A Necessary Adjustment of the Extinction Risk associated with the Red List Criteria?

M De L Brooke

doi:10.5751/ace-00271-040101

Abstract

Brooke, M. de L. 2009. A necessary adjustment of the extinction risk associated with the red list criteria?. Avian Conservation and Ecology - Écologie et conservation des oiseaux 4(1): 1.http://dx.doi.org/10.5751/ACE-00271-040101

Highlights

Some conservationists would assert that species considered threatened because they meet criteria other than E should not be considered to be at risk of extinction within any particular time frame
In a widely quoted and influential study, Thomas et al (2004) concluded that up to 37% of species may be committed to extinction by 2050 as a consequence of climate change, an estimate that partly assumes that "each category [carries] a specified probability of extinction." Redding and Mooers (2006) combined information on evolutionary history and threat status to rank species' conservation priority and "used the criterion E value to assign pe [extinction probability] values to each species." Sekercioglu et al (2004) investigated the ecosystem implications of biodiversity loss and predicted, on the basis of "the extinction probabilities for threatened species
I would argue that the utility of the Red List approach would be seriously undermined if this were not the case and there was a significant mismatch between the extinction risk of organisms listed under different criteria in the same category

Summary

Introduction

Some conservationists would assert that species considered threatened because they meet criteria other than E should not be considered to be at risk of extinction within any particular time frame. There is a widespread assumption, by scientists (e.g. Mace 1994, Collar et al 1994, Crosby et al 1994, Sekercioglu et al 2004, Thomas et al 2004, Redding and Mooers 2006) and by the wider public, that extinction probabilities applicable to criterion E apply to species qualifying for these particular categories under other criteria. The assumption is acknowledged in a recent review of the Red List by Mace et al (2008): '...in the absence of conservation interventions, a larger proportion of species listed in higher threat categories will go extinct over shorter periods.

Results

Conclusion