Australia's recently established predators restore complexity to food webs simplified by extinction.

Since prehistory, humans have altered the composition of ecosystems by causing extinctions and introducing species. However, our understanding of how waves of species extinctions and introductions influence the structure and function of ecological networks through time remains piecemeal. Here, focusing on Australia, which has experienced many extinctions and introductions since the Late Pleistocene, we compared the functional trait composition of Late Pleistocene (130,00-115,000 years before present [ybp]), Holocene (11,700-3,000 ybp), and current Australian mammalian predator assemblages (≥70% vertebrate meat consumption; ≥1 kg adult body mass). We then constructed food webs for each period based on estimated prey body mass preferences. We found that introduced predators are functionally distinct from extinct Australian predators, but they rewire food webs toward a state that closely resembles the Late Pleistocene, prior to the megafauna extinctions. Both Late Pleistocene and current-day food webs consist of an apex predator and three smaller predators. This leads to food web networks with a similar total number of links, link densities, and compartmentalizations. However, this similarity depends on the presence of dingoes: in their absence, food webs become simplified and reminiscent of those following the Late Pleistocene extinctions. Our results suggest that recently established predators, even those implicated in species extinctions and declines, can restore complexity to food webs simplified by extinction.

Preventing extinction in an age of species migration and planetary change.

International and national conservation policies almost exclusively focus on conserving species in their historic native ranges, thus excluding species that have been introduced by people and some of those that have extended their ranges on their own accord. Given that many of such migrants are threatened in their native ranges, conservation goals that explicitly exclude these populations may overlook opportunities to prevent extinctions and respond dynamically to rapidly changing environmental and climatic conditions. Focusing on terrestrial mammals, we quantified the number of threatened mammals that have established new populations through assisted migration (i.e., introduction). We devised 4 alternative scenarios for the inclusion of assisted-migrant populations in mainstream conservation policy with the aim of preventing global species extinctions. We then used spatial prioritization algorithms to simulate how these scenarios could change global spatial conservation priorities. We found that 22% (70 species out of 265) of all identified assisted-migrant mammals were threatened in their native ranges, mirroring the 25% of all mammals that are threatened. Reassessing global threat statuses by combining native and migrant ranges reduced the threat status of 23 species (∼33% of threatened assisted migrants). Thus, including migrant populations in threat assessments provides a more accurate assessment of actual global extinction risk among species. Spatial prioritization simulations showed that reimagining the role of assisted-migrant populations in preventing species extinction could increase the importance of overlooked landscapes, particularly in central Australia, Europe, and the southwestern United States. Our results indicated that these various and nonexhaustive ways to consider assisted-migrant populations, with due consideration of potential conservation conflicts with resident taxa, may provide unprecedented opportunities to prevent species extinctions.

Prevención de la extinción en una época de migración de especies y cambios planetarios Resumen Las políticas de conservación nacionales e internacionales casi siempre se enfocan en la conservación de las especies dentro de su distribución histórica y nativa, por lo que se excluyen especies que han sido introducidas por el humano y algunas que se han extendido por cuenta propia más allá de su distribución. Ya que muchas de estas especies migrantes están amenazadas dentro de su distribución nativa, los objetivos de conservación que excluyen explícitamente a estas poblaciones pueden ignorar las oportunidades para prevenir extinciones y responder de forma dinámica a las condiciones ambientales y climáticas que cambian con rapidez. Nos enfocamos en los mamíferos terrestres para cuantificar el número de especies amenazadas que han establecido poblaciones nuevas mediante la migración asistida (introducción). Diseñamos cuatro escenarios alternativos para la inclusión de las poblaciones con migración asistida dentro de las políticas de conservación generales con el objetivo de prevenir extinciones globales de especies. Después usamos algoritmos de priorización espacial para simular cómo estos escenarios podrían cambiar las prioridades de conservación espacial en todo el mundo. Descubrimos que el 22% (70 de 765 especies) de todos los mamíferos con migración asistida están amenazados dentro de su distribución nativa, lo que es similar al 25% de especies amenazadas de todas las especies de mamíferos. La reevaluación de los estados mundiales de amenaza mediante la combinación de la distribución nativa y migrante redujo el estado de amenaza de 23 especies (∼33% de los migrantes asistidos amenazados). Por esto, incluir a las poblaciones migrantes en la evaluación de amenazas proporciona una evaluación más certera del riesgo de extinción que existe entre las especies a nivel mundial. Las simulaciones de priorización espacial mostraron que reinventar el papel que tienen las poblaciones con migración asistida en la prevención de la extinción de especies podría incrementar la importancia de los paisajes ignorados, particularmente en Australia central, Europa y el suroeste de los Estados Unidos. Nuestros resultados indican que estas maneras diversas y no exhaustivas de considerar a las poblaciones con migración asistida, con la debida consideración de los potenciales conflictos de conservación con los taxones residentes, puede proporcionar oportunidades sin precedentes para prevenir la extinción de las especies.

