Background on Endangered Species

Extinction is forever.  It means the dying out of a species of any living thing.  It is the complete disappearance of a species from the Earth. Animals that are endangered are those in immediate danger of becoming extinct if something isn’t done to save them.  Threatened animals and plants are those that are greatly reduced in number in their natural range or ecosystem.

Fossils, which are the remains of prehistoric animals and plants, show that extinction have occurred throughout earth’s history.  Natural disasters, such as volcanic eruptions or changes in the climate, cause extinction. Organisms that cannot adapt to the changes die.

A large scale extinction occurred about 65 million years ago, when the dinosaurs died out.  One current theory is that a meteorite collided with the earth, creating a cloud of dust that encircle the earth for several years.  The cloud blocked the sun’s light and caused temperatures to fall, resulting in the death of many kinds of plants and animals.

Extinction has been occurring naturally for millions of years and it continues to do so today.  The current problem is that species are becoming extinct because of humans.  One reason is that there are more people on the earth every day.  More people require more space to live in and more natural resources, such as land to farm or build on.  Other organisms have to compete with people for space and natural resources.  People usually win.

Another way humans are endangering animals is by changing the environment.  Each species has special adaptations suited to its habitat.  If this habitat is quickly changed, the organism may not be able to adapt and so it dies. Look around your neighborhood.  The buildings for house and stores and the parking lots and streets cover land that was once the home of plants and animals.  Those not able to find new food and shelter die out.  

Extinction can also come about because of pollution. Again, the source of this problem can be people.  Examples of human caused pollutants that are endangering animals are as follows:

Pesticides are used to get rid of "pest" species, but the poison often harms more than just the pest.

Chemicals dumped into waterways not only affect drinking water supplies for people but can also poison birds, fish, plants and other life forms, as well as the animals that eat these organisms.

Oil spills in both fresh and marine environments threaten and have long lasting effects on the lives of many species.

Polluting gases from the burning of fossil fuels affect all living organisms.

Waste that finds its way into oceans, lakes, and ponds can e mistaken by animals as food.  Plastic and other waste items can be deadly to animals.

Some of the animals that are on the endangered species list include black-footed ferret, California condor, Northern spotted owl, Wyoming toad, Florida panther, manatee, Utah prairie dog, and burrowing owl.  An animal can be endangered in a portion of its range, such as the burrowing owl.  It is listed as endangered in California but is threatened in South Dakota.  Only specific species may be endangered.  There are four species of prairie dogs.  The black-tailed prairie dog native to South Dakota is not endangered.  However, the Utah prairie dog is.

Since 1994, Badlands National Park has been the site of the reintroduction of the black-footed ferret, the most endangered land mammal in North America.  Bred in captivity, these slender weasels are carried into the Badlands Wilderness Area on the backs of researchers and volunteers at night and released into selected prairie dog towns.  The black-footed ferret has become endangered because it has a very specialized diet: it only eats prairie dogs.  With the development of the West and the widespread poisoning of prairie dog towns, the black-footed ferret lost both its home - prairie dog towns - and its prey.  In the late 1970s, the species was thought to be extinct; however, in 1981, over 100 were found living in a prairie dog town near Meteetse, Wyoming.  Biologists were initially excited until canine distemper struck the population, killing all but 18.  The surviving animals were trapped and moved to a captive breeding facility near Laramie, Wyoming.  It is from these 18 animals that all the released black-footed ferrets have been produced.  Ferrets have also been released onto public lands in Montana, Wyoming, and Arizona.