Methods

The current dataset on mammals is the product of one of several global initiatives led by IUCN and partners to rapidly expand the geographic and taxonomic coverage of the IUCN Red List. The dataset is a global, comprehensive assessment of the conservation status of all known mammalian species. Prior to this assessment, the last time all mammals were assessed globally was in 1996, and the majority of those assessments are now out-of-date (assessments are only current for ten years, after which time they are considered out-of-date).

The dataset includes 5,488 species (including Homo sapiens), 412 subspecies and 21 subpopulations. The species level assessments are the culmination of a systematic collection and documentation process conducted over a period of nearly five years (2003-2008), involving a partnership of numerous institutions, universities and museums, and the participation of more than 1,700 experts. This process is outlined in more detail in the sections below.

For every mammal species currently known, the following data were collected (see Description of Data for further information):

  • Species classification
  • Geographic range (including a distribution map)
  • Red List Category and Criteria
  • Population information
  • Habitat preferences
  • Major threats
  • Conservation measures
  • Species Utilisation
  • Other General Information
  • Key literature references

The assessment was implemented in two different ways:

  1. Consultation with IUCN SSC Specialist Groups and stand-alone Red List Authorities
  2. Peer-review mainly through workshops.

1. Consultation with IUCN SSC Specialist Groups and stand-alone Red List Authorities

The IUCN Species Survival Commission is an established knowledge network of ~8,000 volunteer members working in almost every country of the world. SSC members are part of more than 120 Specialist Groups and Task Forces, and around 2,000 members are within the mammal Specialist Group network. Currently, there are 29 Specialist Groups with a taxonomic focus on mammals, and one stand-alone Red List Authority (Small Nonvolant Mammal Red List Authority). Click here to find details of all SSC Mammal Specialist Groups, their contacts, websites, newsletters, mailing lists and profiles.

Compared with other animal groups, the existing network of Specialist Groups for mammals is remarkably strong. Where species were within the jurisdiction of well-coordinated groups, they were, as far as possible, assessed and reviewed by the members of these groups (as part of core Specialist Group activities).

For all of the assessments completed by Specialist Groups, the central coordinating team of the Biodiversity Assessment Unit did final checks of the supporting documentation for each species, and evaluated all IUCN Red List assessments against the supporting data during a series of consistency checks (to ensure both the proper use of the categories and criteria and that supporting evidence was provided).

1. 2. Peer-review mainly through workshopsAuthorities

The SSC network is less developed with regard to small mammals, which represent the greatest majority of mammal species (for example, more than one-half of all mammals are rodents). Therefore, the assessment of these species required a different approach that was implemented in three main stages:

  1. Data Collection
  2. Data Review
  3. Data Consolidation

2.1 Data Collection

Initial data were collected and entered into a data collection tool by teams of researchers who relied on the available literature to document the current state of knowledge. In some cases, an enormous amount of information is available, but in the case of most species very little is known even about the basic ecology of a species in the literature. . The documentation in the species accounts reflects this inequality.

2.2 Data Review

All the data collected in the initial stage of the assessment was subject to peer review. This was done through a series of 28 review workshops held in 18 countries around the world (and usually in collaboration with existing Specialist Groups). These workshops allowed for discussion and interaction between leading species experts to review, improve and complete the assessments, and were very effective in terms of collating the greatest amount of species-based information within a relatively short period of time.

Each workshop focused on a particular region or taxonomic group. Listed below are all the workshops that were held with a photograph of the participants where available.

Africa (Small Mammals): London, U.K., 24–30 January, 2004.
Host: Zoological Society of London

Africa (Small Mammals): London, U.K., 24–30 January, 2004.

South Asia (Non-volant Small Mammals): India, 9-15 February, 2004.
Host: Zoo Outreach Organisation

Southeast Asia (initial assessment workshop): Thailand, 3-7 May, 2004.

Africa (Small Mammals, maps only): United Kingdom, 22-26 August, 2004.
Host: Zoological Society of London

Philippines (initial assessment workshop): Chicago, United States, 2-3 November, 2004.
Host: Field Museum of Natural History, Chicago

Edentates: Brazil, 17-18 December, 2004.
Host: Conservation International – Brazil

Edentates: Brazil, 17-18 December, 2004.

