Published on

Sep 30, 2021

Sep 30, 2021

The IUCN Red List

As if environmental sciences and saving the planet weren't complicated enough already, we get mysterious acronyms thrown about like a lonely-hearts ad.

Milkywire

So what is the IUCN Red List, and why do we talk about it?


In short, it's like a cheat sheet, a barometer of health, providing regularly updated information on the statuses of threatened species. It serves as an effective tool for influencing governmental policy and provides evidence of the incredible work that environmentalists do when a species' extinction threat is reduced. Now, perhaps more than ever, maintaining this database of species and understanding the nine categories describing their survival statuses is critical. At present, there are close to 140,000 species on the list, with almost 39,000 of them threatened with extinction.

Silverback Mountain Gorilla


The IUCN to which we keep referring is the Swiss-based International Union for Conservation of Nature. While they have overall responsibility for the list, multiple units work together to process and compile the data. These include the Global Species Programme Red List Unit in the UK, which receives data from approximately 1,300 organizations and 16,000 scientists globally, and the IUCN Species Survival Commission (SSC), a network of over 9000 expert volunteers around the world. They provide crucial information on biodiversity conservation and ecosystem health. The SSC has a vision: ‘A just world that values and conserves nature through positive action to reduce the loss of diversity of life on Earth.’



The nine categories

There are nine categories in which a taxon can be classified, eight describe the threat level posed to the species, and one, Not Evaluated (NE), is for when a species has not yet been assessed. You may notice that when Milkywire and academic sources refer to one of these categories, the name is capitalized, and you may see the category initialized after a species’s name.

The nine assessed taxon categories are:

  1. Extinct (EX) – no reasonable doubt that the last individual has died

  2. Extinct in the Wild (EW) – known only to survive in cultivation, in captivity, or as a naturalized population well outside its historic range

  3. Critically Endangered (CR) – extremely high risk of extinction in the wild

  4. Endangered (EN) – very high risk of extinction in the wild

  5. Vulnerable (VU) – high risk of extinction in the wild

  6. Near Threatened (NT) – likely to qualify for a threatened category in the future

  7. Least Concern (LC) – does not qualify for a more at-risk category

  8. Data Deficient (DD) – not enough data to make an assessment

  9. Not Evaluated (NE) – for species not yet assessed.

IUCN Red List



Milkywire initiatives

We’re incredibly proud to say that 20 people from of our initiatives on Milkywire are, in fact, members of the IUCN SSC specialist groups. It’s an honor to support the work of such high-caliber scientists and environmentalists. As an example, José Gonzáles-Maya (Amphibians Program) is the co-chair of the IUCN small carnivore specialist group. Through their work on the Jaguar Friendly initiative, he collaborates with local communities to incentivize the protection of flagship species. This is done by offering compensation in the form of agricultural assistance, access to international markets, and eco-labeling in return for assurances of working against poaching and for conservation.

As if having 20 members of SSC specialist groups on Milkywire wasn’t enough, one of them, Andrea Marshall (Marine Megafauna Foundation) from the shark specialist group, was even instrumental in getting manta rays listed as Endangered, having previously been categorized as Data Deficient. Her years of dedication resulted in sufficient data being collated to recategorize the species, which will hopefully enable greater protection of them in the future.

Subscribe to our newsletter

Join our newsletter for the latest insights, updates, and stories from Milkywire.

Subscribe to our newsletter

Join our newsletter for the latest insights, updates, and stories from Milkywire.

We are here to help you take the next steps on your sustainability journey.

© Milkywire AB, 2025. All rights reserved. Mailbox 3306, 112 73 Stockholm, Sweden. All donations are handled by WRLD Foundation Sweden (registered with org ID No "802526 - 9328") and WRLD Foundation US (registered 501(c)(3) charity).

We are here to help you take the next steps on your sustainability journey.

© Milkywire AB, 2025. All rights reserved. Mailbox 3306, 112 73 Stockholm, Sweden. All donations are handled by WRLD Foundation Sweden (registered with org ID No "802526 - 9328") and WRLD Foundation US (registered 501(c)(3) charity).