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1,321 result(s) for "Macdonald, D. W."
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Early warning of trends in commercial wildlife trade through novel machine-learning analysis of patent filing
Unsustainable wildlife trade imperils thousands of species, but efforts to identify and reduce these threats are hampered by rapidly evolving commercial markets. Businesses trading wildlife-derived products innovate to remain competitive, and the patents they file to protect their innovations also provide an early-warning of market shifts. Here, we develop a novel machine-learning approach to analyse patent-filing trends and apply it to patents filed from 1970-2020 related to six traded taxa that vary in trade legality, threat level, and use type: rhinoceroses, pangolins, bears, sturgeon, horseshoe crabs, and caterpillar fungus. We found 27,308 patents, showing 130% per-year increases, compared to a background rate of 104%. Innovation led to diversification, including new fertilizer products using illegal-to-trade rhinoceros horn, and novel farming methods for pangolins. Stricter regulation did not generally correlate with reduced patenting. Patents reveal how wildlife-related businesses predict, adapt to, and create market shifts, providing data to underpin proactive wildlife-trade management approaches. Hinsley and colleagues explore trends in the global wildlife trade, developing a novel machine-learning approach to analyse patent filing related to important taxa from 1970 to 2020. They found higher per year increases in these taxa compared with background trends, giving insight into how wildlife-related businesses predict, adapt to and create market shifts. These results provide data to underpin proactive wildlife-trade management approaches.
Behavioral adjustments of African herbivores to predation risk by lions: Spatiotemporal variations influence habitat use
Predators may influence their prey populations not only through direct lethal effects, but also through indirect behavioral changes. Here, we combined spatiotemporal fine-scale data from GPS radio collars on lions with habitat use information on 11 African herbivores in Hwange National Park (Zimbabwe) to test whether the risk of predation by lions influenced the distribution of herbivores in the landscape. Effects of long-term risk of predation (likelihood of lion presence calculated over four months) and short-term risk of predation (actual presence of lions in the vicinity in the preceding 24 hours) were contrasted. The long-term risk of predation by lions appeared to influence the distributions of all browsers across the landscape, but not of grazers. This result strongly suggests that browsers and grazers, which face different ecological constraints, are influenced at different spatial and temporal scales in the variation of the risk of predation by lions. The results also show that all herbivores tend to use more open habitats preferentially when lions are in their vicinity, probably an effective anti-predator behavior against such an ambush predator. Behaviorally induced effects of lions may therefore contribute significantly to structuring African herbivore communities, and hence possibly their effects on savanna ecosystems.
An interdisciplinary review of current and future approaches to improving human–predator relations
In a world of shrinking habitats and increasing competition for natural resources, potentially dangerous predators bring the challenges of coexisting with wildlife sharply into focus. Through interdisciplinary collaboration among authors trained in the humanities, social sciences, and natural sciences, we reviewed current approaches to mitigating adverse human-predator encounters and devised a vision for future approaches to understanding and mitigating such encounters. Limitations to current approaches to mitigation include too much focus on negative impacts; oversimplified equating of levels of damage with levels of conflict; and unsuccessful technical fixes resulting from failure to engage locals, address hidden costs, or understand cultural (nonscientific) explanations of the causality of attacks. An emerging interdisciplinary literature suggests that to better frame and successfully mitigate negative human-predator relations conservation professionals need to consider dispensing with conflict as the dominant framework for thinking about human-predator encounters; work out what conflicts are really about (they may be human-human conflicts); unravel the historical contexts of particular conflicts; and explore different cultural ways of thinking about animals. The idea of cosmopolitan natures may help conservation professionals think more clearly about human-predator relations in both local and global context. These new perspectives for future research practice include a recommendation for focused interdisciplinary research and the use of new approaches, including human-animal geography, multispecies ethnography, and approaches from the environmental humanities notably environmental history. Managers should think carefully about how they engage with local cultural beliefs about wildlife, work with all parties to agree on