The greatest potential to reduce species extinction risk in the Northern Sub-catchments of San José, Costa Rica, lies in addressing habitat loss and degradation due to livestock farming and ranching, urban expansion, and the spread of non-native invasive species, according to a paper published on Friday, February 13, 2026, in Conservation Biology.
The paper is the first to apply IUCN’s Species Threat Abatement and Restoration (STAR) metric on the ground, translating estimates based on global data into findings grounded in local conditions.
The paper, “Calibration of the species threat abatement and restoration metric’s threat abatement component in a Costa Rican landscape”, presents a pilot application of IUCN’s Species Threat Abatement and Restoration (STAR) metric in the San José Northern Sub-catchments landscape in Costa Rica.
The authors combined specialist knowledge with geospatial analyses of habitat loss to confirm species presence, verify threats and assess the intensity of threats affecting them within the landscape, and used this information to refine the global analysis – known as Estimated STAR – so that the results reflect local conditions – known as Calibrated STAR.
STAR is designed to help set – and monitor progress towards – robust, science-based targets for species conservation, by quantifying how actions to mitigate threats in a particular place could support species extinction risk reduction.
“To achieve whole-of-society goals such as those established in Goal A of the Kunming-Montreal Global Biodiversity Framework and in Sustainable Development Goal 15, we need all actors to be able to set and measure progress towards science-based targets for biodiversity. It is critical that our measurements are accurate and useful from the local to global levels.
“This study shows how the STAR metric provides a way to reflect local realities in conservation decisions, while remaining scalable and comparable across regions, making it a key tool for achieving global goals,” said Randall Jiménez Quirós, Senior Conservation Scientist at IUCN and co-author of the paper, based in Costa Rica.
The study reveals that some threats apply to many more species in northern San José than previously understood, highlighting the need to address multiple drivers of land-use change, such as unsustainable livestock farming and ranching, housing and urban development, logging and wood harvesting, and non-timber crops. The next largest potential contribution to reducing species extinction risk in the area comes from addressing invasive non-native species and diseases, followed by droughts and other climate change impacts.
The paper also highlights that confirming the presence of Fleischmann’s robber frog (Craugastor fleischmanni) in northern San José is an urgent priority, as it is endemic to this landscape and Critically Endangered on The IUCN Red List of Threatened Species™. Just one Fleischmann’s robber frog was recorded in this area between 2000 and 2019.
“The value of local expertise in calibrating global conservation metrics to guide conservation action is demonstrated really clearly in our study. Local specialists not only provided valuable information on threats to species, but were also able to highlight the critical opportunity to prevent the global extinction of Fleischmann’s frog. It is this combination of local expertise with a global perspective that allows the implementation of STAR to support progress towards global species conservation goals,” said Dr Louise Mair, Research Fellow at Newcastle University, member of the IUCN Species Survival Commission’s Global Biodiversity Framework Taskforce and lead author of the paper.
“I am delighted to see Costa Rica – a country long-recognised as a global conservation leader – host this first-ever pilot of STAR calibration, towards delivery of Rapid, High-Integrity, Nature-positive Outcomes. Not only is it extremely important in its own right, but also as a powerful demonstration of how IUCN can advance research which is not only scientifically cutting-edge but also immediately relevant to conservation action on the ground, through collaboration between the Union’s expert Commissions and Regional and Global Programmes,” said Ursula Parrilla, IUCN’s Regional Director for Mexico, Central America and the Caribbean.
Proactive management is important to prevent threats worsening, the authors emphasise. Initial estimates made through STAR highlighted threats that in practice may already have been addressed or be subject to ongoing intervention. The study revealed that these threats have the potential to emerge or intensify, if not managed. The authors particularly recommend monitoring the threat to amphibians from chytrid fungus in northern San José.
The study also demonstrates how STAR can be applied within IUCN’s approach to supporting the delivery and measurement of Rapid High-Integrity Nature-positive Outcomes (RHINO), which is designed to connect locally grounded, credible conservation action with the delivery of the Kunming-Montreal Global Biodiversity Framework.
Through RHINO, STAR provides a practical way to translate local threat reduction into measurable and comparable contributions towards the Framework’s global goals and targets, including the aim to halt human-induced extinction of known threatened species and to reduce extinction risk across all species by 2050.
This pilot was conducted under the design of the LandScale framework, which was funded by the International Climate Initiative (IKI) of the German Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV), and by the European Commission Directorate-General for International Partnerships.