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Butchart, S. H. M.

Publications and source records attributed to Butchart, S. H. M..

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Exploring the use of state of nature metrics to screen global business operations for ecological sensitivity and to select priority sites for disclosure

Businesses are increasingly encouraged to disclose their nature-related dependencies, impacts, risks and opportunities. A common component of sustainability reporting is screening operational sites for ecologically sensitivity to identify locations for further evaluation and action. However, with 600+ biodiversity metrics available, selecting and interpreting appropriate metrics remains challenging for business. We developed a simple screening framework informed by the Taskforce for Nature-Related Financial Disclosures guidance, grouping eleven widely used global biodiversity metrics into four complementary [&prime]baskets[&prime], representing different aspects of biodiversity. We created hypothetical but realistic mining, onshore wind energy and agricultural companies, to assess how metric choice, buffer size, scoring approach and sensitivity thresholds influence screening outcomes. Our basket framework consistently identified similar high-priority sites across metric combinations, but site rankings varied with methodological choices. We recommend clearer guidance on metric selection and application, alongside greater transparency from business regarding assumptions, methods and limitations when screening sites for ecological sensitivity.

ecology↗

Global threat abatement potential for terrestrial vertebrates

1.AimThe Species Threat Abatement and Restoration (STAR) metric was developed to support setting and measuring progress towards science-based targets for species conservation, in alignment with the Kunming-Montreal Global Biodiversity Framework. The STAR metric quantifies the potential reduction in species global extinction risk achievable through actions to abate threats (START) and restore habitat (STARR). The STAR metric is used across multiple sectors to assess contributions to nature-positive species outcomes and implement action for biodiversity. Here we present a substantially enhanced global estimate of START for terrestrial vertebrates. Developed in response to user demand, this work integrates advancements in methodology and data quality, increased spatial resolution, and addition of reptile species. LocationGlobal Time PeriodCurrent Major taxa studiedTerrestrial vertebrates MethodsSTART was estimated at 1km2 resolution for 9,100 species of threatened and Near Threatened birds, mammals, amphibians and reptiles, using IUCN Red List assessments (version 2025-1) and area of habitat (AOH) maps generated using an advanced data-driven methodology and satellite-derived land-cover data. AOH maps were validated using a two-stage protocol using species observation data. ResultsThe six countries with the highest estimated START scores, and therefore the largest individual potential to reduce global extinction risk via tackling threats nationally were Brazil, Madagascar, Indonesia, Mexico, Ecuador and Colombia (each contributing over 5% of global estimated START). The threat with the greatest individual potential to reduce extinction risk was annual and perennial non-timber crops (21.2% of global START). Main conclusionsTargeted actions to tackle a few high-impact threats in a few discrete locations, and cumulative effort across multiple areas with lower individual potential, are both required to meaningfully reduce species extinction risk through threat abatement. This global scale estimation of START enables consistent scoping of conservation opportunity over large areas and provides the critical initial data to support planning and action.

zoology↗

Identifying and ranking species that need urgent management action to achieve Target 4 of the Global Biodiversity Framework

Target 4 of the Kunming-Montreal Global Biodiversity Framework (KMGBF) calls for urgent management actions to halt humaninduced extinctions and enable species recovery. However, most Parties face substantial challenges in determining which species require urgent management actions. Here, we present a transparent, standardised protocol that identifies and ranks species most likely to need urgent management actions at the national level, using globally available data from the IUCN Red List of Threatened Species. The protocol integrates four criteria aligned with Target 4: global extinction risk, rate of decline, population or range restriction, and endemism, to generate a national ranked list of species. Species scoring highly on these four criteria, and therefore most in need of urgent management action, are ranked most highly. We applied this method to all 250 countries and territories listed in the IUCN Red List and pilottested national rankings with participants from eight diverse countries. Across pilots, participants reported that the ranked lists were scientifically robust, timesaving, and valuable starting points for national prioritysetting, while stating the importance of national context, and the need for additional technical and financial support for implementation. Our results demonstrate that a sciencebased approach can meaningfully support Parties in identifying species requiring urgent action under Target 4, in a standardised way. With 2030 approaching rapidly, this protocol provides an immediate, practical tool to accelerate progress toward halting extinctions and advancing species recovery.

