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    Author(s): Steven R. Beissinger; Curtis H. Flather; Gregory D. Hayward; Philip A. Stephens
    Date: 2011
    Source: Frontiers in Ecology and the Environment. 9: 486.
    Publication Series: Scientific Journal (JRNL)
    Station: Rocky Mountain Research Station
    PDF: Download Publication  (51.92 KB)


    Clements et al. (Front Ecol Environ 2011; 9[9]: 521-525) proposed a single metric that describes a "species' ability to forestall extinction" (referred to by the acronym "SAFE") as a "scientifically defendable rule of thumb for when complete demographic data are unavailable" to rank the relative threat status of a species. SAFE is calculated on a logarithmic scale and reflects the difference between a species' current population size and 5000, the estimate for a universal minimum viable population (MVP) promoted by Traill et al. (2010). Clements et al. advocated SAFE as a useful tool for triage to allocate resources in conservation, and as a measure of population viability that would be more easily understood by the public than the IUCN Red List categories (Mace et al. 2008). We believe that SAFE is not a useful metric to guide conservation planning for three main reasons.

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    Beissinger, Steven R.; Flather, Curtis H.; Hayward, Gregory D.; Stephens, Philip A. 2011. No safety in numbers. Frontiers in Ecology and the Environment. 9: 486.


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    species' ability to forestall extinction (SAFE), minimum viable population (MVP)

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