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1.
Mol Ecol ; 31(6): 1907-1923, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35073448

RESUMO

Invasive alien species continue to threaten global biodiversity. CRISPR-based gene drives, which can theoretically spread through populations despite imparting a fitness cost, could be used to suppress or eradicate pest populations. We develop an individual-based, spatially explicit, stochastic model to simulate the ability of CRISPR-based homing and X chromosome shredding drives to eradicate populations of invasive house mice (Mus muculus) from islands. Using the model, we explore the interactive effect of the efficiency of the drive constructs and the spatial ecology of the target population on the outcome of a gene-drive release. We also consider the impact of polyandrous mating and sperm competition, which could compromise the efficacy of some gene-drive strategies. Our results show that both drive strategies could be used to eradicate large populations of mice. Whereas parameters related to drive efficiency and demography strongly influence drive performance, we find that sperm competition following polyandrous mating is unlikely to impact the outcome of an eradication effort substantially. Assumptions regarding the spatial ecology of mice influenced the probability of and time required for eradication, with short-range dispersal capacities and limited mate-search areas producing 'chase' dynamics across the island characterized by cycles of local extinction and recolonization by mice. We also show that highly efficient drives are not always optimal, when dispersal and mate-search capabilities are low. Rapid local population suppression around the introduction sites can cause loss of the gene drive before it can spread to the entire island. We conclude that, although the design of efficient gene drives is undoubtedly critical, accurate data on the spatial ecology of target species are critical for predicting the result of a gene-drive release.


Assuntos
Tecnologia de Impulso Genético , Animais , Biodiversidade , Tecnologia de Impulso Genético/métodos , Espécies Introduzidas , Camundongos , Probabilidade , Vertebrados
2.
Glob Chang Biol ; 27(7): 1443-1456, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33368863

RESUMO

Achieving conservation objectives is time critical, but the vast number of threats and potential actions means some form of ranking is necessary to aid prioritization. Objective methods for ranking conservation actions based on when they are differentially likely to become feasible, or to succeed, are currently unavailable within existing decision-making frameworks but are critical for making informed management decisions. We demonstrate how statistical tools developed for survival (or time-to-event) analysis can be used to rank conservation actions over time, through the lens of invasive mammal eradications on islands. Here we forecast the probability of eradicating commensal rat species (Rattus rattus, R. norvegicus, R. exulans) from the New Zealand archipelago by the government's stated target of year 2050. Our methods provide temporally ranked eradication trajectories for the entire country, thus facilitating meeting nationwide policy goals. This demonstration highlights the relevance and applicability of such an approach and its utility for prioritizing globally effective conservation actions.


Assuntos
Conservação dos Recursos Naturais , Espécies Introduzidas , Animais , Ilhas , Mamíferos , Nova Zelândia , Ratos
3.
Glob Chang Biol ; 26(9): 4880-4893, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32663906

RESUMO

Understanding the likely future impacts of biological invasions is crucial yet highly challenging given the multiple relevant environmental, socio-economic and societal contexts and drivers. In the absence of quantitative models, methods based on expert knowledge are the best option for assessing future invasion trajectories. Here, we present an expert assessment of the drivers of potential alien species impacts under contrasting scenarios and socioecological contexts through the mid-21st century. Based on responses from 36 experts in biological invasions, moderate (20%-30%) increases in invasions, compared to the current conditions, are expected to cause major impacts on biodiversity in most socioecological contexts. Three main drivers of biological invasions-transport, climate change and socio-economic change-were predicted to significantly affect future impacts of alien species on biodiversity even under a best-case scenario. Other drivers (e.g. human demography and migration in tropical and subtropical regions) were also of high importance in specific global contexts (e.g. for individual taxonomic groups or biomes). We show that some best-case scenarios can substantially reduce potential future impacts of biological invasions. However, rapid and comprehensive actions are necessary to use this potential and achieve the goals of the Post-2020 Framework of the Convention on Biological Diversity.


