Assessment Of Extinction Risk Research Articles

Rising Temperatures, Falling Leaves: Predicting the Fate of Cyprus's Endemic Oak under Climate and Land Use Change.

Endemic island species face heightened extinction risk from climate-driven shifts, yet standard models often underestimate threat levels for those like Quercus alnifolia, an iconic Cypriot oak with pre-adaptations to aridity. Through species distribution modelling, we investigated the potential shifts in its distribution under future climate and land-use change scenarios. Our approach uniquely combines dispersal constraints, detailed soil characteristics, hydrological factors, and anticipated soil erosion data, offering a comprehensive assessment of environmental suitability. We quantified the species' sensitivity, exposure, and vulnerability to projected changes, conducting a preliminary IUCN extinction risk assessment according to Criteria A and B. Our projections uniformly predict range reductions, with a median decrease of 67.8% by the 2070s under the most extreme scenarios. Additionally, our research indicates Quercus alnifolia's resilience to diverse erosion conditions and preference for relatively dry climates within a specific annual temperature range. The preliminary IUCN risk assessment designates Quercus alnifolia as Critically Endangered in the future, highlighting the need for focused conservation efforts. Climate and land-use changes are critical threats to the species' survival, emphasising the importance of comprehensive modelling techniques and the urgent requirement for dedicated conservation measures to safeguard this iconic species.

Amphibian conservation status in Brazil: Spatial patterns, threats, and challenges

Extinction risk assessments are valuable conservation tools, especially for sensitive groups like amphibians, which are facing escalating threats from habitat loss and degradation. In this scenario, Brazil stands out as a pivotal player in amphibian conservation due to its exceptional amphibian diversity. Between 2010 and 2014, 973 amphibian species were assessed in Brazil. More recently, from 2017 to 2018, this number increased to 1096. In this study, we (1) compare the extinction risk status of Brazilian amphibians between the 1st and 2nd assessments; (2) evaluate the reasons for changes in status; (3) identify the main threats and research recommendations; and (4) analyze the spatial patterns of threatened species in relation to protected areas and ecoregions in Brazil. Our findings reveal an increase in the number of threatened species from the first to the second assessment. The categories of Least Concern and Critically Endangered experienced the most significant increases, with 169 and 15 more species, respectively, while the count of Data Deficient species dropped by 71. The primary factor contributing to these changes is the availability of new, more precise information, affecting 134 species, or 85.4% of the cases. Threatened species are predominantly clustered within the Atlantic Forest biome, itself the most endangered biome in Brazil, hosting 46 species, or 78% of the total. Notably, one-third of threatened species in Brazil do not inhabit protected areas and thus require immediate conservation attention. While substantial progress has been made in understanding Brazilian amphibians in recent years, an urgent need persists for fundamental research. This research should encompass taxonomy, natural history, and the evaluation of threat impacts, providing a robust foundation for more effective conservation efforts concerning this group.

Reconstructed and projected beach temperatures reveal where flatback turtles are most at risk from climate change

Nest temperature is the predominant driver of emergence success and primary sex ratios in sea turtles, with female offspring produced at higher temperatures due to temperature-dependent sex determination. However, emergence success and primary sex ratios are unfeasible to measure at scale, making methods to estimate these life-history traits from predicted sand temperatures highly desirable for long-term conservation planning in the context of climate change. To address this, we used a mechanistic microclimate model to predict hourly sand temperatures, over 32 nesting seasons since 1986, at 402 West Australian beaches supporting nesting by flatback turtles (Natator depressus). Predicted sand temperatures indicated that ∼70% of these beaches carried a 'very low' to 'intermediate' risk of subjecting embryos to thermal stress. By combining these temperature predictions with a physiological model, current and future emergence success and sex ratios were projected for ten different beaches spanning a range of thermal microclimates, under various climate change scenarios. Under recent climate conditions, emergence success averaged 76%, but declined to 63% and 37% with a 2°C and 4°C increase in air temperature, respectively. The sex ratios of hatchlings varied by location, but extremely skewed sex ratios were anticipated in a 4°C warming scenario. Our projections reveal that 'high risk' nesting beaches will regularly experience clutch failure as climate change progresses, while cooler beaches offer long-term nesting potential and require protection from additional anthropogenic impacts. These projections, covering an entire genetic stock, supply demographic data for assessing extinction risks and this method can be applied to sea turtle populations worldwide.

