Question

The threatened species of organisms have been placed in how many categories? Explain in detail.

Answer 1

Hint: International union for conservation of nature and natural resources (IUCN) categorized species based on a number of criteria. According to them, threatened species are also categorized and are listed in red data books.

Complete answer:
International union of conservation of nature and natural resources (IUCN) is the main authority in the world to look after the issues of the conservation status of species. According to them, species are classified into nine groups namely extinct, extinct in wild, critically endangered, endangered, vulnerable, near threatened, least concern, data deficient, and not evaluated. Threatened species are categorized into three main groups namely critically endangered, endangered, endangered, and vulnerable. Species under high risk of extinction are placed under the category critically endangered. Out of 120372 species, 6811 species are under this category according to the IUCN. The species which are likely to become extinct are placed under the category of endangered species. That particular species may be likely to go extinct either worldwide or in a particular area. The species which are likely to be endangered are placed under the category of vulnerable species. They are likely to endanger unless there is an improvement in reproduction and threat from predators.

Additional Information: - Criteria for the species to be placed in the category of critically endangered species are population size reduction, reduction across geographic range, decline in population and population size, probability of extinction.
- Criteria for the endangered species and vulnerable species are population reduction, extinction of occurrence, population less than 1000 mature individuals, decline 10% within 10 years of 3 generations.

Note: Critically endangered species examples: lemurs, hawksbill. Endangered species examples: Siberian tiger, Blue-throated macaw, the sea turtle. Vulnerable species examples: Hyacinth, macaw, mountain zebra, Blue crane.