Assuntos
Biodiversidade , Espécies Introduzidas , Mudança Climática , Ecossistema , Previsões , Humanos
5.
Ecol Appl ; 29(2): e01838, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30549390

RESUMO

Before-After-Control-Impact (BACI) designs are powerful tools to derive inferences about environmental perturbations (e.g., hurricanes, restoration programs) when controlled experimental designs are unfeasible. Applications of BACI designs mostly rely on testing for a significant interaction between periods and treatments (so-called BACI contrast) to demonstrate the effects of the perturbation. However, significant interactions can emerge for several reasons, including when changes are larger in control sites, such that additional diagnostics must be performed to determine the full complexity of system changes. We propose two measures that detail the nature of change implied by BACI contrasts, along with its uncertainty. CI-divergence (Control-Impact divergence) quantifies to what extent control and impact sites have diverged between the after and the before period, whereas CI-contribution (Control-Impact contribution) quantifies to what extent the change between periods is stronger in impact sites relative to control sites. To illustrate how these two CI measures can be combined with BACI contrast to gain insights about effects of environmental perturbations, we used count data from the Swedish Breeding Bird Survey to investigate how hurricane Gudrun affected the long-term abundances of four bird species in forested areas of southern Sweden. Before-After-Control-Impact contrasts suggested the hurricane affected all four species. However, the values of the two CI measures strongly differed, even among species showing similar BACI contrasts. Those differences highlight qualitatively distinct population trajectories between periods and treatments requiring different ecological explanations. Overall, we show that BACI contrasts do not provide the full story in assessing the effects of environmental perturbations. The two CI measures can be used to assist ecological interpretations, or to specify detailed hypotheses about effects of restoration actions to allow stronger confirmatory inference about their outcomes. By providing a framework to develop more detailed explanations and hypotheses about ecological changes, the two CI measures can improve conclusions and strengthen evidence of effects of conservation actions and impact assessments under BACI designs.


Assuntos
Tempestades Ciclônicas , Ecologia , Animais , Aves , Florestas , Suécia
6.
Proc Natl Acad Sci U S A ; 113(15): 4033-8, 2016 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-27001852

RESUMO

More than US$21 billion is spent annually on biodiversity conservation. Despite their importance for preventing or slowing extinctions and preserving biodiversity, conservation interventions are rarely assessed systematically for their global impact. Islands house a disproportionately higher amount of biodiversity compared with mainlands, much of which is highly threatened with extinction. Indeed, island species make up nearly two-thirds of recent extinctions. Islands therefore are critical targets of conservation. We used an extensive literature and database review paired with expert interviews to estimate the global benefits of an increasingly used conservation action to stem biodiversity loss: eradication of invasive mammals on islands. We found 236 native terrestrial insular faunal species (596 populations) that benefitted through positive demographic and/or distributional responses from 251 eradications of invasive mammals on 181 islands. Seven native species (eight populations) were negatively impacted by invasive mammal eradication. Four threatened species had their International Union for the Conservation of Nature (IUCN) Red List extinction-risk categories reduced as a direct result of invasive mammal eradication, and no species moved to a higher extinction-risk category. We predict that 107 highly threatened birds, mammals, and reptiles on the IUCN Red List-6% of all these highly threatened species-likely have benefitted from invasive mammal eradications on islands. Because monitoring of eradication outcomes is sporadic and limited, the impacts of global eradications are likely greater than we report here. Our results highlight the importance of invasive mammal eradication on islands for protecting the world's most imperiled fauna.


Assuntos
Conservação dos Recursos Naturais , Espécies Introduzidas , Mamíferos , Animais , Biodiversidade , Ilhas
7.
Bioscience ; 65(5): 520-525, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-26955079

RESUMO

Eradications of invasive species from over 1000 small islands around the world have created conservation arks, but to truly address the threat of invasive species to islands, eradications must be scaled by orders of magnitude. New Zealand has eradicated invasive predators from 10% of its offshore island area and now proposes a vision to eliminate them from the entire country. We review current knowledge of invasive predator ecology and control technologies in New Zealand and the biological research, technological advances, social capacity and enabling policy required. We discuss the economic costs and benefits and conclude with a 50-year strategy for a predator-free New Zealand that is shown to be ecologically obtainable, socially desirable, and economically viable. The proposal includes invasive predator eradication from the two largest offshore islands, mammal-free mainland peninsulas, very large ecosanctuaries, plus thousands of small projects that will together merge eradication and control concepts on landscape scales.

