III. EXTINCTION

Background information

When people hear the word endangered, they usually think of a large and majestic species, like the Asian elephant, or a cute and cuddly one like the giant panda. While these animals are indeed endangered, the threat of extinction is not limited to the few species we recognize in pictures or zoos. The threat of extinction affects nearly every species on the planet.

Most people have a general idea of what an endangered, threatened, or extinct species is, but biologists have rather precise definitions for each term. An endangered species is a type of animal or plant that is in immediate danger of extinction. The species usually has a small population and needs protection to survive. The mountain gorilla, the Indian python, the lady lipper orchid, and thousands of other plant and animal species throughout the world areendangered.

Biologists use the word threatened to describe species that face serious problems butwhose populations are not in immediate danger of becoming extinct. Some examples ofthreatened species are the African elephant, the northern spotted owl, the eastern indigo snake.

Extinct species no longer exist anywhere in the world. The dodo, the passengerpigeon, and the dinosaurs are examples of extinct species.

3.1. The following texts are about different things that the WWF (a large international organization working to stop the destruction of the earth’s natural resources) has done. Read these texts and put in the words from the boxes. You may have to make some small changes.

Operation tiger

create left remain save

Seventy years ago there were 100,000 tigers in the wild. Today there are

not more than 8,000 …. In 1972 the World Wildlife Fund launched «Operation Tiger» to … the tigers that …. Eighteen tiger reserves have been … in India and

three in Nepal.

The last thirty oryx

almost hunter natural rare survive wildlife zoo (twice)

By the 1970s, … had killed … all the Arabian oryx. The WWF helped to capture the last thirty … oryx and send them to Phoenix … in Arizona, where a

herd of these … animals has been built up. Other … and … parks have helped,

and the oryx has been introduced into its … surroundings in Oman, Jordan and

Saudi Arabia.

The last thousand polar bear

Arctic alive fewer hunting increase live successfully

Thirty years ago … than 1,000 polar bears were left … in the wild in Norway, Greenland and the USSR. WWF persuaded the five … nations of Canada, the USA, Denmark (Greenland), the USSR and Norway, to agree to control … and promote scientific study. Now the «ice bears» are … and breeding … once again, and those 1,000 bears have … their numbers to about 5,000.

The seas must live

chemical death fur hunt in danger nuclear poison whale campaign

In 1976 the WWF launched its biggest international …, «The Seas Must Live». The seas are polluted by … pesticides, … waste and other … .

… are being hunted to extinction. Turtles are killed for their meat, shell

and oil, crocodiles to make handbags and shoes, walruses for their ivory. Seals are beaten to … to provide … coats. Many species of these animals are … of dying out. The WWF is working to provide sea sanctuaries where whales, dolphins and seals cannot be ….

The tropical forests

dam destroy encourage flood in danger international medicine protect supply

Tropical forests have … us with very many sorts of plants for food, … and industry. They could probably supply many more. They also reduce … and droughts, keep water clean, and slow down the Greenhouse Effect. But the tropical forests are being … to make room for things like farms, ranches, mines and hydroelectric …. About 20 million hectares are lost each year – an area more than twice the size of Austria. WWF is working to … and save the forests that are …; to plant new trees for fuel wood and to slow down the Greenhouse Effect; and to … governments to think about the forests and their importance when giving … aid.

(information supplied by WWF)

3.2. «Why Species Become Endangered».

– hunting animals for sport / for their fur / for food;

– poaching;

– overcollecting?

Other people-related problems that put plant and animal species at risk

include habitat destruction, introduction of exotic species, overexploitation,

pollution and others.

3.3. «Endangered Species».

Work in pairs. Each pair of students should concentrate on a different

passage (communication activities 2, 6, 9, 12, 16, 20). Use the information in

the passage to fill in the required information about your assigned species.

Then take turns giving summary reports to the class.

	Description	Habitat	Range	Population	Survival threat
Asian Elephant
Black Lace Cactus
Manus Island Tree Snail
Kagu
Leatherback Sea Turtle
Karner Blue Butterfly

3.4. Read the passage paying attention to the words and wordcombinations in bold type.

Humans are one of about 1.75 million identified species. Many scientists believe that millions more species inhabit our world yet remain unidentified. Some species have become extinct after less than half a million years, while other species have existed almost unchanged for many millions of years. Contrary to popular belief, extinction is a natural process. For hundreds of millions of years, extinctions have been occurring naturally, as part of the evolutionary process. Some extinctions have been caused by natural disasters, such as volcanic eruptions. Others have been the result of environmental changes, such as shifts in climate. Based on fossil record, the average rate of extinction has been one species out of every million per century. Sometimes extinctions occur on a very large scale, with hundreds or thousands of species becoming extinct over a relatively short time. An example of this is the dinosaurs and their contemporaries, victims of a mass extinction that took place at least 65 million years ago.

Although extinction itself is nothing new, the current high rate of extinction is. Today experts say that at least three animal and plant species become extinct every day, a rate much higher than any in the past 65 million years.

This worldwide endangerment of animals and plants is a phenomenon of the 20th century. It is a product of the continuing use of more and more natural resources for a constantly growing human population. Thus, many wildlife species become endangered because there is less wild space for them to inhabit.

Unfortunately, we are witnessing a great wave of extinctions. The current rate may be as high as several species per day. Among the species of most concern are those confined or endemic to a single island or group of islands. These «island» territories can also be cave systems, parks, and reserves that people have created.

When species are isolated, they are vulnerable to environmental changes and natural catastrophes. These are not the only causes of endangerment to species. Hunting and air, water and land pollution are also responsible for reducing species numbers. So, directly or indirectly, species are becoming threatened because of increasing human population.

– Use the words and word combinations in bold type in sentences of your own.

– Give a summary of the text.

3.5. Which of these statements do you agree with? Which do you disagree with? Discuss your opinion with a partner, and add any other statements that you agree with.

a) More animal reserves should be created and more work should be done to help endangered species to breed in captivity.

b) We can’t afford to worry about animals when millions of human beings are starving.

c) We shouldn’t be too worried about certain species becoming extinct, there are so many species which remain.

d) We are the main threat to wildlife; there should be much stricter laws to

protect the habitats of wild animals.

PS

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