Introduction

The Assessment Process

Establishment of Red List Authorities

Documentation Requirements and Taxonomic Standards

Petitions Process

IUCN Red List Categories and Criteria

Development of the IUCN Red List as an Indicator of Biodiversity Trends

Expanding the Taxonomic Coverage of the Red List

Current limitations

Potential to fill current gaps

Red List Partnership

Since their inception, the IUCN Red Data Books and Red Lists have enjoyed an increasingly prominent role in guiding conservation activities of governments, NGOs and scientific institutions. The IUCN Red Lists are widely recognized as the most comprehensive, apolitical global approach for evaluating the conservation status of plant and animal species. From their small beginnings, the IUCN Red Lists have grown in size and complexity. The introduction in 1994 of a scientifically rigorous approach to determine risks of extinction that is applicable to all species, has become a virtual world standard (WCMC 2000). In order to produce Red Lists of threatened species worldwide, the IUCN Species Survival Commission (SSC) has to draw on and mobilize a network of scientists and partner organizations working in almost every country in the world, who collectively hold what is likely the most complete scientific knowledge base on the biology and conservation status of species. The IUCN Red List supported by its companion information management system (the Species Information Service) are evolving into a broader biodiversity assessments initiative, which will provide fundamental baseline information on the status of biodiversity as it changes over time.

The goals of the IUCN Red List are to:

• Identify and document those species most in need of conservation attention if global extinction rates are to be reduced; and
• Provide a global index of the state of degeneration of biodiversity.

The first of these goals refers to the traditional role of the IUCN Red List, which is to identify particular species at risk of extinction. The role of the IUCN Red List in underpinning priority setting processes for single species remains of critical importance. However, the second goal represents a radical new departure for the SSC and for the Red List, as it focuses on using the data in the Red List for multi-species analyses in order to identify and monitor trends in species status.

To achieve these Goals, the Objectives of the IUCN Red List are:

• To assess, in the long term, the status of a selected set of species;
• To establish a baseline from which to monitor the status of species;
• To provide a global context for the establishment of conservation priorities at the local level; and
• To monitor, on a continuing basis, the status of a representative selection of species (as biodiversity indicators) that cover all the major ecosystems of the world.

In relation to these goals and objectives the IUCN Red List is characterized by the following Operating Principles:

• The Red List should be available to all potential users;
• The process of undertaking status assessments of species should be clear and transparent;
• The listings of species should be based on correct use of the categories and criteria and should be open to challenge and correction, based on the categories and criteria, when necessary;
• All status assessments of species should be correctly documented and supported by the best scientific information available;
• The Red List should exist as an electronic version on the World Wide Web to be updated once a year;
• To publish an analysis of the findings of the Red List approximately every five years; and
• The information on the web should be interactive, providing a mechanism to allow people (through appropriate procedures) to provide information for consideration when updating the list.

IUCN's work on Red List assessments is carried out mainly through the network of expert volunteers in the SSC. This work is supported through projects, and through partnerships with other organizations, such as the Center for Applied Biodiversity Science at Conservation International, BirdLife International, NatureServe and the Zoological Society of London.

In order to achieve the goals and objectives of the Red List, a number of structural and procedural processes have been adopted. Some of these are briefly described below, but further detail on these and particularly the governance aspects may be seen at http://cms.iucn.org/about/work/programmes/species/red_list/about_the_red_list/index.cfm. The processes that have been established help to maintain the high profile and scientific integrity of the IUCN Red List.

The whole process for completing an assessment, submitting it for consideration, to eventual publication on the IUCN Red List is being restructured to improve efficiency and the faster turn-around of assessments, especially with the rapidly increasing number of assessments being completed. The full process is outlined under The Red List Assessment Process page, but in the sections below some specific parts of the process are dealt with in more detail.

The improved objectivity of the 1994 IUCN Red List Categories and Criteria revealed that the previously ad hoc process of including species on the Red List had to change. To achieve this, Red List Authorities are being established for all taxonomic groups included on the IUCN Red List. In most cases, the Red List Authority (RLA) is the SSC Specialist Group responsible for the species, group of species or specific geographic area. An exception is birds, where BirdLife International is the designated RLA. In cases where the SSC and its partner networks do not cover a particular taxonomic group or geographic region, the Red List Unit staff working together with other IUCN Species Programme staff and the Red List Partners will recommend the appointment of other appropriate organizations or networks as Red List Authorities or National Red List Advisory Groups. The latter will also form a much-needed link between the many national Red List initiatives and the IUCN Red List.

