What Is Actually The Definition Of An ‘Endangered Species’?

Nearly everyone has heard the term endangered species. But what is the exact definition of the word? How do species get placed on the endangered species list and, perhaps more importantly, what does it take to get them off the list?

Endangered species: a definition

According to National Geographic, the definition for an endangered species is a “type of organism that is threatened by extinction.” This includes plant and animal species. However, endangered species don’t generally become threatened out of the blue. The two main reasons why species become endangered are loss of genetic diversity and loss of habitat. Nearly 65,000 species are categorized by impending threat of extinction on the IUCN Red List.

The IUCN Red List

Founded in 1964, the IUCN (International Union for Conservation of Nature) Red List of Threatened Species assesses the threat of extinction for thousands of species and subspecies around the world.

The list categorizes species as follows:

  • E (extinct)
  • EW (extinct in the wild)
  • CR (critically endangered)
  • EN (endangered)
  • VU (vulnerable)
  • NT (near threatened)
  • LC (least concern)

Examples of critically endangered animals include the Black Rhino and Orangutan. Black Rhinos are mercilessly hunted by poachers seeking their horns, which fetch a high price in many Asian countries, such as Vietnam, where they use rhino horn in many folk remedies.

A baby black rhino walking next to its mother in the grass.
Black rhinos are critically endangered due to excessive poaching. [Image by Star Max 2/AP Images]

Orangutans move slowly, which makes them an easy target for hunters who kill them for their meat or in revenge for damage the animals caused to their crops. Females are hunted more often than males, and their babies are captured and kept as pets, with many of them dying during transportation or in captivity.

Endangered species include the blue whale, the snow leopard, chimpanzees and sea lions.

Loss of habitat: a definition

When we hear loss of habitat, most of us probably think of man-made problems, such as deforestation and pollution. However, loss of habitat can also happen naturally. For example, the Tyrannosarus rex and other dinosaur species couldn’t adapt to the sudden change to a colder climate, most likely caused by a giant asteroid colliding with the Earth. The results? These gigantic lizards became endangered and, eventually, extinct.

Today, industry, development, and unchecked agriculture are the biggest culprits in robbing species of their natural habitat. A critically endangered species due to loss of habitat is the mountain gorilla. Humans have encroached on the habitat of mountain gorilla, even in supposed protected areas, like the gorilla habitat in Virunga National Park in the Democratic Republic of Congo.

Although the future still looks dire for mountain gorillas, conservation efforts have made a noted difference. In 1989, just 620 mountain gorillas lived in the wild. Today, that number has increased to around 880.

Loss of genetic diversity: a definition

Genetic diversity describes how much genetic variety is present within a species. For the survival of a species, high genetic diversity is important because it helps the organism to adapt and, for example, overcome environmental changes. In many cases, threatened species have low genetic diversity, probably due to the inbreeding caused by smaller populations.

A species well-known for low genetic diversity is the cheetah. In 1983, when a deadly virus spread through an Oregon breeding colony for large cats, it wiped out fifty percent of the cheetah population but left the lions unscathed. Scientists believe this was likely due to the cheetah’s low genetic diversity, and conservation efforts are currently underway to help ensure the feline’s genetic diversity does not decrease any further, which could threaten their survival.

Recent news

Several endangered species have made the news in recent months. One of them is officially no longer considered endangered. As of March 2017, the status of the Manatee has been downgraded from endangered to threatened. However, not all conservationists are thrilled with this definition. In USA Today, Jaclyn Lopez, director for the Center for Biological Diversity in Florida, mentioned that 2016 was among the deadliest years for these gentle sea creatures. Lopez went on to say the following.

“Manatees are still in danger. With ongoing threats posed by boat strikes and habitat loss, we don’t support reducing protections.”

A Manatee on a blue blanket with a man's hand on its back and other people in the background when it is released back into the wild.
Slow swimmers, manatees are often injured or killed by boats. [Image by John Raoux/Getty Images]

In the same month, the rusty patch bumble bee became the first bumble bee species in the U.S. to gain protection under the Environmental Species Act. Although these bumble bees once buzzed around 28 states, they currently only remain in 13. Their population has also decreased by 87 percent since the 1990s.

Under Trump, will the Endangered Species Act itself go extinct?

Passed in 1973, the Endangered Species Act has helped protect many endangered and threatened plants and animals in the United States. However, President Trump stated he believes environmental protection laws are “out of control” in the country. With help from the Trump administration, many opponents of the ESA are fighting to push through legislation which would reduce, defund, or even eliminate the act.

At a Senate hearing in February, the focus was supposedly on “modernizing” the act, which means making it more difficult to list a new species as endangered as well as removing species currently listed at a faster rate.

But Ann Carlson, biologist and climate adaptation specialist at the Wilderness Society, mentioned in National Geographic that, for wildlife, the stakes are very high. If legislation changes, conservationists will not merely be forced to deal with a temporary setback for protecting species in decline. “Once a species is gone, it’s gone,” she said.

[Featured Image by Dorytv/Shutterstock]