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 talking about a species in danger of extinction, allusion is made to those whose total number of individuals is very low, so there is a risk actual disappearance of the species. The latter is known as extinction, and it has occurred naturally throughout the history of the life at planet (due to catastrophes that generate mass extinction or the action of the natural selection over the centuries), or artificially due to human activities (pollution, hunting and indiscriminate logging, etc.). Endangered species are generally considered to be species threatened by the human being.
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 human beings have changed the planet much more radically and rapidly (especially since the Industrial Revolution) that no other species or phenomenon of the history, thus causing the decline in populations most vulnerable, either by direct elimination of their individuals, by destruction of their habitat or as a consequence of the elimination of other members of his food chain, reducing the amount of food available to the endangered species.
Internationally, attempts are being made to protect species in danger of extinction and lists of protected species are drawn up, such as the IUCN Red List, which included in 2009 some 2,448 animal taxa and 2,280 plant taxa considered in danger; 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 the global warming, their prospects are not good at all.
- 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 it is expected that its ecosystem be lost by 70% by 2060, if current environmental conditions continue.
- The blue whale (Balaenoptera musculus). The largest animal on the planet is this mammal Marine whose population was very abundant at the beginning of the 20th century, but which after 40 years of indiscriminate hunting barely reaches around 2000 individuals.
- Hawksbill turtle (Eretmochelys imbricata). Critically endangered, this turtle It is among the most protected species on the planet, since 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 ocean Indo-Pacific.
- The Orinoco crocodile (Crocodylus intermedius). Endemic species of the Orinoco river basin in Venezuela and Colombia, is the largest predator from South America and one of the largest species of crocodile in the world, with its seven meters 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, victim of indiscriminate hunting, the 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). Is a amphibian large (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 typical of the weather subtropical of the Canary Islands, being a vegetal 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
At present, many species of living beings 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.