Coupling state‐of‐the‐art modelling tools for better informed Red List assessments of marine fishes

Abstract In the face of biodiversity loss worldwide, it is paramount to quantify species' extinction risk to guide conservation efforts. The International Union for the Conservation of Nature (IUCN)'s Red List is considered the global standard for evaluating extinction risks. IUCN criteria also inform national extinction risk assessments. Bayesian models, including the state‐of‐the‐art JARA (‘Just Another Red List Assessment’) tool, deliver probabilistic statements about species falling into extinction risk categories, thereby enabling characterisation and communication of uncertainty in extinction risk assessments. We coupled the state‐of‐the‐art VAST (‘Vector Autoregressive Spatio‐Temporal’) modelling tool and JARA, for better informed Red List assessments of marine fishes. In this framework, VAST is fitted to scientific survey catch rate data to provide indices to JARA whose uncertainty is propagated to JARA outcomes suggesting extinction risk categories (under the population reduction criterion). In addition, VAST delivers a valuable habitat assessment to better understand what may be driving extinction risk in the study region. Here, we demonstrate the coupled VAST‐JARA modelling framework by applying it to five contrasting North Sea species, with or without a quantitative stock assessment and with different conservation statuses according to the latest global Red List assessments. The North Sea application coupled with previous assessments and studies suggest that, among the three elasmobranchs, starry ray is in most need of urgent research (and conservation actions where appropriate), followed by spurdog, while lesser‐spotted dogfish is increasing in biomass. Moreover, both the VAST‐JARA modelling framework and previous research indicate that, while European plaice is not of conservation concern, cod has likely met the IUCN criteria for being listed as Endangered recently. Synthesis and applications. The predictions of the VAST‐JARA modelling framework for North Sea species, including JARA output and VAST habitat assessment, constitute valuable supporting information to make interpretations based on Red List guidelines, which will help decision‐makers in their next North Sea Red List assessment. We foresee applications of the modelling framework to assist Red List assessments of numerous marine fishes worldwide. Our modelling framework has many potential advantageous uses, including informing resource management about climate change impacts on species' extinction risks.

Reducing the number of Data Deficient plant species

Although most plant species have yet to have their extinction risk evaluated for the IUCN Red List, current knowledge of plant diversity suggests that tens of thousands (8%–38% of species) are likely to remain assessed as Data Deficient (DD). This impacts evaluations of the overall proportion of threatened species, as well as on setting appropriate priorities for biodiversity conservation. One of the principle causes of Data Deficiency is taxonomic uncertainty: data permitting an IUCN Red List assessment is often lacking, because species that are poorly known are also taxonomically uncertain. Establishing the taxonomic status of DD species thus assists in determining whether confusion over this is causing their evaluation as DD. In this paper, three separate numerical methods – hierarchical clustering, ordination and phylogenetic ordination – were applied to three independent datasets of standardized traits for plant species from China in order to identify, for each DD species, morphologically similar Non-DD species. Semi-automated analysis of morphological disparity quickly identifies which species are in need of further taxonomic research, as shared traits can indicate either potential synonymy or, otherwise, successful adaptations of distinct species to similar ecological conditions. Extinction risk assessments of morphologically and phylogenetically distinct DD species could then be informed by data on habitat preferences, geographic range or population size from Non-DD species with the most similar traits. Ultimately, determination of the morphological distance between DD species and their most similar Non-DD species, and therefore of differences in the trait space occupied by DD and Non-DD species, could be the basis of future research for improved inference of conservation priorities, and help distinct DD species with similar ecological traits as other taxonomically accepted, threatened species to be identified as being threatened themselves.

