Evidence for Modern Extinction in Plants and Animals

29 Pages Posted: 6 Apr 2024

See all articles by Diana O. Fisher

Diana O. Fisher

University of Queensland

Aelys M. Humphreys

Stockholm University


We summarise the types of evidence and frequency reported for plants (170) and animals (816) listed as extinct (EX or EW) under versions of the Red List over the last thirty years. We find that the evidence is remarkably consistent across plants, animals and Red List versions. The most common evidence is 'long time missing', fewer than half of accounts discuss the evidence of survey success or search effort. Among EX, EW and Critically Endangered (CR) species flagged as possibly extinct (CR(PE)), 156 species have been subjects of extinction probability models, and on average each of these has 2.4 models applied to them. Nearly all models applied to birds and mammals agree that the species are extinct. We find that 17 statistical models for estimating the probability that a species is extinct based on search effort, traits and detection rate have been published since 1993 and applied to EX, EW, or CR(PE) species. A tiny fraction of Red List species accounts currently include published model results. However, this is likely to change, because since 2019, Red List guidelines recommend quantitative estimates of the likelihood of extinction, and provide templates for calculations. Combining multiple published statistical models with assessments of species' probability of extinction based on other criteria can strengthen extinction listings of plants and animals, and add to our understanding of the scale of modern species loss.

Keywords: Extinction model, Extinction risk, IUCN Red List, Species extinction

Suggested Citation

Fisher, Diana O. and Humphreys, Aelys M., Evidence for Modern Extinction in Plants and Animals. Available at SSRN: https://ssrn.com/abstract=4786618 or http://dx.doi.org/10.2139/ssrn.4786618

Diana O. Fisher (Contact Author)

University of Queensland ( email )


Aelys M. Humphreys

Stockholm University ( email )

Universitetsvägen 10
Stockholm, SE-106 91

Do you have a job opening that you would like to promote on SSRN?

Paper statistics

Abstract Views
PlumX Metrics