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Nature's water lovers

Ellen Whyte

Beavers: nature's dam builders

Some animals spend half their lives on land, and the other half in the water. Scientists call these animals semi-aquatic. One of the most famous semi-aquatic animals is the beaver.

Beavers are nature's dam builders. Last year Canadian beavers built an 850-metre-long dam in northern Alberta. Their American cousins built one in Montana that was 650 metres long, 4.3 metres high, and 7 metres at the base. The Tsing Yi Bridge is only 610 metres long.

Beavers create dams by felling a big tree and wedging it across a river. They then drag in more trees and driftwood to create a wall. Any remaining holes are plugged with stones and earth.

The pond behind the dam is perfect for growing grasses, water lilies and other aquatic plants. These are the beaver's favourite foods. The pond is really the beaver's farm and food cupboard.

Beaver ponds keep wetlands clean, help clean polluted water, and are good breeding places for salmon and other fish. But critics worry when beaver dams flood farmland.

Would you like to live near a beaver dam?

True or false?

1. Semi-aquatic animals spend all their lives in the water.

2. Beavers live in Europe and North America.

3. Big beaver dams are longer than the Tsing Yi Bridge.

Hippopotamus: African river masters

Choose the correct alternative:

Hippos live in rivers and lakes in sub-Saharan Africa. They are tiny/huge animals. An adult hippo can be 5 metres long and weigh 4,500kg.

Hippos spend most of their day in the water. Even though they are very big, hippos can be hard/easy to spot. Only their eyes, ears, and nose stick out of the water. When the sun goes down, the hippos come out of the river to eat grass.

Male hippos have river territories. The females they mate with live in these territories. Male hippos allow/forbid other males to swim in their territory, but only if they are respectful. If a visiting male hippo tries to mingle with one of the females, there will be a fight!

Giant otter: edge of extinction

Find words that mean the following:

meat eater, to take care of babies, widespread

Giant otter live in slow-moving rivers and lakes in Central and South America. They are carnivores that hunt fish, crabs, small birds and small mammals.

Male and female otters mate for life. They live together with their babies in family groups. Female otters give birth every year to one or two babies. Young otters live with their parents until they are old enough to start their own families.

Giant otter families hunt, eat, sleep and defend their territory together. The older otters baby-sit younger brothers and sisters. When they have time, giant otters play together. Giant otters used to be common. But hunting and habitat destruction have killed so many that there are now less than 5,000 left.

Hong Kong river mammals

The Eurasian otter is easy to recognise as it looks like it's wearing a coat and sweater. This protected animal has a black face, back and tummy with a creamy coloured throat.

The otter hunts mainly at night, searching for fish, birds, insects, frogs, crustaceans and sometimes small mammals. Look for it in Maipo Inner Deep Bay Ramsar Site and nearby areas.

Feral water buffalo also spend a lot of time in the water. They wallow to keep cool, and to keep flies away. And they seem to enjoy lying about in the river, too.

At dusk, dawn, and at night, these animals are more likely to be grazing on land. So look out for water buffalo in ponds and rivers during the day in Kam Tin, and the southern part of Lantau Island.

Capybara, world's biggest rodent

Find the antonyms, words that mean the opposite of:

smallest, old, very bad

Capybara live by lakes and rivers in the northern half of South America. They are about one metre long and weigh 80kg. Although their name means 'water pig', capybara are rodents. They are the largest rodents in the world.

Capybara live in herds of about 25 animals. The chief male mates with the females in the group. When young males want to breed, they have to challenge the leader.

Capybara are crepuscular, which means that they are active at dawn and dusk. They eat grass, grain, fruit and vegetables.

While capybara are eating, they keep an eye out for predators. If one appears, they dive into the water. Capybara are excellent swimmers. They can also stay underwater for five minutes. When they're not hiding from their enemies, capybara also swim to keep cool.

fab fact!

In the past, scientists thought hippopotamuses were members of the pig family. But today we know they are more closely related to whales and dolphins

fab fact!

Elephants are excellent swimmers. They have webbed feet, which makes swimming easy. Plus, they use their trunks as snorkels

compare!

Hippos, capybara and champion divers Herbert Nitsch from Greece and Tanya Streeter from Grand Cayman can stay underwater for up to six minutes. Otters can dive for eight minutes and beavers for 15

now do this

Try to answer the following questions without referring to the text

1 Giant otters live in ...

a. North America and Europe

b. Central and South America

c. Europe and Asia

2 Giant otters are ...

a. carnivores (meat eaters)

b. herbivores (plant eaters)

c. omnivores (meat and plant eaters)

3 Hippos live in ...

a. South America

b. Asia

c. Africa

4 Hippos are ...

a. carnivores

b. herbivores

c. omnivores

5 Capybara live in ...

a. South America

b. Asia

c. Africa

6 Capybara are ...

a. carnivores

b. herbivores

c. omnivores

Look online for more information

Giant river otters

Quick facts, videos, pictures and news about giant otters. Click on A-Z and check out hippos, beavers, and water buffalo, too.

Smithsonian National Zoo

Quick facts, photos as well as lots of videos of hippos, capybara, beavers and otters.

Simple Wiki Capybara

Pictures, a map and quick facts about the capybara. Check out other animals by entering otter, hippo and so on in the search box.

Nat Geo Wild

You can find out more about hippos and otters on Nat Geo Wild's Hippo Hell ( tomorrow at 6pm and Friday at 12pm) and Mission: Giant Otters (Friday at 6pm and Saturday at 12pm)

Answers:

April 22

True or false: T, F, T

Antonyms: near, enemies, normally

Synonyms: coarse, cuddle, herbivores

Fill in the gaps: boars, leaves and fallen fruit, sunburn

Quiz: 1. a, 2. c, 3. b, 4. c, 5. c, 6. a

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