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Sturgeons are a unique group of species that were historically widespread across the northern hemisphere. According to the latest IUCN Red list assessment, more than 80% of the species globally are threatened with extinction, making it essential to identify the life stages at which they are suffering from impacts the most, while at the same time to compare among river systems and populations based on standardized assessment techniques. All sturgeon have similar but not identical, life-history strategies. Therefore, monitoring techniques developed for one sturgeon species would be applicable to most other species. Monitoring can be conducted at each life stage. However, while each life stage will provide different information about the population, not all will necessarily help to assess population trend or status. Life stages that are highly variable prove to be less quantifiable even after expending very high effort. Collectively, these assessments could be very informative on population status, limitations, and trends. However, monitoring at each stage is time-consuming and expensive. Clearly defined objectives are therefore required when embarking on an assessment program. The objective of this study was to review the assessment techniques used for the different life stages including eggs, drifting larvae, age-0, juveniles, subadults, and adults to provide a common basis for population assessments that can be standardized to some extent and thus facilitate comparisons between the results obtained. For this purpose, this review presented the most common assessment techniques for each life stage, assessed the pros and cons of assessing each life stage, and examined if the methodology was qualitative or quantitative to assist in establishing long-term monitoring initiatives. [ABSTRACT FROM AUTHOR]

Chytridiomycosis caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd) is pushing amphibians towards extinction. Whilst mitigation methods were suggested a decade ago, we lack field trials testing their efficacy. We used the agrochemical fungicide, tebuconazole, to treat Bd infected breeding waterbodies of an endangered species that is highly susceptible to the fungus. Just two applications of tebuconazole led to a significant reduction in infection loads in the vast majority of sites, and at six sites the disinfection remained one/two-years post-application. Tebuconazole values drastically decreased in the waterbodies within a week after application, with no significant effects on their hydrochemical and hydrobiological characteristics. Although the use of chemicals in natural populations is undesirable, the growing existential threat to amphibians all over the world indicates that effective interventions in selected populations of endangered species are urgently needed. [ABSTRACT FROM AUTHOR]

The article focuses on the impact of extreme weather events, particularly a heat dome in 2021, on Barn Owl productivity in southwestern Canada. Topics include the heat dome's effects on young birds, the admission of heat-stressed raptors to a rehabilitation facility, and the significance of implementing conservation measures to protect Barn Owls from the increasing frequency of extreme weather events and other threats.

Uma Ramakrishnan, the recipient of the 2023 Molecular Ecology Prize, has had a successful career in population genetics and molecular ecology. She grew up in an academic environment and was exposed to scientists and ecological ideas from a young age. Her interest in animals and ecology led her to pursue degrees and internships in related fields, where she developed skills in genetic analysis and data-driven research. Uma's research has focused on various species, including tigers, bats, and elephants, and has contributed to our understanding of genetic diversity, population structure, and conservation strategies. She has also been involved in mentoring and outreach efforts to inspire and support students, particularly women, in the field of research. [Extracted from the article]

Temperature and interspecific competition are fundamental drivers of community structure in natural systems and can interact to affect many measures of species performance. However, surprisingly little is known about the extent to which competition affects extinction temperatures during extreme warming. This information is important for evaluating future threats to species from extreme high-temperature events and heat waves, which are rising in frequency and severity around the world. Using experimental freshwater communities of rotifers and ciliates, this study shows that interspecific competition can lower the threshold temperature at which local extinction occurs, reducing time to extinction during periods of sustained warming by as much as 2 weeks. Competitors may lower extinction temperatures by altering biochemical characteristics of the natural environment that affect temperature tolerance (e.g., levels of dissolved oxygen, nutrients, and metabolic wastes) or by accelerating population decline through traditional effects of resource depletion on life history parameters that affect population growth rates. The results suggest that changes in community structure in space and time could drive variability in upper thermal limits. [ABSTRACT FROM AUTHOR]

We carried out a literature review to investigate the taxonomic and functional β diversity of zooplankton and its species replacement (βrepl) and richness difference (βrich) components in Brazilian rivers. In addition, the taxonomic (LCBD-t) and functional ecological uniqueness (LCBD-f) were also measured. We tested the following hypotheses: (i) The βrepl component is the main driver of taxonomic β diversity, while βrich is most important for functional β diversity, due to functional simplification; (ii) Sites with lower taxonomic and functional richness are the ones that most contribute to LCBD. Contrary to expectations, βrich drove the taxonomic and functional β diversity. This may have occurred due to environmental constraints and geographic distance, thus causing a loss or gain of species and traits between hydrographic regions. For just two regions, the sites with the lowest functional richness were the ones that most contributed to LCBD-f. This reinforces that sites with lower richness can support species that perform unique functions in the ecosystem. As studies involving zooplankton from lotic systems are still limited in Brazil, we suggest that future research should consider the patterns of β diversity in these dynamic, diverse, and threatened aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Summary: Global change has accelerated local species extinctions and colonizations, often resulting in losses and gains of evolutionary lineages with unique features. Do these losses and gains occur randomly across the phylogeny?We quantified: temporal changes in plant phylogenetic diversity (PD); and the phylogenetic relatedness (PR) of lost and gained species in 2672 semi‐permanent vegetation plots in European temperate forest understories resurveyed over an average period of 40 yr.Controlling for differences in species richness, PD increased slightly over time and across plots. Moreover, lost species within plots exhibited a higher degree of PR than gained species. This implies that gained species originated from a more diverse set of evolutionary lineages than lost species. Certain lineages also lost and gained more species than expected by chance, with Ericaceae, Fabaceae, and Orchidaceae experiencing losses and Amaranthaceae, Cyperaceae, and Rosaceae showing gains. Species losses and gains displayed no significant phylogenetic signal in response to changes in macroclimatic conditions and nitrogen deposition.As anthropogenic global change intensifies, temperate forest understories experience losses and gains in specific phylogenetic branches and ecological strategies, while the overall mean PD remains relatively stable. [ABSTRACT FROM AUTHOR]

Fisheries, climate change, and habitat degradation are triggering the depletion of marine animal populations worldwide. The ecological impacts of the extinction of keystone species such as chondrichthyans can be far-reaching along the entire food web. Here, we first reviewed the trophic ecology of the 81 chondrichthyan species of the Mediterranean Sea through a literature search. We then compared prey composition among chondrichthyan species considering their taxonomic group, body size, and habitat. Finally, we represented the Mediterranean meta-web, emphasizing the chondrichthyan groups, using a qualitative network approach, and tested the vulnerability of the food web to selective removals of threatened chondrichthyan species by applying different extinction scenarios. We found trophic data for 53 species, which highlights the need to complement current knowledge gaps for many species. Diet dissimilarities between chondrichthyan taxa were detected, mainly due to the consumption of crustaceans and cephalopods. We found that large chondrichthyan species had a major contribution to the trophic dissimilarity and the omnivory of the food web when compared to small and medium-sized species. Conservation efforts within the Mediterranean chondrichthyan community may be particularly important for this group, as high levels of omnivory could moderate the occurrence of trophic cascades, while high trophic similarity can lead to less diverse ecosystems. This study provides a first overview of the ecological role of chondrichthyans in the Mediterranean and highlights the urgent research needed to increase the knowledge about these key species in the Mediterranean marine food web. [ABSTRACT FROM AUTHOR]

Human actions threaten animal species with extinction at an accelerating rate. Environmental and Sustainability Education (ESE) is a key factor in tackling biodiversity loss by preparing future citizens to undertake conservation actions. This study deals with the awareness and the attitudes of 401 primary school students toward wild animals, focusing on local threatened species. Although students appear to have a satisfactory level of awareness of wild animals, they are significantly less aware of local species and confused regarding threatened ones. Bird species gain the lowest recognition. Habitat transformation and climate change are not well-known threats. Students have primarily naturalistic, and ecologistic attitudes. They like animals mainly due to their perceived appearance, intelligence and being in danger of extinction, while they dislike them based on the threat they pose to humans and other animals. The findings can inspire ESE practitioners to develop effective educational programs for wild animal conservation. [ABSTRACT FROM AUTHOR]

