Extinction Risk Research Articles

Are local species prioritization lists sufficient for protecting endangered plants? Israeli red list as a test case

AbstractConserving species from extinction requires risk assessment and ranking for conservation priorities. The IUCN criteria of extinction risk are currently accepted globally, but only a small fraction of species were evaluated. When assessing species' extinction risk, sufficient information, in particular rate of population decline, is often partial or missing. Here we utilized the red list of Israeli endangered plant species, which prioritizes them for conservation, and evaluated their local extinction risk using IUCN criteria for local assessment. We found a relatively high similarity between the Israeli red number value and the IUCN assessments. Most pronouncedly, the habitat vulnerability index, used in the Israeli method, is correlated with the IUCN parameter of extinction rate in the last decade. We conclude that in the case of Israel, prioritization ranking of endangered species based on locally available information is a powerful tool for conservation even when some species information is lacking, facilitating local decision‐making. This finding may apply also to other countries using a local assessment system.

Tree traits are a stronger predictor of bee traits and species richness than taxonomic diversity

Abstract Functional traits help to understand biological diversity and the mechanism by which ecological communities are structured and how they respond to the environment. For example, the high tree species diversity within tropical forests can be grouped into a few functional attributes, wood density, size and dependence on animal pollination or seed dispersal. However, little is known about how these traits influence animal taxonomic and functional diversity in the forests. We carried out a vegetation census on six plots (20 × 100 m) within the National Forest of Carajás (Amazon biome) to identify forest canopy species and their functional traits. Within the same plot, we also applied three bee sampling methods (entomological nets, honey traps and scent traps). By characterizing the functional traits of trees and bees, we were able to predict bee functional diversity better than with taxonomic diversity alone via combinations of tree traits like size, wood density, dependence on pollinators and extinction risk. We found that larger trees with low wood density were negatively associated with small, eusocial tree cavity nesting bees. The richness and abundance of trees with high extinction risk was positively associated with the richness of medium‐sized solitary bees. The dominance in the community of pollinator‐dependent trees (average diameter in the basal area) was negatively associated with the richness of above‐ground and cavity nesting bees. Our findings suggest that the composition of the tree community limits the availability of nesting resources for specific groups of bees. Moreover, the presence of trees with higher extinction risk (conservation value) was associated with a greater variety of bee traits and was the only metric associated with overall bee richness. As expected, functional traits shed light on the mechanism that might drive high diversity within tropical forests. In addition, there appears to be complementarity in terms of conservation value and carbon stock potential, as areas that habour tree species with higher extinction risk and higher wood density are also those with overall greater bee and functional diversity. Finally, our study can contribute to the restoration of plant—pollinator community by providing an understanding of the vegetation community that contributes to biodiversity maintenance. Read the free Plain Language Summary for this article on the Journal blog.

Past and recent drivers of extinction risk in endemic New Zealand birds

AbstractLand‐cover change is a major driver of species extinction risk and the overarching loss of biodiversity. However, the impact of such change is nuanced, varying among species due to the mediation of life‐history traits and the timing of land transformation. While diverse studies have pinpointed ecological and life‐history attributes linked to the decline of bird species, the combined effects of past and recent land‐cover change often present a complex picture. In this study, we undertook a modelling approach to assess extinction risk in New Zealand's endemic birds based on life‐history traits and past (1996–2008) and recent (2008–2018) land‐cover change. Our results suggested specific variables driving extinction risk in endemic New Zealand birds. Notably, incubation length emerged as the most influential factor, trailed by past land‐cover change, body size and clutch size. This indicates that past land‐cover change in combination with large body sizes and slow life histories, characterized by low fecundity and extended incubation periods, collectively elevates the extinction risk of endemic birds in New Zealand. These results shed light on the conservation priorities for species with specific biological traits potentially exposed to the negative effects of land‐cover change.

Reducing uncertainty with iterative model updating parses effects of competition and environment on salamander occupancy.

