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1. Understanding whether a species still persists, or the timing of its extinction is challenging, however, such knowledge is fundamental for effective species management.
2. For the vast majority of species our understanding of their existence is based solely on sighting data that can range from museum specimens and clear photographs, through vocalisations, to markings and oral accounts.
3. Here we review the methods that have been developed to infer the extinction of species from a sighting record, providing an understanding of their assumptions and applications. We have also produced an RShiny package which can be used to implement some of the methods presented in the article.
4. While there are a number of potential areas that could be further developed, the methods reviewed provide a useful tool for inferring species extinction.
We report the non-breeding range of an adult Rapa Shearwater Puffinus myrtae, as estimated from data collected by one light logger deployed from 31 August 2019 to 22 July 2020. The Rapa Shearwater is classified as “Critically Endangered”, with a strong decline in breeding numbers reported recently. As the species is threatened by various introduced mammals on the breeding colonies, the main objective of this tracking essay was to identify the oceanic regions where the birds forage during the non-breeding season. The non-breeding range of this bird was located south-east of Rapa Island, where fishery activities are limited. The conservation efforts for the Critically Endangered Rapa Shearwater should first focus on securing mammal-free sites for breeding colonies.
The Pliensbachian–Toarcian succession of North Yorkshire provides a global reference for the interval incorporating the Toarcian Oceanic Anoxic Event (T-OAE, ∼183 Ma). Major and trace element, carbon stable-isotope (δ13Corg) and total organic carbon (TOC) data for the Dove’s Nest core, drilled close to the classic outcrop sections of the Yorkshire coast, demonstrate geochemical, mineralogical and grain-size trends linked to sea level and climate change in the Cleveland Basin. High-resolution correlation between the core and outcrop enables the integration of data to generate a comprehensive chemostratigraphic record. Palaeoredox proxies (Mo, U, V, TOC/P, DOP and Fe speciation) show a progressive shift from oxic bottom waters in the late Pliensbachian through dysoxic–anoxic conditions in the earliest Toarcian to euxinia during the T-OAE. Anoxia–dysoxia persisted into the middle Toarcian. Elemental and isotope data (Re, Re/Mo, δ34SCAS, δ98Mo and ε205Tl) from the coastal sections evidence global expansion of anoxic and euxinic seafloor area driving drawdown of redox-sensitive metals and sulfate from seawater leading to severe depletion in early Toarcian ocean water. The record of anoxia–euxinia in the Cleveland Basin largely reflects global-scale changes in ocean oxygenation, although metal depletion was temporarily enhanced by periods of local basin restriction. Osmium and Sr isotopes demonstrate a pulse of accelerated weathering accompanying the early Toarcian hyperthermal, coincident with the T-OAE. The combined core and outcrop records evidence local and global environmental change accompanying one of the largest perturbations in the global carbon cycle during the last 200 Ma and a period of major biotic turnover.
Harbour seals were extensively hunted in Denmark, but have only been driven to local extinction in one larger area, the South Funen Archipelago and Little Belt, where the species has been absent throughout the 20th century. Despite high growth rates of the Danish harbour seal populations after protection from hunting in 1976, seals have only been observed sporadically in the South Funen Archipelago and Little Belt until recent years, where recolonisation now causes conflicts with fisheries. Here, we review historical sources documenting the local extinction of harbour seals in the area during the 19th century and report the results of aerial surveys of haul-out sites during moulting seasons of 2021–2023 and pupping seasons of 2022 and 2023. Historical sources reveal that seal hunting was a common practice in southern Denmark, but catches dwindled to rarities during the 19th century. During recent surveys, seals were detected at six of the identified potential haul-out sites. Around Aarø Island, an average of 141 (range: 92–186) harbour seals were recorded over four moulting season surveys, constituting the majority (90%) of the total counts of the surveyed area. During the pupping seasons, a total of five pups was encountered at two different haulouts. As none of the haulouts are protected during the pupping and breeding seasons, protective measures may support this recolonisation of the historic harbour seal breeding range.
In its nearly 80-year history, the International Whaling Commission (IWC) has shifted from a “whalers club” to an international governance body chiefly focused on the protection and conservation of global cetacean populations. Drawing on recent scholarship on extinction and its entanglements, this article compares two addresses given by whalers at IWC meetings 40 years apart to problematise the way whaling and its relation to extinction is conceptualised in international environmental governance. Guided by practice-oriented document analysis and recent theorisation of extinction as an entangled process, this article analyses the personal stakeholder testimonies from two different representatives of the North Slope whalers of Northern Alaska to the IWC – one in relation to the 1977 Alaska bowhead whaling controversy and the other in the context of the 2018 negotiations over streamlining Aboriginal Subsistence Whaling management and supporting greater flexibility and Indigenous autonomy. By comparing these two statements from very different points of history for the IWC and the governance of Indigenous whaling, this article illustrates some of the ongoing struggles for environmental governance to recognise extinction as a complex, multifaceted process that reverberates throughout human and more-than-human communities.