Animal cognition and culture mediate predator-prey interactions.

Predator-prey ecology and the study of animal cognition and culture have emerged as independent disciplines. Research combining these disciplines suggests that both animal cognition and culture can shape the outcomes of predator-prey interactions and their influence on ecosystems. We review the growing body of work that weaves animal cognition or culture into predator-prey ecology, and argue that both cognition and culture are significant but poorly understood mechanisms mediating how predators structure ecosystems. We present a framework exploring how previous experiences with the predation process creates feedback loops that alter the predation sequence. Cognitive and cultural predator-prey ecology offers ecologists new lenses through which to understand species interactions, their ecological consequences, and novel methods to conserve wildlife in a changing world.

Mental Experiences in Wild Animals: Scientifically Validating Measurable Welfare Indicators in Free-Roaming Horses.

The mental experiences of animals are what characterises their welfare status. The Five Domains Model for assessing welfare aligns with the understanding that physical and mental states are linked. Following measurement of indicators within each of the four physical/functional Domains (1. Nutrition; 2. Physical environment; 3. Health; and 4. Behavioural interactions), the anticipated negative or positive affective consequences (mental experiences) are cautiously inferred and assigned to Domain 5. Those inferences derive credibility from validated knowledge of the underlying systems of physiology, neurophysiology, neuroethology and affective neuroscience. Any indicators used for assessing welfare need to be scientifically validated. This requires, firstly, evidence of the links between a measurable/observable indicator and the physical/functional impact (in Domains 1 to 4), and secondly, a demonstrable relationship between the physical/functional impact and the mental experience it is inferred the indicators reflect (in Domain five). This review refers to indicators of physical/functional states in Domains 1 to 4, which have been shown to be measurable in free-roaming wild horses, and then evaluates the scientific evidence linking them to inferred mental experiences in Domain 5. This is the first time that the scientific evidence validating a comprehensive range of welfare indicators has been synthesised in this way. Inserting these indicators into the Five Domains Model enables transparently justifiable assessment and grading of welfare status in free-roaming horses.

Savviness of prey to introduced predators.

The prey naivety hypothesis posits that prey are vulnerable to introduced predators because many generations in slow gradual coevolution are needed for appropriate avoidance responses to develop. It predicts that prey will be more responsive to native than introduced predators and less responsive to introduced predators that differ substantially from native predators and from those newly established. To test these predictions, we conducted a global meta-analysis of studies that measured the wariness responses of small mammals to the scent of sympatric mammalian mesopredators. We identified 26 studies that met our selection criteria. These studies comprised 134 experiments reporting on the responses of 36 small mammal species to the scent of six introduced mesopredators and 12 native mesopredators. For each introduced mesopredator, we measured their phylogenetic and functional distance to local native mesopredators and the number of years sympatric with their prey. We used predator and prey body mass as a measure of predation risk. Globally, small mammals were similarly wary of the scent of native and introduced mesopredators; phylogenetic and functional distance between introduced mesopredators and closest native mesopredators had no effect on wariness; and wariness was unrelated to the number of prey generations, or years, since first contact with introduced mesopredators. Small mammal wariness was associated with predator-prey body mass ratio, regardless of the nativity. The one thing animals do not seem to recognize is whether their predators are native.