ecology↗

A functional Red List Index for monitoring trends in functional diversity

Functional diversity supports ecosystem function and resilience but is in decline due to ongoing extinctions. Despite this, no functional diversity metrics are included in the set of indicators adopted by governments to measure progress towards the Global Biodiversity Framework. Monitoring changes in functional diversity is essential to understand differences between taxonomic and functional diversity trends. The Red List Index (RLI) is a widely used metric in conservation policy, and tracks trends in aggregate extinction risk across sets of species over time. We present a functional Red List Index (fRLI), which weights species by their morphological uniqueness at either local or global scales, to indicate the risk that future extinctions could pose to functional diversity. We applied the fRLI on birds and found higher aggregate extinction risk for both local and global fRLI compared with the standard RLI. Species with higher local uniqueness were more likely to be at higher risk of extinction while we found no difference for globally unique species. Globally or locally unique species were not more likely to show escalation in extinction risk between 1988 and 2024 than less unique species; however, locally unique birds had a lower proportion of their resident range covered by site-based conservation measures, leaving them vulnerable to future decline. The fRLI provides a tool to monitor the impact of extinction risk on functional diversity and could be applied to other taxonomic groups with comprehensive or representative coverage of Red List assessments and trait data.

ecology↗

Predicting the responses of the world's bird species to increases in agricultural production

The intensification and expansion of croplands are among the greatest threats to biodiversity, but the likely responses to these changes remain unknown for most species. Using data on responses of 862 bird species to changes in yields of arable crops, we extrapolate vulnerability to agriculture for the worlds other terrestrial birds based on their traits and taxonomy. We estimate that 74-78% of terrestrial bird species globally suffer population declines where natural habitats are replaced by croplands, and that over half cannot persist in cropland at even the lowest current yields. Past impacts of agriculture on birds have been greatest in the tropics, particularly in coastal forest regions of Central and South America and West Africa and in southern and South-East Asia. Using these estimates to model the impacts of future scenarios of agricultural change, we find that continuing current rates of cropland expansion and yield increases (i.e., extrapolating business-as-usual trends to 2050) is expected to have more negative impacts on birds (particularly in Central and South America, Eastern Europe, sub-Saharan Africa and South and East Asia) than a potential alternative of a targeted strategy of closing yield gaps while limiting cropland expansion. However, we also identify biodiverse regions of the world where closing yield gaps may have more severe impacts on birds than business-as-usual, such as the Pampas of South America and parts of the Sahel region in West Africa. The strategy of least impact for a particular area can be predicted from the response characteristics of the communities of species present there, offering opportunities to take account of regional context for designing less damaging global food production systems.

ecology↗

Making the Monitoring Framework of the Kunming-Montreal Global Biodiversity Framework fit for purpose.

The Kunming-Montreal Global Biodiversity Framework (GBF) is the most ambitious agreement on biodiversity conservation and sustainable use to date. It calls for a whole-of government and whole-of-society approach to halt and reverse biodiversity loss worldwide. The Monitoring Framework of the GBF lays out how Parties to the Convention on Biological Diversity (CBD) are expected to report their progress. A CBD expert group provided guidance on its implementation, including a gap analysis to identify the strengths and limitations of the indicators in the Monitoring Framework. We present the results of the gap analysis, highlight where more work is needed and provide recommendations on implementing and improving monitoring to allow effective and comprehensive tracking of the GBFs ambition. We find that with the headline and binary indicators, which Parties are required to use, the Monitoring Framework fully covers 19% of the GBFs ambition and partially covers an additional 40%. Including disaggregations of the headline indicators improves coverage to 22% fully and an additional 41% partially. Adding optional (component and complementary) indicators brings full coverage to 29% with an additional 47% partial coverage. No indicators are available for 12% of the GBF. In practice, the coverage of the Monitoring Framework will depend on which indicators (headline and binary as well as component and complementary) and disaggregations are used by countries. Disaggregations are particularly relevant to monitor the cross-cutting considerations defined under section C. Substantial investment is required to collect the necessary data to compute indicators, infer change, and effectively monitor progress. We highlight important next steps to progressively improve the efficacy of the Monitoring Framework.

ecology↗

What works to improve species conservation state? An analysis of species whose state has improved and the actions responsible

Understanding the consequences of past conservation efforts is essential to inform the means of maintaining and restoring species. Data from the IUCN Red List for 67,217 comprehensively assessed animal species were reviewed and analysed to determine (i) which conservation actions have been implemented for different species, (ii) which types of species have improved in state and (iii) which actions are likely to have driven the improvements. At least 51.8% (34,847) of assessed species have actions reported, mostly comprising protected areas (82.7%), with more actions reported for both terrestrial tetrapods and warm-water reef-building corals and fewer for fish, dragonflies and damselflies and crustaceans. Species at greater risk of extinction have a wider range of species-targeted actions reported compared to less threatened species, reflecting differences in documentation and conservation efforts. Six times more species have deteriorated rather than improved in their Red List category. Almost all species that improved have conservation actions in place; species that improved in state typically were historically at high risk of extinction, have smaller ranges and lacked a range of reported threats, particularly hunting and habitat loss or degradation. All types of conservation action were associated with improvements in state, especially reintroductions and invasive species control, alongside, for amphibians and birds, area management. This suggests a range of conservation interventions have successfully conserved some species at greatest risk but have rarely recovered populations to resilient levels. Scaling up the extent and intensity of conservation interventions, particularly landscape-scale actions that benefit broadly distributed species, is urgently needed to assist the recovery of biodiversity.