what constitutes good evidence, develop processes and methods to mitigate conflicts, and decide how to monitor and evaluate these. Demand for immediate solutions that benefit both conservation and development favors dispute resolution and technical fixes, which obscures important underlying drivers of conflicts. If these drivers are not considered, well-intentioned efforts focused on human-wildlife conflicts will fail. En un mundo en el que los hábitats se reducen y la competencia por los recursos naturales incrementa, los depredadores potencialmente peligrosos resaltan pronunciadamente la dificultad de coexistir con la vida silvestre. Por medio de la colaboración interdisciplinaria entre autores preparados en las humanidades, las ciencias sociales y las ciencias naturales revisamos las estrategias actuales para mitigar los encuentros adversos entre depredadores y humanos y diseñamos una visión para estrategias futuras para entender y mitigar dichos encuentros. Las limitaciones de las estrategias actuales para la mitigación incluyen demasiado enfoque sobre los impactos negativos; la equiparación demasiado simplificada de los niveles de daño con los niveles del conflicto; y los arreglos técnicos infructuosos que resultan del fracaso por involucrar a los locales, hablar sobre los costos ocultos o entender las explicaciones culturales (no científicas) de la causalidad de los ataques. La literatura interdisciplinaria emergente sugiere que para enmarcar de mejor manera y mitigar exitosamente las relaciones negativas entre humanos y depredadores, los profesionales de la conservación necesitan considerar dispensar el conflicto como el marco de trabajo dominante para pensar sobre los encuentros entre humanos y depredadores; descifrar de qué se tratan realmente los conflictos (pueden ser conflictos humano - humano); aclarar los contextos históricos de conflictos particulares; y explorar las diferentes formas culturales de pensar sobre los animales. La idea de naturalezas cosmopolitas puede ayudar a los profesionales de la conservación a pensar de manera más clara sobre las relaciones humano - depredador en el contexto global y en el local. Estas nuevas perspectivas para la futura investigación de la práctica incluyen una recomendación para la investigación interdisciplinaria enfocada y el uso de nuevas estrategias, incluidas la geografía humano - animal, la etnografía de varias especies y estrategias de las humanidades ambientales, notablemente la historia ambiental. Los manejadores deberían pensar cuidadosamente sobre cómo se involucran con las creencias de los locales acerca de la vida silvestre, trabajar con todos los actores para acordar qué constituye una buena evidencia, desarrollar procesos y métodos para mitigar los conflictos, y decidir cómo monitorear y evaluarlos. La demanda por soluciones inmediatas que benefician tanto a la conservación como al desarrollo favorece a la resolución de disputas y a los arreglos técnicos, lo que hace a un lado a importantes conductores subyacentes de los conflictos. Si no son considerados estos conductores, los esfuerzos bien intencionados enfocados en los conflictos humano - vida silvestre fracasarán.
Learning from the past to prepare for the future
Many contemporary species of large-felids (≥ 15 kg) feed upon prey that are endangered, raising concern that prey population declines (defaunation) will further threaten felids. We assess the threat that defaunation presents by investigating a late Quaternary (LQ), ‘present-natural’ counterfactual scenario. Our present-natural counterfactual is based on predicted ranges of mammals today in the absence of any impacts of modern humans Homo sapiens through time. Data from our present-natural counterfactual are used to understand firstly how megafauna extinction has impacted felid communities to date and secondly to quantify the threat to large-felid communities posed by further declines in prey richness in the future. Our purpose is to identify imminent risks to biodiversity conservation and their cascading consequences and, specifically, to indicate the importance of preserving prey diversity. We pursue two lines of enquiry; first, we test whether the loss of prey species richness is a potential cause of large-felid extinction and range loss. Second, we explore what can be learnt from the large-scale large-mammal LQ losses, particularly in the Americas and Europe, to assess the threat any further decline in prey species presents to large-felids today, particularly in Africa and Asia. Large-felid species richness was considerably greater under our present-natural counterfactual scenario compared to the current reality. In total, 86% of cells recorded at least one additional felid species in our present-natural counterfactual, and up to 4–5 more large-felid species in 10% of the cells. A significant positive correlation was recorded between the number of prey species lost and the number of large-felid species lost from a cell. Extant felids most at risk include lion and Sunda clouded leopard, as well as leopard and cheetah in parts of their range. Our results draw attention to the continuation of a trend of megafauna decline that began with the emergence of hominins in the Pleistocene.