8.
FASEB J ; 28(9): 4088-99, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24903275

RESUMO

Inadequate cell proliferation is considered a major causative factor for impaired coronary collateral growth (CCG). Proangiogenic growth factors (GFs) stimulate cell proliferation, but their administration does not promote CCG in patients. These GFs are increased in patients with metabolic syndrome and in animal models, where CCG is impaired. Here, we investigated whether excessive cell proliferation underlies impaired CCG in metabolic syndrome. Normal [Sprague-Dawley (SD)] and metabolic syndrome [James C. Russell (JCR)] rats underwent repetitive ischemia (RI; transient, repetitive coronary artery occlusion and myocardial ischemia). We have shown that CCG was maximal at d 9 of RI in SD rats but did not occur in JCR rats. The increase in cell proliferation (PCNA, Ki-67, cyclin A, phospho- cdc2, p21Waf, p27Kip) was transient (∼4-fold, d 3 RI) in SD rats but greater and sustained in JCR rats (∼8- to 6-fold, d 3-9 RI). In JCR rats, this was associated with increased and sustained miR-21 expression and accumulation of proliferating synthetic vascular smooth muscle cells in the lumen of small arterioles, which failed to undergo outward expansion. Administration of anti-miR-21 blocked RI-induced cell proliferation and significantly improved CCG in JCR rats (∼60%). miR-21-dependent excessive cell proliferation in the later stages of collateral remodeling correlates with impaired CCG in metabolic syndrome.


Assuntos
Proliferação de Células/genética , Circulação Colateral/fisiologia , Doença da Artéria Coronariana/prevenção & controle , Circulação Coronária/fisiologia , Síndrome Metabólica/fisiopatologia , MicroRNAs/metabolismo , Músculo Liso Vascular/citologia , Isquemia Miocárdica/prevenção & controle , Animais , Apoptose , Western Blotting , Células Cultivadas , Doença da Artéria Coronariana/metabolismo , Doença da Artéria Coronariana/patologia , Modelos Animais de Doenças , Técnicas Imunoenzimáticas , Masculino , MicroRNAs/genética , Músculo Liso Vascular/metabolismo , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/patologia , Neovascularização Patológica/prevenção & controle , RNA Mensageiro/genética , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa
9.
Ecol Appl ; 25(3): 685-94, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26214914

RESUMO

Resilience of ecological communities to perturbation is important in the face of increased global change from anthropogenic stressors. Monitoring is required to detect the impact of, and recovery from, perturbations, and before-after-control-impact (BACI) analysis provides a powerful framework in this regard. However, species in a community are not observed with perfect detection, and occupancy analysis is required to correct for imperfect detectability of species. We present a Bayesian community occupancy before-after-control-impact (CO-BACI) framework to monitor ecological community response to perturbation when constituent species are imperfectly detected. We test the power of the model to detect changes in community composition following an acute perturbation with simulation. We then apply the model to a study of the impact of a large hurricane on the forest bird community of Sweden, using data from the national bird survey scheme. Although simulation shows the model can detect changes in community occupancy following an acute perturbation, application to a Swedish forest bird community following a major hurricane detected no change in community occupancy despite widespread forest loss. Birds with landscape occupancy less than 50% required correcting for detectability. We conclude that CO-BACI analysis is a useful tool that can incorporate rare species in analyses and detect occupancy changes in ecological communities following perturbation, but, because it does not include abundance, some impacts may be overlooked.