The role of the Red List Authorities is to ensure that all species within their jurisdiction are correctly assessed against the IUCN Red List Categories at least once every ten years and, if possible, every five years (note, any assessments that are older than ten years are flagged as 'needs updating', as the status and any supporting documentation provided may no longer be correct; such assessments should be used with caution). All assessments should also include the necessary minimum documentation required (see below) and should be done in as consultative manner as is possible. The intention is that no new species assessment will be included on the IUCN Red List until it has been evaluated by at least two members of an appointed Red List Authority or by at least two evaluators appointed by IUCN Species Programme staff. This peer review system places greater responsibility on the SSC network and its partners to ensure that what appears on the IUCN Red List is credible and scientifically accurate.

The listings in the 1996 and 1997 IUCN Red Lists were poorly documented and as a result, the assessments were largely unsubstantiated. To rectify this weakness, a system of minimum documentation requirements has been adopted (see Data Organization). All taxa added to the Red List and any listings that are changed must be documented following these minimum requirements. Red List Authorities have been asked to provide documentation for all of their taxa on the IUCN Red List. The inclusion of this extra documentation to some extent represents a return to the format of the earlier IUCN Red Data Books produced before the current Red List series began. However, with the move of the Red List to a purely electronic medium, the maintenance and continual updating of such documentation is made much easier. Despite the increased level of documentation and the growing similarity to the format of the earlier Red Data Books, the term 'Red List' will be maintained to avoid any confusion.

Another weakness of the IUCN Red Lists has been the lack of sufficiently clear taxonomic standards. Taxonomic standards are being adopted (see under Information Sources and Quality). All new species' listings, and any revisions to listings, must be in accordance with these taxonomic standards, but deviations may be permitted provided they are fully documented and substantiated.

The documentation requirements and taxonomic standards will be reviewed at regular intervals. The documentation and taxonomic validation will make the listing process far more transparent and open to challenge, and will increase its scientific integrity and authority. The entire process will be controlled through the IUCN SSC Species Information Service (SIS) to ensure efficient management and integration of relevant data.

Status assessments presented in the IUCN Red List are open to challenge. Petitions may be made against particular listings. However, such petitions may only be made on the basis of the Red List Categories and Criteria and in reference to any supporting documentation accompanying the listing. It is not possible to change listings for political, emotional, economic, or other reasons.

The appeals process begins with discussions between the Red List Authority and the petitioners. Every effort should be made to reach agreement within the standard Red Listing process. Only if the two groups cannot come to any agreement will the matter be referred to the IUCN SSC Biodiversity Assessments Sub-Committee for an appeal to be heard by the Standards & Petitions Working Group.

For more details on the petitions process see the document entitled The IUCN Red List petitions process on the IUCN site. Any species under petition are indicated by the label "(petitioned)" as an annotation to the Red List Category and Criteria on the search results pages and the species fact sheets. Note that the annotation will only appear if there is a Petition.

The IUCN Red List Categories and Criteria were extensively reviewed between 1997 and 1999. The revised Categories and Criteria (IUCN Red List Categories and Criteria version 3.1) were adopted by IUCN Council in February 2000 and the revised system came into use in 2001. All assessments submitted to the IUCN Red List must use this system.

User Guidelines:
Guidelines on how to use the IUCN Red List Categories and Criteria have been developed and these can be downloaded from http://intranet.iucn.org/webfiles/doc/SSC/RedList/RedListGuidelines.pdf.

Regional Application Guidelines:
Guidelines on the application of the IUCN Red List Criteria at sub-national, national or regional levels have also been developed and are available from http://www.iucn.org/themes/ssc/redlists/regionalguidelines.htm (Assessments using these guidelines do not appear on the IUCN Red List).

Rising to the global challenge of reducing biodiversity loss by 2010 (as adopted by the Parties to the Convention on Biological Diversity (CBD)) requires tools to monitor our progress and highlight where we need to focus our conservation efforts. Hence the driving focus of the SSC Biodiversity Assessments initiative over the next few years will be to develop the IUCN Red List in a manner that allows a Red List Index to be calculated and measured over time. The Red List Index will play a vital role in tracking progress towards the 2010 target and beyond. Red List Indices have been produced which chart overall changes in the threat status of the world's birds and amphibians, the two groups that have been completely assessed. These are based on the number of species that moved between categories as a result of genuine changes in threat status (excluding moves resulting from improved knowledge or taxonomic changes).

Further information about the IUCN Red List Index and how it is calculated can be found in the following papers:

• Measuring Global Trends in the Status of Biodiversity: Red List Indices for Birds (Butchart et al. 2004) - paper published in PloS Biology.
• Using Red List Indices To Measure Progress Towards the 2010 Target and Beyond (Butchart et al. 2005) - paper published in Philosophical Transactions of the Royal Society..
• Improvements to the Red List Index (Butchart et al. 2007) — paper published in PLoS ONE.

