Dolphin - Animal Facts For Kids - Characteristics & Pictures

Common Bottlenose Dolphin - Photo: Andrea Izotti/Shutterstock

Dolphin / Common Bottlenose Dolphin Facts

Size	6.5-13 feet (2-4 meters)
Speed	21 mph (35 km/h) (short distance), 5 mph (8 km/h) (long distance)
Weight	330-660 pounds (150-300 kg)
Lifespan	20-45 years
Food	Fishes
Predators	Sharks, orcas
Habitat	Almost all oceans
Order	Whales
Suborder	Toothed whales
Family	Delphinidae
Scientific name	Delphinidae
Characteristics	Marine mammals with long snouts often leap out of the water

Main Characteristics

Dolphins are marine mammals. They are known for their acrobatic leaps out of the water, swimming in large groups, and hunting for fish. The most well-known among them is the bottlenose dolphin. Its most distinctive features include a long nose and gray skin.

Species

When people talk about dolphins, they usually refer to the bottlenose dolphin. However, there are about 40 species that vary significantly from one another in size, weight, diet, behavior, appearance, and color. For instance, the Risso's dolphin has a short snout, the river dolphin is pink and inhabits rivers, and the orca (which is also a dolphin!) is characterized by its black and white coloring.

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Dolphin Species - Photo: (LR-TB) alexandro900, (Shutterstock), Johann Georg Theron, Arun Vongtacome/Shutterstock

Fish?

Dolphins are often mistaken for fish. Perhaps it's because their bodies are as streamlined as those of fish, or because their fins look similar. However, dolphins are not fish; they are mammals that live in the sea. They differ from fish in that they have lungs instead of gills. Additionally, they give birth to live young, which they nurse. Fish lay eggs.

Whales?

Some dolphins have the word "whale" in their name, which can be quite confusing. For instance, the pilot whale, melon-headed whale, pygmy killer whale, false killer whale and the killer whale (orca) are also dolphins.

Common Bottlenose Dolphin - Photo: alexandro900/Shutterstock

Distribution and Habitat

Dolphins inhabit oceans except for the Arctic and Antarctic seas. They often stay close to shore but can also be found in the open sea. Some dolphins even live in rivers instead of the ocean.

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Lifestyle

Dolphins are not solitary creatures. They form large groups known as "pods". They are very social, maintain friendships, hunt together, and protect one another. Most are active during the day, although there are also nocturnal dolphins. Their activity patterns mainly depend on when they can hunt for prey most effectively.

Dolphin Characteristics - Photo: alekss-sp/Shutterstock

Anatomy and Appearance

Size and Weight

The smallest and lightest is the Heaviside dolphin, which grows to about 3.9-5.2 feet (1.2-1.6 meters) and weighs 88-132 pounds (40-60 kg). The largest and heaviest is the orca, reaching lengths of 20-26 feet (6-8 meters) and weighing nearly six tons. The common bottlenose dolphin typically measures 6.5-13 feet (2-4 meters) in length and weighs 330-660 pounds (150-300 kg).

Fins

Dolphins possess two pectoral fins, a dorsal fin, and a tail fin. The pectoral fins function like a steering wheel, allowing them to navigate, while the dorsal fin provides stability, and the tail fin acts as the "engine" propelling them forward.

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Teeth

The number of teeth varies by species. The common dolphin has 240 teeth, the bottlenose dolphin has 80, and the Risso's dolphin has only 14. The spinner dolphin has the most, boasting 252 teeth!

Color

Dolphins aren't always gray! River dolphins are pink, orcas are black and white, and both the Heaviside dolphin and the Commerson's dolphin share similar coloring. The common dolphin has a dark brown back.

Ears

Do dolphins have ears? Yes, but they lack the outer ear structures that we have. They possess very small ear holes, which is surprising considering they are among the animals with the best hearing.

Stomach

Dolphins have two stomachs. The first stomach stores food, while the second one is responsible for digesting it.

Dolphins Hunting - Photo: Shutterstock

Diet

Dolphins are carnivores. Their diet mainly consists of fish. Additionally, they consume squid and occasionally crustaceans. Large bottlenose dolphins require 18-33 pounds (8-15 kg) of fish daily, while orcas need about 485 pounds (220 kg). Orcas are the only dolphins that hunt seals, penguins, other dolphins, and small whales.