Assuntos
Aves/fisiologia , Tempestades Ciclônicas , Ecossistema , Florestas , Animais , Simulação por Computador , Agricultura Florestal , Modelos Biológicos , Suécia
10.
Inhal Toxicol ; 27 Suppl 1: 2-13, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26667327

RESUMO

Individuals with cardiovascular and metabolic diseases (CVD) are shown to be more susceptible to adverse health effects of pollutants. Rodent models of CVD are used for examining susceptibility variations. CVD models developed by selective inbreeding are shown to represent the etiology of human disease and metabolic dysfunction. The goal of this article was to review the origin and the pathobiological features of rat models of varying CVD with or without metabolic syndrome and healthy laboratory rat strains to allow better interpretation of the data regarding their susceptibility to air pollutant exposures. Age-matched healthy Sprague-Dawley (SD), Wistar (WIS) and Wistar Kyoto (WKY), and CVD-prone spontaneously hypertensive (SH), Fawn-Hooded hypertensive (FHH), SH stroke-prone (SHSP), SHHF/Mcc heart failure obese (SHHF) and insulin-resistant JCR:LA-cp obese (JCR) rat models were considered for this study. The genetics and the underlying pathologies differ between these models. Normalized heart weights correlated with underlying cardiac disease while wide differences exist in the number of white blood cells and platelets within healthy strains and those with CVD. High plasma fibrinogen and low angiotensin converting enzyme activity in FHH might relate to kidney disease and associated hypertension. However, other obese strains with known kidney lesions do not exhibit decreases in ACE activity. The increased activated partial thromboplastin time only in SHSP correlates with their hemorrhagic stroke susceptibility. Increases plasma lipid peroxidation in JCR might reflect their susceptibility to acquire atherosclerosis. These underlying pathologies involving CVD and metabolic dysfunction are critical in interpretation of findings related to susceptibility variations of air pollution health effects.


Assuntos
Poluição do Ar , Doenças Cardiovasculares/patologia , Modelos Animais de Doenças , Doenças Metabólicas/patologia , Ratos Endogâmicos/genética , Animais , Doenças Cardiovasculares/genética , Exposição por Inalação , Doenças Metabólicas/genética , Ratos
11.
Ecology ; 95(8): 2268-76, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25230477

RESUMO

Multiple invasive species have now established at most locations around the world, and the rate of new species invasions and records of new invasive species continue to grow. Multiple invasive species interact in complex and unpredictable ways, altering their invasion success and impacts on biodiversity. Incumbent invasive species can be replaced by functionally similar invading species through competitive processes; however the generalized circumstances leading to such competitive displacement have not been well investigated. The likelihood of competitive displacement is a function of the incumbent advantage of the resident invasive species and the propagule pressure of the colonizing invasive species. We modeled interactions between populations of two functionally similar invasive species and indicated the circumstances under which dominance can be through propagule pressure and incumbent advantage. Under certain circumstances, a normally subordinate species can be incumbent and reject a colonizing dominant species, or successfully colonize in competition with a dominant species during simultaneous invasion. Our theoretical results are supported by empirical studies of the invasion of islands by three invasive Rattus species. Competitive displacement is prominent in invasive rats and explains the replacement of R. exulans on islands subsequently invaded by European populations of R. rattus and R. norvegicus. These competition outcomes between invasive species can be found in a broad range of taxa and biomes, and are likely to become more common. Conservation management must consider that removing an incumbent invasive species may facilitate invasion by another invasive species. Under very restricted circumstances of dominant competitive ability but lesser impact, competitive displacement may provide a novel method of biological control.