More than 17,000 tree species are at risk from rapid global change

Trees are pivotal to global biodiversity and nature’s contributions to people, yet accelerating global changes threaten global tree diversity, making accurate species extinction risk assessments necessary. To identify species that require expert-based re-evaluation, we assess exposure to change in six anthropogenic threats over the last two decades for 32,090 tree species. We estimated that over half (54.2%) of the assessed species have been exposed to increasing threats. Only 8.7% of these species are considered threatened by the IUCN Red List, whereas they include more than half of the Data Deficient species (57.8%). These findings suggest a substantial underestimation of threats and associated extinction risk for tree species in current assessments. We also map hotspots of tree species exposed to rapidly changing threats around the world. Our data-driven approach can strengthen the efforts going into expert-based IUCN Red List assessments by facilitating prioritization among species for re-evaluation, allowing for more efficient conservation efforts.

Determining the generation length and level of morphological and genetic differentiation in the Data Deficient glossy grass skink (Pseudemoia rawlinsoni)

Context Human activities are having a significant impact on biodiversity worldwide, to the extent that we are in the midst of the sixth mass extinction event. Although a substantial proportion of species globally have an elevated risk of extinction, some species are poorly known and there is insufficient information available to adequately assess their risk of extinction. Aims and methods One such species is the glossy grass skink (Pseudemoia rawlinsoni), a widespread but enigmatic lizard species in south-eastern Australia. In order to improve our knowledge of its life history, and particularly its generation length, we examined museum specimens collected from across the range of the species, supplemented with measurements from field-caught individuals. Key results We estimated that the species reaches sexual maturity in 3 years, at approximately 40 mm snout–vent length. Its generation length was estimated as 5 years. Sexual dimorphism was evident, and female body size was positively related to litter size. Although there was no evidence for substantial variation in morphology across the range of the glossy grass skink, a phylogeographic analysis using mitochondrial DNA sequence data (ND4) revealed the presence of seven genetic sublineages (up to 5.1% genetic divergence) within the species. Conclusions The glossy grass skink appears to be a single, but widespread and genetically variable, species. Implications Our study demonstrates how a targeted, multifaceted study can be effective at rapidly gathering data that can be used to contribute vital information to the assessment of extinction risk in Data Deficient species.

Red-list of liverwort and hornwort species of Serbia: 2024 assessment

The new extinction risk assessments of hornwort and liverwort species of Serbia have been completed. Based on the available data, 40% of Serbian liverwort flora is under threat (status 2024). Additionally, 11% of Serbian liverwort flora is considered to be Data Deficient (DD) 11% Near Threatened (NT). These findings clearly indicate the urgent need for field investigation and species biology research in order to define the major threats and adequate conservation measures.

Modelling the probability of meeting IUCN Red List criteria to support reassessments.

Comparative extinction risk analysis-which predicts species extinction risk from correlation with traits or geographical characteristics-has gained research attention as a promising tool to support extinction risk assessment in the IUCN Red List of Threatened Species. However, its uptake has been very limited so far, possibly because existing models only predict a species' Red List category, without indicating which Red List criteria may be triggered. This prevents such approaches to be integrated into Red List assessments. We overcome this implementation gap by developing models that predict the probability of species meeting individual Red List criteria. Using data on the world's birds, we evaluated the predictive performance of our criterion-specific models and compared it with the typical criterion-blind modelling approach. We compiled data on biological traits (e.g. range size, clutch size) and external drivers (e.g. change in canopy cover) often associated with extinction risk. For each specific criterion, we modelled the relationship between extinction risk predictors and species' Red List category under that criterion using ordinal regression models. We found criterion-specific models were better at identifying threatened species compared to a criterion-blind model (higher sensitivity), but less good at identifying not threatened species (lower specificity). As expected, different covariates were important for predicting extinction risk under different criteria. Change in annual temperature was important for criteria related to population trends, while high forest dependency was important for criteria related to restricted area of occupancy or small population size. Our criteria-specific method can support Red List assessors by producing outputs that identify species likely to meet specific criteria, and which are the most important predictors. These species can then be prioritised for re-evaluation. We expect this new approach to increase the uptake of extinction risk models in Red List assessments, bridging a long-standing research-implementation gap.

