface.

Every dolphin has a unique “signature whistle” used to remain in contact and help identify themselves to others.

Bottlenose dolphins routinely swim at speed of 3 to 7 miles per hour and they are capable of reaching burst speeds of 18 to 22 miles per hour. They can jump into the air as high as 20 feet.

Most dolphins dive to depths of 10 to 150 feet. However a dive to 1,795 feet was recorded under controlled conditions.

Helpful hints for viewing the animals

At the Minnesota Zoo, Discovery Bay’s indoor Dolphin Stadium is home to our Atlantic bottlenose dolphin family. Dolphin viewing is accessible from underwater in the Great Hall and from above in the upper amphitheater areas.

Why no dolphin shows?

• In cooperation with other facilities with dolphins, we are growing our dolphin population.
• April and Semo are healthy and active, but they are getting a little too old for many of the high-energy behaviors that have thrilled guests for years.

Bottlenose Dolphin

Care at the Zoo

Training animals can be a form of enrichment. For dolphins living in human care, training allows keepers to constantly monitor and care for the dolphins’ health, while providing the dolphins a rewarding environment that challenges them both mentally and physically.

Training simply put, is teaching. At the Minnesota Zoo, we train dolphins through operant conditioning, a type of learning in which an animal's behavior changes in response to the consequences that follow the behavior. If an animal considers the consequences following a behavior positive, the animal is likely to repeat the behavior.

Through positive reinforcement, the dolphins are rewarded every time they successfully exhibit a desired behavior. Rewards may include food, rubdowns, splashing the dolphins with water, verbal praise, or toys, and are often accompanied by the sound of a whistle. To encourage a positive relationship between the dolphin and its trainer, negative experiences (punishment) are avoided. We positively reinforce only desirable behaviors and simply ignore undesirable behaviors.

Because trainers can’t talk to dolphins, they communicate by using hand signals. Each hand signal corresponds to a specific behavior and the dolphins learn to discriminate between the different signals. If a specific hand signal is given and the dolphin does not respond or responds incorrectly, it is not reinforced. It doesn't take long for the dolphins to figure things out.

To train some behaviors we need to lead the dolphin through the behavior in steps. We can do this by training the dolphin to follow a target. The target is a focus point for the dolphin, something that directs the dolphin, usually our hand. A long stick with a float on the end of it (an extension of our hand) can also be used as a target for behaviors that take place farther away. Once the dolphin learns to follow a target, a variety of behaviors can be shaped. 

Dolphins can be fascinating animals to observe, both in the ocean and in a zoological setting. Unfortunately most people will never get the opportunity to see them in the wild. A public presentation with dolphins performing a variety of behaviors increases the public’s awareness of the unique abilities of dolphins, and provides education through entertainment.

Meet the Animals

“Semo”

Born: about 1965.
Semo has been at the Minnesota Zoo since 1991. Since then he has sired two calves, including Spree.

Distinguishing characteristics:
Semo is thought to be one of the oldest male dolphins in human care. In his mid-40’s, he’s an elderly dolphin no longer able to do the big leaps and fast swims of his prime years. He often takes on the role of the dominant animal, and can be seen chasing other dolphins or displaying a behavior called “jaw clapping.”

How to recognize him:
Semo is larger and darker than the other dolphins at the Minnesota Zoo. Up close, you might notice tougher skin and a relatively short rostrum (beak).

“April”

Born: about 1967.
April arrived at the Minnesota Zoo on January 14, 2008. She is on loan from the Brookfield Zoo in Chicago along with her daughter, Allie. April has given birth to three calves during her lifetime. Although she is elderly, she can produce offspring throughout her lifetime.

Distinguishing characteristics:
April seems to enjoy interacting with her trainers during enrichment sessions, and is often heard vocalizing during these interactions.

How to recognize her:
April can be spotted by the dark gray colorations on her back along with the dark markings on her head.