Making timely management decisions is often hindered by uncertainty. Monitoring reduces two key types of uncertainty. First, it serves to reduce structural uncertainty of how the system works and provides support for expectations of how a system works. Second, it serves to reduce parametric uncertainty of the drivers of system dynamics. By combining monitoring data and quantitative models, we can reduce structural and parametric uncertainty. To demonstrate this, we focus on the Shenandoah salamander (Plethodon shenandoah), a United States Federally Endangered Species. Early work suggested that P. shenandoah extinction risk results from competition with a conspecific (Plethodon cinereus). However, more recent work has found equivocal support for this claim, instead suggesting that abiotic factors, such as moisture and temperature, drive P. shenandoah persistence. Using long-term monitoring data, we find that while competition may play a part in P. shenandoah extinction risk, measures of surface moisture are better predictors of occupancy dynamics. Further, we find decreased detection rates of P. shenandoah when P. cinereus is present, suggesting a conflation of detection probability with actual competition, which cautions against making inference from unadjusted observations of occurrence. Using multiple lines of inquiry allows for more robust understanding of system drivers in the face of high uncertainty, increasing opportunities to manage extinction risk.

Population age structure and conservation status of Ferula sinkiangensis (Apiaceae) in Xinjiang, China

Abstract Ferula sinkiangensis K.M. Shen is a threatened medicinal plant endemic to Xinjiang, China, with a small population size and a narrow distribution range. We assessed the status of this species with respect to its population age structure, the level of threat and extinction risk. Only one population remains, in Yining County, Xinjiang. We conducted field surveys of the population in 2022 and 2023, counting 2,033 and 1,515 individuals, respectively, in 144 sample quadrats. We assessed the age structure of the population by counting the number of basal leaves of each individual. The frequency distribution had an inverted J-shape, indicative of a relatively stable age structure. However, the number of mature individuals was small, raising concerns about the risk of genetic drift and inbreeding. This species is also threatened by habitat destruction and inappropriate collection practices. We recommend that F. sinkiangensis is categorized as Critically Endangered on the IUCN Red List on the basis of criteria B2ab(iii), C2a(i) and D.

Shifts in the habitat suitability for large hammerhead sharks under climate change

One of the chief consequences of climate change is the worldwide redistribution of species in the pursuit of physiologically and ecologically favourable conditions. As part of one of the most threatened groups of vertebrates, assessing how climate change may affect the distribution patterns of key shark species is essential for their long-term conservation and management. The present study aims to assess how climate change projections (based on the representative concentration pathways 2.6, 4.5, 6.0, and 8.5) for the middle and end of the century may affect the global patterns of habitat suitability (HS) for large hammerhead sharks – a unique and particularly threatened group of elasmobranchs. Here, a decline in the global average HS is projected for both Sphyrna lewini and Sphyrna zygaena, with the scale of HS decline generally increasing with time and RCP severity, while a global increase in HS is generally projected for Sphyrna mokarran, albeit reduced over the long-term and overturned under long-term RCP8.5. Meanwhile, poleward shifts are projected for all three species, with considerable tropical declines for both S. lewini and S. zygaena. Additionally, regional shifts in suitability have the potential to affect population connectivity, the access to key habitats, and levels of exposure to other anthropogenic pressures, along with the effectiveness of conservation and management efforts. Taken together, these results showcase the importance of climate change for species’ extinction risk assessments and the urgency of the consideration of climate change within the design and implementation of conservation measures.

Genetic Diversity and Evolutionary Biology of Indian Wildlife- A Review

The genetic diversity and evolutionary biology of Indian wildlife, emphasizing the critical role of genetic variability in ensuring species adaptability and long-term survival. India is one of the world’s megadiverse countries, home to a wide range of unique flora and fauna spread across its biodiversity hotspots, including the Western Ghats and the Eastern Himalayas. However, rapid habitat fragmentation, deforestation, and poaching have severely impacted the genetic health of many wildlife species, leading to reduced gene flow, population bottlenecks, and increased inbreeding. This has heightened the risk of extinction for small, isolated populations such as the Asiatic lion and the Great Indian bustard. Genetic studies using advanced genomic tools have provided key insights into the population structure, phylogenetic relationships, and adaptive potential of species like the Bengal tiger, Asian elephant, and snow leopard. Conservation strategies, including genetic rescue, habitat corridors, and the use of captive breeding programs, are recommended to preserve genetic diversity and prevent further genetic erosion. Technological advances, such as non-invasive sampling and bioinformatics, are transforming wildlife research, enabling more precise and less intrusive genetic monitoring. The integration of genetic data into conservation policies and practices is essential for developing targeted management plans that maintain the evolutionary potential of Indian wildlife.

