We conducted 28 workshops; each contingent upon financial support of donors (for a complete list see the "Methods" in the Supplementary online information). We acknowledge these donors, as well as those individuals (in parentheses) who helped facilitate grant acquisition. We also express our utmost gratitude to all of the IUCN/SSC Specialist Groups for mammals, members of which participated in the workshops and were responsible for coordinating assessments for their respective species groups.

The Africa workshops for small mammals were supported by CEPF, Elsevier (Andy Richford), USAID's Central African Regional Program for the Environment (CARPE) (Juan Carlos Bonilla and John Flynn), and IEA. African Primates were assessed with support from CARPE, the Margot Marsh Biodiversity Foundation (Bill Konstant), and Disney's Animal Programs (Anne Savage). The mammals of Madagascar were assessed with support from the CI-Madagascar CBC (Leon Rajaobelina and Frank Hawkins).

Southwest Asian mammals were assessed with financial support from CEPF. Mongolian mammal assessments were conducted with funds provided by the World Bank's Netherlands-Mongolia Trust Fund for Environmental Reform, ZSL, the National University of Mongolia, the Mongolian Academy of Sciences, the Ministry of Nature and Environment – Mongolia, IUCN, the Wildlife Conservation Society, the Darwin Initiative, Denver Zoo, WWF, the University of Nebraska, and Hustai National Park. A workshop in South Asia to assess non-volant small mammals was supported by the Zoo Outreach Organization (ZOO), India.

Numerous workshops (including those for the small carnivores and Asian primates) were conducted across Southeast Asia and the Philippines in partnership with IEA, through the Southeast Asia Mammal Databank project that is co-funded by the EC. The mammals of Japan were assessed with funds from Switzerland's Office Fédéral de l'Environnement (OFEV). The assessments of the mammals of Australia, Melanesia, and the Pacific Islands were made possible by the Australian Wildlife Conservancy (Atticus Fleming) and CI-Melanesia (François Martel, Bruce Beehler, and Gaikovina Kula).

European Mammals were assessed by a sister project–the European Mammal Assessment (EMA) – at a regional workshop funded by the EC and the Austrian Federal Ministry of Agriculture, Forestry Environment, and Water. The full list of acknowledgements for the EMA is available online: http://ec.europa.eu/environment/nature/conservation/species/ema/acknowledge.htm.

Small mammals of the Andes were assessed with support from Conservation International's (CI) Andes Center for Biodiversity Conservation (CBC), and the CI regional programs in Mesoamerica, Mexico and the Caribbean, with support from CEPF, the United States Fish and Wildlife Service, the Lubee Foundation (Allyson Walsh), and El Centro Zamorano de Biodiversidad. Small mammals from the Southern Cone were assessed with support from the US Department of State Voluntary Contribution to IUCN. The Brazil and Guianas' workshop and the edentates workshop were financed by the Brazil-Guianas CBC. Assessments of Neotropical primates were funded by the Margot Marsh Biodiversity Foundation (Bill Konstant) and Disney's Animal Programs (Anne Savage).

The cetacean workshop was funded by CI through its Global Marine Program (Roger McManus), SeaWorld & Busch Gardens Conservation Fund, the US Marine Mammal Commission, and the United States Voluntary Contribution to IUCN. We also recognize the financial contribution of the US Marine Mammal Commission and CI's Global Marine Program to the pinniped assessments, and for supporting the Sirenia workshop. The cat workshop was made possible by a generous contribution from the Panthera Foundation (Tom Kaplan).

We acknowledge the IUCN/SSC Conservation Breeding Specialist Group (CBSG) and 150 conservation organizations worldwide that have provided institutional and/or financial support to conduct Population and Habitat Viability Assessment (PHVA) Workshops for the four species of tapir between 2003 and 2007. In addition, assessments of Mexican lagomorphs were provided by AMCELA – The Mexican Association for the Study and Conservation of Lagomorphs.

The European Commission (EC) provided support for the assessment of European and Southeast Asian species. Funding for the Mediterranean workshop was kindly provided by the MAVA foundation. We are grateful to Switzerland's Office Fédéral de l'Environnement (OFEV), in particular Olivier Biber, and to the US State Department which provided financial support at a very crucial stage of the process.