Conservation Biology

In recent years, vertebrate population abundance has declined at unprecedented rates (WWF 2020). In response, targeted conservation measures - such as breeding programs or species-specific habitat management - have been applied to halt population declines, aid population recovery, and reduce and reverse the loss of biodiversity (Salafsky et al. 2008; Bolam et al. 2020). Until now, assessments of conservation actions have focused on the extent to which they reduce extinction risk, impact populations within protected areas, or increase the global area of land under protection (Hoffmann et al. 2010, 2015; Barnes et al. 2016; Maxwell et al. 2020; Bolam et al. 2020; Grace et al. 2021a). Here, we record and analyze conservation actions for 26,904 vertebrate populations from 4,629 species, to measure the impact of targeted conservation on vertebrate abundance. Using a counterfactual approach to represent population trends in the absence of conservation, we demonstrate that targeted actions have delivered substantial positive effects on the abundance of recipient vertebrate populations worldwide. We show that, in the absence of conservation, a global indicator of vertebrate abundance would have declined even more. Positive population trends were associated with vertebrate populations subject to species or habitat management. We demonstrate that targeted conservation actions can help to reverse global biodiversity loss and show the value of counterfactual analysis for impact evaluation - an important step towards reversing biodiversity declines.

Finite resources dictate that conservation biologists must prioritise some species over others. Conservation metrics, such as EDGE (Evolutionarily Distinct and Globally Endangered; EDGE1) and FUSE (Functionally Unique, Specialised and Endangered), make prioritisation based on species evolutionary or functional distinctiveness, respectively, and degree of threat. EDGE is in part based on the rationale that the evolutionary distinctiveness it captures serves to maximise biodiversity in form and function. However, doubts exist as to whether or not evolutionary distinctiveness truly serves as a proxy for functional distinctiveness, and, therefore, if the prominent use of EDGE lists by conservation practitioners adequately protects functional distinctiveness. To address this, we conducted a direct global comparison of EDGE against FUSE. Unlike EDGE, FUSE directly measures and prioritises functional distinctiveness. Here, we compare EDGE and FUSE scores for two well-studied groups: mammals (n = 5319 species) and birds (n = 7932 species). These groups are central to global conservation and, until now, have not been assessed under FUSE. We find that species rankings under EDGE and FUSE differ significantly, highlighting that these two metrics capture distinct, complementary aspects of biodiversity. This suggests that conservation strategies based solely on EDGE may overlook species with critical functional roles. Rather than assuming alignment between evolutionary and functional distinctiveness, we propose integrating both within a single measure, leveraging the strengths and benefits of each. To this end, we present a new conservation metric - EFUSE (Evolutionarily and Functionally Unique, Specialised, and Endangered) - which incorporates both evolutionary and functional distinctiveness into a single measure. EFUSE ensures that important components of biodiversity, which relate to ecosystem functioning, natures future contributions to people, and the intrinsic value of species, are adequately maximised in conservation decision-making.

As habitat loss is a major driver of amphibian population declines, protected areas (PAs) can play a crucial role in amphibian conservation. Documenting how well the global PA network captures the evolutionary history of amphibians can inform conservation prioritisation and action. We conducted a phylogenetic gap analysis to assess the extent to which amphibian phylogenetic diversity (PD) is unprotected by the PA network and compared this to other terrestrial vertebrate groups. 78% of amphibian species and 64% of global amphibian PD remains unprotected, which is higher than corresponding figures for squamates, mammals and birds. Amongst amphibians, salamanders were the least well protected, with 78% of PD unprotected, compared with 64% for caecilians and 63% for frogs. We identify areas that offer the greatest opportunity to capture unprotected amphibian evolutionary history. We could capture an additional 29.4% of amphibian PD, representing 40 billion years of evolutionary history, by protecting an additional 1.9% of global amphibian distributions (1.74% of global land area) and increasing the restrictions in 0.6% of amphibian distributions to match the management objectives of PAs in IUCN categories I or II. Importantly, we found that the spatial distribution of unprotected PD was correlated across all groups, indicating that expanding the PA network to conserve amphibian PD can secure imperilled vertebrate diversity more generally.