Long live the cat: Ocelot population viability in a planned reintroduced population in Texas, USA

AbstractReintroductions are often needed to recover carnivore populations and restore ecological processes. Felids are common subjects of reintroduction efforts, but published population models informing felid reintroduction plans are uncommon, and poor planning has sometimes caused issues in felid reintroduction programs. In the United States, ocelots (Leopardus pardalis pardalis) are classified as endangered, and recovery requires population expansion into historic habitat. A multi‐organization effort is underway to establish a new ocelot population in Texas by releasing ocelots into an area of 478 km2 of suitable habitat in ocelots' historic but now unoccupied range. In this study, we used population viability analyses to compare different ocelot reintroduction strategies for the identified reintroduction area. Based on a potential ocelot breeding program's limitations, we modeled reintroduction using a founding population of no more than six ocelots and no more than four ocelots released per year for no more than 15 subsequent years. Within these limitations, we assessed projected population abundances and extinction risks after 30 years for 20 different reintroduction strategies. We found that long‐term releases are necessary to establish a viable population; under conservative model assumptions, releasing six ocelots in the initial year and then releasing four individuals annually for an additional 10–15 years is necessary for attaining a projected population greater than 36.62 ocelots (baseline) with <6% extinction risk. We also found that ocelot population abundance is about equally sensitive to post‐release mortality and inbreeding depression. This highlights the importance of not only supporting reintroduced ocelots' survival but also managing for high genetic diversity in the reintroduction program. Further, we found that realistic but more liberal assumptions on the carrying capacity of the reintroduction area and the age of first reproduction for ocelots increase projected population abundances (53.95 individuals and 61.26 individuals, respectively), and thus reintroduction success. The model's sensitivity to carrying capacity suggests that long‐term habitat protection and expansion are among the most important management actions to support ocelot reintroduction. Our study establishes the first population viability model for an ocelot reintroduction plan anywhere across the species' wide geographic range, and it reinforces several key considerations for wildlife reintroduction efforts worldwide.

Correlates of avian extinction timing around the world since 1500 CE

Avian extinctions have been relatively well documented in modern history, and in the past millennia, more bird species are known to have gone extinct than species in any other vertebrate class. We examined the biological correlates of extinction timing among 216 bird species that recently were either observed to go extinct or disappeared since 1500 CE, performing a novel analysis for examining the extinction trends of birds by modelling traits against the number of years since present day during which species have been extinct. We analyzed a broad range of traits and characteristics that have previously been associated with extinction and extinction risk in birds and compared the effects of these traits simultaneously against one another. In order to provide a more comprehensive and robust assessment of trait-based drivers of global bird loss in comparison to prior studies, we included extinct species recognized by any of the three major avian taxonomies as well those birds that lack recent confirmed sightings and are at least functionally extinct. We found that insular, flightless, larger-bodied, ecologically specialized species, as well as those with high aspect ratio wings, were likely to go extinct earlier in time. Besides identifying the key locations and time periods over the past five centuries where birds have gone extinct, and highlighting specific extinction-prone taxonomic groups, we provide a complete and unified dataset of traits used in this study that helps address the lack of extensive public data on modern extinct species.

Morphological complexity promotes origination and extinction rates in ammonoids.

