Current Extinction Rates Research Articles

Conservation gaps and priorities of range-restricted birds in the Northern Andes.

The ongoing destruction of habitats in the tropics accelerates the current rate of species extinction. Range-restricted species are exceptionally vulnerable, yet we have insufficient knowledge about their protection. Species' current distributions, range sizes, and protection gaps are crucial to determining conservation priorities. Here, we identified priority range-restricted bird species and their conservation hotspots in the Northern Andes. We employed maps of the Area of Habitat (AOH), that better reflect their current distributions than existing maps. AOH provides unprecedented resolution and maps a species in the detail essential for practical conservation actions. We estimated protection within each species' AOH and for the cumulative distribution of all 335 forest-dependent range-restricted birds across the Northern Andes. For the latter, we also calculated protection across the elevational gradient. We estimated how much additional protection community lands (Indigenous and Afro-Latin American lands) would contribute if they were conservation-focused. AOHs ranged from 8 to 141,000 km2. We identified four conservation priorities based on cumulative species richness: the number of AOHs stacked per unit area. These priorities are high-resolution mapped representations of Endemic Bird Areas for the Tropical Andes that we consider critically important. Protected areas cover only 31% of the cumulative AOH, but community lands could add 19% more protection. Sixty-two per cent of the 335 species have ranges smaller than their published estimates, yet IUCN designates only 23% of these as Threatened. We identified 50 species as top conservation priorities. Most of these concentrate in areas of low protection near community lands and at middle elevations where, on average, only 34% of the land is protected. We highlight the importance of collaborative efforts among stakeholders: governments should support private and community-based conservation practices to protect the region with the most range-restricted birds worldwide.

To be alive or not to be alive: Radiocarbon data provide new perspective on species diversity in the Caspian Sea

Abstract The Caspian Sea is undergoing a severe biodiversity crisis. However, estimates of current extinction rates are difficult to obtain due to the lack of reliable pre‐Anthropocene baseline data. For example, because the majority of endemic gastropod species was described from “fresh looking” shells, it remains unclear which species still existed prior to the Anthropocene. This study therefore used the species‐rich microgastropod family Hydrobiidae to assess the extent to which endemic species were collected alive during the Anthropocene. Literature and database searches were performed. In addition, 14C dating was conducted on “fresh looking” shells collected in the Caspian Sea during the last 150 years. The literature review revealed that 75% of the “recent” species are only known from empty shells and 25% were recorded with a soft body. The 14C data showed that all “recent” specimens examined had an age between 1624 cal BC and 1888 cal AD. Two species studied predate the beginning of the Anthropocene. Two other species potentially or likely existed during the Anthropocene. This suggests that the number of endemic species still present at the beginning of the Anthropocene is lower than previously thought. The data also suggest that there was a substantial loss of species between the late 18th century and the 1950s and that only two endemic hydrobiid species have recently been found alive. These findings further contribute to the notion of a severe biodiversity crisis in the Caspian Sea. For accurate estimates of current extinction rates of Caspian Sea gastropods, pre‐Anthropocene biodiversity data need to be further corroborated. Particularly, studies are required to clarify the taxonomic status of the dubious taxa and a possible “collection crisis” in the Caspian Sea due to decreasing sampling efforts in recent decades. In addition, comprehensive IUCN assessments are urgently required.

Witnessing mass extinction: What's invisible, what's visible, what's possible

We are living in the time of the Sixth Mass Extinction. While many details elude us, we know that a mass extinction is underway from comparisons between background and current extinction rates, precipitous drops in wildlife populations, the shrinking of wild places, and the critical endangerment of biodiverse ecologies such as grasslands, tropical forests, wetlands, rivers and lakes, coral reefs, and continental shelves. This paper dissects the underpinnings of the Sixth Mass Extinction, with the intention of joining many other activists and thinkers to disrupt its seeming inevitability. First, I discuss what has been invisible about anthropogenic mass extinction—the event itself—and the factors of silence, ignorance, and denial underlying its invisibility. Then I turn to the visible dimension of the Sixth Mass Extinction, namely, the action orientation of “entitled instrumentalism” that is driving it; I describe entitled instrumentalism as the wholesale assimilation of the natural world into a human-owned domain. I end with considering the possibility of humanity charting an altogether different course. We must recognize mass extinction as the inevitable upshot of nature colonization and awaken to the need to restore and preserve Earth's cosmic wealth.

