The Red Book: the Red List of threatened species

In 1963, the International Union for Conservation of Nature (IUCN) decided to address the creation of a document that would reflect the conservation of species worldwide. The Red Book was born, also called the Red List. Below we will tell you what this document consists of and why it is so important to update it.

What is the Red Book?

This document is considered as the inventory more complete state of conservation worldwide of all animal and plant species.

It is prepared by IUCN, the largest environmental organization in the world and was founded in 1948 . Apart from this, many countries and organizations develop their own Red Book, where they include especially vulnerable regional species.

For their elaboration, experts from other organizations are involved as BirdLife International or the Zoological Society of London. Based on a series of extinction risk criteria, they update the Red Book annually.

In addition, a review is carried out on a larger scale every four years , and new species are added or eliminated. Through an intense process of peer review.

The book's ultimate goal is to raise awareness of the urgency and need for species conservation. It also serves as a tool to help and advise the international community.

What categories do you have?

Depending on the extinction risk of the species, currently the IUCN considers nine categories or degrees of risk , ordered from highest to lowest:

• Extinct.
• Extinct in the wild.
• Critically endangered.
• Endangered.
• Vulnerable.
• Nearly threatened.
• Minor concern.
• Insufficient data.
• Not evaluated.

The different species can vary their degree of risk, depending on the annual analysis. For example, in 2018 the gorilla Mountain ( Gorilla beringei beringei ) has gone from being 'critically endangered' to 'endangered' thanks to the recovery of its population.

Another example it is the Mexican tortoise ( Gopherus flavomarginatus ), which has fallen from 'vulnerable' to 'critically endangered'. This has been due, in large part, to the loss of their habitat.

What about the species in Spain?

Within our forests, seas and mountains there are many species which are cataloged within the Red Book. This is the case of the Barbary Macaque ( Macaca sylvanus ) , which lives in the Rock of Gibraltar. It is currently in the 'endangered' category.

Another animal that is in that category is the Canary Island shrew ( Crocidura canariensis ) , a small animal endemic to the islands.

An example that may surprise you is the common rabbit ( Oryctolagus cuniculus ) . Despite being included in the list of the 100 most harmful invasive alien species in the world, its current status is classified as 'almost threatened'.

Much of the reduction of its population has a viral origin. The clearest exponent is myxomatosis, a disease transmitted through fleas and ticks that killed up to 90% of wild rabbits.

The reduction in the number of rabbits, in turn, is affecting to other animals that fed on the rabbit.