Endangered species are living things whose population is
so reduced that they are threatened with extinction.
Thousands of species are included in this category. The
International Union for the Conservation of nature and
Natural Resources publishes a list of threatened mammals,
birds, reptiles, amphibians, and (many people don't
consider them) plants.
CAUSES OF EXTINCTION
Millions of years before humans, extinction of living
things was linked to geological and climate, the effects of
which were translated into major alternation of the
environment. Environmental change is still the primary
cause of the extinction of animals, but now the changes are
greatly accelerated by humans activity. Clearing land for
farms and towns, lumbering, mining, building dams, and
draining wetlands all alter the environments so extensively
that ecosystems may be completely destroyed. With a
burgeoning human population requiring food, shelter, and
clothing and constantly demanding more energy-using
devices, the temperation to exploit land for human use
without regard for consequences is great.
Frequently, several forms of environmental change are
responsible for the disappearance of species. For example,
as tropical forests are cut down, primates have
progressively smaller feeding and living spaces. They also
become more accessible to hunters, who kill monkeys for
food and trap many primates for sale as pets, research
animals, and zoo specimens. Some animal species may move
into human communities when their own are destroyed.
Extermination of marauding monkeys, roaming tigers, or
foraging deer is easy to justify by people whose livelihood
Pollution is another form of environments change. Forty
species of birds in the United States, including peregrine
hawk, bald eagle, pelicans, and roseate terns, lay
thin-shelled as a result of ingesting degradation products
of and some other chlorination hydrocarbon insecticides
that make their way into the food chain. Species of
salamanders in New England are dying out because the ponds
in which they breed and the moist soil in which they must
live are watered by acid rain (water that combines with
pollutants in the air to form acid, sulfuric acid, and
other corrosive compounds. Industrial waste dumped in the
Mediterranean have so depleted the oxygen supply that some
species of bacteria that decompose sewage have been wiped
out and the nutrient cycles disturbed. Even the ocean
environment has been altered by dumping.
Many species have been exterminated or endangered as a
result of humans killing the individuals for food. The
Hawaiian state bird, the none (a type of goose), is almost
as easy to catch a the legendary do do and nearly met the
same fate. The 22 finds of clams and 30 kinds of fish
imperiled in the United States are probably all endangered
by varying combinations of naturally changing environments,
pollution, and over-harvesting.
Whale species are on the endangered list. Whaling is often
justified as supplying a source of protein for protein-poor
populations. Actually, whales supply only 1% of the protein
needs of any countries, such as Japan, that is actively
engaged in whaling. In the soviet Union, whaling meat is
used to feed animals that are raised for their pelts, such
as sable and mink. Thus, the wearer of a ranch-raised
Russian sable coat may have indirectly contributed to the
ultimate disappearance of the great whales.
Many species have been hunted to the point of extinction
for their fur, hides or feathers. These include the big
cats, alligators, kimonos, quetzel birds, eastern gray
kangaroos, egrets, and bids of paradise. Many people and
groups have taken measure to stop the killing of endangered
species. Whether the species were killed deliberately, or
if by accident (in a oil pill) these groups are trying to
stop the killing. In conclusion I just want every one to
know that endagered species can be as big as a blue whale
or as small as a tiny little ant.
"Endagered Species," Grolier Encyclopedia, VII (1993),1-6.
Gore, Rick. "The March Toward Extinctotion." National
Geographic,CLXXV (June, 1993), 662-698.
Smith, Robert J. Endagered Species. Ed. by Derek Clien. New
York,New York; Scholastic Inc., 1998 pp.1-