How are species classified under the IUCN Red List?

Recently, both species of African Elephants were severely degraded in the new IUCN Red List for Threatened Species. This led to immense panic amongst wildlife biologists. You may ask, what exactly is this Red List? And how exactly are species classified by International Union of the Conservation of Nature (IUCN)?

IUCN Red List for Threatened Species

Founded in 1964, IUCN Red List is the most comprehensive inventory of the world’s wildlife. It provides an insight into the conservation of various species of plant, animal and fungi. The list is re-evaluated every 5-10 years by Species Survival Commission Specialist Groups of the IUCN.

As of 2021, 134,000 species have been evaluated and classified into seven different categories. These categories are represented below in Figure 1. Out of these seven categories, two are considered lower risk. Three are considered threatened. Meanwhile two categories revolve around extinction at different scales.

However, only 5% of the world’s species have been evaluated in the IUCN Red List. Two additional categories account for species which have either not been evaluated, or have data deficiency.

Figure 1: IUCN Red List Categories

IUCN Criteria for Classification

All species are strictly evaluated against various criteria. This includes geographic range, population size, projected population change, extinction probability . Numeric thresholds for each criteria determine the conservational status of a species. Figure 2 provides a broad overview of these thresholds.

The number of species classified under the threatened classes has increased substantially. In the last 25 years, the number of “critically endangered” species has increased from 1,820 to 8,188. Similar observations were noted in the “endangered” and “vulnerable” categories. However, these observations cannot be solely linked to biodiversity loss. The number of species evaluated by the IUCN has risen substantially over the year. Figure 1 of the IUCN’s updated Red List can attest to this.

Nonetheless, the IUCN Red List continues to be a massive indicator of biodiversity health. Understanding intraspecific trends can help mould conservational efforts. In fact, the IUCN classifications often form the basis of species relocation, such as the planned re-introduction of cheetahs into the Indian Subcontinent. We hope the next Red List has a more positive outlook.

Help us Help Them! Think Wildlife Foundation is a non profit organization with various conservation initiatives. Our most prominent campaign is our Caring for Pari intiative. Pari is a rehabilitated elephant at the Wildlife SoS Hospital. 25% of the profits from our store are donated to the elephant hospital for Pari. Other than buying our wonderful merchandise, you could donate directly to our Caring For Pari fundraiser.