Major theories link threat learning processes to anxiety symptoms, which typically emerge during adolescence. While this developmental stage is marked by substantial maturation of the neural circuity involved in threat learning, research directly examining adolescence-specific patterns of neural responding during threat learning is scarce. This study compared adolescents and adults in acquisition and extinction of conditioned threat responses assessed at the cognitive, psychophysiological, and neural levels, focusing on the late positive potential (LPP), an event-related potential (ERP) component indexing emotional valence.
Method
Sixty-five adults and 63 adolescents completed threat acquisition and extinction, 24 h apart, using the bell conditioning paradigm. Self-reported fear, skin conductance responses (SCR), and ERPs were measured.
Results
Developmental differences emerged in neural and psychophysiological responses during threat acquisition, with adolescents displaying heightened LPP responses to threat and safety cues as well as heightened threat-specific SCR compared to adults. During extinction, SCR suggested comparable reduction in conditioned threat responses across groups, while LPP revealed incomplete extinction only among adolescents. Finally, age moderated the link between anxiety severity and LPP-assessed extinction, whereby greater anxiety severity was associated with reduced extinction among younger participants.
Conclusions
In line with developmental theories, adolescence is characterized by a specific age-related difficulty adapting to diminishing emotional significance of prior threats, contributing to heightened vulnerability to anxiety symptoms. Further, LPP appears to be sensitive to developmental differences in threat learning and may thus potentially serve as a useful biomarker in research on adolescents, threat learning, and anxiety.
This chapter introduces the concept of the proposed new geological epoch, and the main paradoxes and dilemmas that follow. The Anthropocene requires us simultaneously to see human beings as occupying a position of unprecedented responsibility for the ecosphere, and as a tragically blundering species, caught by the unforeseen consequences of previous actions. Further uncertainties derive from the current interim state in which urgent warnings coexist with stubborn normality. Ecological threats such as global warming and the extinction crisis defy representation because, in the words of Timothy Clark, they present us with ‘derangements of scale’, displacing the timescape of conventional narrative and challenging our habitual sense of what is trivial and what is important. Through close readings of essayists Kathleen Jamie, Jessica Gaitán Johannesson, Richard Smyth, Rebecca Tamás, and Jean Sprackland, the chapter examines the implications of these ideas for the form, style, and content of the contemporary environmental essay.
Patterns of extinction risk can vary across taxa, with species of some groups being particularly vulnerable to extinction. Rails (Aves: Rallidae) represent one of the most extreme yet well-documented cases of mass extinction within a modern vertebrate group. Between 54 and 92% of rail species became extinct following waves of human contact during both the Holocene and the Anthropocene eras, and a third of the extant species are currently threatened or near-threatened. Here, we (1) examine extinction filters through consecutive human contacts with rails, investigating the role of intrinsic life-history traits and (2) investigate the drivers of contemporary vulnerability. During the most recent wave of extinction, we found that body size was an important correlate of rail extinctions, with both smaller and larger bodied species more likely to become extinct. Island endemism and small clutch size were the strongest predictors of contemporary vulnerability. Overall, island endemic rails tend to follow the same trajectory as extinct species, suffering mostly from invasive predators and overhunting, but with different traits targeted contemporarily compared to past extinctions. Moreover, modern anthropogenic threats have created the potential for new intricate pathways – or a contemporary ‘field of bullets’ – making future vulnerability potentially less predictable.