Dark future for a black salamander: effects of climate change and conservation implications for an endemic alpine amphibian

Climate change is threatening several montane species across the world, including a large number of endemics, needing the development of forward-looking conservation strategies to foster their future survival. In this context, Species Distribution Models (SDMs) represent a useful method to forecast changes in species’ habitat suitability under different scenarios of global warming, often advising conservation frameworks with credible, defensible and repeatable information. In this paper, we estimate the environmental and bioclimatic suitability for an endemic mountain amphibian (Salamandra lanzai) in the western European Alps through an SDM approach, considering both current and future scenarios, to address short- and long-term management and conservation actions, and to update the current IUCN extinction risk assessment. The ensemble model forecasts predict a dramatic decline of the climatically suitable area for the Lanza’s alpine salamander in the next 20–40 years, even considering an optimistic CO2 emissions scenario, leading to a theoretical extinction of this species in 2100 in case the worst global warming prediction will be actualised. This underlines the urgent need for up-to-date conservation and management strategies to ensure the successful mitigation of climate change effects on S. lanzai, especially by adapting and improving the network of protected areas, immediately removing additional threats and identifying possible management actions able to increase fine-scale habitat suitability and connectivity among populations. In addition, a significant range contraction in the future has to be considered when assessing the extinction risk for this species, possibly exacerbating the effect of other threatening factors, such as the spread of lethal pathogens. Keywords: Salamandra lanzai, ensemble models, environmental suitability, bioclimatic suitability, future projections

Advancements of ”CAPTAIN” in Plants Conservation Compared to Traditional Techniques

The rapid decline in plant diversity has become a pressing issue with significant implications for humanity. Numerous methods and technologies are being developed to address this problem. Traditional methods, primarily based on statistical analysis, are being used alongside modern conservation methods that leverage AI (Artificial Intelligence) technology. Among many conservation approaches, we compare the traditional and modern methods to find out how AI has been involved. Based on our research, two traditional models have been chosen for this report. Marxan has been widely used since it was developed. Based on the IUCN Red List database, PACA accelerates plant extinction risk assessments. However, these models have some limitations, including unsuitability for rapid and urgent conservation management, poor adaptability, etc. In contrast, CAPTAIN, based on artificial intelligence technology, not only overcomes the limitations of traditional models but also offers advantages such as non-locality and upgradability. By analysing the differences and correlations between statistical technology and AI technology, we aim to enhance our understanding of the advancements of AI in plant conservation and summarize their development status and prospects.

Diurnal temperature range as a key predictor of plants’ elevation ranges globally

A prominent hypothesis in ecology is that larger species ranges are found in more variable climates because species develop broader environmental tolerances, predicting a positive range size-temperature variability relationship. However, this overlooks the extreme temperatures that variable climates impose on species, with upper or lower thermal limits more likely to be exceeded. Accordingly, we propose the ‘temperature range squeeze’ hypothesis, predicting a negative range size-temperature variability relationship. We test these contrasting predictions by relating 88,000 elevation range sizes of vascular plants in 44 mountains to short- and long-term temperature variation. Consistent with our hypothesis, we find that species’ range size is negatively correlated with diurnal temperature range. Accurate predictions of short-term temperature variation will become increasingly important for extinction risk assessment in the future.

A new species of Mollinedia (Monimiaceae, Laurales) from the Quadrilátero Ferrífero, Brazil.

Monimiaceae comprises approximately 26 genera and 250 species, with a pantropical distribution, predominantly occurring in humid forests. In Brazil, it is represented by five genera and 47 species, most of which are found in the Atlantic Forest, particularly in dense ombrophilous forest. Nevertheless, studies on this family in other biomes and vegetation types in Brazil are still scarce. The Quadrilátero Ferrífero (QF), a region located in the state of Minas Gerais, exhibits high plant species richness and endemism. During collections and analysis of herbarium materials from this region, some specimens of Mollinedia caught our attention due to a combination of characteristics that do not match those of any described species within the genus. For this reason, we describe this new taxon and assess its risk of extinction. Additionally, we review the occurrences of Monimiaceae in the QF and provide maps of its geographical distribution. With the description of this new species, the region now hosts eight species of Monimiaceae, two from the genus Macropeplus and six from Mollinedia. The new species is the first endemic species of the Monimiaceae family to be described in the QF. Concerning the extinction risk assessment, the new species was assessed as critically endangered.

