Addressing Threats and Ecosystem Intactness to Enable Action for Extinct in the Wild Species

Abstract

The species listed as Extinct in the Wild (EW) in the IUCN Red List of Threatened Species consist of 84 plants and animals that have been lost from their indigenous range. EW species are therefore restricted to ex situ conservation facilities and often have populations founded with few individuals. Our analysis demonstrates that 60% of EW species are associated with ecoregions that have very low proportions of intact habitat. Furthermore, threats such as invasive species, pollution, and climate change affect just over half of EW species and compound the obstacles facing their reinstatement to the wild. Despite these bleak assessments, there are various options for EW recovery. We present five scenarios that encapsulate the circumstances facing EW species and suggest potential conservation action for each of these situations. We illustrate these scenarios using case studies of EW species that demonstrate how the various options of ex situ management, reintroduction, and assisted colonisation to new habitat can be used to address the very exacting requirements of EW species. Our aim is to present a broad review of the obstacles facing the recovery of EW species whilst inspiring action to prevent the extinction of the most imperilled species on the planet.