African Primates: Florida, United States, 26-30 January, 2005.
Host: Disney's Animal Programs

African Primates: Florida, United States, 26-30 January, 2005.

Madagascar: Antananarivo, Madagascar, 4-8 April, 2005.
Host: Conservation International - Madagascar

Sirenia: Sapporo, Japan, 1 August, 2005.
Host: Ninth International Mammalogical Congress

Japan: Tokyo, Japan, 6-8 August, 2005.
Host: Conservation International - Japan

Japan: Tokyo, Japan, 6-8 August, 2005.

Australia/Pacific: Adelaide, Australia, 15-19 August, 2005.
Host: South Australian Museum

Brazil and Guyanas: Aracruz, Brazil, 16-19 October, 2005.
Host: Fundacao Biodiversitas

Mongolia: Mongolia, 31 October - November 4, 2005.
Host: Hustai National Park

Southwest Asia: Samsun, Turkey, 22-25 November, 2005.
Host: Doğa Derneği

Andes (Small Mammals): Colombia, 6-10 February, 2006.
Host: El Instituto Alexander von Humboldt

Asian Squirrels: India, 27-29 March, 2006.

Philippines: Philippines, 9-10 April, 2006.
Host: Wildlife Conservation Society of the Philippines, CI-Philippines, and the Katala Foundation

Southeast Asia (Large Mammals and Bats): Indonesia, 2-6 May, 2006.
Host: Conservation International   Indonesia

Southeast Asia (Rodents): New York, United States, 2-5 May, 2006.
Host: American Museum of Natural History, New York

Southeast Asia (Rodents): New York, United States, 2-5 May, 2006.

Europe: Austria, 18-22 May, 2006.
Host: Austrian Ministry of the Environment (held in Illmitz National Park Information Centre)

Old World Small Carnivores: Vietnam, 3-7 July, 2006.
Host: Cuc Phuong National Park and Owston's Civet Conservation Program

Old World Small Carnivores: Vietnam, 3-7 July, 2006.

Asian Primates: Cambodia, 7-12 September, 2006.
Host: Conservation International - Indo-Burma

Cetaceans: United States, 22-26 January, 2007.
Host: Scripps Institute of Oceanography and NOAA SW Fisheries

Cetaceans: United States, 22-26 January, 2007.

Southern Cone: Brazil, 8-12 October, 2006.
Host: Fundacao Biodiversitas

Cats: United Kingdom, 21-22 September, 2007.
Host: Wildlife Conservation Research Unit, University of Oxford

Mediterranean Mammals: Malaga, Spain, 29 October – 2 November, 2007.
Host: IUCN Centre for Mediterranean Cooperation

Mediterranean Mammals: Malaga, Spain, 29 October - 2 November, 2007.

Neotropical Primates: Florida, United States, 28 November – 2 December, 2007.
Host: Disney's Animal Programs

Neotropical Primates: Florida, United States, 28 November – 2 December, 2007.

Mesoamerica and the Caribbean (Small Mammals): Honduras, 25-30 January, 2008.
Host: Escuela Agrícola Panamericana, Carrera de Desarrollo Socioeconómico y Ambiente, El centro Zamorano de Biodiversidad

At each workshop, species experts were invited to contribute their knowledge as well as to comment on the data already compiled by the regional coordinators. Under the guidance of facilitators trained in the use of the 2001 IUCN Red List Categories and Criteria, the species experts then evaluated each species against a variety of thresholds for geographic range size, population size, and rates of population reduction to make an assessment of extinction risk.

2.3 Data Consolidation

Following each workshop, all of the supporting documentation for each species was subject to final checks, while all IUCN Red List assessments were evaluated against the supporting data during a series of consistency checks (to ensure both the proper use of the categories and criteria and that supporting evidence was provided). There was also resolution of outstanding issues, mainly to do with taxonomic problems, as well as the inclusion of newly described species, and other taxonomic changes that had occurred after the workshop had taken place.