La hipótesis de la ingenuidad de la presa plantea que ésta es vulnerable a los depredadores introducidos porque se requiere que muchas generaciones atraviesen una coevolución lenta y gradual para que se desarrollen las respuestas de evasión adecuadas. La hipótesis supone que la presa será más sensible a los depredadores introducidos que difieren notoriamente de los nativos y de aquellos recién establecidos. Realizamos un metaanálisis global de estudios que midieron las respuestas cautelosas de mamíferos pequeños ante el rastro de meso depredadores simpátricos para probar estas suposiciones. Identificamos 26 estudios que cumplieron con nuestro criterio de selección. Estos estudios estuvieron conformados por 134 experimentos que reportaban las respuestas de 36 especies de mamíferos pequeños ante el rastro de seis meso depredadores introducidos y 12 nativos. Medimos la distancia funcional y filogenética entre cada meso depredador introducido y los meso depredadores locales nativos y el número de años simpátricos con su presa. Usamos la masa corporal del depredador y la presa como medida del riesgo de depredación. A nivel mundial, los mamíferos pequeños compartieron la cautela ante el rastro de los meso depredadores nativos e introducidos; la distancia funcional y la filogenética entre los meso depredadores introducidos y el meso depredador nativo más cercano no tuvieron efecto sobre la cautela; y la cautela no estuvo relacionada con el número de generaciones de la presa, o años, desde el primer contacto con los meso depredadores introducidos. La cautela de los mamíferos pequeños estuvo asociada con las proporciones de masa corporal entre el depredador y la presa, sin importar el origen. Lo único que los animales parecen no reconocer es si el depredador es nativo o no.

Review of the Foundational Knowledge Required for Assessing Horse Welfare.

A detailed understanding of what is usual for a species under optimal conditions is critical for identifying and interpreting different features of body function that have known impacts on animal welfare and its assessment. When applying the Five Domains Model to assess animal welfare, the key starting point is therefore to acquire extensive species-specific knowledge relevant to each of the four physical/functional Domains of the Model. These Domains, 1 to 4, address areas where objective information is evaluated and collated. They are: (1) Nutrition; (2) Physical environment; (3) Health; and (4) Behavioural interactions. It is on the basis of this detailed knowledge that cautious inferences can then be made about welfare-relevant mental experiences animals may have, aligned with Domain 5, Mental State. However, this review is focused entirely on the first four Domains in order to provide a novel holistic framework to collate the multidisciplinary knowledge of horses required for undertaking comprehensive welfare assessments. Thus, inferring the potential mental experiences aligned with Domain 5, the final step in model-based welfare assessments, is not considered here. Finally, providing extensive information on free-roaming horses enables a better understanding of the impacts of human interventions on the welfare of horses in both free-roaming and domestic situations.

Re-Thinking Felid-Human Entanglements through the Lenses of Compassionate Conservation and Multispecies Studies.

With many felid species in widespread decline, re-thinking the messy felid-human entanglements is a necessary step for fostering coexistence as current conservation frameworks centered on human exceptionalism and widespread violence toward wild animals are conspicuously failing felids. This paper argues for fostering a critical awareness of how we understand our relationships with nonhuman animals, particularly in the context of conservation. We bring two distinct but related interdisciplinary fields into a dialogue to critically question the values and conceptual assumptions that frame the practices of felid conservation today. Compassionate conservation and multispecies studies share many synergies and conceptual overlaps despite emerging from different academic domains. We identified four key areas for further exploration: (1) A shift in emphasis from practices of killing to the underlying assumptions that make forms of killing permissible and ethically unproblematic. (2) Re-engagement with individuals, not just species, in conservation settings. (3) Unsettling human exceptionalism through an emphasis on the agency of animals and an ethic involving compassion. (4) Acknowledging the ways in which humans co-become with other animals and cultivating relationships of multispecies cohabitation and flourishing.

Heavy metal habitat: A novel framework for mapping heavy metal contamination over large-scale catchment with a species distribution model.