The Javan tiger Panthera tigris sondaica and the Bali tiger P. tigris balica were categorized as Extinct on the IUCN Red List in both 2003 and 2008, leaving only the Sumatran subspecies P. tigris sumatrae extant in Indonesia. There have, however, been occasional, more recent reports of the Javan tiger but without conclusive evidence. Here, a potential observation in 2019 of a Javan tiger in a community plantation near the village of Cipendeuy in the forest of South Sukabumi, West Java, and a single hair found on a fence nearby, are assessed. The cytochrome b mitochondrial DNA (mtDNA) gene sequence of the putative Javan tiger hair were compared with that of a Javan tiger specimen in Museum Zoologicum Bogoriense, collected in 1930; hair samples of several tiger subspecies and the Javan leopard Panthera pardus melas were used as controls. The results showed that the genetic distances (d) of the putative Javan tiger hair with the Sumatran, Bengal P. tigris tigris and Amur P. tigris altaica tigers and the Javan leopard are 0.074 ± SE 0.009, 0.071 ± SE 0.009, 0.072 ± SE 0.009 and 0.088 ± SE 0.010, respectively, whereas the genetic distance of the putative Javan tiger hair with the Javan tiger museum specimen is 0.040 ± SE 0.006. In addition, phylogenetic trees showed that the putative Javan tiger hair sample belongs to the same group as the museum specimen of the Javan tiger, but is differentiated from other tiger subspecies and the Javan leopard. Whether the Javan tiger still occurs in the wild needs to be confirmed with further genetic and field studies.
The Namibian Swakara industry, a type of sheep farming focused on the production of lamb pelts for the fashion industry, currently faces a crisis situation. Formerly one of the most important export products from Namibia, a combination of drought, falling pelt prices and the effects of the COVID-19 pandemic now threaten the survival of Swakara, the Namibian Karakul. The current crisis is articulated in extinction narratives. The potential end of Swakara farming as a way of life and a set of knowledge practices is narratively interwoven with the potential disappearance of Swakara from the Namibian landscape. Extinction narratives in the context of Swakara farming in Namibia blur the lines of human and nonhuman ways of life and their disappearance.
This research studies the robustness of permanence and the continuous dependence of the stationary distribution on the parameters for a stochastic predator–prey model with Beddington–DeAngelis functional response. We show that if the model is extinct (resp. permanent) for a parameter, it is still extinct (resp. permanent) in a neighbourhood of this parameter. In the case of extinction, the Lyapunov exponent of predator quantity is negative and the prey quantity converges almost to the saturated situation, where the predator is absent at an exponential rate. Under the condition of permanence, the unique stationary distribution converges weakly to the degenerate measure concentrated at the unique limit cycle or at the globally asymptotic equilibrium when the diffusion term tends to 0.
This Element provides an exploration of antinatalism, the view that assigns a negative value to reproduction. First, the history of Western philosophy as a two-and-a-half millennia reaction to antinatalist sentiments. Human life has no obvious meaning and philosophers have been forced to build elaborate theories to invent imaginary purposes. Second, analysis of the concept of antinatalism in the light of human extinction. If people stop having children, the species will cease to exist, and this prospect has prompted attempts to find alternatives and excuses. Third, outlines a normative view defending antinatalism both theoretically and practically. If it is wrong to bring about suffering in the absence of redeeming meaning and if it is possible to create meaning only by imposing a pronatalist mentality upon children before they can make up their own minds, parents morally corrupt themselves by procreating. This title is also available as Open Access on Cambridge Core.
Infectious disease is an important driver of extinctions and population declines. With a few exceptions, such as the fungal disease chytridiomycosis in frogs, disease is probably underestimated as a cause of both local and global extinction because it often co-occurs with other more overt drivers of extinction, and its signs can be easily overlooked. Here, we discuss issues around attributing extinction to infectious disease and overview key underlying factors. We then examine the extent to which anthropogenic influences, such as climate change, habitat destruction and exotic species introductions, are likely to lead to increased extinction risk in association with infectious disease. Finally, we discuss strategies to mitigate the threat of extinction due to infectious disease.
Branching processes, which are the focus of this chapter, arise naturally in the study of stochastic processes on trees and locally tree-like graphs. Similarly to martingales, finding a hidden branching process within a probabilistic model can lead to useful bounds and insights into asymptotic behavior. After a review of the extinction theory of branching processes and of a fruitful random-walk perspective, we give a couple examples of applications in discrete probability. In particular we analyze the height of a binary search tree, a standard data structure in computer science. We also give an introduction to phylogenetics, where a “multitype” variant of the Galton–Watson branching process plays an important role; we use the techniques derived in this chapter to establish a phase transition in the reconstruction of ancestral molecular sequences. We end this chapter with a detailed look into the phase transition of the Erdos–Renyi graph model. The random-walk perspective mentioned above allows one to analyze the “exploration” of a largest connected component, leading to information about the “evolution” of its size as edge density increases.