The causes of heterogeneity in evolutionary rates are a key question in macroevolution. Origination and extinction rates are closely related to abiotic factors, such as climate1,2 and geography,3,4 as well as biotic factors such as taxonomic richness5,6 and morphology,7 which are influenced by phylogeny.8,9 Studies on the relationship between morphology and macroevolution have focused on morphological traits, including body size,6,7,9 shape,10 color,11,12 and complexity,13,14,15 and have proposed biological laws, such as the zero-force evolutionary law16 and Cope's rule.17 However, the relationship between morphological complexity and turnover rates remains poorly defined because of the lack of suitable measures for various subjects.18,19 Here, we establish a quantitative method, the two-dimensional ornamentation index (2D-OI), which allows the description of the ornamental complexity of ammonoids. Ammonoids are one of the most abundant and well-studied fossil groups, with complex conch structures.20 Ammonoids display some similarities with trilobites and mammals21,22 in terms of their high evolutionary rates; however, the underlying mechanisms remain elusive. Moreover, ammonoids exhibit marked heterogeneity in turnover rates across spatiotemporal scales23 and clades,23,24 making them key clades for investigating the relationship between turnover rates and morphological complexity. The results show that morphologically complex genera and species often have higher origination and extinction rates than morphologically simple taxa. Diversity fluctuations of taxa with complex ornamentation generally overimprint and control the overall net diversification rates of ammonoids. This double-edged sword of rapid evolution and increased extinction risk driven by complex morphologies has significant implications for our understanding of how species survive over geological timescales.

Requiem for Argentine mammals: A spatial framework for mapping extinction risk

Requiem for Argentine mammals: A spatial framework for mapping extinction risk

Conservation biology of three threatened Limonium species endemic to Zakynthos Island (Ionian Islands, Greece)

Abstract Knowledge of the life history traits, reproductive biology and demography of rare species is fundamental for their conservation, yet plant population monitoring is uncommon. The restricted ranges of the Limonium species endemic to the Mediterranean area, combined with the vulnerability of their specialized littoral habitats, indicate the need for appropriate conservation measures. We evaluate the conservation status and estimate the future extinction risk of three Limonium species endemic to Zakynthos Island in the Ionian Islands, Greece (Limonium korakonisicum, Limonium phitosianum and Limonium zacynthium) using 5 years of monitoring data. We compile information on their geographical distribution, population dynamics, reproductive biology and genetic diversity. Population sizes and survival rates of seedlings exhibited marked annual fluctuations, although fecundity and relative reproductive success remained high throughout the monitoring period. We observed a dominance of mature individuals in all three species, indicating their increased tolerance to salinity. Three subpopulations each of L. phitosianum and L. zacynthium were genotyped using five microsatellite loci. The observed number of alleles and the low gene flow value potentially indicate reduced genetic diversity, inbreeding, and limited gene flow within and among subpopulations of both species. Based on the IUCN categories and criteria, we assess L. korakonisicum as Critically Endangered, L. phitosianum as Near Threatened and L. zacynthium as Endangered. Population viability analyses predict that, among the three species, L. zacynthium will face the highest risk of extinction within the next 50 years. Knowledge of the biology of these species provides data essential for identifying critical factors for their survival and for proposing targeted conservation measures.

Coleus hakgalensis (Lamiaceae), a new species from Sri Lanka

Coleus hakgalensis, a new species in family Lamiaceae, is described from the central highlands of Sri Lanka. The dry specimens of the new species are morphologically similar to Coleus paniculatus specimens but distinguishable by its much branched habit with arcuate branches, stem up to 1m in height, elongated inflorescence, bracts being occasionally persistent and shortly petiolated, having hairs inside the upper lip of calyx, semi-circular lateral lobes of upper lip of corolla being much shorter than median lobes, navicular lower lip of corolla with densely pilose inside, stamens united at base and anterior projection of the disc equal or shorter than ovary with an acute apex. The new species is under high risk of extinction in the wild thus ex-situ conservation measures have been implemented.

Universal prediction of vertebrate species age at maturity

Animal age at maturity can be used as a universal and simple predictor of species extinction risk. At present, methods to estimate age at maturity are typically species-specific, limiting comparisons among species, or are infeasible due to practical constraints. To overcome this, here we develop a universal predictor of species-level age at maturity for vertebrates. We show that modelling the frequency of ‘CG’ sequences (CpG sites) in gene promoter regions yields rapid predictions of vertebrate age at maturity. Our models predict age at maturity with remarkable accuracy and generalisability, with median error rates of 30% (less than 1 year) and are robust to genome assemblies of varying quality. We generate predictions for 1912 vertebrate species for which age at maturity estimates were previously absent from public databases. The predictions can be used to help to inform management decisions for the many species for which more detailed population information is currently unavailable.