Assuntos
Aves/fisiologia , Ecossistema , Espécies Introduzidas , Modelos Biológicos , Ratos/fisiologia , Animais , Monitoramento Ambiental , Ratos/classificação , Especificidade da Espécie
12.
Arterioscler Thromb Vasc Biol ; 33(4): 727-36, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23393394

RESUMO

OBJECTIVE: Transient, repetitive occlusion stimulates coronary collateral growth (CCG) in normal animals. Vascular smooth muscle cells (VSMCs) switch to synthetic phenotype early in CCG, then return to contractile phenotype. CCG is impaired in the metabolic syndrome. We determined whether impaired CCG was attributable to aberrant VSMC phenotypic modulation by miR-145-mediated mechanisms, and whether restoration of physiological miR-145 levels in metabolic syndrome (JCR rat) improved CCG. APPROACH AND RESULTS: CCG was stimulated by transient, repetitive left anterior descending artery occlusion and evaluated after 9 days by coronary blood flow measurements (microspheres). miR-145 was delivered to JCR VSMCs via adenoviral vector (miR-145-Adv). In JCR rats, miR-145 was decreased late in CCG (≈ 2-fold day 6; ≈ 4-fold day 9 versus SD), which correlated with decreased expression of smooth muscle-specific contractile proteins (≈ 5-fold day 6; ≈ 10-fold day 9 versus SD), indicative of VSMCs' failure to return to the contractile phenotype late in CCG. miR-145 expression in JCR rats (miR-145-Adv) on days 6 to 9 of CCG completely restored VSMCs contractile phenotype and CCG (collateral/normal zone flow ratio was 0.93 ± 0.09 JCR+miR-145-Adv versus 0.12 ± 0.02 JCR versus 0.87 ± 0.02 SD). CONCLUSIONS: Restoration of VSMC contractile phenotype through miR-145 delivery is a highly promising intervention for restoration of CCG in the metabolic syndrome.


Assuntos
Circulação Colateral , Circulação Coronária , Terapia Genética , Síndrome Metabólica/terapia , MicroRNAs/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Vasoconstrição , Adenoviridae/genética , Animais , Vasos Coronários/metabolismo , Vasos Coronários/fisiopatologia , Modelos Animais de Doenças , Técnicas de Transferência de Genes , Vetores Genéticos , Masculino , Síndrome Metabólica/genética , Síndrome Metabólica/metabolismo , Síndrome Metabólica/patologia , Síndrome Metabólica/fisiopatologia , Proteínas Musculares/biossíntese , Músculo Liso Vascular/patologia , Músculo Liso Vascular/fisiopatologia , Miócitos de Músculo Liso/patologia , Fenótipo , Ratos , Ratos Endogâmicos SHR , Ratos Sprague-Dawley , Ratos Zucker , Fatores de Tempo
13.
Arterioscler Thromb Vasc Biol ; 33(6): 1339-49, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23599440

RESUMO

OBJECTIVE: We have previously shown that transient coronary artery occlusion stimulated coronary collateral growth (CCG) in healthy (Sprague Dawley) but not in metabolic syndrome (JCR:LA-cp [JCR] ) rats. Here, we sought to determine whether matrix metalloproteinases (MMPs) negatively regulate CCG in the metabolic syndrome via release of endostatin and angiostatin. APPROACH AND RESULTS: Rats underwent transient, repetitive left anterior descending occlusion and resultant myocardial ischemia (RI) for 0 to 10 days. CCG was measured in the collateral-dependent and normal zones using microspheres, MMP activation by Western blot, and endostatin and angiostatin by ELISA on days 0, 3, 6, 9, or 10 of RI. Endostatin and angiostatin were increased in JCR but not in Sprague Dawley rats on days 6 and 9 of RI. Increased endostatin and angiostatin correlated with increased MMP12 (≈ 4-fold) activation in JCR but not in Sprague Dawley rats on days 6 and 9 of RI. Inhibition of MMP12 in JCR rats nearly completely blocked endostatin (≈ 85%) and angiostatin (≈ 90%) generation and significantly improved CCG (collateral-dependent zone flow was ≈ 66% of normal zone flow versus ≈ 12% for JCR RI). CONCLUSIONS: Compromised CCG in the metabolic syndrome is, in large part, because of increased MMP12 activation and consequent increased generation of endostatin and angiostatin, which inhibits late-stage collateral remodeling.