Heavy metal(loid)s (HMs) have been consistently entering the food chain, imposing great harm on environment and public health. However, previous studies on the spatial dynamics and transport mechanism of HMs have been profoundly limited by the field sampling issues, such as the uneven observations of individual carriers and their spatial mismatch, especially over large-scale catchments with complex environment. In this study, a novel methodological framework for mapping HMs at catchment scale was proposed and applied, combining a species distribution model (SDM) with physical environment and human variables. Based on the field observations, we ecologicalized HMs in different carriers as different species. This enabled the proposed framework to model the 'enrichment area' of individual HMs in the geographic space (termed as the HM 'habitat') and identify their 'hotspots' (peak value points) within the catchment. Results showed the output maps of HM habitats from secondary carriers (soil, sediment, and wet deposition) well agreed with the influence of industry contaminants, hydraulic sorting, and precipitation washout process respectively, indicating the potential of SDM in modeling the spatial distributions of the HM. The derived maps of HMs from secondary carriers, along with the human and environmental variables were then input as explanatory variables in SDM to predict the spatial patterns of the final HM accumulation in river water, which was observed to have largely improved the prediction quality. These results confirmed the value of our framework to leverage SDMs from ecology perspective to study HM contamination transport at catchment scale, offering new insights not only to map the spatial HM habitats but also help locate the HM transport chains among different carriers.

A novel trophic cascade between cougars and feral donkeys shapes desert wetlands.

Introduced large herbivores have partly filled ecological gaps formed in the late Pleistocene, when many of the Earth's megafauna were driven extinct. However, extant predators are generally considered incapable of exerting top-down influences on introduced megafauna, leading to unusually strong disturbance and herbivory relative to native herbivores. We report on the first documented predation of juvenile feral donkeys Equus africanus asinus by cougars Puma concolor in the Mojave and Sonoran Deserts of North America. We then investigated how cougar predation corresponds with differences in feral donkey behaviour and associated effects on desert wetlands. Focusing on a feral donkey population in the Death Valley National Park, we used camera traps and vegetation surveys to compare donkey activity patterns and impacts between wetlands with and without cougar predation. Donkeys were primarily diurnal at wetlands with cougar predation, thereby avoiding cougars. However, donkeys were active throughout the day and night at sites without predation. Donkeys were ~87% less active (measured as hours of activity a day) at wetlands with predation (p < 0.0001). Sites with predation had reduced donkey disturbance and herbivory, including ~46% fewer access trails, 43% less trampled bare ground and 192% more canopy cover (PERMANOVA, R2  = 0.22, p = 0.0003). Our study is the first to reveal a trophic cascade involving cougars, feral equids and vegetation. Cougar predation appears to rewire an ancient food web, with diverse implications for modern ecosystems. Our results suggest that protecting apex predators could have important implications for the ecological effects of introduced megafauna.

Ethical Treatment of Invasive and Native Fauna in Australia: Perspectives through the One Welfare Lens.

The One Welfare concept is proposed to guide humans in the ethical treatment of non-human animals, each other and the environment. One Welfare was conceptualized for veterinarians but could be a foundational concept through which to promote the ethical treatment of animals that are outside of direct human care and responsibility. However, wild-living animals raise additional ethical conundrums because of their multifarious values and roles, and relationships that humans have with them. At an open facilitated forum, the 2018 Robert Dixon Memorial Animal Welfare Symposium, a panel of five experts from different fields shared their perspectives on "loving and hating animals in the wild" and responded to unscripted questions from the audience. The Symposium's objectives were to elucidate views on the ethical treatment of the native and invasive animals of Australia and to identify some of the resultant dilemmas facing conservationists, educators, veterinarians and society. Here, we document the presented views and case studies and synthesize common themes in a One Welfare framework. Additionally, we identified points of contention that can guide further discourse. With this guide in place, the identification and discussion of those disparate views was a first step toward practical resolutions on how to manage wild-living Australian fauna ethically. We concluded that there was great utility in the One Welfare approach for any discourse about wild animal welfare. It requires attention to each element of the triple bottom line and ensures that advocacy for one party does not vanquish the voices from other sectors. We argue that, by facilitating a focus on the ecology in the context of wild animal issues, One Welfare is more useful in this context than the veterinary context for which it was originally developed.

The Impacts of Drought on the Health and Demography of Eastern Grey Kangaroos.