Behavior

Underwater

Diving

Dolphins can dive as deep as 1,970 feet (600 meters) – for instance, the Risso's dolphin. However, they typically do not dive that deep, as most of their prey is found at depths of 0-980 feet (0-300 meters).

Breathing

Dolphins cannot breathe underwater because they have lungs instead of gills. They need to hold their breath. They can dive for 15-20 minutes without breathing, but usually, they only stay underwater for a few minutes.

Jumping

Height

Dolphins can leap several meters out of the water. It is quite impressive to see them shoot upwards, twisting in the air or making a splash as they re-enter the water. The highest recorded jump of a dolphin was 26 feet (7.92) meters high.

Why Do Dolphins Jump Out of the Water?

Dolphins don’t just jump out of the water for fun. The hard impact on the water's surface helps them get rid of parasites that cling to their skin. Jumping is also used during hunting to startle their prey.

Water Needs

Do dolphins ever get thirsty? If so, what do they drink, seawater? Of course, dolphins need fluids, but they meet all their hydration needs through their diet. They do not drink seawater, as it is far too salty and would harm them.

Social Behavior

Assistance in Need

When a dolphin is sick or injured, or is giving birth, the others protect it. If necessary, they lift it to the surface so it can breathe.

Protection of Young

Dolphins lovingly care for their young, even if they are not their own. In every group, there are "aunts" who help keep watch.

Hunting Strategy

Most dolphins hunt together. They use clicking sounds to herd fish into a large school, increasing their chances of catching as many as possible. They employ echolocation to find fish in murky waters. River dolphins are the only ones that do not hunt in groups.

Defense

When dolphins are attacked by a shark or an orca, they stick together. While part of the group protects the young, the others attack and "ram" the aggressor. This way, they can even kill large sharks.

Are Dolphins Dangerous?

Dolphins are dangerous – to fish! For humans, it is quite rare. On the contrary, there are numerous reports of dolphins rescuing people in distress. For instance, they have guided boats through bad weather back home, pulled exhausted individuals to shore, or supported drowning people from below so they could breathe. There are even accounts of them protecting humans from sharks. Nevertheless, dolphins are wild animals. If provoked or threatened, they can become aggressive and may bite with their sharp teeth.

Dolphin Ear Close-Up - Photo: Alicia Chelini/Shutterstock

Abilities and Senses

Speed

Dolphins are fast swimmers. The bottlenose dolphin can reach speeds of up to 21 mph (35 km/h). The orca can swim at a speed of 34 mph (56 km/h). However, this is only when they are hunting or fleeing. Typically, they swim at a pace of 5 mph (8 km/h).

Sleeping

Dolphins must stay near the water's surface to breathe. After all, they are not fish with gills; they are mammals with lungs. So how can dolphins sleep and swim at the same time? The answer is that they activate the 'energy-saving mode' in one hemisphere of their brain - similar to a computer. This allows them to close one eye while performing simple swimming movements. Occasionally, a dolphin may 'forget' to surface for air. Fortunately, these animals look out for each other and gently nudge one another.

Sounds

Dolphins can produce over 100 different sounds. They chirp, click, whistle, shout, call, moan, grunt, squeak, and even make noises like creaking doors.

Can Dolphins Talk?

This question has only one correct answer: possibly. However, it has not yet been definitively established whether their sounds represent words or if they can form sentences, much like whales do. What scientists currently know is that slow clicking sounds and high-pitched whistles indicate contentment, while sharp, deep squeals express anger. Additionally, it is believed that they also use body language for communication.

Senses

Even though dolphins lack outer ears, they are still among the animals with the best hearing. They pick up sound waves through their jawbones and heads, transmitting the vibrations to their inner ears. Except for river dolphins, their vision is also well-developed, despite their small eyes.

Photo: Chase Dekker/Shutterstock

Intelligence

Dolphins are among the most intelligent animals on the planet. Here are a few examples:

• They call their peers by name.
• They recognize when their companions are in distress and assist them.
• They pass the mirror test and use tools.
• They share their knowledge with their young.
• When hunting, they coordinate their behavior with one another.