The world is facing a major pulse of ecological and social changes that may favor the risk of zoonotic outbreaks. Such risk facilitation may occur through the modification of the host's community diversity and structure, leading to an increase in pathogen reservoirs and the contact rate between these reservoirs and humans. Here, we examined whether anthropization alters the relative abundance and richness of zoonotic reservoir and non-reservoir rodents in three Socio-Ecological Systems. We hypothesized that anthropization increases the relative abundance and richness of rodent reservoirs while decreasing non-reservoir species. We first developed an Anthropization index based on 15 quantitative socio-ecological variables classified into five groups: 1) Vegetation type, 2) Urbanization degree, 3) Water quality, 4) Potential contaminant sources, and 5) Others. We then monitored rodent communities in three regions of Northwestern Mexico (Baja California, Chihuahua, and Sonora). A total of 683 rodents of 14 genera and 27 species were captured, nine of which have been identified as reservoirs of zoonotic pathogens (359 individuals, 53%). In all regions, we found that as anthropization increased, the relative abundance of reservoir rodents increased; in contrast, the relative abundance of non-reservoir rodents decreased. In Sonora, reservoir richness increased with increasing anthropization, while in Baja California and Chihuahua non-reservoir richness decreased as anthropization increased. We also found a significant positive relationship between the anthropization degree and the abundance of house mice (Mus musculus) and deer mice (Peromyscus maniculatus), the most abundant reservoir species in the study. These findings support the hypothesis that reservoir species of zoonotic pathogens increase their abundance in disturbed environments, which may increase the risk of pathogen exposure to humans, while anthropization creates an environmental filtering that promotes the local extinction of non-reservoir species. [ABSTRACT FROM AUTHOR]

Urbanization is rapidly shaping and transforming natural environments, creating networks of modified land types. These urbanization‐driven modifications lead to local extinctions of several species, but the surviving ones also face numerous novel selection pressures, including exposure to pollutants, habitat alteration, and shifts in food availability and diversity. Based on the assumption that the environmental pool of microorganisms is reduced in urban habitats due to habitat alteration, biodiversity loss, and pollution, we hypothesized that the diversity of bacterial microbiome in digestive tracts of arthropods would be lower in urban than rural habitats. Investigating the gut bacterial communities of a specialist ground beetle, Carabus convexus, in forested rural versus urban habitats by next generation high‐throughput sequencing of the bacterial 16S rRNA gene, we identified 3839 bacterial amplicon sequence variants. The composition of gut bacterial samples did not significantly differ by habitat (rural vs. urban), sex (female vs. male), sampling date (early vs. late spring), or their interaction. The microbiome diversity (evaluated by the Rényi diversity function), however, was higher in rural than urban adults. Our findings demonstrate that urbanization significantly reduced the diversity of the gut bacterial microbiome in C. convexus. [ABSTRACT FROM AUTHOR]

Microbial interactions are key to maintaining soil biodiversity. However, whether negative or positive associations govern the soil microbial system at a global scale remains virtually unknown, limiting our understanding of how microbes interact to support soil biodiversity and functions. Here, we explored ecological networks among multitrophic soil organisms involving bacteria, protists, fungi, and invertebrates in a global soil survey across 20 regions of the planet and found that positive associations among both pairs and triads of soil taxa governed global soil microbial networks. We further revealed that soil networks with greater levels of positive associations supported larger soil biodiversity and resulted in lower network fragility to withstand potential perturbations of species losses. Our study provides unique evidence of the widespread positive associations between soil organisms and their crucial role in maintaining the multitrophic structure of soil biodiversity worldwide. [ABSTRACT FROM AUTHOR]

Protected areas are of paramount relevance to conserving wildlife and ecosystem contributions to people. Yet, their conservation success is increasingly threatened by human activities including habitat loss, climate change, pollution, and species overexploitation. Thus, understanding the underlying and proximate drivers of anthropogenic threats is urgently needed to improve protected areas’ effectiveness, especially in the biodiversity-rich tropics. We addressed this issue by analyzing expert-provided data on long-term biodiversity change (last three decades) over 14 biosphere reserves from the Mesoamerican Biodiversity Hotspot. Using multivariate analyses and structural equation modeling, we tested the influence of major socioeconomic drivers (demographic, economic, and political factors), spatial indicators of human activities (agriculture expansion and road extension), and forest landscape modifications (forest loss and isolation) as drivers of biodiversity change. We uncovered a significant proliferation of disturbance-tolerant guilds and the loss or decline of disturbance-sensitive guilds within reserves causing a “winner and loser” species replacement over time. Guild change was directly related to forest spatial changes promoted by the expansion of agriculture and roads within reserves. High human population density and low nonfarming occupation were identified as the main underlying drivers of biodiversity change. Our findings suggest that to mitigate anthropogenic threats to biodiversity within biosphere reserves, fostering human population well-being via sustainable, nonfarming livelihood opportunities around reserves is imperative [ABSTRACT FROM AUTHOR]

This article analyses camera systems utilized in deep sea science, focussing on surveys and representations of deep sea coral devastated by trawl fishing in the South Pacific. Various custom, advanced camera technologies are used by governmental and non-governmental science agencies, including Australia's CSIRO and Aotearoa New Zealand's NIWA, to record footage of the deep water and the ocean floor in aid of monitoring marine ecosystems and tracing environmental transformation. This footage is often also deployed in science communication, being utilized in promotional videos and livestreamed online. This article locates such camera systems among an array of cinematic antecedents, adjacent contemporary camera technologies, and film-theoretical notions including underwater cinemas, naturecams, and Bazanian realism in order to investigate their capacities as a technology of and for discovery, documentation, and exploration that also manages affective aspects of human-nonhuman encounter. A film studies approach to the work of the camera makes possible an understanding of how, by mediating an encounter for human viewers with abyssal lifeforms on the edge of ecological extinction, it sets in motion the potential for an ethics of care to emerge across time, space, and species. [ABSTRACT FROM AUTHOR]

The Philippines is a hotspot of biodiversity due to its high species richness and endemism and the great threat of species and habitat loss brought about by anthropogenic activities. While efforts have been made to document animal and plant biodiversity in the country, only a little can be said of the so-called hidden biodiversity - the microbial world. To contribute to the documentation of the total biodiversity in the country, we conducted a systematic literature review of novel microorganisms described in the Philippines. Novel microorganisms are potentially new sources of compounds for pharmaceutical, environmental, and biotechnological applications and could play key roles in many ecosystem processes; their continued discovery and further research allow the science community to study these microorganisms to impact local communities. Our checklist reported species of archaea, bacteria, protists, algae, and fungi, including lichens, that were discovered as new to science by Filipino or foreign-based scientists from specimens collected in the country. We recorded 708 novel species as reported in published literature until October 2023. These are grouped as Archaea (n = 12), Bacteria (n = 28), lower fungi (n = 11), higher fungi (n = 142), protists (n = 13), algae (n = 251), and lichens (n = 251). Most of the discovered novel microbes were isolated or collected from major islands of the country, particularly Luzon, and this highlights the numerous areas where studies on microbial diversity are limited or nonexistent. In addition, the research also identified challenges that impeded the progress of Philippine microbial taxonomy and offered solutions. This checklist is the first attempt to document novel species of microorganisms as a strategy to raise awareness of the need to document our microbial biodiversity. [ABSTRACT FROM AUTHOR]