Extreme climatic events such as droughts and floods are expected to become more intense and severe under climate change, especially in the southern and eastern parts of Australia. We aimed to quantify the relationship between body condition scores (BCS), demography, activity rate, and parasitic infections of eastern grey kangaroos on a large conservation property under different climate extremes by employing camera traps established at artificial water points (AWPs). The survey period included a severe drought, broken by a significant flooding event. Climatic and environmental conditions were documented using remotely sensed indices of moisture availability and vegetation productivity. These conditions were found to affect all health and population parameters measured. BCS, juvenile proportions, and sex ratios were most correlated with 6-month lags in climatic conditions, while the activity rate of kangaroos at AWPs was most correlated with vegetation productivity. Ticks were mostly found on individuals with a poorer BCS, while the concentration of parasitic eggs in feces was higher in autumn than in spring. Our study offers a glimpse into some of the environmental drivers of eastern grey kangaroo populations and their health, information that may become increasingly important in today's climate. It further emphasizes the importance of this knowledge for wildlife conservation efforts appropriate to managing the impact of climate change alongside other threats.

Use of Remote Camera Traps to Evaluate Animal-Based Welfare Indicators in Individual Free-Roaming Wild Horses.

We previously developed a Ten-Stage Protocol for scientifically assessing the welfare of individual free-roaming wild animals using the Five Domains Model. The protocol includes developing methods for measuring or observing welfare indices. In this study, we assessed the use of remote camera traps to evaluate an extensive range of welfare indicators in individual free-roaming wild horses. Still images and videos were collected and analysed to assess whether horses could be detected and identified individually, which welfare indicators could be reliably evaluated, and whether behaviour could be quantitatively assessed. Remote camera trapping was successful in detecting and identifying horses (75% on still images and 72% on video observation events), across a range of habitats including woodlands where horses could not be directly observed. Twelve indicators of welfare across the Five Domains were assessed with equal frequency on both still images and video, with those most frequently assessable being body condition score (73% and 79% of observation events, respectively), body posture (76% for both), coat condition (42% and 52%, respectively), and whether or not the horse was sweating excessively (42% and 45%, respectively). An additional five indicators could only be assessed on video; those most frequently observable being presence or absence of weakness (66%), qualitative behavioural assessment (60%), presence or absence of shivering (51%), and gait at walk (50%). Specific behaviours were identified in 93% of still images and 84% of video events, and proportions of time different behaviours were captured could be calculated. Most social behaviours were rarely observed, but close spatial proximity to other horses, as an indicator of social bonds, was recorded in 36% of still images, and 29% of video observation events. This is the first study that describes detailed methodology for these purposes. The results of this study can also form the basis of application to other species, which could contribute significantly to advancing the field of wild animal welfare.

Wildlife-friendly farming recouples grazing regimes to stimulate recovery in semi-arid rangelands.

While rangeland ecosystems are globally important for livestock production, they also support diverse wildlife assemblages and are crucial for biodiversity conservation. As rangelands around the world have become increasingly degraded and fragmented, rethinking farming practice in these landscapes is vital for achieving conservation goals, rangeland recovery, and food security. An example is reinstating livestock shepherding, which aims to recouple grazing regimes to vegetation conditioned to semi-arid climates and improve productivity by reducing overgrazing and rewiring past ecological functions. Tracking the large-scale ecosystem responses to shifts in land management in such sparsely vegetated environments have so far proven elusive. Therefore, our goal was to develop a remote tracking method capable of detecting vegetation changes and environmental responses on rangeland farms engaging in contrasting farming practices in South Africa: wildlife friendly farming (WFF) implementing livestock shepherding with wildlife protection, or rotational grazing livestock farming with wildlife removal. To do so, we ground-truthed Sentinel-2 satellite imagery using drone imagery and machine learning methods to trace historical vegetation change on four farms over a four-year period. First, we successfully classified land cover maps cover using drone footage and modelled vegetation cover using satellite vegetation indices, achieving 93.4% accuracy (к = 0.901) and an r-squared of 0.862 (RMSE = 0.058) respectively. We then used this model to compare the WFF farm to three neighbouring rotational grazing farms, finding that satellite-derived vegetation productivity was greater and responded more strongly to rainfall events on the WFF farm. Furthermore, vegetation cover and grass cover, patch size, and aggregation were greater on the WFF farm when classified using drone data. Overall, we found that remotely assessing regional environmental benefits from contrasting farming practices in rangeland ecosystems could aid further adoption of wildlife-friendly practices and help to assess the generality of this case study.

Equids engineer desert water availability.

