Calibration of the species threat abatement and restoration metric's threat abatement component in a Costa Rican landscape

Achieving global conservation policy goals requires the ability to set and measure progress toward science-based targets for biodiversity. The species threat abatement and restoration (STAR) metric was developed to enable actors to set science-based targets for species. STAR scores quantify the potential contribution of actions to abate threats and restore habitat to reduce species extinction risk in a particular place and can be aggregated and disaggregated among species, threats, and areas of interest. Estimated STAR scores are based on data from the International Union for Conservation of Nature Red List and provide initial information on the species and threats expected to be present in an area. Operationalization of the metric requires verification of the presence of species and the presence and severity of threats in the area to inform calculation of a calibration STAR score. We applied a pilot calibration process for the threat abatement component of STAR (STAR_T) in the San Jose northern subcatchments landscape in Costa Rica. We used specialist knowledge and geospatial analyses of habitat loss to determine the species present and the intensity of threats affecting them in the landscape. Calibration yielded a more even distribution of scores among threats than was apparent from estimated STAR_T and identified that reducing the threat from livestock farming and ranching had the greatest potential to reduce species extirpation risk. Calibration also showed that there is an opportunity to prevent the extinction of a critically endangered endemic amphibian, but the species' presence requires confirmation. The pilot demonstrated how specialist knowledge and geospatial analyses can be combined during calibration to produce a calibrated STAR_T score capable of informing science-based targets for species conservation. Our calibration process can be applied to other areas.