The Critically Endangered Nubian Flapshell Turtle (Cyclanorbis elegans) is found in the White Nile River system in South Sudan and northern Uganda. Over the past few decades, its populations have sharply declined, primarily due to human-induced threats, leading to its near-extinction across almost its entire range. In this paper, we present the results of a comprehensive threat analysis undertaken to pinpoint the challenges confronting the species within its natural habitat, specifically in the only known sites where it currently exists. We aimed to develop a conceptual framework to understand causal relationships among driving forces, threats and the target species. This framework allows the visualisation and analysis of the web of intricate interactions that contribute to the species' decline and vulnerability. We convened a panel of experts who identified three primary direct threats to the Nubian Flapshell Turtle: (1) Sand mining (IUCN code 3.2); (2) Overfishing by native fishers and refugees (code 5.4) and (3) Habitat loss at nesting sites (code 7.3). Among these threats, overfishing had the largest geographical extension, the highest intensity and duration, while habitat loss occurred at the highest frequency. These threats varied significantly in intensity and frequency. Additionally, when assessing the overall magnitude of these threats, habitat loss and overfishing had the highest impact, with significantly higher scores compared to sand mining. Our experts also identified the underlying driving forces behind these threats: (1) Economic interests driving sand mining activities along the Nile; (2) The influence of civil conflict and refugee populations, which contribute to the demand for bushmeat; (3) the Chinese expatriates, that lead to overfishing; (4) The removal of bank vegetation serves as a catalyst for habitat loss at nesting sites. The resulting conceptual framework serves as a valuable tool for defining targeted conservation measures for each distinct threat. [ABSTRACT FROM AUTHOR]

Wolves use howls to maintain large territories, intra-pack communication and social bonding. Besides their physical presence, howls are also instrumental in creating fear and impacting foraging behaviour among the lower cascade. Anthropocene-led behavioural alteration in vocalization has been observed in a wide range of species, but the effect on wolf howl is unknown. In this context, we have studied the howling behaviour of the Indian wolf through playback surveys (n = 264) across the anthropogenic gradient. We found a disparity in their howl response – based on the distance to villages. In the low disturbed East-Maharashtra (EM), wolves mostly avoided responding to howling surveys (HS) if done within 1200 m of villages [response rate (RR) = 0.03 ± 0.021], but they did respond once it was done far from villages (>1200 m) (RR = 0.226 ± 0.075). In high human-density West-Maharashtra (WM), wolves showed high RR within 1200 m from the villages (RR = 0.148 ± 0.031). But the RR within 500 m from villages was less as howling near villages might lead to easy detection. The collared wolf data showed significantly high RR (0.635 ± 0.067) in their home-range core, but low RR if the core area was close to a village. Therefore, howling too close to a village is disadvantageous, although their tolerance for responding to HS has increased in the human-dominated landscape. The extent of the village may increase further with development, which will leave fewer areas for the wolf to defend territory with a long-range howl. The wolves might behaviourally adapt to a human-modified landscape by reducing their howling intensity. Adaptation to a fragmented habitat may save the wolves from extinction, but the repercussions of the fundamental behavioural alteration might adversely impact wolf behaviour and the ecological cascade. Whereas ecologists are mainly concerned with the extinction of species, this study highlights the vulnerability of fundamental behaviour of a keystone species attributed to human-induced contemporary evolution. [ABSTRACT FROM AUTHOR]

In ecological systems, the predator-induced fear dampens the prey's birth rate; yet, it fails to extinguish their population, as they endure and survive even under significant fear-induced costs. In this study, we unveil a modified Leslie–Gower predator–prey model by incorporating the fear of predators, cooperative hunting, and predator-taxis sensitivity. We embark upon an exploration of the positivity and boundedness of solutions, unearthing ecologically viable equilibrium points and their stability conditions governed by the model parameters. Delving deeper, we unravel the scenario of transcritical, saddle-node, Hopf, Bogdanov–Takens, and generalized-Hopf bifurcations within the system's intricate dynamics. Additionally, we observe the bistable nature of the system under some parametric conditions. Further, the nonautonomous extension of our model introduces the intriguing interplay of seasonality in some crucial parameters. We establish a set of sufficient conditions that guarantee the permanence of the seasonally driven system. By conducting a numerical study on the seasonally forced model, we observe a myriad of phenomena manifesting the predator–prey dynamics. Notably, periodic solutions, higher periodic solutions, and bursting patterns emerge, alongside intriguing chaotic dynamics. Specifically, seasonal variations of the predator-taxis sensitivity and hunting cooperation can lead to the extinction of prey species and even the control of chaotic (higher periodic) solutions through the generation of a simple periodic solution. Remarkably, the seasonal forcing has the capacity to govern the chaotic behavior, leading to an exceptionally quasi-periodic arrangement in both prey and predator populations. [ABSTRACT FROM AUTHOR]

Life history traits are used to predict asymptotic odds of extinction from dynamic conditions. Less is known about how life history traits interact with stochasticity and population structure of finite populations to predict near‐term odds of extinction. Through empirically parameterized matrix population models, we study the impact of life history (reproduction, pace), stochasticity (environmental, demographic), and population history (existing, novel) on the transient population dynamics of finite populations of plant species. Among fast and slow pace and either a uniform or increasing reproductive intensity or short or long reproductive lifespan, slow, semelparous species are at the greatest risk of extinction. Long reproductive lifespans buffer existing populations from extinction while the odds of extinction of novel populations decrease when the reproductive effort is uniformly spread across the reproductive lifespan. Our study highlights the importance of population structure, pace, and two distinct aspects of parity for predicting near‐term odds of extinction. [ABSTRACT FROM AUTHOR]

Desert communities are threatened with species loss due to climate change, and their resistance to such losses is unknown. We constructed a food web of the Mojave Desert terrestrial community (300 nodes, 4080 edges) to empirically examine the potential cascading effects of bird extinctions on this desert network, compared to losses of mammals and lizards. We focused on birds because they are already disappearing from the Mojave, and their relative thermal vulnerabilities are known. We quantified bottom‐up secondary extinctions and evaluated the relative resistance of the community to losses of each vertebrate group. The impact of random bird species loss was relatively low compared to the consequences of mammal (causing the greatest number of cascading losses) or reptile loss, and birds were relatively less likely to be in trophic positions that could drive top‐down effects in apparent competition and tri‐tropic cascade motifs. An avian extinction cascade with year‐long resident birds caused more secondary extinctions than the cascade involving all bird species for randomized ordered extinctions. Notably, we also found that relatively high interconnectivity among avian species has formed a subweb, enhancing network resistance to bird losses. [ABSTRACT FROM AUTHOR]

Human disturbance including rapid urbanization and increased temperatures can have profound effects on the ecology of local populations. Eusocial insects, such as ants, have adapted to stressors of increasing temperature and urbanization; however, these evolutionary responses are not consistent among populations across geographic space. Here we asked how urbanization and incubation temperature influence critical thermal maximum (CTmax) and various ecologically relevant behaviors in three ant species in urban and rural locations in Worcester, MA, USA. We did this by incubating colonies of three species of cavity dwelling ant (Aphaenogaster picea, Tapinoma sessile, and Temnothorax longispinosus) from 2 habitat types (Rural and Urban), for 60‐days at multiple temperatures. We found that incubation temperature, urbanization, and species of ant all significantly affected overall colony critical thermal maximum. We also found that recruitment time, colonization time, and defense response were significantly affected by incubation temperature and varied between species of ant, while recruitment and colonization time were additionally affected by urbanization. These variable changes in performance and competitive traits across species suggest that responses to urbanization and shifting temperatures are not universal across species. Changes in behavioral responses caused by urbanization may disrupt biodiversity, creating unusual competitive environments as a consequence of natural adaptations and cause both direct and indirect mechanisms for which human disturbance can lead to local species extinction. [ABSTRACT FROM AUTHOR]