In order for the Red List Indices to be calculated from the Red List, two important changes need to be implemented: a) the further documentation of species on the Red List as described above and b) the expansion of the taxonomic groups covered by the Red List (see below). The taxonomic coverage of the Red List will be improved in part in the coming years through the Sampled Red List Index (SRLI). This is being developed based on a sample of species from selected taxonomic groups to provide trends in extinction risk that are more representative of global biodiversity.

Both the full IUCN Red List Index and the Sampled Red List Index are central to monitoring the progress of global efforts to reduce biodiversity loss and will be critical for guiding decision makers as to what and where conservation action is necessary.

IUCN is currently managing data on approximately 41,500 species, with this number set to increase to well over 50,000, perhaps even 60,000, by 2008. Of the 41,500, only approximately 15,000 species are currently well documented, with information on ecology, population size, threats, conservation measures and utilization. There are also about 10,000 species with distribution maps (many of which are now included on the Red List). The number of well-documented species with distribution maps may reach 25,000 by 2008. The data cover non-threatened as well as threatened species, and certain taxonomic groups have been completely, or almost completely assessed (mammals, birds, amphibians, conifers and cycads).

There are some important limitations to the current dataset. The species groups covered so far are biased towards terrestrial, and in particular forest, ecosystems. Among the better-documented species, there is also a strong bias towards animals, rather than plants.

IUCN is prioritising a number of new assessments to address these biases through enhancing both taxonomic and geographical coverage (see Biodiversity Assessments and Indicators work on the IUCN web site). However, both the pace and the extent of further developing the IUCN SSC biodiversity assessments is hugely constrained by the limited availability of financial resources.

Taxonomic gaps:

Plant species – Although there are over 12,000 plant species on the IUCN Red List, fewer than one thousand of these are properly documented. To address this gap, IUCN SSC is pursuing global assessments of legumes and palms. Both of these groups have many species of high economic value. The conifer and cycad species already on the IUCN Red List need to be fully documented. IUCN is also prioritising a global preliminary assessment of all plant species as called for in Target 2 of the CBD Global Strategy for Plant Conservation. This will cover 300,000 species, and will help to identify groups of plants that require full assessment. For further information see IUCN SSC plant conservation work.

Freshwater species – The freshwater system represents the most threatened of all ecosystems, and many freshwater species have a very high livelihood value for local human communities. IUCN's freshwater focus is on the following taxonomic groups: fish; molluscs; crabs and crayfish; and dragonflies. Global assessment of these groups is being pursued through a series of regional projects, such as one for Africa that is currently being implemented (see the IUCN Freshwater Biodiversity Unit for further details).

Marine species – The marine realm is very poorly covered in the IUCN Red List, comprising less than 5% of the species included. IUCN SSC has identified priority taxonomic groups of marine fish, invertebrates, plants (mangroves and seagrasses) and macro-algae (seaweeds). If these priority groups can be assessed, the number of marine species on the IUCN Red List will be increased more than six-fold. For further details about the Global Marine Species Assessment see IUCN Marine Conservation Sub Committee and Global Marine Species Assessment site at Old Dominion University.

Arid and semi-arid species – With the severe degradation of land across the globe exacerbated by the impacts of global climate change, arid and semi-arid systems are expanding. At present, arid ecosystems are very poorly covered by the species groups assessed so far, and are also increasingly becoming degraded in most parts of the world. A complete assessment of all the world's 8,000–9,000 reptile species is recommended to fill this gap (this would also complete the assessment of all terrestrial vertebrates). The reptile assessment is being initiated through a series of regional projects.

As these additional species are included on the Red List and the biases in the data are reduced, the IUCN SSC biodiversity assessments will provide an even more solid basis for conducting worldwide analyses. In addition, these data will provide the basis for the indicators needed to measure progress towards the achievement of the CBD's 2010 target and beyond, as well as the Millennium Development Goals.

The massive expansion of the Red List coverage cannot be achieved and maintained by IUCN and SSC alone. As a result, other organizations were approached to help with the expansion and a formal agreement on co-operation was negotiated. This resulted in the formation of the Red List Consortium in 2000. Following an external review of the Consortium in 2004 all the parties agreed to move to a looser partnership arrangement involving bilateral or multi-lateral agreements as required. The partners currently involved in supporting the Red List and the wider biodiversity assessments initiative include: IUCN (in particular its Species Survival Commission), BirdLife International, the Center for Applied Biodiversity Science (CABS) at Conservation International (CI), NatureServe, and the Institute of Zoology at the Zoological Society of London.

For further information about the Red List and for other Red List stories and results please read the Red List issue of World Conservation and the Global Species Assessment (click on the images below).