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Species Threat Abatement and Restoration Metric (STAR)

Los Quetzales National Park
World Database on Protected Areas

Logo for Species Threat Abatement and Restoration Metric (STAR)

The Species Threat Abatement and Restoration Metric (STAR) allows quantification of the potential contributions that species threat abatement and restoration activities offer towards reducing extinction risk across the world.

STAR can inform decisions made by businesses, governments, civil society, and other actors towards global goals for halting extinctions. As such, STAR helps identify actions that have the potential to bring benefits for threatened species, and it supports the establishment of science-based targets for species biodiversity, and commitments relevant to the post-2020 biodiversity framework.

STAR is calculated from data on the distribution, threats, and extinction risk of threatened species derived from the IUCN Red List of Threatened Species™.

STAR is simple to use and interpret as the analysis is carried out automatically in IBAT. STAR insights can be gained by using IBAT site-specific reports, which calculate estimated STAR values for a given Area of Interest, as well as by using IBAT Multi-site Reports to gain a broad understanding at the portfolio/supply chain level. Additionally, the raw raster layer is available to download at the global level and at local scale with 5km granularity.

STAR is standardised across the globe as every grid cell can be directly compared using the same objective criteria. STAR is also scalable as users can sum their potential contributions across sites, regions and countries throughout the world to determine their overall opportunities for nature-positive action.

IBAT has produced an Industry Briefing Note on STAR. For more information on the calculation and interpretation of STAR, please refer to IBAT’s Business User Guidance.

The scientific publication behind STAR in Nature Ecology & Evolution was the result of collaboration by more than 50 organisations around the world and is freely available to access: Mair et al., 2021

Any questions on the STAR Metric and how to use it should be directed to

Species Threat Abatement & Restoration Metric - STAR

A new global metric to support nature-positive action. Designed to be simple, standardised and scalable, STAR quantifies the contribution of operating at specific locations to reduce the threat of species extinction risk. Based on the number of species, their extinction risk and their population, STAR Scores can be aggregated between sites - especially with IBAT's Multi-site Report.

STAR currently includes distribution and threat information from threatened or Near-Threatened terrestrial Birds, Mammals and Amphibians. Additional taxonomic groups that have been comprehensively assessed will be incorporated when current and historical Area of Habitat maps are available.

STAR Scores for any Area of Interest ( AOI; a site, administrative region, corporate footprint, etc) are calculated in two ways; firstly to assess the potential for reducing extinction risk by abating the threats to the species present at the AOI (the STAR-t score in the STAR report), and secondly to assess the potential for reducing species extinction risk by restoring habitat for species that have been lost from the AOI (the STAR-r score in the STAR report). The STAR-t score is generated by calculating the proportion of each species’ extent of current Area of Habitat (AOH) that is within the Area of Interest, weighting that value by the species’ extinction risk (Near-Threatened, Vulnerable, Endangered or Critically Endangered), and then adding up the total of those values. The contribution of each threat to the total STAR score for the AOI is the sum of the contributions of that threat to each of the species present at the AOI. The STAR-r score is calculated in a similar way, but instead of using the species’ current AOH, the calculation uses the historical AOH to assess the amount of habitat for the species that could be restored in the AOI. The STAR-r value is then adjusted by a multiplier of 0.3 (effectively a discount rate) as the impact of restoration on species extinction risk is slower and more risky than that of abatement of risks in existing habitat.

IBAT released an introductory webinar on STAR, and have developed an Industry Briefing Note on STAR, as well as a more in-depth Business User Guidance. The scientific publication on STAR is available at Mair et al., 2021.

STAR data for the global terrestrial surface are mapped to 5-km grid squares and are available to subscribers through the IBAT portal.

STAR offers users a scientifically robust method of assessing and comparing opportunities to reduce species extinction risk in particular places- sites, administrative units or corporate footprints. STAR reports indicate how users can assess, reduce and manage biodiversity extinction risk. Examples of applications include comparing possible nature-positive investments, planning project or site-level biodiversity threat mitigation and offsets, assessing and managing project-related biodiversity impact risk, and investment portfolio selection. In addition STAR is appropriate for setting and tracking progress towards corporate targets and international policy goals, such as those due to be developed under the post-2020 Global Biodiversity Framework and the Sustainable Development Goals.

STAR is primarily designed to quantify and guide actions that bring about reductions in species extinction risk. However, STAR can also provide a quantification of biodiversity risk, through comparison of the relative importance of threats identified at a site as part of the STAR score with the activities of a particular business at the site. If corporate activities are likely to increase the magnitude of threats at a site, particularly those threats that have high STAR scores, then STAR can be used to identify the kinds of actions necessary to mitigate these threats. This type of screening should be done in conjunction with IBAT’s other core datasets -the World Database on Protected Areas, the Key Biodiversity Areas database and threatened species distributions from the IUCN Red List of Threatened Species. These data sets can identify other kinds of biodiversity-related risk, for instance that caused by activity within or adjacent to protected areas.