Harvesting wild populations is increasingly used to support conservation initiatives, including translocations, captive assurance colonies, and breeding programs. Best‐practice guidelines recommend that population viability analyses should be developed to assess the potential impact of harvest on source populations, allowing quantification of the risk incurred by the conservation programme. We developed a stochastic population model to assess the relative impact of harvesting southern bell frogs (Litoria raniformis) from three well‐studied populations. We compared the probability of local extinction when harvesting from three life stages (spawn, tadpoles, and adults) and at 21 harvest proportions (from 0 to 1, in 0.05 increments). Source populations with an estimated average of 100 adult frogs and with three or fewer breeding opportunities every 5 years showed increased risk of local extinction and lower minimum adult populations from all harvest strategies. Sources with an estimated average population >600 adult frogs and breeding opportunities in at least eight out of every 10 years were more resilient to harvest. For these populations, harvesting up to 25% of spawning masses or late‐stage tadpoles had a negligible impact on the probability of local extinction and caused a slight decrease in the minimum adult population. Harvesting adults impacted source populations more strongly than harvesting spawn or tadpoles. Our model highlights the importance of frequent breeding opportunities to offset the effects of harvesting L. raniformis. Populations sustained by environmental water delivery should be prioritized for the two consecutive breeding seasons following harvest in the absence of natural wetland inundation. We demonstrate a tractable approach to assess and compare the relative risk of wild harvest for threatened amphibians, with implications for the conservation of our focal species, L. raniformis. We encourage conservation practitioners to implement population viability analyses prior to wild harvest, whenever sufficient demographic information is available to build the requisite models. [ABSTRACT FROM AUTHOR]

Different forest systems can influence the function, traits, diversity, and distribution of ferns. By comparing ferns based on their functional traits, we can explore how species loss affects functional diversity, and consequently alter the forest ecosystem. We investigated the impact of abandoned silviculture on fern diversity (taxonomic and functional) and abundance. Our hypothesis suggests a positive effect of nutrients and soil humidity in native forests, while canopy openness in silviculture has a negative effect on monilophyte diversity. This study was conducted in three sites of native forest and three sites of Pinus silviculture. Each site was subdivided into three areas, with three plots per area, resulting in 54 plots (3 sites × 3 areas × 3 plots × 2 forest types). Each plot covered an area of 100 m2 (10 m × 10 m; 5400 m2 in total). In each plot, we estimated abundance, functional attributes (richness, evenness, divergence, and dispersion) based on leaf thickness, leaf width, petiole length, stem length, leaf division, sori shape, indusium presence, and taxonomic diversity. Results indicate that native forest exhibit higher taxonomic and functional diversity (richness—Fric) compared to abandoned Pinus plantations, which may be attributed to high habitat diversity and species specialization in specific microhabitats. In silviculture, diversity homogenization leads to an increase in the redundancy of functional attributes (evenness—Feve), resulting in the filtering out of similar organisms. Abiotic factors such as light and canopy openness negatively influence plant establishment and growth, leading to a decrease in leaf division and indusium presence/absence (by CWMs), supporting niche complementarity theory in natural forest and mass ratio theory in silviculture. Our findings highlight the enduring negative impact of silviculture, even after 20 years, on both the taxonomic and functional diversity of monilophytes, underscoring the crucial role of native forests in preserving fern diversity. [ABSTRACT FROM AUTHOR]

Habitat fragmentation due to dams is a well‐known threat to freshwater fish. Yet, the global consequences of fragmentation for the viability of freshwater fish populations are unknown. Here, we provide the first global assessment of the threats of dams to the persistence of freshwater fish species. We developed a global macroecological relationship between freshwater fish range size and body size and used this relationship to assess whether isolated range fragments are too small to support a species. Our assessment includes 7369 freshwater fish species and considers the effects of 31,780 dams globally. Furthermore, we performed a more detailed analysis of the threats of dams in Brazil, the greater Mekong region and the United States, using complementary national and regional data sets. Globally, more than half of the species analysed face extirpation in a part of their geographic range, with an average potential range loss of 3.3% (95%‐range: 0%–31.8%) across all species analysed. For 74 fish species, occurring in Brazil, China, India, the Mekong basin, the United States, South‐Africa and the East Adriatic Coast, more than 50% of their range is potentially lost. This includes 18 species threatened with extinction across their whole range. Our complementary regional analysis revealed that the potentially lost range increases by a factor of 2–4 when considering both large and small dams compared with considering only large dams (≥15 m), highlighting the need to establish more comprehensive global dam inventories. Our novel approach and global analysis identifies species at risk of extirpation as well as geographic hotspots of extirpation threat by dams, which can aid in establishing more effective strategies for global hydropower development and barrier removal efforts to optimise the trade‐offs between biodiversity conservation and the socio‐economic benefits of dams. [ABSTRACT FROM AUTHOR]

Genomic diversity is associated with the adaptive potential of a population and thereby impacts the extinction risk of a species during environmental change. However, empirical data on genomic diversity of populations before environmental perturbations are rare and hence our understanding of the impact of perturbation on diversity is often limited. We here assess genomic diversity utilising whole‐genome resequencing data from all four species of the Lake Constance Alpine whitefish radiation. Our data covers a period of strong but transient anthropogenic environmental change and permits us to track changes in genomic diversity in all species over time. Genomic diversity became strongly reduced during the period of anthropogenic disturbance and has not recovered yet. The decrease in genomic diversity varies between 18% and 30%, depending on the species. Interspecific allele frequency differences of SNPs located in potentially ecologically relevant genes were homogenized over time. This suggests that in addition to the reduction of genome‐wide genetic variation, the differentiation that evolved in the process of adaptation to alternative ecologies between species might have been lost during the ecological disturbance. The erosion of substantial amounts of genomic variation within just a few generations in combination with the loss of potentially adaptive genomic differentiation, both of which had evolved over thousands of years, demonstrates the sensitivity of biodiversity in evolutionary young adaptive radiations towards environmental disturbance. Natural history collections, such as the one used for this study, are instrumental in the assessment of genomic consequences of anthropogenic environmental change. Historical samples enable us to document biodiversity loss against the shifting baseline syndrome and advance our understanding of the need for efficient biodiversity conservation on a global scale. [ABSTRACT FROM AUTHOR]

Premise: Cultivation and naturalization of plants beyond their natural range can bring previously geographically isolated taxa together, increasing the opportunity for hybridization, the outcomes of which are not predictable. Here, we explored the phenotypic and genomic effects of interspecific gene flow following the widespread cultivation of Mentha spicata (spearmint), M. longifolia, and M. suaveolens. Methods: We morphologically evaluated 155 herbarium specimens of three Mentha species and sequenced the genomes of a subset of 93 specimens. We analyzed the whole genomes in a population and the phylogenetic framework and associated genomic classifications in conjunction with the morphological assessments. Results: The allopolyploid M. spicata, which likely evolved in cultivation, had altered trichome characters, that is possibly a product of human selection for a more palatable plant or a byproduct of selection for essential oils. There were signs of genetic admixture between mints, including allopolyploids, indicating that the reproductive barriers between Mentha species with differences in ploidy are likely incomplete. Still, despite gene flow between species, we found that genetic variants associated with the cultivated trichome morphology continue to segregate. Conclusions: Although hybridization, allopolyploidization, and human selection during cultivation can increase species richness (e.g., by forming hybrid taxa), we showed that unless reproductive barriers are strong, these processes can also result in mixing of genes between species and the potential loss of natural biodiversity. [ABSTRACT FROM AUTHOR]