zoology↗

Area of Habitat maps for the world's terrestrial birds and mammals

Area of Habitat (AOH) is the habitat available to a species, that is, habitat within its range. It complements a geographic range map for a species by showing potential occupancy and reducing commission errors. AOH maps are produced by subtracting areas considered unsuitable for the species from their range map, using information on each species associations with habitat and elevation. We present AOH maps for 5,481 terrestrial mammal and 10,651 terrestrial bird species (including 1,816 migratory bird species for which we present separate maps for the resident, breeding and non-breeding areas). Our maps have a resolution of 100 m. On average, AOH covered 66{+/-}28% of the range maps for mammals and 64{+/-}27% for birds. The AOH maps were validated independently, following a novel two-step methodology: a modelling approach to identify outliers and a species-level approach based on point localities. We used AOH maps to produce global maps of the species richness of mammals, birds, globally threatened mammals and globally threatened birds.

ecology↗

The costs of global protected-area expansion (Target 3 of the post-2020 Global Biodiversity Framework) may fall more heavily on lower-income countries

One of the biggest stumbling blocks for global environmental agreements is how higher-income and lower-income countries share the costs of implementing them. This problem has become particularly acute as biodiversity and climate ambitions have increased across recent COPs (Conferences of Parties). Here, we estimate the likely distribution of costs for one of the most ambitious proposals: draft Target 3 of the Global Biodiversity Framework (GBF), which would increase coverage of protected and conserved areas (PCAs) to 30% of global land and sea area - more than triple the current value. Since the GBF does not specify where new PCAs would be placed, we use three scenarios of how Target 3 might be implemented, cost those scenarios, and then compare the mean distribution of costs across World Bank income groups. We find that in relative terms, lower-income countries could face considerably larger financial burdens than high-income countries, even though the benefits of conservation are disproportionately enjoyed by high-income countries. Lower-income countries would also face larger increases in the amount of land or sea under conservation, implying higher opportunity and establishment costs. Resolving this potential cost-sharing inequity may be a key requirement to achieve consensus on draft Target 3, and indeed on ambitious environmental proposals more generally.

ecology↗

A validation standard for Area of Habitat maps for terrestrial birds and mammals

Area of Habitat (AOH) is a deductive model which maps the distribution of suitable habitat at suitable altitudes for a species inside its broad geographical range. AOH maps have been validated using presence-only data for small subsets of species for different taxonomic groups, but no standard validation method exists when absence data are not available. We develop a novel two-step validation protocol for AOH which includes first a model-based evaluation of model prevalence (i.e, the proportion of suitable habitat within a species range), and second a validation using species point localities (presence-only) data. We applied the protocol to AOH maps of terrestrial birds and mammals. In the first step we built logistic regression models to predict expected model prevalence (the proportion of the range retained as AOH) as a function of each species elevation range, mid-point of elevation range, number of habitats, realm and, for birds, seasonality. AOH maps with large difference between observed and predicted model prevalence were identified as outliers and used to identify a number of sources of systematic error which were then corrected when possible. For the corrected AOH, only 1.7% of AOH maps for birds and 2.3% of AOH maps for mammals were flagged as outliers in terms of the difference between their observed and predicted model prevalence. In the second step we calculated point prevalence, the proportion of point localities of a species falling in pixels coded as suitable in the AOH map. We used 48,336,141 point localities for 4889 bird species and 107,061 point localities for 420 mammals. Where point prevalence exceeded model prevalence, the AOH was a better reflection of species distribution than random. We also found that 4689 out of 4889 (95.9%) AOH maps for birds, and 399 out of 420 (95.0%) AOH maps for mammals were better than random. Possible reasons for the poor performance of a small proportion of AOH maps are discussed.

zoology↗

A habitat class to land cover translation model for mapping Area of Habitat of terrestrial vertebrates