Megafauna play important roles in the biosphere, yet little is known about how they shape dryland ecosystems. We report on an overlooked form of ecosystem engineering by donkeys and horses. In the deserts of North America, digging of ≤2-meter wells to groundwater by feral equids increased the density of water features, reduced distances between waters, and, at times, provided the only water present. Vertebrate richness and activity were higher at equid wells than at adjacent dry sites, and, by mimicking flood disturbance, equid wells became nurseries for riparian trees. Our results suggest that equids, even those that are introduced or feral, are able to buffer water availability, which may increase resilience to ongoing human-caused aridification.

Functional traits of the world's late Quaternary large-bodied avian and mammalian herbivores.

Prehistoric and recent extinctions of large-bodied terrestrial herbivores had significant and lasting impacts on Earth's ecosystems due to the loss of their distinct trait combinations. The world's surviving large-bodied avian and mammalian herbivores remain among the most threatened taxa. As such, a greater understanding of the ecological impacts of large herbivore losses is increasingly important. However, comprehensive and ecologically-relevant trait datasets for extinct and extant herbivores are lacking. Here, we present HerbiTraits, a comprehensive functional trait dataset for all late Quaternary terrestrial avian and mammalian herbivores ≥10 kg (545 species). HerbiTraits includes key traits that influence how herbivores interact with ecosystems, namely body mass, diet, fermentation type, habitat use, and limb morphology. Trait data were compiled from 557 sources and comprise the best available knowledge on late Quaternary large-bodied herbivores. HerbiTraits provides a tool for the analysis of herbivore functional diversity both past and present and its effects on Earth's ecosystems.

Emotion as a source of moral understanding in conservation.

Recent debates around the meaning and implications of compassionate conservation suggest that some conservationists consider emotion a false and misleading basis for moral judgment and decision making. We trace these beliefs to a long-standing, gendered sociocultural convention and argue that the disparagement of emotion as a source of moral understanding is both empirically and morally problematic. According to the current scientific and philosophical understanding, reason and emotion are better understood as partners, rather than opposites. Nonetheless, the two have historically been seen as separate, with reason elevated in association with masculinity and emotion (especially nurturing emotion) dismissed or delegitimated in association with femininity. These associations can be situated in a broader, dualistic, and hierarchical logic used to maintain power for a dominant male (White, able-bodied, upper class, heterosexual) human class. We argue that emotion should be affirmed by conservationists for the novel and essential insights it contributes to conservation ethics. We consider the specific example of compassion and characterize it as an emotional experience of interdependence and shared vulnerability. This experience highlights conservationists' responsibilities to individual beings, enhancing established and widely accepted beliefs that conservationists have a duty to protect populations, species, and ecosystems (or biodiversity). We argue compassion, thus understood, should be embraced as a core virtue of conservation.

El Sentimiento como Fuente de Entendimiento Moral en la Conservación Resumen Los debates recientes en torno al significado y las implicaciones de la conservación compasiva sugieren que algunos conservacionistas consideran al sentimiento como una base falsa y engañosa para el juicio moral y la toma de decisiones. Seguimos estas creencias hasta una convención sociocultural prolongada y relacionada con el género y argumentamos que el menosprecio por el sentimiento como fuente del entendimiento moral es problemático empírica y moralmente. De acuerdo con el conocimiento científico y filosófico actual, la razón y el sentimiento se entienden de mejor manera como pareja, en lugar de como opuestos. Sin embargo, ambos conceptos han estado históricamente separados, con la razón como concepto elevado asociado con la masculinidad y el sentimiento (especialmente el sentimiento de crianza) rechazado o deslegitimado en asociación con la feminidad. Estas asociaciones pueden situarse dentro de una lógica más general, dualista y jerárquica usada para mantener el poder de la clase humana del macho dominante (blanco, sin discapacidades, de clase alta, heterosexual). Sostenemos que el sentimiento debería ser ratificado por los conservacionistas por el conocimiento novedoso y esencial que contribuye a la ética de la conservación. Consideramos el ejemplo específico de la compasión y lo caracterizamos como una experiencia emocional de la interdependencia y la vulnerabilidad compartida. Esta experiencia resalta las responsabilidades que los conservacionistas tienen con los individuos, fortaleciendo las creencias establecidas y ampliamente aceptadas de que los conservacionistas tienen el deber de proteger a las poblaciones, especies y ecosistemas (o a la biodiversidad). Sostenemos que la compasión, entendida así, debería ser aceptada como una virtud nuclear de la conservación.

