What is the Definition of Endangered Species?

By Darlene Zagata; Updated April 24, 2017
What is the Definition of Endangered Species?

Endangered species are at risk of extinction. This means that they would no longer exist upon this planet. It is estimated that 40% of the earth's species are endangered. It is important that steps are taken to preserve these species as they are all important parts of our natural ecosystem.


The definition of an endangered species is a population that is in danger of becoming extinct. Several factors may be related to the decreasing numbers of a population which puts a species at risk for becoming extinct. These factors may include loss of natural habitat due to human expansion, hunting and depletion of prey species which are necessary for the endangered species' survival.


Whereas some species become extinct due to the natural selection of nature as may have been the case in the demise of the dinosaurs other species become extinct due to the depletion of natural habitat and resources through the carelessness and exploitation of humankind. There are are some species that have been hunted nearly to the brink of extinction; others have lost their habitat due to the destruction of forests and other natural areas where wildlife once existed in abundance. We are consuming natural resources at an alarming rate which is a process that is taking its toll on both the earth and the other species that inhabit our planet.


In 1973 the United States Congress passed the Endangered Species Act. This act prohibits the hunting of any species placed under this act as well as the destruction of habitat inhabited by the species. Species listed as Critically Endangered are at the highest risk of extinction. Those listed as Endangered are at a high risk of extinction. Species listed as Vulnerable could be facing the risk of extinction. The Endangered species act has been successful in preventing the extinction of certain species. If numbers increase sufficiently an endangered species may be removed from the protection of the Endangered Species List. The gray whale and bald eagle are examples of two species improving in numbers sufficiently to be removed from the Endangered Species List.


There are several factors determining whether a species remains protected under the Endangered Species Act or is removed. Those factors include breeding success rates, current threats and whether their numbers will increase over time. Environmental factors such as climate change have a huge impact on many species. Polar bears are an example of species affected by global warming. Each species on earth has its place in the ecosystem and each of those species helps to maintain the delicate balance of our ecosystem. With each species that becomes extinct our planet loses a little more of its diversity.


There are several species listed as endangered under the Endangered Species act. Among those species are the addax, cougar, clouded leopard, African wild dog, orangutan, ostrich, chimpanzee, cheetah, tiger, jaguar, ocelot, blue whale, gray wolf, giant panda, bactrian camel, bowhead whale, black rhinoceros and many others. It would be a terrible tragedy if these species disappeared from the earth as many have done before. It is important that we take steps to protect and preserve these and other species.


There are captive breeding programs in several places that work to preserve and increase the numbers of endangered species and reintroduce them to the wild. Many species are protected in controlled environments such as wildlife preserves. There are several organizations such as World Wildlife Organization that are dedicated to the goal of protecting and preserving these species. We can help endangered species by staying informed and supporting organizations that work to protect these animals. It is also important to mention that animals are not the only endangered species. There are plenty of plant species that are also endangered and their continued existence is important to our ecosystem as well.