Low STAR scores mean that an area does not represent such a large opportunity to reduce the global extinction risk of threatened species of birds, mammals and amphibians, compared to some other parts of the world. This may mean that an intervention at that site may represent a lower risk of biodiversity impacts compared to sites that have high scores. STAR scores for individual pixels in the report are presented through categories from “Very Low” to “Very High”, but it should be recognised that even in “Very Low” grid cells, there is often still important biodiversity present, and it should not be assumed that these areas have no biodiversity significance.

Additionally, STAR’s focus on globally threatened and near-threatened species may underestimate the biodiversity significance of an area that supports species in taxonomic groups or on national Red Lists that are not included in the current STAR layer. Low STAR scores may also occur where the only species present in the AOI are widely distributed threatened species, as the opportunity to reduce species extinction risk at an AOI that represents a small part of a widely distributed species’ range is small. For example, African savannas supporting high numbers of threatened but wide-ranging animals such as vultures, antelope, and lions may show relatively low STAR values but provide significant opportunities for conservation action. Low scores may also mean that species-focused action is not the most appropriate conservation intervention at a particular site and that other activities may be required to deliver conservation outcomes, for instance ecosystem conservation.

There are plans to include freshwater and marine species in STAR over the next few years.

STAR has three phases. 1) An Estimated STAR score based on published global species distribution data and threat information from the IUCN Red List of Threatened Species (available through IBAT Reports), 2) the Calibrated STAR score that confirms the presence of threats and species at a site, establishing a baseline against which conservation management can be planned and targets set, and 3), a Realized STAR score, which takes into account the measurable reduction of threats generated by management activities. More information on Calibrated and Realized STAR can be found in the Business User Guidance. Standardized methods for calibrated and realized STAR are in development.

Both STAR Reports and the STAR Raster data layer are available through an IBAT Subscription or to download via pay-as-you-go functionality.

Any questions on using STAR for your organization can be directed by email to where a member of the STAR team will be able to respond.

The plan is to work towards updates of the Estimated STAR layer after updates of the IUCN Red List assessments. It is anticipated that this will happen every 2-3 years. There will be an update to the existing STAR layers once the initial Early Access period finishes, probably towards the end of 2022.

New information gathered during calibrated and realized STAR will be very valuable to contribute to Red List species reassessments . All new data of this kind can be sent to

We are developing a routine accessible through the IBAT portal to calculate individual species’ STAR scores by AOI. It is anticipated that this will be available at the end of 2022.

STAR can be a very powerful mechanism to generate objective evidence for NNL/Net Gain commitments. The most simple way for this to happen is for companies wishing to make such commitments to assess the potential for delivering species extinction risk reduction in the sites or places around the world where they have direct authority to change management practices, either themselves or through suppliers or service providers. Once the potential for species extinction risk reduction has been assessed through the Estimated STAR-t and STAR-r reports available through IBAT, a company could then take the following steps:

- Evaluate the sites/ locations where there is the maximum opportunity to reduce species extinction risk.
- Identify in those sites which aspects of the production or sourcing process that the company benefits from are likely to be linked to the threats affecting the species present.
- Using the guidance on moving from Estimated to Calibrated to Realised STAR, set targets to reduce species extinction risk in the priority sites, and apply management to deliver the targets.

KBAs are able to deliver a large proportion of global STAR, but the extinction reduction contribution measured by STAR that can be made at a particular KBA refers only to globally threatened and Near-threatened species (KBA Criterion A1), not those species that trigger KBA status for the AOI because they represent a certain proportion of the global population of Geographically Restricted species (KBA criteria B1, B2, B3) or species with Demographic Aggregations (KBA criteria D1 or D2).

We are working on a publication about the experience of companies and NGOs in the use of STAR.

Users should measure their Delivered STAR values compared to a specific STAR dated layer used for the Calibrated STAR calculation. Each updated STAR layer will have a version code that should be used as the basemap for further analyses.

In practice at the moment, it is not possible to distinguish between the threats that apply to one species compared to another, at least at the Estimated STAR stage. Management proposals developed for sites to reduce species extinction risk will address those threats that contribute the most to the STAR score. Ideally abating both would be the best. It may be that it is simpler to abate the threat for a CR species, as the number of threats requiring abatement will likely be fewer for one species than for four. However at a particular AOI, it will likely be the case that abating the threats for the CR species as a priority will contribute significantly to the abatement of threats to the other species.

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