Area of Habitat (AOH) is defined as the habitat available to a species, that is, habitat within its range and is produced by subtracting areas of unsuitable land cover and elevation from the range. Habitat associations are documented using the IUCN Habitats Classification Scheme, and unvalidated expert opinion has been used so far to match habitat to land-cover classes generating a source of uncertainty in AOH maps. We develop a data-driven method to translate IUCN habitat classes to land-cover based on point locality data for 6,986 species of terrestrial mammals, birds, amphibians and reptiles. We extracted the land-cover class at each point locality and matched it to the IUCN habitat class(es) assigned to each species occurring there. Then we modelled each land cover class as a function of IUCN habitat using logistic regression models. The resulting odds ratios were used to assess the strength of the association of each habitat land-cover class. We then compared the performance of our data-driven model with those from a published expert knowledge translation table. The results show that some habitats (e.g. forest and desert) could be more confidently assigned to land-cover classes than others (e.g. wetlands and artificial). We calculated the association between habitat classes and land-cover classes as a continuous variable, but to map AOH, which is in the form of a binary presence/absence, it is necessary to apply a threshold of association. This can be chosen by the user according to the required balance between omission and commission errors. We demonstrate that a data-driven translation model and expert knowledge perform equally well, but the model provides greater standardization, objectivity and repeatability. Furthermore, this approach allows greater flexibility in the use of the results and allows uncertainty to be quantified. Our model can be developed regionally or for different taxonomic groups.

ecology↗

Preventing extinctions post-2020 requires recovery actions and transformative change

Stopping human-induced extinctions will require strong policy commitments that comprehensively address threats to species. In 2021, a new Global Biodiversity Framework will be agreed by the Convention on Biological Diversity. Here we investigate how the suggested targets could contribute to reducing threats to threatened vertebrates, invertebrates, and plants, and assess the importance of a proposed target to implement recovery actions for threatened species. We find that whilst many of the targets benefit species, extinction risk for over one third of threatened species would not be reduced sufficiently without a target on recovery actions, including ex situ conservation, reintroductions and other species-specific interventions. A median of 41 threatened species per country require such actions, and they are found in most countries of the world. To prevent future extinctions, policy commitments must include recovery actions for the most threatened species in addition to broader transformative change.

ecology↗

Effectiveness of protected areas in conserving tropical forest birds

Protected areas are the cornerstones of global biodiversity conservation efforts1,2, but to fulfil this role they must be effective at conserving the ecosystems and species that occur within their boundaries. This is particularly imperative in tropical forest hotspots, regions that concentrate a major fraction of the worlds biodiversity while also being under intense human pressure3-5. But these areas strongly lack adequate monitoring datasets enabling to contrast biodiversity in protected areas with comparable unprotected sites6,7. Here we take advantage of the worlds largest citizen science biodiversity dataset - eBird8 - to quantify the extent to which protected areas in eight tropical forest biodiversity hotspots are effective at retaining bird diversity, and to understand the underlying mechanisms. We found generally positive effects of protection on the diversity of bird species that are forest-dependent, endemic to the hotspots, or threatened or Near Threatened, but not on overall bird species richness. Furthermore, we show that in most of the hotspots examined this is driven by protected areas preventing both forest loss and degradation. Our results support calls for increasing the extent and strengthening the management efforts within protected areas to reduce global biodiversity loss9-11.

ecology↗

Conservation attention necessary across at least 44% of Earth’s terrestrial area to safeguard biodiversity

More ambitious conservation efforts are needed to stop the global biodiversity crisis. Here, we estimate the minimum land area to secure important sites for terrestrial fauna, ecologically intact areas, and the optimal locations for representation of species ranges and ecoregions. We discover that at least 64 million km2 (44% of terrestrial area) requires conservation attention. Over 1.8 billion people live on these lands so responses that promote agency, self-determination, equity, and sustainable management for safeguarding biodiversity are essential. Spatially explicit land-use scenarios suggest that 1.3 million km2 of land requiring conservation could be lost to intensive human land-uses by 2030, which requires immediate attention. However, there is a seven-fold difference between the amount of habitat converted under optimistic and pessimistic scenarios, highlighting an opportunity to avert this crisis. Appropriate targets in the post-2020 Global Biodiversity Framework to ensure conservation of the identified land would contribute substantially to safeguarding biodiversity.

ecology↗

Area requirements to safeguard Earth’s marine species

Despite global policy commitments to preserve Earths marine biodiversity, many species are in a state of decline. Using data on 22,885 marine species, we identify 8.5 million km2 of priority areas that complement existing areas of conservation and biodiversity importance. New conservation priorities are found in over half (56%) of all coastal nations, with key priority regions in the northwest Pacific Ocean and Atlantic Ocean. We identify where different conservation actions, ranging from marine protected areas to broader policy approaches, may best overcome anthropogenic threats to these areas. This analysis shows 26-41% of the ocean (depending on targets used for species representation) needs to be effectively conserved through a combination of site-based actions and wider policy responses to achieve global conservation and sustainable development agendas.\n\nOne Sentence SummaryAt least 26% of the ocean needs a combination of site-based conservation and wider policy responses to achieve global conservation goals.

ecology↗