Calculation- how close to recovery is a species?
The recovery definition is translated into a Green Score (G), a numeric value from 0-100%, using this equation:
Photo: IUCN Green Status of Species
Where s = a spatial unit, WS = weight of the state in the spatial unit, WF = weight of the functional state (9), and N = number of indigenous spatial units. In addition to being viable (weight 6) or functional (9), a spatial unit could also be assessed as present (3) or absent (0).
A species that is Extinct in the Wild (absent in all spatial units) would have a Green Score of 0%, and a species that is not threatened with extinction and fully functional in all spatial units would have a Green Score of 100%.
Current Status: The Species Recovery Score
The Green Score calculated at the time of assessment is the Species Recovery Score. This score could be tracked over time as species are reassessed to create an index of recovery.
However, Green Scores can also be calculated under other scenarios besides at the time of assessment—see Measuring Conservation’s Impact.
| << How Does the Green Status Define Recovery? | Measuring Conservation’s Impact >> |