“Allie”

Born: 1987
Allie arrived at the Minnesota Zoo with her mother, April, in January 2008. She is on loan from the Brookfield Zoo in Chicago.

Distinguishing characteristics:
Allie is in the prime of her dolphin life. She can often be seen playing with the other dolphins and leaping out of the water.

How to recognize her:
Allie can be distinguished by her long, slender rostrum and light gray coloration.

Things you can do

You can protect all dolphins by helping to keep their environment clean. If you find trash floating at sea or on the beach, pick it up and dispose of it properly.

Carry a Seafood Watch Pocket Guide
Use these region-specific guides from the Monterey Bay Aquarium to help you choose ocean-friendly seafood wherever you live and travel.

Your visit to the Zoo helps support our conservation programs. You can also sponsor an animal at the Zoo.

 

 

Bottlenose Dolphin

Bottlenose dolphins are not an endangered species. They are, however, protected (as are all marine mammals) in U.S. waters by the Marine Mammal Protection Act of 1972. Threats to the species include pollution, habitat destruction, and accidental catches in fishing gear and nets, and human activities such as boating.

Things the Zoo's done/doing

Dolphins at the Minnesota Zoo are managed in coordination with six other facilities to promote breeding programs that ensure a diverse gene pool within zoos and aquariums. These seven organizations are known as the Dolphin Consortium and include: National Aquarium in Baltimore, Brookfield Zoo, Texas State Aquarium, Dolphin Connection, Indianapolis Zoo, Living Seas at Epcot, and the Minnesota Zoo.

 

Population Status

Bottlenose dolphins are not an endangered species. They are, like all marine mammals, protected in U.S. waters by the Marine Mammal Protection Act of 1972. Due to a lack of data, worldwide populations are unknown, but certain localized populations are depleted. Threats to this species include pollution, habitat destruction, and accidental catches in fishing gear and nets, and human activities such as boating. Human interactions of feeding and swimming with wild dolphins also pose a threat by altering their natural behaviors.

Bottlenose Dolphin

The most familiar of the 37 species of dolphins, bottlenose dolphins are named for their prominent bottle-shaped beak (rostrum). Their backsides are dark gray, their sides a lighter gray fading to a whitish to pink color on their underside. When seen from above or below, this counter shading helps camouflage them from predators. With a sleek, well insulated body, these powerful animals are designed for swimming long distances. Pointed pectoral fins aid in steering, broad horizontal tail flukes move up and down, propelling them through the water, and a single, curved dorsal fin on their back provides them stability as they move through the water.

Range and Habitat
Bottlenose dolphins live in temperate and tropical waters worldwide. Their distribution is generally limited to water with surface temperatures of 50°-90° F. They live in a variety of habitats, from coastal waters to the open ocean.

Diet
Active predators, dolphins eat a wide variety of fish, squid, and crustaceans such as shrimp, consuming approximately 4 to 6% of their body weight daily. Depending on the availability of food, dolphins employ different feeding strategies, including hunting their prey individually or cooperatively in groups. They will also chase fish onto mud banks or herd them into shallower waters where catching them is easier. Dolphins feed in association with human fishing as well. They do not chew their food, but swallow it whole. Larger fish are broken up by shaking or rubbing them on the bottom.

Predators
Some species of sharks (tiger, dusky, and bull sharks) and orcas will occasionally prey upon dolphins, however humans pose a greater threat either through harassment or accidental catches.

Social Groups
Bottlenose dolphins are very social animals and live in groups called pods. Several pods may also join temporarily to form larger groups of up to several hundred animals called “herds.” The size of a pod varies from 2-15 animals and may be composed of members based on age, sex, and reproductive status. Females with their young often comprise one group type. At three to six years of age juveniles leave the maternal group and form juvenile groups. Young male dolphins join bachelor groups where the young males form strong social bonds that may last their entire lives. Juvenile females will often return to the maternal group.