Antinatalism assigns reproduction a negative value. There should be fewer or no births. Those who say that there should be fewer births have been called conditional antinatalists. A better name for their view would be selective pronatalism. Those who say that there should be no births face two challenges. They must define the scope of their no-birth policy. Does it apply only to human or sentient beings or can it also be extended to all organic life, perhaps even to machine consciousness? And whatever the scope, they have to justify the eventual extinction of humankind or other life forms, an inevitable consequence of unconditional antinatalism. Different axiologies and moral theories produce different responses to these challenges. It is argued that a two-value conflict-sensitive negative utilitarianism would produce a kind and reasonable justification for ending at least human and factory-animal reproduction. The conclusion is purely moral and supports only voluntary extinction for humankind.
Investigations of the parasites associated with extinct avian species provide unique insights into the ecology and evolution of both hosts and their parasitic counterparts. In the present paper, a new quill mite species, Peristerophila conuropsis sp. n., belonging to the family Syringophilidae (Prostigmata: Cheyletoidea) is described from the Carolina parakeet Conuropsis carolinensis Linnaeus (Psittaciformes: Psittacidae). This new species was collected from museum dry skin of the Carolina parakeet, the only native representative of the Psittacidae in the United States, which was an abundant resident of the southeastern and midwestern states and has been extinct in the beginning of the 20th century. Comment on the current taxonomic state and host associations of the genus Peristerophila are provided. Based on the host associations and habitats occupied by Peristerophila and related genera on parrots, it is hypothesized with the high probability that P. conuropsis has been extinct along with its host.
Exposure therapy is widely recognized as an effective psychological treatment for OCD but it is not successful in every case. Poorly executed exposure techniques could be implicated. Negative perceptions contribute to poor execution, pitfalls, or the underutilization of this therapy altogether. This, along with common ED misconceptions that are cultural and disorder-specific, can also result in poor treatment for those with EDs. It is important that the therapist has a thorough understanding of the patient’s presentation to ensure that exposures target the precise core fear for new learning. Lack of understanding can lead to mistakes and missed opportunities to enhance exposure, such as failing to explain the rationale, reducing safety behaviors, or overusing a hierarchy. An inexperienced therapist may not understand the importance of discussing the role of family and friends and how their accommodation can perpetuate symptoms, hindering new learning and preventing lasting change. The therapist should be able to identify the core fear, triggers, and avoidance behaviors in the patient and use strategies to enhance inhibitory learning and maximize the chances of successful treatment.
We continue with the systematic study of the speed of extinction of continuous-state branching processes in Lévy environments under more general branching mechanisms. Here, we deal with the weakly subcritical regime under the assumption that the branching mechanism is regularly varying. We extend recent results of Li and Xu (2018) and Palau et al. (2016), where it is assumed that the branching mechanism is stable, and complement the recent articles of Bansaye et al. (2021) and Cardona-Tobón and Pardo (2021), where the critical and the strongly and intermediate subcritical cases were treated, respectively. Our methodology combines a path analysis of the branching process together with its Lévy environment, fluctuation theory for Lévy processes, and the asymptotic behaviour of exponential functionals of Lévy processes. Our approach is inspired by the last two previously cited papers, and by Afanasyev et al. (2012), where the analogue was obtained.
In early human societies, community norms specified where and how living resources should be used within sacred groves and in exploited places. Many rulers of ancient and medieval societies issued decrees reserving game and other wild resources for royalty and limiting peasant uses. Colonial rulers criminalized Indigenous uses of wild species and privatized and commercialized landscapes. Intensive exploitation led to the depletion and extinction of many species and laid the foundation for formal conservation. Concern about deforestation in colonial India led to early forest reserves. The utilitarian disciplines of wildlife management, forestry, range management, and soil science arose in response to threats to living natural resources due to conquest, including intensive exploitation, habitat alteration, and the introduction of non-native species. These disciplines focus on the exploitation of economically valuable species to protect a long-term supply. Early forest reserves in the USA were set aside to regulate the use of forest resources.
Economic, technological, and demographic changes after World War II created new pressures on species, habitats, and human environments. Concerns about human impacts on the environment mounted. Rachel Carson, Charles Elton, Barry Commoner, and others articulated concerns about pesticides and other harmful substances in air and water, introduced species, escalating extinction rates, and the modification and fragmentation of habitats. Ecologists, economists, and philosophers like Paul Ehrlich, Garrett Hardin, John Kenneth Galbraith, Lynne White, Norman Myers, and Arne Naess attributed these problems to varied causes, including population growth, tragedies of the commons, excessive resource consumption and disparities in consumption, militarism, the misuse of science and technology, externalities, and anthropocentrism. In response to these developments and to increasing awareness of the limitations of utilitarian conservation, a preservationist approach to conservation that seeks to protect species and regardless of their economic value became prominent.