Ongoing declines for the world’s amphibians in the face of emerging threats

Systematic assessments of species extinction risk at regular intervals are necessary for informing conservation action1,2. Ongoing developments in taxonomy, threatening processes and research further underscore the need for reassessment3,4. Here we report the findings of the second Global Amphibian Assessment, evaluating 8,011 species for the International Union for Conservation of Nature Red List of Threatened Species. We find that amphibians are the most threatened vertebrate class (40.7% of species are globally threatened). The updated Red List Index shows that the status of amphibians is deteriorating globally, particularly for salamanders and in the Neotropics. Disease and habitat loss drove 91% of status deteriorations between 1980 and 2004. Ongoing and projected climate change effects are now of increasing concern, driving 39% of status deteriorations since 2004, followed by habitat loss (37%). Although signs of species recoveries incentivize immediate conservation action, scaled-up investment is urgently needed to reverse the current trends.

Using the Fossil Record to Understand Extinction Risk and Inform Marine Conservation in a Changing World.

Understanding the long-term effects of ongoing global environmental change on marine ecosystems requires a cross-disciplinary approach. Deep-time and recent fossil records can contribute by identifying traits and environmental conditions associated with elevated extinction risk during analogous events in the geologic past and by providing baseline data that can be used to assess historical change and set management and restoration targets and benchmarks. Here, we review the ecological and environmental information available in the marine fossil record and discuss how these archives can be used to inform current extinction risk assessments as well as marine conservation strategies and decision-making at global to local scales. As we consider future research directions in deep-time and conservationpaleobiology, we emphasize the need for coproduced research that unites researchers, conservation practitioners, and policymakers with the communities for whom the impacts of climate and global change are most imminent.

Trichoglottis quadriga (Orchidaceae: Epidendroideae: Vandeae: Aeridinae), a new species from Central Highlands of Sri Lanka

Trichoglottis quadriga is described as a new species from the montane and sub-montane forests, between 900–1800 m elevations in Central Highlands of Sri Lanka. It is morphologically similar to Vietnamese endemic, T. canhii, but differs significantly in having 4-flowered racemes (vs. 5–12-flowered racemes); longer, terete spur, 3.2 mm long and 1.2 mm in diameter with bi-lobed apex (vs. shorter, broadly conical spur, 1.4–1.8 mm long and 1.2–1.5 mm in diameter near the base with roundish apex) and larger labellum, 5.5 mm long and 3.5 mm wide (vs. labellum 3.8–4.0 mm long, 1.8–2.0 mm wide). Colour plates, line drawing and field identification key are provided along with detailed taxonomic description, notes on habitat, ecology and distribution. A preliminary assessment of extinction risk according to the IUCN guidelines is also provided for the new species.

An invasive pathogen drives directional niche contractions in amphibians.

Global change is causing an unprecedented restructuring of ecosystems, with the spread of invasive species being a key driver. While population declines of native species due to invasives are well documented, much less is known about whether new biotic interactions reshape niches of native species. Here we quantify geographic range and realized-niche contractions in Australian frog species following the introduction of amphibian chytrid fungus Batrachochytrium dendrobatidis, a pathogen responsible for catastrophic amphibian declines worldwide. We show that chytrid-impacted species experienced proportionately greater contractions in niche breadth than geographic distribution following chytrid emergence. Furthermore, niche contractions were directional, with contemporary distributions of chytrid-impacted species characterized by higher temperatures, lower diurnal temperature range, higher precipitation and lower elevations. Areas with these conditions may enable host persistence with chytrid through lower pathogenicity of the fungus and/or greater demographic resilience. Nevertheless, contraction to a narrower subset of environmental conditions could increase host vulnerability to other threatening processes and should be considered in assessments of extinction risk and during conservation planning. More broadly, our results emphasize that biotic interactions can strongly shape species realized niches and that large-scale niche contractions due to new species interactions-particularly emerging pathogens-could be widespread.

Comprehensive approaches for assessing extinction risk of endangered tropical pitcher plant Nepenthes talangensis.