EXPONENTIAL GROWTH OF HUMAN POPULATION IS SOLELY RESPONSIBLE FOR THE HABITAT DESTRUCTION AND LOSS OF BIODIVERSITY ON THE MOTHER EARTH

There are a number of clearly defined processes leading to destruction of habitat and loss of biodiversity, but the ultimate cause of all these is the increasing human population. Most endangered species are threatened by numerous factors, but habitat loss worldwide is generally viewed as the single largest cause of biodiversity loss. When humans convert uninhabited areas for agriculture, forestry, urban development, or water projects like construction of dams, hydropower, and irrigation channels, they reduce or eliminate its usefulness as a habitat for the other species that live there. Biodiversity is the natural variety of living creatures we see around us. It is the variety of all forms of life on this terrestrial ecosystem. High rates of extinction are quickly reducing biodiversity especially in areas with high human population density and growth in the world. The direct and indirect effects of human interference on biodiversity are very challenging. Quantifying loss of genetic diversity is difficult, but it is clear that the extinction of species and declines in their population lead to a loss of genetic diversity. Unfortunately, the majority of the human population growth is seen within the greatest biodiversity hotspots. Scientific studies demonstrates that 87.9 percent of variation in endangered species can be explained by the single factor of human population density. In history many natural extinctions of species were witnessed, but the current rates of extinction are estimated to be roughly 100- times higher than the typical rates in the fossil record, and this increase of extinction will be 1000- 10,000 times higher in the future.

Seeing the green cucumber: Reflections on variation theory and teaching plant identification

Societal Impact StatementOvercoming ‘plant blindness’ is a critical goal for society and especially for education. In this article, we suggest variation theory can be a useful approach to plant identification training and evaluation in higher education contexts. We discuss an example from Swedish higher education in which we reflect on our teaching. We propose that the conscious use of variation theory may be useful in developing pedagogical tools and processes in the teaching of plant identification.Summary Given the importance of the ecological functions of plants and current extinction rates, overcoming ‘plant blindness’, the inability to notice plants in our environment, is a critical goal for society as a whole, and for education in particular. In response to this social challenge, we suggest that a theoretical approach to learning can be a useful lens through which plant identification training and evaluation in higher education contexts can be understood on a deeper level, informed by theoretical tools from the learning sciences. In this article, we discuss an example from Swedish higher education in which we reflect upon our teaching using the principles of the variation theory of learning, which emphasises the ability to discern different features or aspects of what is being learned. We also propose that a deliberate use of learning theories, especially variation theory, may be useful in developing pedagogical tools and processes in botanical education.

Thinking about the Biodiversity Loss in This Changing World

Extinction of species has been a recurrent phenomenon in the history of our planet, but it was generally outweighed in the course of quite a long geological time by the appearance of new species, except, especially, for the five geologically short times when the so-called “Big Five” mass extinctions occurred. Could the current decline in biodiversity be considered as a signal of an ongoing, human-driven sixth mass extinction? This note briefly examines some issues related to: (i) The hypothesized current extinction rate and the magnitude of contemporary global biodiversity loss; (ii) the challenges of comparing them to the background extinction rate and the magnitude of the past Big Five mass extinction events; (iii) briefly considering the effects of the main anthropogenic stressors on ecosystems, including the risk of the emergence of pandemic diseases. A comparison between the Pleistocene fauna dynamics with the present defaunation process and the cascading effects of recent anthropogenic actions on ecosystem structure and functioning suggests that habitat degradation, ecosystem fragmentation, and alien species introduction are important stressors increasing the negative impact on biodiversity exerted by anthropogenic-driven climate changes and their connected effects. In addition, anthropogenic ecological stressors such as urbanization, landscapes, and wildlife trade, creating new opportunities for virus transmission by augmenting human contact with wild species, are among the main factors triggering pandemic diseases.