Since European colonisation of Australia in 1788, nine Australian bird species (1.2% of the Australian total) have become extinct, along with 22 subspecies (of 16 species). Consistent with global patterns, Australia's island endemic birds have been particularly susceptible, comprising eight of the nine species' extinctions (38% of the bird species endemic to islands smaller than Tasmania), and 13 of the 22 subspecies' extinctions. The extinction of only one bird species (Paradise Parrot Psephotellus pulcherrimus) from the Australian mainland contrasts with the far higher rate of extinctions of Australian mammals (27 of 312 species that occurred on the Australian mainland), and is comparable with the rate of extinctions of birds on the mainland of other continents over this period. Extinctions of Australian birds were caused mainly by introduced predators (especially for island taxa), habitat degradation, and hunting (for some island taxa). The timing of some extinctions is uncertain, but the first bird extinction subsequent to European colonisation was the loss of the flightless White Gallinule Porphyrio albus from Lord Howe Island over the period 1788–1790. Extinctions have occurred in most decades since then, with the most recent being for Norfolk Island's White-chested White-eye Zosterops albogularis in the decade 2000–2009. Environmental legislation, an extensive conservation reserve system, and dedicated conservation management efforts have prevented some extinctions. However, local extirpations continue, many threatened species continue to decline and, without an increase in conservation efforts, the rate of extinctions is likely to increase, mainly due to the direct and compounding impacts of climate change. Extinctions of Australian birds have occurred in most decades since European colonisation of Australia. Island bird taxa have proven particularly susceptible, and many of the most imperilled birds are island endemics. Conservation management actions and policies have prevented (and continue to do so) some otherwise probable extinctions. The direct and indirect impacts of climate change will increase the likelihood of extinction for many bird taxa. There is uncertainty about the persistence or extinction of some bird taxa, and these are priorities for surveys and, if found, urgent management interventions. [ABSTRACT FROM AUTHOR]

This article provides an overview of the trends and lessons learned from thirty years of Australian threatened bird action plans. It emphasizes the importance of these action plans in assessing the extinction risk of Australian birds and using the ultrataxon as the basic unit for conservation efforts. The article acknowledges that Australian birds are experiencing gradual declines, with some taxa becoming extinct since the implementation of the first action plan. It highlights the need for long-term monitoring, improved quality of monitoring efforts, and research on the threats faced by Australian threatened bird taxa, including climate change. The article also discusses the success of conservation interventions in preventing extinctions, particularly for migratory shorebird taxa, and the use of the Red List Index to assess conservation performance. It mentions the decline in extinction risk for certain bird groups, such as mangrove birds and seabirds, due to specific interventions, but notes that the reasons for the reduction in extinction risk across Australian birds are largely unknown. The article emphasizes the importance of predicting which taxa are likely to become threatened based on biological characteristics and understanding the barriers to threat alleviation. It also highlights the involvement of First Peoples in threatened bird conservation and the need for funding and support for their management of Country. The article concludes by emphasizing the need to prioritize biodiversity conservation as a fundamental objective and the significance of local values in reducing extinction risk. [Extracted from the article]

Threatened species receive much attention in conservation science and practice. Species currently declining, but not yet listed as threatened, also deserve consideration to reduce their risk of sliding towards extinction and to maintain their functional roles in ecosystems. Information on declining bird species in Australia is available from four main sources: national databases, syntheses of historical change, regional monitoring programmes and summaries for guilds of species. Many species show evidence of decline; declines of species are occurring nation-wide, and they are ongoing. Trends for individual species vary geographically; they may be declining in part of their range but stable elsewhere. Common trajectories of population decline include: (a) a downward linear trend; (b) a marked downturn, sustained at a lower level; and (c) fluctuations through time associated with episodic events (e.g. drought) and incomplete recovery. Ongoing declines affect ecosystems through reduced species richness, homogenisation of bird communities, changes to interspecific interactions and ecosystem services, and contributing to extinction debt. Improving the conservation outlook for declining species requires systematic monitoring to know where, when and how much decline is occurring, together with protection of critical habitats and source populations, ambitious programmes of restoration, and identification and effective control of threats. Responding to declining species offers opportunities for community engagement, monitoring and action at a local and regional level. New ways are needed to incorporate such species in conservation planning and environmental regulation at a regional scale, to give them greater visibility and avoid local declines accumulating until taxa become nationally threatened. Many bird species in Australia, not (yet) listed as threatened, are experiencing population decline and warrant greater attention in conservation planning and management. Patterns of change for individual species vary regionally, depending on past land-use and current pressures. Ongoing decline and loss of species has profound consequences for Australian ecosystems, including depleted and homogenised bird communities and reductions in the diverse ecosystem services that birds provide. New approaches are needed to provide formal recognition and appropriate management for declining species, particularly at a regional level, so they become more visible in environmental planning and can persist in regional landscapes. [ABSTRACT FROM AUTHOR]

Australia recently committed through the Kunming-Montreal Global Biodiversity Framework (GBF) to halt human-induced extinction of known threatened species and to reduce extinction risk of threatened species significantly by 2030. We review recent trends in extinction risk of Australian birds to provide context for current and future conservation efforts. We calculate the Red List Index (RLI) for all Australian birds as well as subsets based on geography, habitat and taxonomy. Over the period 2010 to 2020, the number of taxa reassigned to lower categories of extinction risk (n = 20; 1.5% of all taxa included) was greatly outweighed by the number moved to higher categories owing to deteriorating status (n = 93; 7%). This resulted in the steepest decadal decline in the RLI since data were first compiled in 1990. It was chiefly driven by rapid population declines in migratory shorebirds, loss of suitable habitat for species affected by wildfire in 2019–2020 and, to a lesser extent, declines in the abundance of upland rainforest birds. To a small extent, these losses were counterbalanced by improvements in status of some bird species resulting from local eradication of invasive mammals, primarily from Macquarie Island. For Australia to meet the commitments recently adopted through the GBF, conservation interventions (and hence funding) will need to be scaled up substantially. The RLI is well placed for monitoring progress towards the GBF targets and for communicating trends in the extinction risk to national avifaunas. Australia is committed to reducing extinction risk through its adoption of the Kunming-Montreal Global Biodiversity Framework. A Red List Index (RLI) for all Australian birds from 1990 to 2020 shows their extinction risk increased by 3.34%. More than 50% of the increase in extinction risk between 2010 and 2020 was caused by the 2019–2020 wildfires. The greatest increases in overall avian extinction risk were in Queensland, South Australia and New South Wales, where drought and wildfire effects were most pronounced. Red List Index trends can reflect the impact of individual threats or conservation interventions, and represent an important tool for monitoring national and global progress towards international agreements. [ABSTRACT FROM AUTHOR]

Over 750 native bird species reside in or regularly migrate to Australia, many of which have experienced rapid changes in habitat extent over the past two centuries. By 2020, eight taxa were considered Extinct and 10% threatened with extinction. Understanding the underlying extrinsic and intrinsic factors that increase extinction risk can allow prioritisation of conservation management and research. Here, we use state-of-the-art phylogenetic comparative models to reveal the most important biological traits that predispose Australian bird species to elevated extinction risk. We use an extensive database of their biological traits and relate these to each species' national and global IUCN extinction risk status as assessed over the past three decades (in 1990, 2000, 2010, and 2020). We show that high evolutionary distinctiveness (uniqueness), island endemism, and an inability to take advantage of agricultural habitats were the most important traits explaining elevated extinction risk in species when phylogeny is controlled for, suggesting that extinction risk is disproportionately high in species with high evolutionary distinctiveness. Extinct taxa were characterised by large body mass and island endemism compared to taxa extant in 2020. Our study provides the largest and most up-to-date analysis of the intrinsic traits of Australian birds in relation to their extinction risk, and can be used as a baseline in future studies, for prioritisation of conservation actions, and for policy advice on a broad scale. Phylogenetic analyses are a useful tool for anticipating extinction risk. Extinction risk over the past three decades is highest among species with a high level of evolutionary distinctiveness. Species-level assessments can mask higher extinction risk at the subspecies-level. Conservation actions that reduce extinction risk can influence the variables deemed important in predictive models. [ABSTRACT FROM AUTHOR]

