Endangered Species ABC’s
(Adapted from Nature Scope - Endangered Species: Wild and
Rare)
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See Also How Many Bears Can Live in the Forest
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Standard Statement(s): 4.7.4 C - Define and understand extinction.
Content Objective(s): Students will be able to: Describe several threatened and endangered plants and animals. Assessment Strategies:
Background: THE BIG PICTURE Scientists have identified and cataloged more than one and one-half million of the species that exist on Earth today. By some recent estimates, at least 20 times that many species inhabit the planet. But we’re losing many of these plant and animal species even before they are discovered. Each year, more and more of the species we do know about become threatened with extinction. No Uncertain Terms: Most of us have a general idea of what an endangered, threatened or extinct species is, but biologists have certain definitions for each. In general, an endangered species is one that’s in immediate danger of becoming extinct. Its numbers are usually low, and it needs protection in order to survive. The giant panda, the whooping crane, the green pitcher plant and thousands of other plants and animals throughout the world are endangered. Threatened species – the red kangaroo, the eastern indigo snake and many others are those species whose populations aren’t yet low enough to be in immediate danger of extinction. They face serious problems, though, and are likely to become endangered if the problems affecting them don’t let up. Extinct species are no longer living. The Stegosaurus, the dodo and the passenger pigeon are examples of extinct species. A Natural process: Extinction is not a recent phenomenon. When you look at the history of life on Earth, it’s clear that extinction has always been part of the natural evolutionary process. As one group of plants or animals became extinct, for example, others often evolved. The "new" organisms may have out-competed the "old" ones with more efficient hunting skills, better defense tactics, or any number of other advantages. Natural disasters and major environmental changes, such as volcanic eruptions or shifts in the climate, also caused extinctions. Sometimes die-offs occurred on a massive scale, with hundreds or even thousands of species disappearing over a period of only a few million years (a short time, geologically). For example, the dinosaurs and many of their contemporaries were casualties of a mass extinction that occurred some 65 million years ago. |
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Extinction on the Rise: Although extinctions have been occurring naturally for hundreds of millions of years, the current rate of extinction is something new. Scientists estimate that the total number of species lost each year may climb to 40,000 by the year 2000, a rate far exceeding any in the last 65 million years.
This accelerated rate of extinction is directly linked to the human population explosion. The number of people on Earth has reached a phenomenal level – from fewer than one billion in 1600, for example, to about five billion today. Scientists estimate that there will probably be over six billion of us by the turn of the century.
Politics, People and Endangered Species: What’s the connection between endangered species and the rising human population? Many of the problems are pretty obvious. For example, more people take up more space – with their homes, shopping centers, farms, grazing lands and so on – and that means less living space for those species that can’t adapt to changing conditions. People also alter or destroy habitat to get lumber, minerals, oil and other products from the land. Pollution, illegal and excessive wildlife trade, introduced species and other people-related problems also take their toll.
The problems people create for other species are not always so obvious. Because the human world is parceled into separate nations, each with different priorities and interests, there are a variety of political, social and economic crises that affect all species. For example, in some countries where the standard of living is very low, endangered species are usually not a priority. Yet many of these developing nations have many threatened and endangered species that need help to survive.
To add to the problem, many multinational corporations and others exploit the resources in these less-developed countries. Government policies in affluent nations often support environmentally unsound practices abroad.
Worth the Effort: Although many people agree that the rising human population is pushing more and more plants and animals toward extinction, not everyone agrees on just how important it is to slow down the trend, especially considering that it can be very expensive and time-consuming to keep certain endangered plants or animals from becoming extinct and there are never any guarantees that the efforts will be successful. There are a lot of important reasons for helping endangered species recover and for preventing plants and animals from ever becoming threatened or endangered in the first place. Here are just a few:
A Moral Obligation – To some, the fact that people are responsible for the possible extinction of so many animals and plants is reason enough to save species from extinction. Each species represents thousands or even millions of years of evolution – but humans have the ability to wipe out such complex evolutionary "designs" almost overnight. Many people question whether this ability to abruptly "interrupt" evolution by causing so many extinctions gives us the right to do so. They feel that, as the source of the problems so many species face, we are morally obligated to do everything we can to help endangered plants and animals recover.
We’re All in This Together – The vitality of Earth is reflected in the variety of its inhabitants. So many species being in trouble is a sign that the planet isn’t as healthy as it could be. The more successful we are at maintaining or improving the living conditions of as many organisms as possible, the better our chances will be of maintaining or improving the quality of all species’ lives on Earth (humans included).
We Can’t Afford to Lose Them – The 30 million or more species of plants and animals living in the world today represent more than just a big number. They also represent an incredible variety of life forms. Within the three and one-half billion years or so that life has existed on Earth, animals and plants have evolved into millions of different shapes and sizes, developed a wide range of behaviors and taken up residence in every type of habitat on the planet.
This biological diversity has been extremely important to people in many different ways. Thousands of different kinds of plants and animals, for example, have been the sources of medicines used in treating cancer, heart disease and other illnesses. By cross-breeding wild plants with domestic ones, scientists have bred disease-resistant food crops that have improved and revitalized older, more vulnerable strains. The diversity of plants and animals has also been the source of a lot of the products we use every day: fibers, paper and plastics, to name a few.
Free Services – Biological diversity provides us with much more than products, though. It also provides us with a variety of special "ecosystem services," such as clean water, a breathable atmosphere and natural climate control. For example, as water cycles through a natural community, the plants and animals that live there continually add waste materials to the water. Decomposers in the community continually clean up the waste material by breaking it down into nutrients and incorporating them into their own bodies. This complex interaction of plants, animals and microorganisms maintains a constant supply of fresh water on the planet. Tampering with this complex system by eliminating certain plant and animal species could have serious consequences for worldwide water quality. Plants, animals and microorganisms also help remove natural and people-made wastes from the air, help prevent erosion and flooding and help maintain the balance of carbon dioxide in the atmosphere.
The Spice of Life – Preserving the diversity that has given us so much (and can continue to do so) is, in most scientists’ view, the principal reason for slowing the rate of extinction we’ve set in motion. Since most of the species that are estimated to become extinct each year are probably animals and plants that have never been identified, described or cataloged, we don’t even know what we’re losing. Many people feel that every time we lose a species, the world becomes a poorer place – and that the loss of diversity will ultimately make our own lives poorer too.
Procedures:
Hundreds of plants and animals around the world are threatened with extinction. In this alphabet activity, introduce students to the variety of wildlife that is in danger of becoming extinct. Begin by passing out copies of student pages to each person, along with 13 sheets of paper. Also provide glue, scissors, markers or crayons, paper punches and yarn. Explain that plants and animals pictured are either threatened or endangered. Also explain that not all turtles, butterflies, snails, etc. are in trouble – but the kinds shown are. (See What’s What for more about each of the plants and animals shown.) Then have students color the plant and animal pictures, cut them out and use them to make an alphabet book by following these directions:
Once students have made their booklets, tell them to draw the first letter of the plant or animal’s name next to each picture. Then go through the plant and animal names as a group, helping students learn how to pronounce each one. For older primary children, pass out the simple rhyme on student pages and have the students copy each rhyme underneath the appropriate picture. Afterward, go through the rhyme as a group.
Note: The only letter without an animal or plant is X. You can have students skip that letter or use that page to draw a picture of an extinct plant or animal and write the word extinct next to it.
Student Page – Copycat Page – ABCs Sheet #1
Student Page – Copycat Page – ABCs Sheet #2
