GOAL:

To develop an understanding of the interdependence of all organisms and the need for conserving natural resources

An adequate and continuous supply of soil, water, air, and energy are essential to the survival of living things.

Ecology O5.00 To understand methods and problems involved in wildlife preservation

5.01 define: endangered, extinct.

5.02 List reasons why species are becoming endangered.

5.03 List ways species can be saved.

I. Wildlife classifications
A. Endangered
B. Extinct
II. Destruction of natural habitats
A. Forests
B. Marshes
C. Stream channelization
D. Doming
E. Strip mining
F. Highway construction
III. Commercial hunting
IV. Introduction of alien species
V. Pollution
VI. Predator control
VII. Habitat preservation
VIII. Captive breeding
IX. Legal actions

GOAL:

To enable students to demonstrate the processes of science by posing questions and investigating phenomena through language, methods and instruments of science.

1.4 ANALYZING - Data should be examined to find patterns and relationships that may suggest cause and effect or support inferences and hypotheses.

1.4b - The accuracy and precision of data should be used to determine the selection or rejection of any given piece of data.

BENCHMARK: Accurate descriptions of observations enable students to compare results with others.

One instructional period

Endangered species, extinct species, protected species, poaching, wetlands

This lesson addresses Instructional Objectives 5.01 and 5.02.

The bald eagle is our national symbol. Has anyone ever seen a bald eagle? (pause) Why hasn't everyone seen one? Everyone has seen a robin or cardinal. Eagles are very rare. They are an endangered species. Today we are going to learn what endangered and extinct animals are and why they are becoming so and how we can save them.

Extinction happens when all members of species cannot adapt and disappear forever. Extinction is a natural event, part of the natural process of evolution and change. One of the most familiar examples is the demise of the dinosaur approximately 65 million years ago. Many other waves of extinction have occurred throughout the period of life an earth. Altogether probably 99% of all species that have even existed are now extinct.

Endangered species are defined as those species of organisms that are considered to be in immediate danger of extinction. In 1988, 300 to 400 species of mammals and 400 to 500 species of birds were listed as endangered. However these numbers are dwarfed by the numbers of endangered plants and smaller animals such as insects, mites, and worms. If the present rates continue, a total of one million species could become extinct by the year 2000.

Think of an animal. Draw a picture of where it usually lives in the natural environment. This is its habitat. No organism can survive if its habitat is destroyed. More than 3/4 of the species that are in danger of extinction today are threatened because their forest habitats are being destroyed. Tropical rain forests cover a mere 7% of the earth's surface, yet house 3/4 of its species, and the rain forests are being lost at an alarming rate. The destruction of habitat may be subtle. Even though there are millions of acres of forest in the U.S., almost all have been lumbered. When a forest is harvested for timber, trees are cut and removed before they die of old age and decay. The disruption of decay cycle disrupts the entire food web. The insects that feed on the rotting trees are a food source for other species such as the woodpecker. The ivory-billed woodpecker, once common in the southeast, is now believed to be extinct, a victim of current methods of timber management.

Also, damming, draining, and filling have destroyed many wetland areas, which, in turn, have resulted in wildlife and plant losses. Other signs of progress such as mining, highway construction, and buildings also disrupt the ecological balance.

When organisms are introduced into an area for the first time, the mechanisms that lead to a balanced ecosystem do not exist, thus introduction of foreign species, either by accident or on purpose to manage a problem, can cause species to become extinct. One example is the giant tortoise of the Galapagos Islands. When investigated, it was found some fishermen had introduced goats onto the islands. There were no predators for the goats and they multiplied rapidly and ate all the food that the tortoises had depended on for survival.

Has anyone been hunting? Was there a limit on the amount you could kill? Limits are set very carefully to preserve ecosystems. Overpopulation in the ecosystem causes starvation and disease. Managed harvests of wildlife resources do not disrupt biological systems. Wanton destruction may be harmful and can lead to extinction. In many countries, especially in poorer regions of Africa and Asia, enforcement of wildlife management programs has not been effective. Species that are hunted for commercial purposes because of their value are caught in a vicious cycle. The more they are hunted, the rarer they become, and the rarer they become, the more highly they are prized, and thus the more they are hunted. Some examples include hides from leopards, jaguars, and cheetahs which are used to make coats. Rhinoceros' horns are used for medicine. Rare birds are sold for pets. Plants such as cactus are removed from their habitats for personal use.

Another persistent conflict between humans and animals has been with predators, particularly the large carnivores. Humans have always been in competition with carnivores for food and they have also been feared as dangerous enemies. Farmers almost invariably believe that the benefits of killing predators outweigh the disadvantages. They see that the predators kill sheep or young cattle and may not realize that they also kill rabbits and mice which compete with the sheep and cattle for grass.

Pollution has grown to a global problem. Many ecosystems have been altered drastically by chemicals.

There are five major reasons species become extinct. Choose one and find a specific example of a species that has become extinct or endangered because of this reason.

"Here Today Gone Tomorrow," Project Wild, Secondary

This clasroom connector addresses Instructional Objective 5.03.