Whether more species are required to maintain ecosystem functioning as spatial scale increases or across environmental gradients has frequently been studied by examining whether different species drive ecosystem functioning in different sites. However, this approach does rule out the counterfactual scenario where a few species could potentially maintain ecosystem functioning across sites as this requires examining which species can (or cannot) compensate for the loss of others.Here, I used an observational study and a field‐based transplant experiment to examine the effects of species loss on biomass productivity in an intertidal marine macroalgal system. I calculated the number of species required to maintain biomass productivity across four depth zones reflecting a water emersion gradient using two commonly used observational approaches. Then, I combined hypothetical simulated extinction scenarios with field‐based transplant data of relative growth rates of all species across the four depth zones to explore how the number of species required to maintain biomass productivity across depth zones changed under counterfactual scenarios where species compensated for species loss.The observational analyses suggested that between three and four species were required to maintain productivity across the depth zones. The simulated extinction scenarios did not. Rather, decreases in biomass productivity due to the loss of some species (e.g. Fucus spiralis, Ascophyllum nodosum) were easily compensated by other species (e.g. Fucus vesiculosus). However, for some species like F. vesiculosus, the extinction simulations suggested that compensation would be unlikely.Commonly used observational approaches may overestimate the number of species required to maintain ecosystem functioning across environmental gradients and spatial scales. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Rapid environmental changes—in climate, land use, and biotic interactions—are accelerating species extinctions and extirpations globally. Identifying drivers that threaten populations is essential for conservation yet can be difficult given the variable nature of the response of an organism to biotic and abiotic stressors. We analyzed a long-term monitoring data set to explore demographic responses of fishers (Pekania pennanti) to rapid environmental change in the southern Sierra Nevada, California, United States. Fisher survival was sensitive to both biotic and abiotic factors, although the strength and direction of these effects were ultimately mediated by age and sex. Specifically, male survival was lower among young individuals and decreased with increasing temperatures and fungi consumption. Female survival was resilient to age effects and diet but increased with greater forest heterogeneity and decreased with increasing temperatures and snow depth. Our findings suggest that continued climate change will likely have consequences for fishers through both incremental stressors and extreme weather events, but increasing forest heterogeneity may help to buffer against the impacts of such change. Further, we illustrate the importance of disentangling the effects of intrinsic and extrinsic factors on survival, especially among species with distinct sexual or ontogenetic differences. As global drivers of environmental change intensify in strength and frequency, understanding these complex relationships will allow practitioners to best manage for population persistence and habitat resilience concurrently. [ABSTRACT FROM AUTHOR]

The end-Permian mass extinction was the most severe ecological event during the Phanerozoic and has long been presumed contemporaneous across terrestrial and marine realms with global environmental deterioration triggered by the Siberian Traps Large Igneous Province. We present high-precision zircon U-Pb geochronology by the chemical abrasion-isotope dilution-thermal ionization mass spectrometry technique on tuffs from terrestrial to transitional coastal settings in Southwest China, which reveals a protracted collapse of the Cathaysian rainforest beginning after the onset of the end-Permian marine extinction. Integrated with high-resolution geochronology from coeval successions, our results suggest that the terrestrial extinction occurred diachronously with latitude, beginning at high latitudes during the late Changhsingian and progressing to the tropics by the early Induan, spanning a duration of nearly 1 million years. This latitudinal age gradient may have been related to variations in surface warming with more degraded environmental conditions at higher latitudes contributing to higher extinction rates. [ABSTRACT FROM AUTHOR]

Systems of differential equations with polynomial right-hand sides are very common in applications. In particular, when restricted to the positive orthant, they appear naturally (according to the law of mass-action kinetics) in ecology, population dynamics, as models of biochemical interaction networks, and models of the spread of infectious diseases. Their mathematical analysis is very challenging in general; in particular, it is very difficult to answer questions about the long-term dynamics of the variables (species) in the model, such as questions about persistence and extinction. Even if we restrict our attention to mass-action systems, these questions still remain challenging. On the other hand, if a polynomial dynamical system has a weakly reversible single linkage class ( W R 1 ) realization, then its long-term dynamics is known to be remarkably robust: all the variables are persistent (i.e., no species goes extinct), irrespective of the values of the parameters in the model. Here we describe an algorithm for finding W R 1 realizations of polynomial dynamical systems, whenever such realizations exist. [ABSTRACT FROM AUTHOR]

The fifth mass extinction event (MEE) at the Cretaceous–Palaeogene (K–Pg) boundary 66 million years ago (Ma) led to massive species loss but also triggered the diversification of higher taxa. Five models have been proposed depending on whether this diversification occurred before, during or after the K–Pg boundary and the rate of species accumulation. While the effects of the K–Pg MEE on vertebrate evolution are relatively well understood, the impact on invertebrates, particularly in freshwater ecosystems, remains controversial. One example is the hyperdiverse Hydrobiidae—the most species‐rich family of freshwater gastropods. Whereas some studies place its origin in the Jurassic or even Carboniferous, most fossil records postdate the K–Pg event. We therefore used robustly time‐calibrated multi‐locus phylogenies of >400 species representing >100 hydrobiid genera to unravel its evolutionary history and patterns of diversification. We found that the family started diversifying shortly after the K–Pg boundary (∼60 Ma; 95% highest posterior density 52–69 Ma). Lineage richness gradually increased to the present and phylogenetic diversity until ∼25 Ma. These findings suggest that diversification was not initially driven by ecological opportunity. Combining the two criteria of timing and rate of diversification, a soft‐explosive diversification model of aquatic vertebrates best fits the patterns observed. We also show that most higher hydrobiid taxa (i.e. subfamilies) diversified from the Middle Oligocene to Middle Miocene (i.e. 12–28 Ma). Two of the 15 major clades delimited are described here as new subfamilies (i.e. Bullaregiinae n. subfam. and Pontobelgrandiellinae n. subfam.), whose members are restricted to subterranean waters. Our results are an important contribution to understanding how the fifth MEE has shaped evolution and patterns of biodiversity in continental aquatic systems. Given the high extinction risks faced by many hydrobiids today, they also emphasise the need to study the biodiversity of vulnerable ecosystems. [ABSTRACT FROM AUTHOR]

Anurans of the genus Brachycephalus are among the smallest vertebrates in the world, due to an extreme process of miniaturization. As an example of this process, Brachycephalus species show loss of fingers, loss of the eardrum and middle ear, bone fusions, and the presence of paravertebral plates and parotic plaque. However, no studies addressing the consequences of miniaturization on internal organs, such as the lungs and heart, are currently available. Thus, this study aimed to investigate if overall small body size has affected the cardiorespiratory system. We investigated, via dissections, individuals of four Brachycephaloidea species: Brachycephalus rotenbergae, B. pitanga, Eleutherodactylus johnstonei, and Ischnocnema parva. We observed that B. rotenbergae and B. pitanga present a reduction of the atrial septum and absence of the carotid body. On the other hand, despite being a member of the sister genus to Brachycephalus (both genera belong to the Brachycephalidae), individuals of Ischnocnema present a heart with a complete septum and carotid body; this is also observed in E. johnstonei (Eleutherodactylidae). We observed that B. rotenbergae and B. pitanga have thin skin with a one to two cell thick germ layer, and their lungs likely exhibit lower blood supply when compared to individuals of the E. johnstonei and I. parva species. Based on the observed structures, we suggest that in species of Brachycephalus, respiration is performed mainly through the skin, and their lungs may have a reduced respiratory function. [ABSTRACT FROM AUTHOR]

