How many bird and mammal extinctions has recent conservation action prevented?

Newcastle University, Sapienza University of Rome, University of the Philippines Los Baños, University of Tasmania, International Union for Conservation of Nature, World Agroforestry Centre, Imperial College London, BirdLife international, Zoological Society of London, Centre National de la Recherche Scientifique, École Pratique des Hautes Études, Université de Montpellier, Centre d'Écologie Fonctionnelle et Évolutive, Université Paul-Valéry Montpellier, Institut de Recherche pour le Développement, International Union for Conservation of Nature (United Kingdom), Universidad de Huelva, South African National Biodiversity Institute, University of Pretoria, Wildfowl & Wetlands Trust, The University of Sydney, Data61, Charles Darwin Foundation, The University of Queensland, Charles Darwin University, University of Kent, Durrell Wildlife Conservation Trust, Colorado State University, Entertainment Industries Council, Manchester Metropolitan University, Cornell University, Ghent University, Universiti Brunei Darussalam, Pronatura Noroeste, Universidade de São Paulo, Arthur Rylah Institute for Environmental Research, The University of Melbourne, Pontificia Universidad Javeriana, Botanic Gardens Conservation International, Texas Parks and Wildlife Department, Global Wildlife Conservation, Texas A&M University, Endangered Wildlife Trust, Rasmussen College, Instituto de Ecología, Universidad Nacional Autónoma de México, International Institute for Applied Systems Analysis, University College London, University of Cambridge