A large number of regional (i.e., sub-national, national and regional) Red Data Books and Red Data Lists have been published around the world. Europe alone is estimated to have some 3,500 different Red Data Books and Lists. In some of these publications, the Red List assessments are based on classification systems of threat developed and adopted within the country concerned; others have used classifications based on the pre-1994 system of qualitative IUCN Red List Categories; but an ever increasing number of regional Red List assessments are based on the IUCN Red List Categories and Criteria. The IUCN Red List Categories and Criteria, however, were developed primarily for application at the global level. Hence assessments of non-endemic species at national levels based on these criteria could result in incorrect and even misleading (especially when linked to conservation priority setting schemes) listings. As a result, IUCN through the Red List Programme formulated regional guidelines to guide the assessment of endemic and non-endemic species at the regional level.
The regional application guidelines are not a fixed set of rules that must be followed, but are instead a set of best-practice guidelines that indicate the preferred approaches to be followed and the issues that need to be addressed. The use of the regional guidelines helps make regional Red Lists more comparable and promotes the sharing of species information between neighbouring countries, and the better flow of information between the regional and global levels. A regional approach to identifying threatened species complements global conservation status assessments, and provides information at an appropriate scale for international conservation treaties (such as the Bern Convention) and legislation (such as the EU Habitats Directive) that have a regional focus. The information provided here will help to put national conservation priorities into an EU-wide and continental context, thus maximising the effectiveness of local and national conservation measures, and facilitating the development of integrated regional conservation strategies.