Assuntos
Angiostatinas/metabolismo , Circulação Colateral/fisiologia , Oclusão Coronária/metabolismo , Endostatinas/metabolismo , Metaloproteinase 12 da Matriz/metabolismo , Síndrome Metabólica/metabolismo , Angiostatinas/análise , Animais , Western Blotting , Circulação Coronária/fisiologia , Oclusão Coronária/fisiopatologia , Modelos Animais de Doenças , Endostatinas/análise , Ensaio de Imunoadsorção Enzimática , Síndrome Metabólica/fisiopatologia , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Valores de Referência
14.
Br J Nutr ; 111(5): 924-32, 2014 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-24094067

RESUMO

We hypothesised that hypothalamic feeding-related neuropeptides are differentially expressed in obese-prone and lean-prone rats and trigger overeating-induced obesity. To test this hypothesis, in the present study, we measured energy balance and hypothalamic neuropeptide Y (NPY) and pro-opiomelanocortin (POMC) mRNA expressions in male JCR:LA-cp rats. We compared, in independent cohorts, free-feeding obese-prone (Obese-FF) and lean-prone (Lean-FF) rats at pre-weaning (10 d old), weaning (21-25 d old) and early adulthood (8-12 weeks). A group of Obese-pair-feeding (PF) rats pair-fed to the Lean-FF rats was included in the adult cohort. The body weights of 10-d-old Obese-FF and Lean-FF pups were not significantly different. However, when the pups were shifted from dams' milk to solid food (weaning), the obese-prone rats exhibited more energy intake over the days than the lean-prone rats and higher body and fat pad weights and fasting plasma glucose, leptin, insulin and lipid levels. These differences were consistent with higher energy consumption and lower energy expenditure. In the young adult cohort, the differences between the Obese-FF and Lean-FF rats became more pronounced, yielding significant age effects on most of the parameters of the metabolic syndrome, which were reduced in the Obese-PF rats. The obese-prone rats displayed higher NPY expression than the lean-prone rats at pre-weaning and weaning, and the expression levels did not differ by age. In contrast, POMC expression exhibited significant age-by-genotype differences. At pre-weaning, there was no genotype difference in POMC expression, but in the weanling cohort, obese-prone pups exhibited lower POMC expression than the lean-prone rats. This genotype difference became more pronounced at adulthood. Overall, the development of hyperphagia-induced obesity in obese-prone JCR rats is related to POMC expression down-regulation in the presence of established NPY overexpression.


Assuntos
Núcleo Arqueado do Hipotálamo/metabolismo , Regulação para Baixo , Regulação da Expressão Gênica no Desenvolvimento , Hiperfagia/metabolismo , Neuropeptídeo Y/biossíntese , Obesidade/etiologia , Pró-Opiomelanocortina/metabolismo , Adiposidade , Animais , Comportamento Animal , Restrição Calórica , Ingestão de Energia , Metabolismo Energético , Hiperfagia/fisiopatologia , Masculino , Síndrome Metabólica/etiologia , Síndrome Metabólica/prevenção & controle , Neurônios/metabolismo , Neuropeptídeo Y/genética , Neuropeptídeo Y/metabolismo , Obesidade/prevenção & controle , Pró-Opiomelanocortina/genética , RNA Mensageiro/metabolismo , Distribuição Aleatória , Ratos , Ratos Mutantes , Receptores para Leptina/genética , Receptores para Leptina/metabolismo , Desmame
15.
Trends Ecol Evol ; 39(3): 258-266, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38114338

RESUMO

Atoll islands are often perceived as inevitably lost due to rising sea levels. However, unlike other islands, atoll islands are dynamic landforms that have evolved, at least historically, to vertically accrete at a pace commensurate with changing sea levels. Rather than atoll islands' low elevation per se, the impairment of natural accretion processes is jeopardising their persistence. While global marine impacts are deteriorating coral reefs, local impacts also significantly affect accretion, together potentially tipping the scales toward atoll island erosion. Maintaining atoll island accretion requires intact sediment generation on coral reefs, unobstructed sediment transport from reef to island, and available vegetated deposition sites on the island. Ensuring the persistence of atoll islands must include global greenhouse gas emission reduction and local restoration of accretion processes.