New Online Resource on the 3Rs Principles of Animal Research for Wildlife Biologists, Ecologists, and Conservation Managers

The Earth’s biodiversity is in crisis. Without radical action to conserve habitats, the current rate of species extinction is predicted to accelerate even further. Efficient species conservation requires planning, management, and continuous biodiversity monitoring through wildlife research. Conservation biology was built on the utilitarian principle, where the well-being of species, populations, and ecosystems is given priority over the well-being of individual animals. However, this tenet has been increasingly under discussion and it has been argued that wildlife researchers need to safeguard the welfare of the individual animals traditionally subjected to invasive or lethal research procedures. The 3Rs principles of animal use (Replacement, Reduction, and Refinement) have become the cornerstone of ethical scientific conduct that could minimize the potential negative impact of research practices. One of the obvious strategies to implement the 3Rs in wildlife studies is to use non-invasive or non-lethal research methods. However, in contrast to toxicological or pharmacological research on laboratory animal models, up to now no 3Rs databases or online resources designed specifically for wildlife biologists, ecologists, and conservation managers have been available. To aid the implementation of the 3Rs principles into research on wildlife, I developed an online resource whose structure is outlined in this paper. The website contains a curated database of peer-reviewed articles that have implemented non-invasive or non-lethal research methods that could be used as a guideline for future studies.

Current extinction rate in European freshwater gastropods greatly exceeds that of the late Cretaceous mass extinction

The Cretaceous–Paleogene mass extinction event 66 million years ago eradicated three quarters of marine and terrestrial species globally. However, previous studies based on vertebrates suggest that freshwater biota were much less affected. Here we assemble a time series of European freshwater gastropod species occurrences and inferred extinction rates covering the past 200 million years. We find that extinction rates increased by more than one order of magnitude during the Cretaceous–Paleogene mass extinction, which resulted in the extinction of 92.5% of all species. The extinction phase lasted 5.4 million years and was followed by a recovery period of 6.9 million years. However, present extinction rates in European freshwater gastropods are three orders of magnitude higher than even these revised estimates for the Cretaceous–Paleogene mass extinction. Our results indicate that, unless substantial conservation effort is directed to freshwater ecosystems, the present extinction crisis will have a severe impact to freshwater biota for millions of years to come.

The inflated significance of neutral genetic diversity in conservation genetics.

The current rate of species extinction is rapidly approaching unprecedented highs, and life on Earth presently faces a sixth mass extinction event driven by anthropogenic activity, climate change, and ecological collapse. The field of conservation genetics aims at preserving species by using their levels of genetic diversity, usually measured as neutral genome-wide diversity, as a barometer for evaluating population health and extinction risk. A fundamental assumption is that higher levels of genetic diversity lead to an increase in fitness and long-term survival of a species. Here, we argue against the perceived importance of neutral genetic diversity for the conservation of wild populations and species. We demonstrate that no simple general relationship exists between neutral genetic diversity and the risk of species extinction. Instead, a better understanding of the properties of functional genetic diversity, demographic history, and ecological relationships is necessary for developing and implementing effective conservation genetic strategies.

Benchmark for the ESA: Having a Backbone Is Good for Recovery

To forestall the current rate of global extinction, we need to identify strategies that successfully recover species. In the last decade, the recovery record for the United States Endangered Species Act (ESA) has improved. Our aim was to review federal delisting documents for recovered species and quantify patterns in taxonomy, history of threats, policy, funding and actions that are associated with species recovery. In comparison to species still listed, the average recovered species was a vertebrate, had been listed longer under the ESA, was exposed to a lower number of threats at the time of listing, and received relatively higher levels of funding. Based on our review, we suggest the following strategies to improve species recovery: provide more time for ESA protection, allocate more funding for recovery, maintain environmental regulations that facilitate recovery, establish more private landowner agreements, and increase the area of protected lands.

Vascular plant extinction in the continental United States and Canada.

Extinction rates are expected to increase during the Anthropocene. Current extinction rates of plants and many animals remain unknown. We quantified extinctions among the vascular flora of the continental United States and Canada since European settlement. We compiled data on apparently extinct species by querying plant conservation databases, searching the literature, and vetting the resulting list with botanical experts. Because taxonomic opinion varies widely, we developed an index of taxonomic uncertainty (ITU). The ITU ranges from A to F, with A indicating unanimous taxonomic recognition and F indicating taxonomic recognition by only a single author. The ITU allowed us to rigorously evaluate extinction rates. Our data suggest that 51 species and 14 infraspecific taxa, representing 33 families and 49 genera of vascular plants, have become extinct in our study area since European settlement. Seven of these taxa exist in cultivation but are extinct in the wild. Most extinctions occurred in the west, but this outcome may reflect the timing of botanical exploration relative to settlement. Sixty‐four percent of extinct plants were single‐site endemics, and many occurred outside recognized biodiversity hotspots. Given the paucity of plant surveys in many areas, particularly prior to European settlement, the actual extinction rate of vascular plants is undoubtedly much higher than indicated here.