A synopsis of Monimiaceae (Laurales) in the Brazilian Amazon

This synopsis of Monimiaceae in the Brazilian Amazon provides illustrations, an identification key, the diagnosis and comments on the taxonomy and conservation status of the species. Data were collected from both physical and virtual herbaria as well as from relevant literature in order to compile information on morphological characteristics, geographic distribution and conservation status. Six species of Mollinedia are found in the Brazilian Amazon, including our proposal to reinstate Mollinedia krukovii, and a new record of Mollinedia repanda for Brazil. Mollinedia ptariensis is considered a synonym of M. repanda in this study. Macropeplus was previously reported for this biome but is now being excluded because it resulted from an incorrect identification. Furthermore, we document new occurrences of five species across various states within the Amazon. With respect to the risk of extinction, four species are categorized as ‘least concern' and two species remain formally non‐assessed. An initial regional assessment is presented in this work for the species not yet evaluated. In our preliminary assessment, M. krukovii was considered as presenting insufficient data for a risk assessment and Mollinedia grazielae was assessed as endangered. Overall, this study underscores the Amazon forest as the second largest center of richness of Monimiaceae species in Brazil.

Native woody species depend on the soil microbiome to establish on burned soils, while non‐native do not

Abstract Wildfires are important natural disturbances with profound ecological impacts. However, our understanding of how to restore plant–soil microbiome interactions following wildfires remains limited, revealing a key knowledge gap in post‐wildfire ecosystem restoration. To assess the restoration of plant‐microbiome interactions in fire‐affected ecosystems, we conducted greenhouse experiments simulating wildfire effects on soil collected from Maulino Coastal Forest of central Chile, a biodiversity hotspot. We measured the plant height and photosynthesis over 90 days, and two‐year survival probability, of three common native (Aristotelia chilensis, Nothofagus glauca and N. alessandrii) and three non‐native species (Eucalyptus globulus, Pinus radiata and Genista monspessulana) planted in three soils (unburned, burned and burned soil inoculated with the native microbiome). Available nutrient concentrations (N, P and K) and activities of microbial enzymes (dehydrogenase, β‐glucosidase and urease) were also measured over 360 days. Available nutrient concentrations were consistently higher in burned and burned‐inoculated soils than in unburned soils. Enzyme activities in unburned and burned‐inoculated soils remained higher than in burned soil, indicating that the native microbiome restored microbial enzyme activities. The increase in height over 90 days was lower in burned soils compared with unburned soils for native species. However, inoculation with the native microbiome mitigated this negative effect, resulting in height increases similar to those in unburned soils. For non‐native species, burning and inoculation had negligible effects on the height increases. Similar patterns were observed for the increase in photosynthetic rate, with native species showing a reduced rate in burned soils, which was offset by microbiome inoculation, while non‐native species were unaffected by both treatments. Survival probability of native species declined in burned soil, but was the same in burned‐inoculated soil as in unburned soil. That of non‐native species was unaffected by burning or by inoculation with the native microbiome. Synthesis and applications. Native microbiomes are evidently promising tools to safeguard ecosystem functionality and mitigate species extinction risks arising from climate change and human‐induced wildfires. We advocate integrating microbiomes into future active restoration strategies for fire‐affected ecosystems.

Rancang Bangun Sistem Pendeteksi Kebakaran Hutan Menggunakan Drone Berbasis Computer Vision

The danger of forest and land fires in Indonesia is a serious threat that continues to recurevery year. According to U.S. data Fire Service, there are more than 700 forest fires everyyear burning more than 7 million hectares of land. These fires not only damage ecosystems,but also cause the loss of important biodiversity. Many of Indonesia's endemic flora andfauna have fallen victim, increasing the risk of extinction. The use of UAVs can also changedisaster management. This technology can be integrated with early warning systems basedon analytical data and artificial intelligence, increasing the accuracy of fire predictions andmore proactive responses. Thus, the application of this technology is not just a temporarysolution, but a long-term strategic step to maintain environmental sustainability andcommunity welfare. Technological solutions such as UAVs and cooperation betweenvarious parties are needed to overcome this challenge effectively. The aim of this researchis to create a computer vision-based system that uses deep learning algorithms, especiallyYou Only Look Once (YOLO), to detect forest fires quickly and accurately. In mitigating forest fire disasters, early detection of hotspots is an important step to prevent fires fromspreading to other areas and reduce the damage caused by fires to humans and theenvironment. To achieve the objectives of this study, several actions were taken. First,forest fire image data is collected and processed for use in training the YOLO model. Next,the model is trained using a dataset that covers various forest fire conditions, such as fireintensity, time of day, and weather conditions, to ensure that the model can find firehotspots in various conditions.