Assuntos
Antozoários , Resiliência Psicológica , Animais , Recifes de Corais
16.
PLoS Negl Trop Dis ; 17(9): e0011624, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37672535

RESUMO

There has been a recent upsurge in human cases of leptospirosis in New Zealand, with wildlife a suspected emerging source, but up-to-date knowledge on this topic is lacking. We conducted a cross-sectional study in two farm environments to estimate Leptospira seroprevalence in wildlife and sympatric livestock, PCR/culture prevalence in wildlife, and compare seroprevalence and prevalence between species, sex, and age groups. Traps targeting house mice (Mus musculus), black rats (Rattus rattus), hedgehogs (Erinaceus europaeus) and brushtail possums (Trichosurus vulpecula) were set for 10 trap-nights in March-April 2017 on a dairy (A) and a beef and sheep (B) farm. Trapped wild animals and an age-stratified random sample of domestic animals, namely cattle, sheep and working dogs were blood sampled. Sera were tested by microagglutination test for five serogroups and titres compared using a Proportional Similarity Index (PSI). Wildlife kidneys were sampled for culture and qPCR targeting the lipL32 gene. True prevalence in mice was assessed using occupancy modelling by collating different laboratory results. Infection profiles varied by species, age group and farm. At the MAT cut-point of ≥ 48, up to 78% of wildlife species, and 16-99% of domestic animals were seropositive. Five of nine hedgehogs, 23/105 mice and 1/14 black rats reacted to L. borgpetersenii sv Ballum. The sera of 4/18 possums and 4/9 hedgehogs reacted to L. borgpetersenii sv Hardjobovis whilst 1/18 possums and 1/9 hedgehogs reacted to Tarassovi. In ruminants, seroprevalence for Hardjobovis and Pomona ranged 0-90% and 0-71% depending on the species and age group. Titres against Ballum, Tarassovi and Copenhageni were also observed in 4-20%, 0-25% and 0-21% of domestic species, respectively. The PSI indicated rodents and livestock had the most dissimilar serological responses. Three of nine hedgehogs, 31/105 mice and 2/14 rats were carrying leptospires (PCR and/or culture positive). True prevalence estimated by occupancy modelling in mice was 38% [95% Credible Interval 26, 51%] on Farm A and 22% [11, 40%] on Farm B. In the same environment, exposure to serovars found in wildlife species was commonly detected in livestock. Transmission pathways between and within species should be assessed to help in the development of efficient mitigation strategies against Leptospira.


Assuntos
Animais Selvagens , Leptospira , Cães , Humanos , Animais , Camundongos , Ratos , Bovinos , Ovinos , Gado , Estudos Transversais , Leptospira/genética , Nova Zelândia/epidemiologia , Ouriços , Estudos Soroepidemiológicos , Animais Domésticos
17.
Proc Biol Sci ; 279(1729): 767-74, 2012 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-21775327

RESUMO

Local spatio-temporal resource variations can strongly influence the population dynamics of small mammals. This is particularly true on islands which are bottom-up driven systems, lacking higher order predators and with high variability in resource subsidies. The influence of resource fluctuations on animal survival may be mediated by individual movement among habitat patches, but simultaneously analysing survival, resource availability and habitat selection requires sophisticated analytical methods. We use a Bayesian multi-state capture-recapture model to estimate survival and movement probabilities of non-native black rats (Rattus rattus) across three habitats seasonally varying in resource availability. We find that survival varies most strongly with temporal rainfall patterns, overwhelming minor spatial variation among habitats. Surprisingly for a generalist forager, movement between habitats was rare, suggesting individuals do not opportunistically respond to spatial resource subsidy variations. Climate is probably the main driver of rodent population dynamics on islands, and even substantial habitat and seasonal spatial subsidies are overwhelmed in magnitude by predictable annual patterns in resource pulses. Marked variation in survival and capture has important implications for the timing of rat control.


