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1.
Glob Chang Biol ; 28(7): 2461-2475, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34962005

RESUMO

As a nature-based and cost-effective solution, forestation plays a crucial role in combating global warming, biodiversity collapse, environmental degradation, and global well-being. Although China is acknowledged as a global leader of forestation and has achieved considerable overall success in environmental improvements through mega-forestation programs, many negative effects have also emerged at local scales due to the planting of maladapted tree species. To better help achieve carbon neutrality and the new vision of an ecological civilization, China has committed to further increase forestation. However, where forestation lands and such efforts should really be located is not so well understood yet and agreed upon, especially in the face of rapid climate change. Based on an ensemble-learning machine, we predicted the spatial habitats (ecological niche) of the forest, grassland, shrubland, and desert under present and future climate conditions based on the natural climax vegetation distribution across China. We show that the potential forestation lands are mainly located in eastern China, which is east of the Hu Line (also known as the Heihe-Tengchong Line). Under future climate change, forests will shift substantially in the latitudinal, longitudinal, and elevational distribution. Potential forestation lands will increase by 33.1 million hectares through the 2070s, mainly due to the conversions of shrub and grassland to forests along the Hu Line. Our prediction map also indicates that grassland rehabilitation is the universal optimal vegetation restoration strategy in areas west of the Hu Line. This analysis is consistent with much of the observed evidence of forestation failures and recent climate-change-induced forest range shifts. Our results provide an overview and further show the importance of adaptive science-based forestation planning and forest management.


Assuntos
Agricultura Florestal , Florestas , China , Mudança Climática , Ecossistema , Árvores
2.
Conserv Biol ; 36(6): e13964, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35674098

RESUMO

In China, as elsewhere, amphibians are highly endangered. Anthropogenic environmental change has affected the distribution and population dynamics of species, and species distributions at a broad scale are strongly driven by climate and species' ability to disperse. Yet, current knowledge remains limited on how widespread human activity affects the distribution patterns of amphibians in China and whether this effect extends beyond climate. We compiled a relatively comprehensive database on the distribution of 196 amphibian species in China from the literature, public databases, and field data. We obtained 25,826 records on almost 50% of known species in China. To test how environmental factors and human activities influence the current distribution of amphibians (1960-1990), we used range filling, which is species realized ranges relative to their potential climate distribution. We used all species occurrence records to represent realized range and niche models to predict potential distribution range. To reduce uncertainty, we used 3 regression methods (beta regression, generalized boosted regression models, and random forest) to test the associations of species range filling with human activity, climate, topography, and range size. The results of the 3 approaches were consistent. At the species level, mean annual precipitation (climate) had the most effect on spatial distribution pattern of amphibians in China, followed by range size. Human activity ranked last. At the spatial level, mean annual precipitation remained the most important factor. Regions in southeastern of China that are currently moist supported the highest amphibian diversity, but were predicted to experience a decline in precipitation under climate change scenarios. Consequently, the distributions of amphibians will likely shift to the northwest in the future, which could affect future conservation efforts.


En China, como en todos lados, los anfibios están gravemente en peligro. El cambio ambiental antropogénico ha afectado la distribución y dinámica poblacional de especies, y la distribución de especies a gran escala están muy influidas por el clima y la habilidad de dispersión de las especies. Sin embargo, el conocimiento actual sigue siendo limitado sobre cómo la actividad humana generalizada afecta a los patrones de distribución de anfibios en China y si este efecto se extiende más allá del clima. A partir de literatura, bases de datos públicas y datos de campo, integramos una base datos relativamente completa sobre la distribución de 196 especies de anfibios en China. Obtuvimos 25,826 registros de casi 50% de las especies conocidas en China. Para probar cómo los factores ambientales y las actividades humanas influyen en la distribución actual de anfibios (1960-1990), utilizamos la ocupación de rango, que contrasta los rangos de distribución observada de las especies en relación con su distribución climática potencial. Utilizamos los registros de ocurrencia de todas las especies para representar el rango observado y modelos de nicho para predecir el rango de distribución potencial. Para reducir la incertidumbre, utilizamos 3 métodos de regresión (regresión beta, modelos de regresión acelerada generalizada y bosque aleatorio) para probar las asociaciones de la ocupación de rango de especies con la actividad humana, clima, topografía y extensión de rango. Los resultados de los tres métodos fueron consistentes. A nivel de especie, la precipitación media anual (clima) tuvo el mayor efecto sobre el patrón de distribución de anfibios en China, seguida por la extensión del rango. La actividad humana ocupó el último lugar. A nivel espacial, la precipitación media anual siguió como el factor más importante. Las regiones en el sureste de China que aun son húmedas sostuvieron la mayor diversidad de anfibios, pero se pronosticó que la precipitación declinará bajo escenarios de cambio climático. Consecuentemente, la distribución de anfibios muy probablemente cambiará hacia el noreste, lo cual podría afectar esfuerzos futuros de conservación.