Protected areas (PAs) are the last refuges for wild biodiversity, yet human pressures (or threats) are increasingly prevalent within their boundaries. Human pressures have the potential to negatively impact species and undermine their conservation, but their overlap with sensitive threatened species in PAs remains rarely quantified. Here, we analyse the co-occurrence of nineteen threatening human activities within the distributions of 146 threatened terrestrial vertebrates in the European Union (EU), accounting for species-specific sensitivities to each pressure and thereby mapping potential human impacts on species within EU PAs. We find that human pressures extend across > 1.022 million km2 (94.5%) of EU protected land, with potential negative impacts on threatened species across 1.015 million km2 (93.8%). A total of 122 out of 146 species (84%) have > 50% of their EU protected ranges potentially impacted, and 83 out of 146 species (57%) more than 90% of their protected range. More species have a smaller proportion of their protected range potentially impacted in Natura2000 sites than in non-Natura2000 sites, and the same is true for species in nature reserves and wilderness areas compared to less strictly managed PAs. Our results show that threatened species in Europes PAs are exposed to immense human pressures, and suggest that areas designated for species conservation are ineffective for halting biodiversity decline. We recommend that the EU Biodiversity Strategy develops and enforces a comprehensive PA threat management program to reduce the negative impacts of human activities on wildlife in European protected lands.

Even during ongoing global biodiversity losses and extinctions, numerous species have shown recoveries in terms of increased abundance and/or range extent. Understanding the mechanisms that contribute to, or limit, these recoveries is critical not just to ensure they continue, but to promote similar recoveries across broader ecosystems. Here, we explore the changes in abundance and range extent of selected 47 recovering species (24 mammals and 23 birds) in Europe using official data reported by EU Member States and supplemented using the Living Planet Index database. We investigate how the diversity of ongoing threats and conservation measures contribute to the likelihood and extent of recoveries. For birds, long-term recoveries were less likely among species impacted by a greater diversity of threats, although this may be mitigated by the diversity of conservation measures in place. Similarly, for mammals, populations with reported threats recovered less quickly while those with management actions in place recovered more quickly. To achieve the aims of the UN Decade on Restoration, we need to ensure, even for recovering species, that threats continue to be reduced and that conservation management actions are ongoing and effective.

Biological invasions threaten biodiversity, ecosystem services, human health, and cultural heritage, yet their impacts are often underappreciated, leading to insufficient management efforts and suboptimal conservation results. We argue that the lack of quantitative, continuous metrics of impact of invasive alien species (IAS) contribute this lack of appreciation. To bridge this knowledge-action gap, we propose the Extinction Potential Metric (EPM), a suite of quantitative metrics designed to assess the ecological damage caused by IAS. The EPM score of an IAS is the number of current and future species extinctions attributable to this IAS over the next 50 years under a business-as-usual scenario. EPM includes three variants: EPM-A (absolute EPM), EPM-R (relative EPM, which accounts for other anthropogenic pressures), and EPM-U (EPM for Unique species, adjusted for phylogenetic uniqueness of impacted native species), to capture different dimensions of IAS impacts. We applied EPM to evaluate the impact of IAS on 2178 amphibians, 920 birds, 865 reptiles, and 473 mammals. Our analyses revealed that the impact of the worst IAS was between 90 and 380 times higher than any IAS with an impact of 1 extinct native species. Importantly, several of the most impactful IAS disproportionately affect evolutionarily unique native species. The EPM framework offers a standardised approach for measuring ecological impacts of IAS but also other anthropogenic pressures at different spatial, temporal, and taxonomic scales. EPM could also guide the development of standardised indicators for assessing the impacts of other anthropogenic stressors. Ultimately, EPM will pave the way to answer ecological questions important to design better conservation policies, to enhance the management of biological invasions and reach global biodiversity conservation goals.