English

The incidence of snake bite in rural West Africa is reportedly high with an 11–17% mortality rate. Nigeria has one third of the cases for snake bite cases in this region.Thus, most tribes in North-western part of Nigeria depend on medicinal plants for snakebites. However, it appears that a gap exists on documentation of these plants especially tropical flora used in the management of snake bite. This led to increase depletion of medicinal plant resources and knowledge of their traditional use. Consequently, this survey provided knowledge and data on medicinal plants use in management of snake bite which will help retard the current rate of extinction and decimation of the medicinal plants in these areas and then provide need to conserve what is left as medicinal plants for posterity sake. The study was carried in three northwestern states of Nigeria namely Sokoto, Kebbi and Zamfara for three months. A semi-structured questionnaire was administered and fourteen respondents made up of herb sellers (7%), traditional medical practitioners (93%). The majority of the respondents were male (100%) and 34% were above 50 years of age.  From the study, the data collected shows 25 medicinal plants were in use by different categories of practitioners. Botanical names, local names, family names, plant part (s) use and number of citations were also obtained and documented. Key words: North-western Nigeria, snakebites, medicinal plants. &nbsp

The dynamics underlying avian extinction trajectories forecast a wave of extinctions.

Population decline is a process, yet estimates of current extinction rates often consider just the final step of that process by counting numbers of species lost in historical times. This neglects the increased extinction risk that affects a large proportion of species, and consequently underestimates the effective extinction rate. Here, we model observed trajectories through IUCN Red List extinction risk categories for all bird species globally over 28 years, and estimate an overall effective extinction rate of 2.17 × 10-4/species/year. This is six times higher than the rate of outright extinction since 1500, as a consequence of the large number of species whose status is deteriorating. We very conservatively estimate that global conservation efforts have reduced the effective extinction rate by 40%, but mostly through preventing critically endangered species from going extinct rather than by preventing species at low risk from moving into higher-risk categories. Our findings suggest that extinction risk in birds is accumulating much more than previously appreciated, but would be even greater without conservation efforts.

Decreased Precipitation Predictability Negatively Affects Population Growth through Differences in Adult Survival.

Global climate change is leading to decreased climatic predictability. Theoretical work indicates that changes in the climate's intrinsic predictability will affect population dynamics and extinction, but experimental evidence is scarce. Here, we experimentally tested whether differences in intrinsic precipitation predictability affect population dynamics of the European common lizard (Zootoca vivipara) by simulating more predictable (MP) and less predictable (LP) precipitation in 12 seminatural populations over 3 years and measuring different vital rates. A seasonal age-structured matrix model was parametrized to assess treatment effects on vital rates and asymptotic population growth (λ). There was a nonsignificant trend for survival being higher in MP than in LP precipitation, and no differences existed in reproductive rates. Small nonsignificant survival differences in adults explained changes in λ, and survival differences among age classes were in line with predictions from cohort resonance. As a result, λ was significantly higher in MP than in LP precipitation. This experimentally shows that small effects have major consequences on λ, that forecasted decreases in precipitation predictability are likely to exacerbate the current rate of population decline and extinction, and that stage-structured matrix models are required to unravel the aftermath of climate change.

Carnivores, competition and genetic connectivity in the Anthropocene

Current extinction rates are comparable to five prior mass extinctions in the earth’s history, and are strongly affected by human activities that have modified more than half of the earth’s terrestrial surface. Increasing human activity restricts animal movements and isolates formerly connected populations, a particular concern for the conservation of large carnivores, but no prior research has used high throughput sequencing in a standardized manner to examine genetic connectivity for multiple species of large carnivores and multiple ecosystems. Here, we used RAD SNP genotypes to test for differences in connectivity between multiple ecosystems for African wild dogs (Lycaon pictus) and lions (Panthera leo), and to test correlations between genetic distance, geographic distance and landscape resistance due to human activity. We found weaker connectivity, a stronger correlation between genetic distance and geographic distance, and a stronger correlation between genetic distance and landscape resistance for lions than for wild dogs, and propose a new hypothesis that adaptations to interspecific competition may help to explain differences in vulnerability to isolation by humans.