There are many endangered species and extinct species. Why should we care if there are no more bald eagles or green pitcher plant? Write on your paper your opinion about saving a species is important. (Pause) We are the losers when any species disappears. In most cases the dependency is hard to see, as when a little known plant is a vital link in a complicated food chain. Also we don't know which of the hundreds of endangered species may hold a new miracle drug, the seeds of a new food crop, or a product we haven't dreamed of yet. In nature, everything is linked together. When a species is wiped out, a link is destroyed. We never know how many links can be removed before an entire ecosystem collapses. Today we are going to learn what we are going to learn what we can do to save endangered species.

The most effective way to preserve species is to maintain natural habitats by establishing wildlife preserves, parks, or refuses. The first such park was 12,000 square kilometers, Kruger Park in 1895. Kruger Park preserves nearly 500 species of birds and 114 species of mammals, not a single species has been lost from this park since it was established.

In the late 1800's an entirely new concept in land management was initiated. There was a belief that certain areas are so special that they should remain permanently within the control of the federal government. In 1872, the system of National Parks was initiated with the establishment of Yellowstone Park. Parks are a very important part of habitat preservation. How many established parks can you name in your area. (List three on the board)

Federal lands are also controlled by the Bureau of Land Management and National Forest Service. The government originally owned these lands because people felt they were useless but now the government and society are in constant because people want to use these lands for commercial use. They want to use it for logging, mining, and recreation. Since there are valuable resources that are needed in these wild areas critics argue that national interests demand that these areas be exploited. As a compromise, The Wilderness Act, passed in 1964, set aside 54 special areas. In 1980, the total wilderness area was quadrupled by the Alaskan Lands Act, which established large tracts of wilderness areas in Alaska. (Investigate to see if there are specifically designated wilderness areas in our area.

More than three-quarters of the species that are in danger of extinction today are threatened because their forest habitats are being destroyed. The tropical rainforests cover a mere seven percent of the earth's surface, yet they house about three-quarters of its species. Worldwide attention has been drawn to the consequence of the destruction of the tropical rain forests.

Another main habitat in danger is wetlands. In the U.S. alone, half of our wetlands had been destroyed by 1985. Many people consider swamps and marshes to be areas of wasted, useless land. After all, you can't grow wheat or build a house in a marsh. They are a nuisance to hike through and are often choked with mosquitoes, gnats, and even alligators. In a recent survey, twenty-eight percent of the people in Florida thought the wetlands had no redeeming qualities and should be drained or buried with fill. Let's see if we can think of wildlife habitats in our area that need to be preserved? Another method of preserving species is through captive breeding. When a species becomes rare, biologists sometime capture some of the few remaining animals and attempt to breed them in captivity. Breeding in captivity may involve artificial insemination, farming out juveniles or eggs to females of other species to act as foster mothers and various other devices for increasing the number of offspring.

There have been many success stories with captive breeding. One of these is the American Bald Eagle. In 1979, there were 205 bald eagles counted in Tennessee, with 113 at Reelfoot Lake but none reported in 1961. The banning of DDT and successful breeding projects have been successful and the eagle is making a comeback. In 1986, Tennessee had at least seven Bald Eagle breeding territories, where eagles built one or more nests. According to computerized projectime, there is a potential for approximately fifty successful eagle nests within the Tennessee area of influence by the year 2002.

Supporters of the programs argue that it is better to maintain a small population in captivity than to allow a species to slide into extinction. Critics argue that it is difficult and expensive to induce many animals to breed in captivity and even if breeding is successful that their animals may not be able to cope with life in the wild. Some animals breed well in captivity while others do not. The life span of some animals is greatly increased. Here are some examples:

Species

Average Life Span

In captivity

Pheasant

9 months

8 years

Wild Turkey

24 months

12 years

Mule Deer

12 months

20 years

Golden Eagle

24 months

30 years

Black Bear

4-7 years

41 years

Several legal approaches have been used to preserve species. One is to enact laws regulating the killing of members of certain species, with severe penalties for breaking the law. For instance, in the U.S., the hunting of deer is controlled by allowing hunting only during a specific time of year and issuing tags to each person who applies for a hunting license. Fines await those caught with a dead deer without a tag or killed out of season. (Invite a wildlife officer to class to talk about hunting laws in your area)

Even strict penalties do not eliminate poaching if the products can be sold for a high price. In 1969, the hides of 113, 069 ocelots, 7,934 leopards, and 1,885 cheetahs were imported into the U.S. Conservationists realized that legal action was necessary. In 1975, 81 nations signal the Convention an International Trade in Endangered Species, which prohibits all trade of endangered species, which prohibits all trade of endangered species or their products, but the World Wildlife Fund estimates that illegal trade in plants and animals amounts to $2 to $5 billion annually. In the U.S., the Marine Mammal Protection Act of 1972 and the Endangered Act of 1973, have been passed to protect species in the marine and terrestrial environments. The Endangered Species Act states that it is illegal to import or transport endangered species or products of endangered species into the United States. It is illegal to sell an endangered species across a State line unless the buyer has obtained a special endangered species permit. (To see how the Endangered Species Act has been a major factor in the life of the average citizen, investigate the conflicts that arose in the building of the Tellico Dam or logging in the Northwest.)

As individuals we can help to save species through our knowledge of habitat preservation, captive breeding procedures, and laws regarding different animals.

This is the time this file has been accessed since 01/06/03.

The University of Tennessee at Martin is not responsible for the information or views expressed here.

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