Among the conservation community, it is well known that Earths mass species extinction crisis is getting worse. Yet, an often neglected problem is the need for effectively communicating the species extinction crisis to diverse audiences in ways that catalyse immediate action. Here we generated a streamlined threatened species recovery report card methodology, which combined two input indicators including planning and funding, one output indicator capturing habitat protection, and one outcome indicator which highlights threatened species trajectories, to provide simple scores for all Australian threatened species. We show that just 41 (2.3%) of species achieved an A grade for the input indicator (i.e., recovery plans and federal funding), 240 (13.3%) achieved a C grade, and 1,521 (84.4%) achieved an F. Five hundred and twenty nine (29.3%) species achieved an A for the output indicator (i.e, habitat protection), 130 (7.2%) achieved a B, 158 (8.8%) achieved a C, 189 (10.5%) achieved a D, 212 (11.8%) achieved an E, and 584 (32.4%) achieved a F. While five (0.3%) species achieved an A for the output indicator (i.e., threat status improvement), every other species (99.7%) achieved an F. We provide a method to combine scores to test how individual jurisdictions are tracking and show that Australia is achieving an F for the input and outcome indicators, and a D for the output indicator. While the threatened species recovery report card highlighted a clear failure in many federal environmental legislation responsibilities, it provides a baseline from which different governments can track policy progress and outlines clear direction for immediate improvement including developing adequate recovery plans, funding the actions in the recovery plans, protecting habitat from further destruction, verifying recovery through monitoring and evaluation of species trajectories, and supporting transparency and collaboration on the execution on the plans through an improved data infrastructure. Without an immediate step change in how Australia communicates and faces its species crisis, we will leave a tragic legacy of extinction and fail our obligations to future generations of Australians, and the international community.

An increasing number of countries in the Global North have enacted, or are considering, import bans on hunting trophies to protect wildlife. We interrogate arguments used to characterize trophy hunting using data from the Convention on International Trade in Endangered Species (CITES), the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, and empirical research. We show that trophy hunting is not a major threat to any CITES-listed species traded as a trophy during 2000-2022. Yet, 60% of global trade in trophies involving these species may be impacted by bans, with significant implications for conservation. We therefore question whether such legislative actions are proportionate. Wildlife trade solutions may appear simple but evidence-based policy is needed to conserve biodiversity and avoid harming people.

Protecting habitat of species-at-risk is critical to their recovery, but can be contentious. For example, protecting species that are locally imperilled but globally common (e.g. species that only occur in a jurisdiction at the edge of their geographic range) is often thought to distract from protecting globally-imperilled species. However, such perceived trade-offs are based on the assumption that threatened groups have little spatial overlap, which is rarely quantified. Here, we compile range maps of terrestrial species-at-risk in Canada to assess the geographic overlap of nationally and globally at-risk species with each other, among taxonomic groups, and with protected areas. While many nationally-at-risk taxa only occurred in Canada at their northern range edge (median=4% of range in Canada), nationally-at-risk species were not significantly more peripheral in Canada than globally-at-risk species. Further, 56% of hotspots of nationally-at-risk taxa were also hotspots of globally-at-risk taxa in Canada, undercutting the perceived trade-off in their protection. Hotspots of nationally-at-risk taxa also strongly overlapped with hotspots of individual taxonomic groups, though less so for mammals. While strong spatial overlap across threat levels and taxa should facilitate efficient habitat protection, <7% of the area in Canadas at-risk hotspots is protected, and more than 70% of nationally and globally-at-risk species in Canada have <10% of their Canadian range protected. Our results counter the perception that protecting nationally vs. globally at-risk species are at odds, and identify critical areas to target as Canada strives to increase its protected areas and promote species-at-risk recovery.