Assuntos
Comportamento Animal , Animais , Teorema de Bayes , Clima , Meio Ambiente , França , Geografia , Modelos Teóricos , Densidade Demográfica , Dinâmica Populacional , Ratos
18.
Animals (Basel) ; 12(3)2022 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-35158633

RESUMO

Aotearoa-New Zealand has embarked on an ambitious goal: to completely eradicate key invasive mammals by 2050. This will require novel tools capable of eliminating pests on a large scale. In New Zealand, large-scale pest suppression is typically carried out using aerial application of the toxin sodium fluoroacetate (1080). However, as currently applied, this tool does not remove all individuals. A novel application method, dubbed '1080-to-zero', aims to change this and reduce the abundances of target pests to zero or near-zero. One such target is black rats (Rattus rattus), an invasive species challenging to control using ground-based methods. This study monitored and compared the response of black rats to a 1080-to-zero operation and a standard suppression 1080 operation. No difference in the efficacy of rat removal was found between the two treatments. The 1080-to-zero operation did not achieve its goal of rat elimination or reduction to near-zero levels, with an estimated 1540 rats surviving across the 2200 ha treatment area. However, 1080 operations can produce variable responses, and the results observed here differ from the only other reported 1080-to-zero operation. We encourage further research into this tool, including how factors such as ecosystem type, mast fruiting and operational timing influence success.

19.
J Exp Zool A Ecol Integr Physiol ; 337(4): 381-392, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35167183

RESUMO

Seabird breeding success is known to reflect oceanic conditions. Gray-faced petrels (Pterodroma gouldi) breeding on the east coast of Auckland, New Zealand, exhibit poor reproductive success and slow chick development compared to west coast conspecifics. This study mapped changes in physiological traits (corticosterone [CORT] and hematological parameters) indicative of sublethal stress in this Procellariiform species between the west coast (Ihumoana) and east coast (Hawere) island colonies. We found adult gray-faced petrels on the east coast to be lighter and, unlike west coast birds, exhibited an attenuation of response CORT levels between incubation and chick-rearing phases. Such responses were also reflected in east coast chicks that were lighter and had higher feather CORT titers than west coast chicks. Measures of adult hematology and plasma biochemistry revealed significantly lower glucose levels in east coast birds and indicated that chick rearing is the most stressful phase of breeding for this species Combined; these results suggest that east coast birds are under greater nutritional stress and that parents appear to transfer the costs of poor foraging to their chicks to preserve their own condition, consequently increasing chick developmental stress. Our results suggest that any long-term decrease in ocean conditions and/or climatic shifts would be more acutely felt by east coast chicks and potentially their parents, resulting in years of poor breeding success rates on a local scale.


Assuntos
Aves , Corticosterona , Animais , Biomarcadores , Aves/fisiologia , Plumas , Reprodução
20.
Sci Rep ; 12(1): 13391, 2022 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-35948555

RESUMO

Islands are global hotspots for biodiversity and extinction, representing ~ 5% of Earth's land area alongside 40% of globally threatened vertebrates and 61% of global extinctions since the 1500s. Invasive species are the primary driver of native biodiversity loss on islands, though eradication of invasive species from islands has been effective at halting or reversing these trends. A global compendium of this conservation tool is essential for scaling best-practices and enabling innovations to maximize biodiversity outcomes. Here, we synthesize over 100 years of invasive vertebrate eradications from islands, comprising 1550 eradication attempts on 998 islands, with an 88% success rate. We show a significant growth in eradication activity since the 1980s, primarily driven by rodent eradications. The annual number of eradications on islands peaked in the mid-2000s, but the annual area treated continues to rise dramatically. This trend reflects increases in removal efficacy and project complexity, generating increased conservation gains. Our synthesis demonstrates the collective contribution of national interventions towards global biodiversity outcomes. Further investment in invasive vertebrate eradications from islands will expand biodiversity conservation while strengthening biodiversity resilience to climate change and creating co-benefits for human societies.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Animais , Mudança Climática , Humanos , Espécies Introduzidas , Vertebrados
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