It has been 23 years since the conservation status of highland tropical pitcher plant Nepenthes talangensis was assessed in 2000. A number of existing threats (anthropogenic and environmental) may be increasing the risk of extinction for the species. A better understanding of the ecology and conservation needs of the species is required to manage the wild populations. Specifically, better information related to population distributions, ecological requirements, priority conservation areas, the impact of future climate on suitable habitat, and current population structure is needed to properly assess extinction risks. A better understanding of the requirements of the species in its natural habitat would benefit for successfully securing the species at Botanic Gardens. We have identified 14 new occurrence records of N. talangensis in Mount Talang. Study on the ecological requirement using Random Forest (RF) and Artificial Neural Network (ANN) suggested that elevation, canopy cover, soil pH, and slope are four important variables. The population of N. talangensis was dominated by juvenile and mature (sterile) individuals, we found only a few mature males (7 individuals) and females (4 individuals) in the sampled areas. Our modelling of current conditions predicted that there were 1,076 ha of suitable habitat to very highly suitable habitat in Mount Talang, which is 14.7% of the total area. Those predicted habitats ranged in elevation from 1,740-2,558 m. Suitable habitat in 2100 was predicted to decrease in extent and be at higher elevation in the less extreme climate change scenario (SSP 1-2.6) and extreme climate change scenario (SSP 5-8.5). We projected larger habitat loss in the SSP 5-8.5 compared to the SSP 1-2.6 climate change scenario.. We proposed the category CR B1ab(iii,v), C2a(ii) as the new conservation status of N. talangensis. The status is a higher category of threat compared to the current status of the species (EN C2b, ver 2.3). Nepenthes talangensis seedlings and cuttings established in a Botanic Garden have relatively high survival rate at about 83.4%. Sixty percent of the seeds germinated in growth media successfully grew to become seedlings.

Phylogenetic discordance and integrative species delimitation in the Mammillaria haageana species complex (Cactaceae)

Species complexes consist of very close phylogenetic relatives, where morphological similarities make it difficult to distinguish between them using traditional taxonomic methods. Here, we focused on the long-standing challenge of species delimitation in the Mammillaria haageana complex, a group that presents great morphological diversity that makes its taxonomy a puzzle. Our work integrates genomic, morphological, and ecological data to establish the taxonomic limits in the M. haageana complex, and we also studied the evolutionary relationships with the remainder of the M. ser. Supertextae species. Our genetic analyses, as well as morphological and ecological evidence, led us to propose that the M. haageana complex is made up of six distinct entities (M. acultzingensis, M. conspicua, M. haageana, M. lanigera, M. meissneri, and M. san-angelensis), mainly as a result of ecological speciation. A recent taxonomic proposal considered these taxa as a single species; therefore, we propose their recognition at the species level. Our results also show a high level of incomplete lineage sorting rather than reticulation, which is especially likely in recently diverged species such as those comprising M. ser. Supertextae. The species hypotheses proposed here may be useful in future extinction risk assessments and conservation strategies.

Assessing the extinction risks of amphibians impacted by infectious diseases

Emerging infectious diseases (EIDs) are a major threat to amphibians worldwide. Determining the extinction risk of species susceptible to EIDs is challenging because of data limitations, especially in the initial stages of emergence and spread of disease. The fast rate of spread of many EIDs makes it necessary to assess the extinction risk of impacted host species before detailed mechanistic (epidemiological) or correlative (ecological niche) models can be developed. We present a simple method for identifying species that are at the highest risk of extinction due to an EID. Our method incorporates projections of the spatial spread of disease into IUCN Red List assessments under criteria A3 (based on future population reductions), D2 (plausible future threats), and E (probability of extinction). We apply this method to assess the extinction risk of salamander species in Europe susceptible to population declines caused by Batrachochytrium salamandrivorans (Bsal), the agent of the salamander plague. Our results indicate a high risk of extinction for European salamanders as a result of the spreading Bsal infection. Depending on the rate of spread from the current Bsal localities, and the emergence of new localities through human travel and transport, the number of species threatened by Bsal can range from a few to almost 30 of the 40 species that occur in Europe. Our method allows preliminary assessments of extinction risk based on limited information. For species at risk of extinction due to fast-spreading EIDs, it provides a pragmatic and precautionary solution until more realistic models can be developed.