Red data books are produced by IUCN, which stands for the International Union for Conservation of Nature. These books are a type of conservation tool used to identify and assess the conservation status of various species around the world.

The IUCN Red List of Threatened Species is the most well-known red data book produced by the organization. This list provides a comprehensive overview of the conservation status of tens of thousands of species, including mammals, birds, reptiles, fish, and plants.

The main purpose of red data books is to provide information on species that are at risk of extinction or are already extinct. This information can be used to inform conservation efforts, such as habitat preservation, captive breeding programs, and wildlife reintroduction programs.

Red data books typically include information on the following:

- The scientific name of the species
- The common name of the species
- The population size of the species
- The geographic range of the species
- The habitat of the species
- The reasons why the species is at risk of extinction
- The conservation measures that are being taken to protect the species

In addition to the IUCN Red List, other organizations also produce red data books that focus on specific regions or groups of species. For example, the European Red List is produced by the European Commission and includes information on the conservation status of European species.

Overall, red data books are an important conservation tool that helps to raise awareness about the plight of endangered species and inform conservation efforts around the world.