Introduced herbivores restore Late Pleistocene ecological functions.

Large-bodied mammalian herbivores dominated Earth's terrestrial ecosystems for several million years before undergoing substantial extinctions and declines during the Late Pleistocene (LP) due to prehistoric human impacts. The decline of large herbivores led to widespread ecological changes due to the loss of their ecological functions, as driven by their unique combinations of traits. However, recently, humans have significantly increased herbivore species richness through introductions in many parts of the world, potentially counteracting LP losses. Here, we assessed the extent to which introduced herbivore species restore lost-or contribute novel-functions relative to preextinction LP assemblages. We constructed multidimensional trait spaces using a trait database for all extant and extinct mammalian herbivores ≥10 kg known from the earliest LP (∼130,000 ybp) to the present day. Extinction-driven contractions of LP trait space have been offset through introductions by ∼39% globally. Analysis of trait space overlap reveals that assemblages with introduced species are overall more similar to those of the LP than native-only assemblages. This is because 64% of introduced species are more similar to extinct rather than extant species within their respective continents. Many introduced herbivores restore trait combinations that have the capacity to influence ecosystem processes, such as wildfire and shrub expansion in drylands. Although introduced species have long been a source of contention, our findings indicate that they may, in part, restore ecological functions reflective of the past several million years before widespread human-driven extinctions.

Recognizing animal personhood in compassionate conservation.

Compassionate conservation is based on the ethical position that actions taken to protect biodiversity should be guided by compassion for all sentient beings. Critics argue that there are 3 core reasons harming animals is acceptable in conservation programs: the primary purpose of conservation is biodiversity protection; conservation is already compassionate to animals; and conservation should prioritize compassion to humans. We used argument analysis to clarify the values and logics underlying the debate around compassionate conservation. We found that objections to compassionate conservation are expressions of human exceptionalism, the view that humans are of a categorically separate and higher moral status than all other species. In contrast, compassionate conservationists believe that conservation should expand its moral community by recognizing all sentient beings as persons. Personhood, in an ethical sense, implies the individual is owed respect and should not be treated merely as a means to other ends. On scientific and ethical grounds, there are good reasons to extend personhood to sentient animals, particularly in conservation. The moral exclusion or subordination of members of other species legitimates the ongoing manipulation and exploitation of the living worlds, the very reason conservation was needed in the first place. Embracing compassion can help dismantle human exceptionalism, recognize nonhuman personhood, and navigate a more expansive moral space.

Reconocimiento de la Calidad de Persona en los Animales dentro de la Conservación Compasiva Resumen La conservación compasiva está basada en la posición ética que parte de que las acciones tomadas para proteger a la biodiversidad deberían estar dirigidas por la compasión por todos los seres sintientes. Los críticos de esta postura argumentan que hay tres razones nucleares por las que el daño a los animales es aceptable dentro de los programas de conservación: el principal motivo de la conservación es la protección de la biodiversidad; la conservación ya es compasiva con los animales; y la conservación debería priorizar la compasión hacia los humanos. Usamos un análisis de argumentos para aclarar los valores y la lógica subyacentes al debate en torno a la conservación compasiva. Encontramos que el rechazo a la conservación compasiva es una expresión de la excepcionalidad humana, la visión de que los humanos están en un nivel categóricamente separado y de mayor moral que todas las demás especies. Por el contrario, los conservacionistas compasivos creen que la conservación debería expandir su comunidad moral al reconocer a todos los seres sintientes como personas. La calidad de persona, en un sentido ético, implica que el individuo merece respeto y no debería ser tratado solamente como un medio para otros fines. Si hablamos desde fundamentos científicos y éticos, existen muy buenas razones para extender la calidad de persona a todos los animales sintientes, particularmente en la conservación. La exclusión moral o la subordinación de los miembros de otras especies justifica la continua manipulación y explotación de los seres vivos, la justa razón por la que necesitamos de la conservación desde el principio. La aceptación de la compasión nos puede ayudar a desmantelar la excepcionalidad humana, a reconocer la calidad de persona no humana y a navegar un espacio moral más expansivo.