Ensuring that species of conservation concern achieve favorable conservation status (FCS) is central to European Union (EU) biodiversity conservation targets. A key criterion for FCS is exceeding the favorable reference range (FRR)--the range extent needed for long-term species stability and full ecological variation. However, due to data limitations, FRRs are often unknown, undermining their applicability. We developed a machine-learning approach to estimate and standardize FRRs across the EU. Applied to amphibians, mammals, and reptiles, our method provided FRRs for 99.5% of species of conservation concern, compared to 17.5% previously available (with satisfactory modelling performance: R2 0.75). We reassessed conservation status using the estimated FRRs, finding that species in FCS (34.8%) are notably fewer than reported in official documentation (69.1%). The average proportional distance to FRR for species in unfavorable conservation status is -64.4%. Our approach may support periodic FCS reassessments and help refine the targets of EU conservation policies.

Conserving and managing biodiversity in the face of ongoing global change requires sufficient evidence to assess status and trends of species distributions. Here we analyze national trajectories in closing spatiotemporal knowledge gaps for terrestrial vertebrates (1950-2019) based on novel indicators of data coverage and sampling effectiveness. Despite a rapid rise in data coverage, particularly in the last two decades, strong geographic and taxonomic biases persist. For some taxa and regions, a tremendous growth in records failed to directly translate into newfound knowledge due to a sharp decline in sampling effectiveness. But nations coverage is stronger for species they hold greater stewardship for. As countries under the post-2020 Global Biodiversity Framework renew their commitments to an improved, rigorous biodiversity knowledge base, our findings highlight opportunities for international collaboration to close critical information gaps.

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.

Climate change causes global species redistribution and elevates extinction risk, making early identification of vulnerable species critical for timely conservation. The IUCN Red List provides guidelines for assessing climate-related extinction risk using species distribution models (SDMs) and spatially explicit population models (SEPMs). However, a systematic evaluation of these guidelines is currently missing. Using simulations of virtual species with diverse life-history traits and range dynamics, we found that SDMs consistently underestimated extinction risk for range-shifting species. This was due to a concave relationship between population size and habitat loss, which contradicts the linear assumption in the Red List guidelines. For range-contracting species, SDMs provided adequate warning times. Probabilistic extinction estimates from SEPMs provided delayed warning for all species, particularly for highly threatened ones. Our results reveal key limitations of current Red List guidelines under climate change. Based on our findings, we provide tentative recommendations for updating the IUCN Red List guidelines.

While the importance of ecosystem integrity has long been recognised (Leopold, 1949), conservation science has tended to focus on measuring and monitoring species and habitats, avoiding the complexities of working at the ecosystem level. Ecosystems are highly dynamic, defined by both living and non-living components as well as their interactions (CBD, 1992), making it difficult to assess baseline levels of integrity. We present a novel index that represents the integrity of all terrestrial ecosystems globally at 1km2 resolution: the Ecosystem Integrity Index (EII). The index provides a simple, yet scientifically robust, way of measuring, monitoring and reporting on ecosystem integrity. It is formed of three components; structural, compositional and functional integrity, and measured against a natural (current potential) baseline on a scale of 0 to 1. We find that ecosystem integrity is severely impacted in terrestrial areas across the globe with approximately one fifth of all ecosystems and one quarter of all ecoregions having lost, on average, over half of their ecosystem integrity. At a national scale, we estimate similar challenges with 115 nations or territories having lost, on average, over half of their ecosystem integrity. This presents a significant threat for humanity as such levels of degradation are likely to be linked to substantial declines in the ecosystem services on which humanity is reliant. The EII has been developed principally to help national governments measure and report on Goal A of the Kunming-Montreal Global Biodiversity Framework (GBF) (CBD, 2022a), for which it has been listed as a Component Indicator. The EII will also be useful in helping non-state actors measure and report their contributions to the GBF and is listed as an indicator by both the Taskforce for Nature-Related Financial Disclosures (TNFD) (TNFD, 2023) and the Science Based Targets Network (SBTN) (SBTN, 2023). The EII aims to enable these actors to make informed decisions on the conservation, restoration and sustainable use of ecosystems for which they are wholly or partly responsible. We propose that with sufficient effort, ecosystem integrity can be restored and contribute towards the GBFs vision of living in harmony with nature, resulting in the safeguarding of the ecosystem services on which humanity depends.