Life Expectancy

In the wild, dolphins can live between 30 to 50 years. Orcas can even reach ages of 70 to 80 years.

Enemies and Threats

Natural Enemies

The main natural predators of dolphins are sharks and orcas.

Humans

The greatest threat to dolphins comes from humans.

Hunting

Dolphins are killed because their meat is considered a delicacy. The Japanese coastal town of Taiji and the Faroe Islands have gained sad notoriety: each year, the waters in their bays turn blood-red as hundreds of animals are slaughtered. The meat is heavily contaminated with mercury and is far from healthy. Additionally, dolphin meat is used as bait for sharks, as their fins are also regarded as a delicacy.

Fishing

Dolphins are often found near fish, as they are part of their diet. Unfortunately, they become unintentional bycatch, getting tangled in fishing nets and drowning painfully. Want to make a difference? It’s simple: dolphins need fish for food, but we humans do not. Consider giving up fish. There are fantastic plant-based alternatives that taste similar and do not cause harm to animals.

Environmental Pollution

A significant threat to animal health is the increasing pollution of the oceans. Dolphins have alarmingly high levels of mercury, microplastics, and plasticizers in their bodies. This makes them ill. Their organs, especially the brain, heart, kidneys, and liver, suffer greatly. The reproductive organs are also damaged. No reproduction – no dolphins.

Dolphinariums

Dolphins are kept in zoos so that we can observe them up close. While they swim many kilometers daily in the wild, they must live in tiny tanks in dolphinariums. Their lives are quite monotonous, as there are no natural rocks, coral reefs, aquatic plants, waves, currents, or other sea creatures in the tanks. The water is also filled with chemicals to keep it clean. Additionally, the animals are forced to perform tricks, which they do because they have no other distractions. The confined space leads to stress, fighting, injuries, depressive behavior, and even miscarriages – ultimately resulting in an early death. What are your thoughts on dolphins being kept in zoos?

Are Dolphins an Endangered Species?

The bottlenose dolphin is (currently) not an endangered species. The river dolphins and the Hector's dolphin are particularly at risk.

Importance for the Ecosystem

Dolphins play a crucial role in maintaining balance in nature. They help prevent fish and squid populations from becoming too large.

Dolphin Calf - Photo: vkilikov/Shutterstock

Reproduction

Mating

Male dolphins attract females by performing special jumps, nudging them, or trying to play with them.

Gestation period

Depending on the species, dolphins have a gestation period of 10 to 18 months.

Birth

Dolphin calves are born underwater. They arrive with their tails first and are immediately lifted to the surface so they can breathe. During the birthing process, other dolphins swim protectively around the mother to shield her from potential attacks by sharks or orcas.

Raising

Depending on the species, dolphin calves are nursed for 12 to 20 months. During this time, they are taught how to hunt so they can catch fish independently.

Terminology

A dolphin baby is also referred to as a calf. The mother is called a cow, and the father is known as a bull.

Fun Facts

Can Dolphins Survive Outside of Water?

Two things are particularly tricky for dolphins: heat and their own weight. Imagine it's 41 degrees Fahrenheit (5 degrees Celsius) outside, and you're walking around in a thick winter coat, scarf, and hat. Now, you get on a plane and fly to a tropical country without being able to take off your clothes. What happens? Sooner or later, you would suffer from heat shock. Dolphins experience something similar on land. Their own weight is also a significant issue. In water, the pressure on their organs is different. On land, the animals are crushed by their own weight.

Animals in the Same Biome:

• Giant Oceanic Manta Ray
• Hammerhead Shark
• Lion's Mane Jellyfish
• Loggerhead Sea Turtle
• Sea Cucumber
• Seahorse

Sources:

• „Risso's dolphins perform spin dives to target deep-dwelling prey“ (https://www.guinnessworldrecords.com)
• „Highest jump by a dolphin“ (https://www.guinnessworldrecords.com)
• „Smallest dolphin species“ (https://www.guinnessworldrecords.com)
• „Largest dolphin species“ (https://www.guinnessworldrecords.com)

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