It is an urgent needs to address climate change and pollution in aquatic systems using suitable mitigation measures to avoid the aquatic animals' extinction. The vulnerability and extinction of the aquatic animals in the current scenario must be addressed to enhance safe fish food production. Taking into consideration of such issues in fisheries and aquaculture, an experiment was designed to mitigate high temperature (T) and low pH stress, as well as arsenic (As) pollution in fish using copper (Cu) containing diets. In the present investigation, the Cu-containing diets graded with 0, 4, 8, and 12 mg kg-1 were prepared and fed to Pangasianodon hypophthalmus reared under As, low pH, and high-temperature stress. The gene expression was highly affected in terms of the primary, secondary, and tertiary stress response, whereas supplementation of Cu-containing diet mitigates the stress response. Oxidative stress genes such as catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were significantly upregulated by stressors (As, As + T, and As + pH + T). Whereas, heat shock protein (HSP 70), inducible nitric oxide synthase (iNOS), metallothionine (MT), caspase 3a (Cas 3a), and cytochrome P450 (CYP 450) were highly upregulated by stressors, while dietary Cu at 8 mg kg-1 diet significantly downregulated these gene expressions. Indeed, the immunity-related genes viz. TNFα, Ig, TLR, and immune-related attributes viz. albumin, globulin, total protein, A:G ratio, blood glucose, NBT, and myeloperoxidase (MPO) were also improved with Cu-containing diets. Cu containing diets substantially improved neurotransmitter enzyme (AChE) and vitamin C (Vit C). DNA damage was also reduced with supplementation of Cu at 8 mg kg-1 diet. The growth index viz. final body weight gain (%), specific growth rate, protein efficiency ratio, food conversion ratio, relative feed intake, and daily growth index were noticeably enhanced by Cu diets (4 and 8 mg kg-1 diet). The growth-related genes expressions viz. growth hormone (GH), growth hormone regulator 1 (Ghr1), growth hormone regulator β (Ghrβ,) myostatin (MYST), and somatostatin (SMT) supported the growth enhancement with Cu at 8 mg kg-1 diet. The bioaccumulation of As was reduced with Cu-containing diets. The fish were infected with Aeromonas hydrophila at the end of the 105 days experimental trial. Cu at 8 mg kg-1 diet improved immunity, reduced the cumulative mortality, and enhanced the relative percentage survival of the fish. The results revealed that the innovative Cu diets could reduce the extinction of the fish against climate change and pollution era and produce the safest production that is safe to humans for consumption. [ABSTRACT FROM AUTHOR]

Dysfunctional fear responses in post-traumatic stress disorder (PTSD) may be partly explained by an inability to effectively extinguish fear responses elicited by trauma-related cues. However, only a subset of individuals exposed to traumatic stress develop PTSD. Therefore, studying fear extinction deficits in animal models of individual differences could help identify neural substrates underlying vulnerability or resilience to the effects of stress. We used a rat model of social defeat in which rats segregate into passively and actively coping rats. In previous work, we showed that passively coping rats exhibit disruptions in social interaction whereas actively coping rats do not display behaviors differently from controls, indicating their resilience. Here, adult male rats exposed to 7 days of social defeat were tested for fear extinction, retention of extinction, and persistence of retention using contextual fear and ethologically-relevant fear tests. Passively coping rats exhibited elevated freezing in response to the previously extinguished context. Analyses of cFos expressing cells across select brain regions showed high correlations within dorsal hippocampal subregions, while passively coping rats had high correlations between the dorsal hippocampus CA1 and the central and basolateral subregions of the amygdala. Importantly, although control and actively coping rats showed similar levels of behavioral extinction, there was little similarity between activated structures, suggesting stress resilience in response to chronic social defeat involves an adaptive differential recruitment of brain circuits to successfully extinguish fear memories. [ABSTRACT FROM AUTHOR]

Anthropogenic mortality is a major cause of global mortality in terrestrial vertebrates. Quantifying its impact on the dynamics of threatened species is essential to improve their conservation. We investigated cause-specific mortality in Canarian houbara bustards (Chlamydotis undulata fuertaventurae), an endangered subspecies endemic to the Canary Islands. We monitored 51 individuals tagged with solar-powered GSM/GPRS loggers for an average of 3.15 years, and recorded 7 casualties at aerial lines (13.73% of the sample; 5 at power lines, 2 at telephone lines), 1 (1.96%) at a wire fence, 4 road kills (7.84%) and 1 case of predation by cat (1.96%). Cox proportional hazards models showed that anthropogenic and natural annual mortality rates were similar (respectively, 6.20% and 6.36% of the individuals). We estimate that 33–35 houbaras die each year in the Canary Islands due to anthropogenic causes. Population viability models using these data and juvenile productivity values obtained over seven years predicted the extinction of the species in 50 years. Eliminating anthropogenic mortality, the population could be recovered, but would still require management actions to improve habitat quality. Conservation measures to reduce anthropogenic mortality due to power line fatalities, roadkills and predation by cats, as well as to increase productivity, are urgently needed, particularly on Fuerteventura, where houbaras are on the brink of extinction. [ABSTRACT FROM AUTHOR]

Humans are regularly cited as the main driver of current biodiversity extinction, but the impact of historic volcanic activity is often overlooked. Pre-human evidence of wildlife abundance and diversity are essential for disentangling anthropogenic impacts from natural events. Réunion Island, with its intense and well-documented volcanic activity, endemic biodiversity, long history of isolation and recent human colonization, provides an opportunity to disentangle these processes. We track past demographic changes of a critically endangered seabird, the Mascarene petrel Pseudobulweria aterrima, using genome-wide SNPs. Coalescent modeling suggested that a large ancestral population underwent a substantial population decline in two distinct phases, ca. 125,000 and 37,000 years ago, coinciding with periods of major eruptions of Piton des Neiges. Subsequently, the ancestral population was fragmented into the two known colonies, ca. 1500 years ago, following eruptions of Piton de la Fournaise. In the last century, both colonies declined significantly due to anthropogenic activities, and although the species was initially considered extinct, it was rediscovered in the 1970s. Our findings suggest that the current conservation status of wildlife on volcanic islands should be firstly assessed as a legacy of historic volcanic activity, and thereafter by the increasing anthropogenic impacts, which may ultimately drive species towards extinction. [ABSTRACT FROM AUTHOR]

Cope's rule posits that evolution gradually increases the body size in lineages. Over the last decades, two schools of thought have fueled a debate on the applicability of Cope's rule by reporting empirical evidence, respectively, for and against Cope's rule. The apparent contradictions thus documented highlight the need for a comprehensive process-based synthesis through which both positions of this debate can be understood and reconciled. Here, we use a process-based community-evolution model to investigate the eco-evolutionary emergence of Cope's rule. We report three characteristic macroevolutionary patterns, of which only two are consistent with Cope's rule. First, we find that Cope's rule applies when species interactions solely depend on relative differences in body size and the risk of lineage extinction is low. Second, in environments with higher risk of lineage extinction, the recurrent evolutionary elimination of top predators induces cyclic evolution toward larger body sizes, according to a macroevolutionary pattern we call the recurrent Cope's rule. Third, when interactions between species are determined not only by their body sizes but also by their ecological niches, the recurrent Cope's rule may get inverted, leading to cyclic evolution toward smaller body sizes. This recurrent inverse Cope's rule is characterized by highly dynamic community evolution, involving the diversification of species with large body sizes and the extinction of species with small body sizes. To our knowledge, these results provide the first theoretical foundation for reconciling the contrasting empirical evidence reported on body-size evolution. The processes underlying Cope's rule of increasing body size in animal lineages are investigated using computational models. Varied levels of extinction risk may alter the conformity of a lineage to Cope's rule. [ABSTRACT FROM AUTHOR]

Until recently, most ecological network analyses investigating the effects of species' declines and extinctions have focused on a single type of interaction (e.g. feeding). In nature, however, diverse interactions co-occur, each of them forming a layer of a 'multilayer' network. Data including information on multiple interaction types has recently started to emerge, giving us the opportunity to have a first glance at possible commonalities in the structure of these networks. We studied the structural features of 44 tripartite ecological networks from the literature, each composed of two layers of interactions (e.g. herbivory and pollination), and investigated their robustness to species losses. Considering two interactions simultaneously, we found that the robustness of the whole community is a combination of the robustness of the two ecological networks composing it. The way in which the layers of interactions are connected to each other affects the interdependence of their robustness. In many networks, this interdependence is low, suggesting that restoration efforts would not automatically propagate through the whole community. Our results highlight the importance of considering multiple interactions simultaneously to better gauge the robustness of ecological communities to species loss and to more reliably identify key species that are important for the persistence of ecological communities. Author summary: In the face of the current biodiversity crisis, predicting how species loss will affect ecological communities is becoming increasingly relevant. Previous studies including only one type of ecological interactions (e.g. feeding or pollination) revealed the relevance of the structure of ecological networks for the persistence of ecological communities. However, there is mounting evidence that considering multiple interactions simultaneously can alter the results based on a single interaction. Here, we study the robustness of ecological networks with two interaction types to the loss of plant species, and we show that it is a combination of the robustness of the two bipartite ecological networks composing the ecological community. By analyzing networks from multiple communities, we are able to identify commonalities across interaction types, as well as singularities specific to a given interaction type, caused by underlying biological constraints. Our results highlight that a multi-interaction approach is crucial to better gauge the overall robustness of ecological communities, and to correctly determine the relative importance of different plants species at the whole community level, which can be key for biodiversity conservation. [ABSTRACT FROM AUTHOR]