Dynamic interactions between apex predators reveal contrasting seasonal attraction patterns
Apex predators play important roles in ecosystem functioning and, where they coexist, intraguild interactions can have profound effects on trophic relationships. Interactions between predators range from intraguild predation and competition to facilitation through scavenging opportunities. Despite the increased availability of fine-scale GPS data, the determinants and outcomes of encounters between apex predators remain understudied. We used simultaneous GPS data from collared spotted hyaenas (Crocuta crocuta) and African lions (Panthera leo) in Hwange National Park, Zimbabwe, to determine the environmental conditions of the encounters between the two species, which species provoked the encounter, and which species dominated the encounter. Our results show that encounters between hyaenas and lions are mostly resource-related (over a carcass or around waterholes). In the wet season, encounters mainly occur at a carcass, with lions being dominant over its access. In the dry season, encounters mainly occur in the absence of a carcass and near waterholes. Movements of hyaenas and lions before, during, and after these dry-season encounters suggest two interference scenarios: a passive interference scenario whereby both predators would be attracted to waterholes but lions would leave a waterhole used by hyaenas because of prey disturbance, and an active interference scenario whereby hyaenas would actively chase lions from waterhole areas, which are prime hunting grounds. This study highlights the seasonal dynamics of predator interactions and illustrates how the relative importance of negative interactions (interference competition during the dry season) and positive interactions (scavenging opportunities during the wet season) shifts over the course of the year.
Low-coverage vaccination strategies for the conservation of endangered species
A wolf at Bay The Ethiopian wolf Canis simensis is a specialist carnivore found only in seven isolated mountain pockets in Ethiopia, where they prey on rodent communities. They live in family packs with an intricate social organization. Fewer than 500 individuals now survive following rabies outbreaks in 1992 and 2003 that severely depleted the population in the Bale Mountains region. Work carried out there as part of the Ethiopian Wolf Conservation Programme ( http://www.ethiopianwolf.org ) has included the development of a vaccination strategy that could be an important model for other conservation projects. The aim is to control the spread of disease through habitat corridors between subpopulations using only low vaccination coverage. This reduces the extent of rabies outbreaks, and should significantly enhance the population's long-term survival chances. Cover photograph by Martin Harvey ( http://www.wildimagesonline.com ). A vaccination strategy against rabies in the endangered Ethiopian wolf aims to control the spread of disease through habitat corridors between subpopulations using only low vaccination coverage. This approach reduces the extent of rabies outbreaks, and should significantly enhance the long-term persistence of the population. The conventional objective of vaccination programmes is to eliminate infection by reducing the reproduction number of an infectious agent to less than one 1 , which generally requires vaccination of the majority of individuals. In populations of endangered wildlife, the intervention required to deliver such coverage can be undesirable and impractical 2 ; however, endangered populations are increasingly threatened by outbreaks of infectious disease for which effective vaccines exist 3 , 4 . As an alternative, wildlife epidemiologists could adopt a vaccination strategy that protects a population from the consequences of only the largest outbreaks of disease. Here we provide a successful example of this strategy in the Ethiopian wolf, the world's rarest canid 5 , which persists in small subpopulations threatened by repeated outbreaks of rabies introduced by domestic dogs 6 . On the basis of data from past outbreaks, we propose an approach that controls the spread of disease through habitat corridors between subpopulations and that requires only low vaccination coverage. This approach reduces the extent of rabies outbreaks and should significantly enhance the long-term persistence of the population. Our study shows that vaccination used to enhance metapopulation persistence through elimination of the largest outbreaks of disease requires lower coverage than the conventional objective of reducing the reproduction number of an infectious agent to less than one 1 .
Fatal attraction in rats infected with Toxoplasma gondii
We tested the hypothesis that the parasite Toxoplasma gondii manipulates the behaviour of its intermediate rat host in order to increase its chance of being predated by cats, its feline definitive host, thereby ensuring the completion of its life cycle. Here we report that, although rats have evolved anti-predator avoidance of areas with signs of cat presence, T. gondii's manipulation appears to alter the rat's perception of cat predation risk, in some cases turning their innate aversion into an imprudent attraction. The selectivity of such behavioural changes suggests that this ubiquitous parasite subtly alters the brain of its intermediate host to enhance predation rate whilst leaving other behavioural categories and general health intact. This is in contrast to the gross impediments frequently characteristic of many other host-parasite systems. We discuss our results in terms of their potential implications both for the epidemiology of toxoplasmosis and the neurological basis of anxiety and cognitive processes in humans and other mammals.
