Endangered Species – What it is, concept and examples

We explain what an endangered species is, the reasons why they are in danger and some examples of these species.

What is an endangered species?

When speaking of an endangered species, allusion is made to those whose total number of individuals is very low, so there is a real risk of disappearance of the species. The latter is known as extinction, and it has occurred naturally throughout the history of life on the planet (due to catastrophes that generate mass extinction or the action of natural selection over the centuries), or artificially due to human activities (pollution, hunting and indiscriminate logging, etc.). Species threatened by humans are generally considered endangered species.

While it is true that animals and life in general make efforts to adapt to changes in their environmental conditions, it is also true that humans have changed the planet much more radically and rapidly (especially since the Industrial Revolution) than any other species or phenomenon in history, thus causing the decline in the most vulnerable populations, either by direct elimination of their individuals, by destruction of their habitat or as a consequence of the elimination of other members of its trophic chain, reducing the amount of food available to the endangered species.

Internationally an attempt is made to protect endangered species and lists of protected species are drawn up, such as the IUCN Red List, which in 2009 included some 2,448 animal taxa and 2,280 plant taxa considered endangered; as well as some 1,665 animal and 1,575 plant taxa considered critically endangered.

Examples of endangered species

Some of the main endangered species in the world are the following:

• Polar bears (Ursus maritimus). The exact number of individuals in the wild is unknown (between 20,000 and 25,000 approximately), but given the conditions of polar melt caused by global warming, their prospects are not good.
• Bengal tigers (Panthera tigris). The second largest species of tiger on the planet, and one of the most threatened species on the planet, its total number is estimated to be around 2,500 individuals, and its ecosystem is expected to be lost by 70% by 2060, if the continued current environmental conditions.
• The blue whale (Balaenoptera musculus). The largest animal on the planet is this marine mammal whose population was very abundant at the beginning of the 20th century, but which after 40 years of indiscriminate hunting barely reaches 2,000 individuals.
• Hawksbill turtle (Eretmochelys imbricata). Critically endangered, this turtle is among the most protected species on the planet, as its meat is considered a delicacy in many eastern countries. Its appearance is similar to that of other marine species, and it is found among the coral reefs of the Atlantic and the Indo-Pacific Ocean.
• The Orinoco crocodile (Crocodylus intermedius). An endemic species of the Orinoco river basin in Venezuela and Colombia, it is the largest predator in South America and one of the largest crocodile species in the world, with its seven meters in length. Since 1970, attempts have been made to breed new offspring in captivity to reintroduce them into adulthood, but after 1996 they are considered critically endangered.
• The mountain gorilla (Gorilla beringei). At critical risk of extinction, with just 900 living individuals, this species is concentrated in the jungles of Central Africa and in Uganda, a victim of indiscriminate hunting, war and the deforestation of its habitat. Its resemblance to our own species has not protected it from being near extinction.
• The giant Chinese salamander (Andrias davidianus). It is a large amphibian (it can reach 1.8 meters) endemic to China, where its population is decreasing, given its hunting as food and as a source of medicinal supplies.
• The dragon tree (Dracaena draco). This species of tree is typical of the subtropical climate of the Canary Islands, being a plant symbol of the island of Tenerife, but also of western Morocco. They are particularly long-lived species, with stems without a growth ring and fleshy fruits, reaching up to 600 meters in altitude. Your species is in a state of vulnerability, just the state prior to entering the formal list of species in imminent danger of extinction.

Danger of Extinction

Nowadays many species of living things are more or less close to extinction, mainly due to activities resulting from human labor. That is, they are at risk or in danger of becoming extinct. These species are classified (according to the IUCN Red List) according to the number of remaining live specimens, in several categories:

• Extinct (Ex). When there are no living specimens of the species left.
• Extinct in the Wild (EW). When the remaining specimens live only in captivity and the species can no longer be observed in its natural habitat.
• Critically Endangered (CR). When its population of mature individuals is estimated to be equal to or less than 250, or when its total population has decreased by 80% to 90% in the last 10 years or 3 generations.
• Endangered (EN). When its population of mature individuals is estimated between 250 and 2500 specimens, or when its total population has decreased between 70% and 80% in the last 10 years or 3 generations.
• Vulnerable species (VU). When they are not directly in danger of immediate extinction, but they are threatened by this possibility. This is considered when the number of specimens is high, but tending to the downside.
• Near threatened species (NT). When it does not meet the requirements to be a vulnerable species, but it is not considered out of all risk either. In this rung they are considered “low risk” species.
• Least Concern (LC). For species that are not under apparent risk of extinction, since their numbers are stable or even growing.