Genomic studies of species threatened by extinction are providing crucial information about evolutionary mechanisms and genetic consequences of population declines and bottlenecks. However, to understand how species avoid the extinction vortex, insights can be drawn by studying species that thrive despite past declines. Here, we studied the population genomics of the muskox (Ovibos moschatus), an Ice Age relict that was at the brink of extinction for thousands of years at the end of the Pleistocene yet appears to be thriving today. We analysed 108 whole genomes, including present‐day individuals representing the current native range of both muskox subspecies, the white‐faced and the barren‐ground muskox (O. moschatus wardi and O. moschatus moschatus) and a ~21,000‐year‐old ancient individual from Siberia. We found that the muskox' demographic history was profoundly shaped by past climate changes and post‐glacial re‐colonizations. In particular, the white‐faced muskox has the lowest genome‐wide heterozygosity recorded in an ungulate. Yet, there is no evidence of inbreeding depression in native muskox populations. We hypothesize that this can be explained by the effect of long‐term gradual population declines that allowed for purging of strongly deleterious mutations. This study provides insights into how species with a history of population bottlenecks, small population sizes and low genetic diversity survive against all odds. [ABSTRACT FROM AUTHOR]

Biodiversity is declining globally, yet many biodiversity hotspots still lack comprehensive species conservation assessments. Using multiple International Union for Conservation of Nature (IUCN) Red List criteria to evaluate extinction risks and millions of herbarium and forest inventory records, we present automated conservation assessments for all tree species of the Atlantic Forest biodiversity hotspot, including ~1100 heretofore unassessed species. About 65% of all species and 82% of endemic species are classified as threatened. We rediscovered five species classified as Extinct on the IUCN Red List and identified 13 endemics as possibly extinct. Uncertainties in species information had little influence on the assessments, but using fewer Red List criteria severely underestimated threat levels. We suggest that the conservation status of tropical forests worldwide is worse than previously reported. [ABSTRACT FROM AUTHOR]

Plant and pollinator communities are vital for transnational food chains. Like many natural systems, they are affected by global change: rapidly deteriorating conditions threaten their numbers. Previous theoretical studies identified the potential for community-wide collapse above critical levels of environmental stressors—so-called bifurcation-induced tipping points. Fortunately, even as conditions deteriorate, individuals have some adaptive capacity, potentially increasing the boundary for a safe operating space where changes in ecological processes are reversible. Our study considers this adaptive capacity of pollinators to resource availability and identifies a new threat to disturbed pollinator communities. We model the adaptive foraging of pollinators in changing environments. Pollinator's adaptive foraging alters the dynamical responses of species, to the advantage of some—typically generalists—and the disadvantage of others, with systematic non-linear and non-monotonic effects on the abundance of particular species. We show that, in addition to the extent of environmental stress, the pace of change of environmental stress can also lead to the early collapse of both adaptive and nonadaptive pollinator communities. Specifically, perturbed communities exhibit rate-induced tipping points at stress levels within the safe boundary defined for constant stressors. With adaptive foraging, tipping is a more asynchronous collapse of species compared to nonadaptive pollinator communities, meaning that not all pollinator species reach a tipping event simultaneously. These results suggest that it is essential to consider the adaptive capacity of pollinator communities for monitoring and conservation. Both the extent and the rate of stress change relative to the ability of communities to recover are critical environmental boundaries. Author summary: Plant and pollinator communities, which support global food chains, are threatened. A significant problem is the reduction of pollination, where not enough plants are pollinated and are at risk of becoming extinct. Environmental change, such as climate change or increasing pesticide use, can cause this reduction. As long as these changes stay under certain boundaries, undesirable ecological processes like the reduction in pollination are reversible. Crossing these boundaries means tipping of pollinator communities might occur; the system might collapse. Pollinator communities can adapt, for instance, through adaptive foraging by changing which plants they prefer in response to environmental deterioration. We include adaptive foraging in a theoretical model of plant and pollinator communities. We show that plant and pollinator communities are vulnerable to the extent of stressors but also to how fast these stressors increase. Our model shows that, with adaptation, the extinction of species is more sequential and spreads out in time and may even temporarily favor especially generalist species. [ABSTRACT FROM AUTHOR]

Red Queen (RQ) theory states that adaptation does not protect species from extinction because their competitors are continually adapting alongside them. RQ was founded on the apparent independence of extinction risk and fossil taxon age, but analytical developments have since demonstrated that age-dependent extinction is widespread, usually most intense among young species. Here, we develop ecological neutral theory as a general framework for modeling fossil species survivorship under incomplete sampling. We show that it provides an excellent fit to a high-resolution dataset of species durations for Paleozoic zooplankton and more broadly can account for age-dependent extinction seen throughout the fossil record. Unlike widely used alternative models, the neutral model has parameters with biological meaning, thereby generating testable hypotheses on changes in ancient ecosystems. The success of this approach suggests reinterpretations of mass extinctions and of scaling in eco-evolutionary systems. Intense extinction among young species does not necessarily refute RQ or require a special explanation but can instead be parsimoniously explained by neutral dynamics operating across species regardless of age. [ABSTRACT FROM AUTHOR]

Many animals follow annual cycles wherein physiology and behavior change seasonally. Hibernating mammals undergo one of the most drastic seasonal alterations of physiology and behavior, the timing of which can have significant fitness consequences. The environmental cues regulating these profound phenotypic changes will heavily influence whether hibernators acclimate and ultimately adapt to climate change. Hence, identifying the cues and proximate mechanisms responsible for hibernation termination timing is critical. Northern Idaho ground squirrels (Urocitellus brunneus)—a rare, endemic species threatened with extinction—exhibit substantial variation in hibernation termination phenology, but it is unclear what causes this variation. We attached geolocators to free-ranging squirrels to test the hypothesis that squirrels assess surface conditions in spring before deciding whether to terminate seasonal heterothermy or reenter torpor. Northern Idaho ground squirrels frequently reentered torpor following a brief initial emergence from hibernacula and were more likely to do so earlier in spring or when challenged by residual snowpack. Female squirrels reentered torpor when confronted with relatively shallow snowpack upon emergence, whereas male squirrels reentered torpor in response to deeper spring snowpack. This novel behavior was previously assumed to be physiologically constrained in male ground squirrels by testosterone production required for spermatogenesis and activated by the circannual clock. Assessing surface conditions to decide when to terminate hibernation may help buffer these threatened squirrels against climate change. Documenting the extent to which other hibernators can facultatively alter emergence timing by reentering torpor after emergence will help identify which species are most likely to persist under climate change. [ABSTRACT FROM AUTHOR]

potential of using this method to detect the presence of the critically endangered Sumatran tiger. The research demonstrates the effectiveness of eDNA sampling in detecting the presence of elusive species and highlights its potential for conservation efforts.Overall, this document provides a range of research articles related to wildlife rehabilitation and conservation. The articles cover various topics such as the impact of oil spills on marine megafauna, translocation of bird species, trophic behavior of whales, human-wildlife conflicts, veterinary care for wildlife species, tooth wear in Tasmanian devils, plastic ingestion in shorebirds, and reference intervals for laboratory tests in badgers. These articles contribute to our understanding of wildlife and provide valuable insights for conservation efforts. [Extracted from the article]