Lion trophy hunting in West Africa: A response to Bouché et al
About the Authors: H. Bauer * E-mail: hans.bauer@zoo.ox.ac.uk Affiliation: Wildlife Conservation Research Unit, Zoology, University of Oxford, Recanati-Kaplan Centre, Tubney, United Kingdom ORCID http://orcid.org/0000-0001-5031-5842 P. Henschel Affiliation: Panthera, New York, New York, United States of America C. Packer Affiliations Wildlife Conservation Research Unit, Zoology, University of Oxford, Recanati-Kaplan Centre, Tubney, United Kingdom, Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, Minnesota, United States of America C. Sillero-Zubiri Affiliation: Wildlife Conservation Research Unit, Zoology, University of Oxford, Recanati-Kaplan Centre, Tubney, United Kingdom B. Chardonnet Affiliation: African Protected Areas & Wildlife, Saint Cloud, France E. A. Sogbohossou Affiliation: Laboratory of Applied Ecology, University of Abomey-Calavi, Cotonou, Benin H. H. De Iongh Affiliation: Institute for Environmental Sciences, University of Leiden, Leiden, The Netherlands D. W. Macdonald Affiliation: Wildlife Conservation Research Unit, Zoology, University of Oxford, Recanati-Kaplan Centre, Tubney, United Kingdom Figures Fig 1 Fig 1 Fig 1 Citation: Bauer H, Henschel P, Packer C, Sillero-Zubiri C, Chardonnet B, Sogbohossou EA, et al. Whichever quota is used, income for the hunting outfitter at current market price is only around 15,000 USD per lion and its economic impact, including any increased price for non-lion trophies, is unlikely to provide significant benefits. Lion hunting packages and the trophy fees which go to wildlife authorities (only 1600 USD in Burkina Faso; http://www.safari-evasion.com/burkina_evasion/chasse/taxes_abattage.php) are still by far the lowest on the continent in Benin and Burkina Faso, even though West Africa has by far the rarest lions, belonging to a distinct sub-species[12], and listed as Critically Endangered[13]. Lion persistence in WAP is most strongly linked to the number of patrol staff and average annual management budgets per km2, and minimum operations budgets for site protection of 125 USD/km2 (excluding ranger salaries) are needed to assure lion persistence[14].
Scale-free dynamics in the movement patterns of jackals
Using conventional radio-tracking techniques employed by field ecologists, evidence for scale-free (fractal) behaviour in the foraging trajectories of a species of African jackal is presented. It is believed that the particular form of foraging strategy observed here is a response by the jackal to its need to locate resources in an unpredictable environment. The methods used in this study are completely general and can be applied to other radio-tracked species, thus beginning a systematic investigation of foraging strategies in mammals.
Wild meat: a shared resource amongst people and predators
Millions of people throughout the tropics consume wild meat. Overhunting reduces food security for people and large predators, yet little is known of the impact of hunting in systems where people and predators target the same prey species. We collate published data on predator diet in Belize with interview data about the consumption of wild and domestic meat by Belizeans, to compare the wild-meat diets of humans, jaguars Panthera onca and pumas Puma concolor and assess the sustainability of the combined offtake by humans and jaguars. Six wild mammal species (nine-banded armadillo Dasypus novemcinctus, paca Cuniculus paca, collared peccary Pecari tajacu, white-lipped peccary Tayassu pecari, red brocket deer Mazama americana and white-tailed deer Odocoileus virginianus) comprised 7% of the animal-protein meals eaten by Belizeans. Overall, 80% of these meals were eaten by 20% of interviewees, suggesting a necessary role of wild meat for the minority. The same species were found in 69 and 86% of jaguar and puma scats, respectively. We estimate a national annual harvest of c. 4,000 tonnes of these six wild mammals by humans and jaguars, of which 78% is hunted by people. Sustainability is difficult to evaluate because prey population data are lacking in Belize. However, simple models suggest that a sustainable harvest at this rate would require higher prey population densities than averages recorded in hunted Neotropical forests. We emphasize the need for robust regional estimates of game species densities, to improve assessments of sustainability and inform hunting regulations. We recommend that the requirements of predators as well as those of people be considered when assessing wild meat harvests.