In recent decades, increased anthropogenic impact has led to a global decline in genetic diversity. Before the Kunming-Montreal Global Biodiversity Framework (2022), the absence of international consensus on how to directly assess and monitor genetic diversity, hampered large-scale conservation efforts. Scarcity of assessable genetic data has hindered the evaluation of conservation policies in safeguarding genetic diversity. This study presents the first global approach for evaluating the protection of genetic diversity. By examining the global distribution of mammalian intraspecific mitochondrial DNA and protected area coverage, we identify regions with high genetic diversity and insufficient protection coverage, e.g. regions of critical importance for biodiversity in the Brazilian Atlantic Forest. Additionally, we estimate the impact of global change scenarios on genetically diverse regions with a low degree of protection, revealing high vulnerability of areas in Central Africa. Nonetheless, integrating robust analysis into conservation planning remains challenging. Incorporating Macrogenetics into conservation planning holds the potential to reverse biodiversity decline.

Many range-restricted taxa are currently experiencing population declines yet lack fundamental information regarding distribution and population size. Establishing baseline estimates for both these key biological parameters is however critical for directing conservation planning for at-risk range-restricted species. The International Union for the Conservation of Nature (IUCN) Red List uses three range metrics that define species distributions and inform extinction risk assessments: extent of occurrence (EOO), area of occupancy (AOO) and area of habitat (AOH). However, calculating all three metrics using standard IUCN approaches relies on a geographically representative sample of locations, which for rare species is often spatially biased. Here, we apply model-based interpolation using Species Distribution Models (SDMs), correlating occurrences with remote-sensing covariates, to calculate IUCN range metrics, protected area coverage and a global population estimate for the Critically Endangered Philippine Eagle (Pithecophaga jefferyi). Our final range wide continuous SDM had high predictive accuracy (Continuous Boyce Index = 0.927) and when converted to a binary model estimated an AOH = 23,185 km2, a maximum EOO = 605,759 km2, a minimum EOO = 272,272 km2, with an AOO = 53,867 km2. Based on inferred habitat from the AOH metric, we estimate a global population of 318 breeding pairs (range: 258-362 pairs), or 636 mature individuals, across the Philippine Eagle global range. Protected areas covered 34 % of AOH, 15 % less than the target representation, with the continuous model identifying key habitat as priority conservation areas. We demonstrate that even when occurrences are geographically biased, robust habitat models can be built that enable quantification of baseline IUCN range metrics, protected area coverage, and a population size estimate. In the absence of adequate location data for many rare and threatened taxa, our method is a promising spatial modelling tool with widespread applications, in particular for island endemics facing high extinction risk.

Global conservation agreements emphasize protected area coverage targets, such as the Kunming-Montreal Global Biodiversity Frameworks 30x30 target, yet their effectiveness in safeguarding biodiversity remains uncertain. We measure the intersection between marine protected area (MPAs) coverage and the distribution of sharks and rays. Using global range maps and MPA boundaries within national Exclusive Economic Zones, we calculate the percent of species ranges within MPAs, focusing on no-take areas. We reveal significant shortfalls in species-level protection. Within national waters, no Critically Endangered species has more than 5% of its range in no-take MPAs, and 79% of threatened species have less than 1%. We also find the WDPA contains major gaps in take-status reporting, only one third of countries (34%) report take-status of any MPAs to the WDPA, further limiting estimates of meaningful protection. These results highlight the implementation gap between global coverage targets and biodiversity outcomes, reinforcing the need for species-focused protection.

