探秘海豚生活 Dolphin Life

2020-09-10 07:22:44曹雪
关键词:探秘捕食者海豚

曹雪

Dolphins live together in groups. These groups are called pods or herds.

A pod has up to 40 dolphins. A herd can have up to several hundred! Beginning at birth, each dolphin depends on other dolphins in the group for survival.

Baby Dolphins

When a dolphin is born, its mother and other dolphins take care of it.

A baby dolphin is called a calf. It is born underwater and usually comes out tail first. It can’t swim at first, so its mother pushes it to the surface to breathe. Sometimes another dolphin called an auntie, helps the mother to do this.

Calves stay close to their mother. When calves are hungry, they drink milk from their mother’s body. This is called nursing. A dolphin baby needs to nurse three to eight times an hour. It nurses for over a year. In just a few weeks, the calf will double in size.

When the mother is away hunting, the calf is often watched by an auntie dolphin or other adults in the group.

The calf stays with its mother for as long as six years. During this time, it learns about life in the ocean.

Communication

Dolphins use echolocation(回声定位) to communicate with each other. Each dolphin has its own special way of clicking and whistling.

Baby dolphins first learn to imitate their mother’s whistles. Later they develop a special whistle of their own. Dolphins learn to recognize each other by these sounds. When dolphins are together, the ocean is filled with the noise of their clicks and whistles.

Dolphins also communicate by touch. When the mother and baby swim together, they often brush against each other to make sure the other is close by.

If the calf doesn’t behave, the mother will push it to the bottom and hold it there a little while. Sometimes the mother even butts(用頭抵撞)the baby’s head to show it who’s boss!

Dolphin Play

Dolphins spend a lot of time playing together. They even seem to have “best friends.” They chase each other. They make circles in the water with bubbles and try to swim through them. They leap out of the water and fall back in. They slap their tails in the water to get attention.

Since dolphins like the waves boats make, they sometimes swim alongside boats.

Baby dolphins are especially playful. When they play, they throw seaweed at each other. They balance rocks on their flippers(鳍状肢). All this play helps them practice skills they’ll use later for swimming and hunting.

Hunting

Dolphins hunt together for fish and squid. By acting as a team, they catch a lot more food than they would alone.

Using echolocation, they communicate with each other about where the fish are.

Because fish are easier to catch when they are close together, the dolphins swim in circle around them. The fish move together in a big cluster. Then the dolphins move in for a feast!

Sometimes dolphins spread out in wide groups to catch as many fish as possible. They herd the fish into shallow waters or onto beaches and rocks, where they can’t escape. Using their strong flippers, dolphins can pull up to the shore on their stomachs and eat as many fish as they want.

Dolphins to the Rescue

Dolphins protect each other. When a dolphin is in danger, it sends out a distress call(遇险信号). Other dolphins come to the rescue! Sometimes a weak dolphin can’t get to the surface. Other dolphins help push it to the surface to breathe.

When a shark or killer whale threatens(威脅)the group, stronger dolphins make a protective circle around the weaker ones. Then they drive the predator(捕食者)away by butting tit with their hard noses.

Dolphins are wonderful creatures. They live and work together. They play together and take care of each other. They do many things people do. But the reason dolphins are amazing is not because they act like people. They’re amazing because they act just like themselves!

★Learn More

1. Calves learn to swim about 30 minutes after they’re born.

2. Baby dolphins are around three feet long and weigh 25-50 pounds when they’re born.

3. When the baby needs protection, the mother holds it close with her flippers.

4. To teach it her special sound, the mother whistles to the calf constantly (不断地;经常地)for the first two weeks.

5. Dolphins sometimes use their strong tails and sharp teethe as weapons(武器).

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