Testing absolute and percentage thresholds in the identification of key biodiversity areas

Just as quantitative criteria associated with the IUCN Red List of Threatened Species provide a benchmark of relative species extinction risk, criteria that identify ‘key biodiversity areas’ (KBAs, Eken et al., 2004) allow consistent recognition of sites with global significance for biodiversity conservation. Clearly, with habitat change ranking as the major threat worldwide (Baillie et al., 2004), site conservation approaches are urgently needed to stem the current extinction crisis (Boyd et al., 2008). This is articulated in the recently agreed 2020 strategic plan for the Conservation of Biological Diversity (http://www.cbd.int/decision/cop/ ?id=12268), which sets explicit targets to stop extinction (Target #12) and to protect sites of particular significance for biodiversity (Target #11). Global recognition of sites of high biodiversity value assists managers when planning protected area networks, increases local ownership of and pride in natural heritage, and allows conservation and intergovernmental organizations to direct funding and focus activities at sites where needed most. The identification of KBAs and related critical areas for conservation has accelerated greatly in recent years through initiatives from civil society [e.g. the Alliance for Zero Extinction (http:// www.zeroextinction.org)], international collaborations [e.g. the Global Ocean Biodiversity Initiative (http://openoceans deepseas.org)] and the private sector [e.g. the Integrated Biodiversity Assessment Tool (https://www.ibatforbusi ness.org)].