The rapid decline of biodiversity as a consequence of increased environmental impact by human activities requires urgent action against the ongoing crisis. At the heart of conservation policy is the debate on quality versus quantity: should the post-2020 Global Biodiversity Framework focus on maximising total protected area, or pursue instead qualitative targets? To improve conservation practices, we need to both understand the current trend of biodiversity and the factors driving the decline. We address this by: (1) projecting current European butterfly population trends for the next 50 and 100 years, (2) comparing the decline in species richness, phylogenetic diversity and habitat specialization among different habitats, and (3) estimating the relationship between recent trends in habitat quality or quantity and the decline of multiple metrics of European butterfly diversity. We do not find any significant relationship between diversity loss and habitat area loss and conclude that neither long-term nor short-term changes in habitat area are primary predictors of large-scale butterfly decline in Europe. Habitat quality emerges as the most crucial factor in our analyses - both the area affected and the severity of habitat quality reduction. Habitat degradation causes vegetation changes in structure and diversity, which affect butterfly survival. We also estimate a higher decline of habitat specialists than generalist species. We conclude that habitat protection cannot focus solely on the maximization of habitat area but urgently needs to restore high quality ecosystems to provide the full range of ecological requirements for biodiversity.

The international wildlife trade presents severe conservation and environmental security risks. However, no international regulatory framework exists to monitor the trade of species not listed in the appendices of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). We explored the composition and dynamics of internationally regulated versus non-regulated trade, focussing on importations of wild-caught terrestrial vertebrates entering the United States of America (US) from 2009-2018. The prominence of the US in global wildlife imports and its detailed data collection conventions allows a unique opportunity to formally assess this substantial but often overlooked and understudied component of the legal wildlife trade. We found 3.6 times the number of unlisted species in US imports compared with CITES-listed species (1,366 versus 378). CITES-listed species were more likely to face reported conservation threats relative to the unlisted species (71.7% vs 27.5%). Yet, we found 376 unlisted species facing conversation threats, 297 species with unknown population trends and 139 species without an evaluation by the IUCN Red List of Threatened Species. Unlisted species appeared novelly in imports at 5.5 times higher rates relative to CITES-listed species, where unlisted reptiles saw the largest rate of entry, averaging 53 unique species appearing in imports for the first time per year. Overall trade volumes were substantially larger for unlisted imports with approximately 11 times the number of animals relative to CITES-listed imports, however, import volumes were similar when compared at a species-by-species level. We found that the countries that were top exporters for CITES-listed shipments were mostly different from exporters of unlisted species. In highlighting the vulnerabilities of the wild-caught unlisted vertebrate trade entering the US and in the face of increasing global demand, we recommend governments adapt policies to monitor the trade of all wildlife.

Indigenous Peoples lands cover over one-quarter of the Earths surface, a significant proportion of which is still free from industrial-level human impacts. As a result, Indigenous Peoples lands are crucial for the long-term persistence of Earths biodiversity and ecosystem services. Yet, information on species composition within Indigenous Peoples lands globally remains unknown. Here, we provide the first comprehensive analysis of terrestrial vertebrate composition across mapped Indigenous lands by using distribution range data for 20,328 IUCN-assessed mammal, bird and amphibian species. We estimate that 12,521 species (62%) have [&ge;]10% of their ranges in Indigenous Peoples lands, and 3,314 species (16%) have >half of their ranges within these lands. For threatened species assessed, 1,878 (41.5% of all threatened of all threatened mammals, birds and amphibians) occur in Indigenous Peoples lands. We also find that 3,989 species (of which 418 are threatened) have [&ge;]10% of their range in Indigenous Peoples lands that have low human pressure. Our results are conservative because not all known Indigenous lands are mapped, and this analysis shows how important Indigenous Peoples lands are for the successful implementation of international conservation and sustainable development agendas.