Percentage of decreasing species classified by IUCN (International Union for Conservation of Nature) as "endangered" or "low concern" in terrestrial vertebrates

Range Table - link %
Organism Vertebrates
Reference Ceballos G, Ehrlich PR, Dirzo R. Biological annihilation via the ongoing sixth mass extinction signaled by vertebrate population losses and declines. Proc Natl Acad Sci U S A. 2017 Jul 25 114(30):E6089-E6096. doi: 10.1073/pnas.1704949114 p.E6093 figure 4PubMed ID28696295
Method Abstract: "That conclusion is based on analyses of the numbers and degrees of range contraction (indicative of population shrinkage and/or population extinctions according to the International Union for Conservation of Nature) using a sample of 27,600 vertebrate species, and on a more detailed analysis documenting the population extinctions between 1900 and 2015 in 177 mammal species."
Comments P.E6093 right column top paragraph: "Roughly a third (8,851/27,600) of all land vertebrate species examined are experiencing declines and local population losses of a considerable magnitude (Figs. 2–4). Such proportion of decreasing species varies, depending on the taxonomic group, from 30% or more in the case of mammals, birds, and reptiles, to 15% in the case of amphibians. Furthermore, of the decreasing species, many are now considered endangered (Fig. 4). Beyond that, roughly 30% of all decreasing species are still sufficiently common that they are considered of “low concern” by IUCN, rather than “endangered.” That so many common species are decreasing is a strong sign of the seriousness of the overall contemporary biological extinction episode."
Entered by Uri M
ID 117266