Non-adaptedness and vulnerability to climate change threaten Plathymenia trees (Fabaceae) from the Cerrado and Atlantic Forest

Climate change is increasing species extinction risk. The ability of a species to cope with climate change can be quantified by projecting distribution models and by estimating the risk of non-adaptedness using genomic data. The Cerrado and the Atlantic Forest in Tropical South America are increasingly threatened by habitat loss and anthropogenic climate change. This work aims to evaluate the ecological and genomic vulnerability of Plathymenia taxa and its lineages, P. reticulata, a Cerrado species, and P. foliolosa, an Atlantic Forest species, to determine their current and future habitat suitability and the mismatch between current local adaptation with the expected climate changes. The species distribution models predicted a high range loss for the Plathymenia lineages. The genotype-environment association analyses showed that the Plathymenia lineages have populations adapted to different precipitation and temperature seasonality regimes. The genomic offset analyses predict a mismatch between local adaptations and future climate for the Plathymenia indicating a high risk of non-adaptedness, especially in the pessimistic scenario. Our results show an elevated extinction risk of the species due to climate change. We suggest reevaluating the extinction risk and management of the Plathymenia species separately based on their differences in vulnerability to climate change.

Stable detection frequency of the threatened Christmas Island Boobook Ninox natalis, 2012–2022

ABSTRACT Both island species and raptors are at particularly high risk of extinction but few island raptor populations have been the subject of long-term monitoring. To determine trends in abundance in the Christmas Island Boobook, surveys were conducted annually from 2012–2017, in 2019 and in 2022. Across the survey period the population appears to have been either stable or to have increased slightly. Almost no part of the island lacked owls during the most recent survey. The detection rate averaged 1.56 (out of four surveys at a site); it was lowest in 2013 (1.22) and highest in 2022 (2.38). Detection was more likely on nights with low wind, at wetter sites and in closed vegetation, rather than in open or very low vegetation. In a separate analysis on the same data, the top-ranked dynamic occupancy-detection model found that occupancy increased with increasing elevation and vegetation height. No effect of a suspected threat, the presence of invasive yellow crazy ants Anoplolepis gracilipes at a site, could be detected. We recommend ongoing monitoring and research, potentially using automated recording devices and the tracking of individual owls to understand and refine the assumptions underpinning the interpretation of survey results.

Evaluating the IUCN conservation status of Tritaxis kurnoolensis (R.R.V.Raju & Pull.) R.Y.Yu. & Welzen (Euphorbiaceae), an endemic tree species found in the Eastern Ghats region of Andhra Pradesh, India

Tritaxis kurnoolensis, a small tree of the Euphorbiaceae family, is endemic to a valley within the Sullavai Sandstone plateau in close proximity to the Paleru Reservoir (Owk dam). The species is a narrow endemic. No documented sightings of this species have been recorded beyond the type locality since its description in 1994 by Venkataraju & Pullaiah as Dimorphocalyx kurnoolensis from the Nandyal District of Andhra Pradesh. In this study, the authors applied the grid method for quantification and subjected the species to a meticulous analysis aligning with IUCN Red List Criteria. The distribution was found to be restricted due to habitat (valley) fragmentation, reservoir which is arresting seed dispersal, and destruction caused by tunnel construction civil works. The area of occupancy (AOO) at 16 km² and the extent of occurrence (EOO) at 0.474 km², were systematically computed using GeoCAT. The species is assessed here using the Red List methodology for evaluating extinction risk. Based on its AOO, EOO, and population size, it has been classified as Critically Endangered.