Avian mitochondrial genomes retrieved from museum eggshell

Avian eggshell is a bio-ceramic material with exceptional properties for preserving DNA within its crystalline structure, presenting an opportunity to retrieve genomic information from extinct or historical populations of birds. However, intracrystalline DNA has only been recovered from the large, thick eggshell of palaeognaths; members of their more-diverse sister group (neognaths) lay smaller, thinner eggs that may not exhibit the same propensity for DNA preservation. Here, we use three 40-60-year-old museum eggshell specimens of Australian neognath birds to determine the minimum mass of eggshell from which intracrystalline DNA can be retrieved, and to characterize the yield and quality of such DNA. In doing so, we describe the first protocol for successful extraction of intracrystalline DNA from neognath eggshells, with the view to unlocking the potential of vast museum egg collections for genetic research. We were able to retrieve DNA fragments over 200bp in length from 10mg of eggshell powder from all three specimens, and demonstrate that expanding the existing blow-hole can allow sufficient material to be collected for DNA extraction while minimizing damage to the appearance and structural integrity of the egg. Furthermore, we were able to reconstruct near-complete mitochondrial genomes at a coverage of 40-83X through shotgun sequencing of these extracts on three NextSeq lanes. Given the current extinction and extirpation rates of many avian species world-wide, genetic data from eggshell could provide a rapid and cost-effective approach to examining temporal changes in avian diversity, which is not only becoming crucial for conservation management, but also serve to deepen our understanding of genome-wide evolutionary processes.

The macroecology and macroevolution of plant species at risk.

Contents Summary 708 I. Introduction 708 II. Fossils and phylogenies: learning from our past 708 III. Threatened species and Red Lists 710 IV. The geography of threat 710 V. The taxonomy of threat 710 VI. Predicting species at risk 711 VII. Conclusion 711 Acknowledgements 712 References 712 SUMMARY: Current rates of extinction are unprecedented in human history. The fossil record and newer molecular phylogenies illuminate historical patterns of speciation and extinction. They reveal both spectacular radiations and the characteristic features of mass extinction events in our geological past. The IUCN Red List provides insight into present-day species declines. There is emerging synthesis that species at risk are nonrandomly distributed across space and phylogeny. This pattern may be explained by geographical variation in driver intensity and species differential sensitivities. However, traits that confer resistance to one global change driver may increase susceptibility to a different driver. A complete understanding of extinction risk requires consideration of the interaction between extinction drivers, ecological traits, and species' evolutionary histories.

Implications of management on immunogenetic variation in the European grayling (Thymallus thymallus)

Implications of management on immunogenetic variation in the European grayling (Thymallus thymallus)

Doomsday for insects? The alarming decline of insect populations around the world

Current rates of extinction exceed largely the standard background rate and all living species can be affected. Insects, the most successful group of eukaryotic organisms from their ancient origin almost 480 my ago are no exception. Despite their fundamental roles in all terrestrial and freshwater ecosystems, insects are victims of the anthropogenic intereference (habitat destruction, overharvesting, pathogens, pesticides, pollution, urbanization, transport of invasive species, and greenhouse gases emissions) that is causing the declination of their populations around the world. Although most insects are not charismatic as many vertebrates or plants, they deserve the same level of protection as other species with which humans are more concerned. It is a duty for all entomologists to study an implement conservation measures of insect species, and educate the general public about their inmense relevance for the Biosphere.

Doomsday for Insects? The Alarming Decline of Insect Populations around the World

Current rates of extinction exceed largely the standard background rate and all living species can be affected. Insects, the most successful group of eukaryotic organisms from their ancient origin almost 480 my ago are no exception. Despite their fundamental roles in all terrestrial and freshwater ecosystems, insects are victims of the anthropogenic intereference (habitat destruction, overharvesting, pathogens, pesticides, pollution, urbanization, transport of invasive species, and greenhouse gases emissions) that is causing the declination of their populations around the world. Although most insects are not charismatic as many vertebrates or plants, they deserve the same level of protection as other species with which humans are more concerned. It is a duty for all entomologists to study an implement conservation measures of insect species, and educate the general public about their inmense relevance for the Biosphere.