Why we should aim for zero extinction

The Alliance for Zero Extinction (AZE), a partnership comprising 67 of the world's biodiversity conservation non-governmental organizations, has pinpointed where Endangered and Critically Endangered species exist at one remaining known location [1xPinpointing and preventing imminent extinctions. Ricketts, T.H. et al. Proc. Natl. Acad. Sci. U. S. A. 2005; 102: 18497–18501Crossref | PubMed | Scopus (215)See all References[1]. Discussing conservation triage, Bottrill et al. [2xBottrill, M.C. et al. Trends Ecol. Evol. 2008; 1007: 649–654Abstract | Full Text | Full Text PDF | Scopus (198)See all References[2] view efforts to ‘reverse the extinction rate’ as unfeasible because of their ‘astronomical’ cost and they dismiss AZE as ‘neglecting to factor in diminishing returns and uncertainty of investment’.We think their assumptions are faulty. The cost of effective global biodiversity conservation is only ‘astronomical’ in one sense – being the same order of magnitude as current resources for space exploration [3xEconomic reasons for conserving wild nature. Balmford, A. et al. Science. 2002; 297: 950–953Crossref | PubMed | Scopus (691)See all References[3]. And highly threatened species are not necessarily impossible, or costly, to save.With the goal of avoiding extinctions, AZE sites contain ∼95% or more of the known population of an Endangered or Critically Endangered species. The protection of these sites is a front line of global defense against species extinctions. However, conservation reality departs from triage theory when deciding which patients to treat and which not. Predicting possible survival is far less certain for a threatened species than for a human patient and we usually have much more time for intervention than would battlefield doctors. A narrow triage approach might have written off the Whooping Crane, the population of which stood at 15 individuals in the early 20th century; however, thanks to conservation efforts, >500 cranes now survive. There are many similar examples.At AZE sites, we already see much conservation progress, with one-third of sites legally protected, another sixth partially so, and conservation actions greatly strengthened at many others. Interventions do not have to be costly to work, and examples range from private reserve networks to community-based conservation and outreach programs, to captive-breeding and reintroduction projects, and ecotourism developments. Many AZE sites contain several highly endangered, site-endemic species (no less than 14 in the Massif de la Hotte, Haiti) and a host of other narrow endemics (including those not yet assessed for the Red List) that all benefit when the site is conserved.With new funding possibilities (e.g. through carbon financing) on the horizon, and considering that the amounts needed to protect all AZE sites are insignificant in comparison to the economic packages currently being discussed for the US auto industry alone, now is not the time to decide what we abandon but to move boldly forward to save as many species as possible. Smart decision making is the exact reason why AZE needs to be given priority. If we follow this approach, we just might save everything.