Assuntos
Anfíbios , Conservação dos Recursos Naturais , Animais , Humanos , Mudança Climática , Atividades Humanas , China , Ecossistema
3.
Arch Virol ; 159(11): 3101-5, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25000900

RESUMO

A hemagglutinating virus (8KS0813) was isolated from a red-necked stint. Hemagglutination inhibition and neutralization tests indicated that 8KS0813 was antigenically related to a prototype strain, APMV-6/duck/Hong Kong/18/199/77, but with an 8- and 16-fold difference, respectively, in their titers. The full genome sequence of 8KS0813 showed 98.6 % nucleotide sequence identity to that of APMV-6/duck/Italy/4524-2/07, which has been reported to belong to an APMV-6 subgroup, and showed less similarity to that of the prototype strain (70.6 % similarity). The growth of 8KS0813 and the prototype strain in four different cell cultures was greatly enhanced by adding trypsin. Interestingly, this virus induced syncytia only in Vero cells. 8KS0813 was identified as APMV-6/red-necked stint/Japan/8KS0813/08, but it is antigenically and genetically distinguishable from the prototype strain, suggesting that variant APMV-6 is circulating in migratory birds.


Assuntos
Variação Antigênica , Antígenos Virais/genética , Infecções por Avulavirus/veterinária , Avulavirus/genética , Doenças das Aves/virologia , Migração Animal , Animais , Animais Selvagens/imunologia , Animais Selvagens/fisiologia , Animais Selvagens/virologia , Anticorpos Antivirais/imunologia , Antígenos Virais/imunologia , Avulavirus/crescimento & desenvolvimento , Avulavirus/imunologia , Avulavirus/isolamento & purificação , Infecções por Avulavirus/imunologia , Infecções por Avulavirus/virologia , Doenças das Aves/imunologia , Aves/fisiologia , Aves/virologia , Genoma Viral , Testes de Inibição da Hemaglutinação , Dados de Sequência Molecular , Filogenia
4.
Zoolog Sci ; 31(7): 430-7, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25001914

RESUMO

Avian nest-site selection is an important research and management subject. The hooded crane (Grus monacha) is a vulnerable (VU) species according to the IUCN Red List. Here, we present the first long-term Chinese legacy nest data for this species (1993-2010) with publicly available metadata. Further, we provide the first study that reports findings on multivariate nest habitat preference using such long-term field data for this species. Our work was carried out in Northeastern China, where we found and measured 24 nests and 81 randomly selected control plots and their environmental parameters in a vast landscape. We used machine learning (stochastic boosted regression trees) to quantify nest selection. Our analysis further included varclust (R Hmisc) and (TreenNet) to address statistical correlations and two-way interactions. We found that from an initial list of 14 measured field variables, water area (+), water depth (+) and shrub coverage (-) were the main explanatory variables that contributed to hooded crane nest-site selection. Agricultural sites played a smaller role in the selection of these nests. Our results are important for the conservation management of cranes all over East Asia and constitute a defensible and quantitative basis for predictive models.


Assuntos
Aves/fisiologia , Modelos Biológicos , Comportamento de Nidação/fisiologia , Animais , China , Ecossistema , Análise Multivariada
5.
Sci Rep ; 14(1): 7213, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38531933

RESUMO

The currently available distribution and range maps for the Great Grey Owl (GGOW; Strix nebulosa) are ambiguous, contradictory, imprecise, outdated, often hand-drawn and thus not quantified, not based on data or scientific. In this study, we present a proof of concept with a biological application for technical and biological workflow progress on latest global open access 'Big Data' sharing, Open-source methods of R and geographic information systems (OGIS and QGIS) assessed with six recent multi-evidence citizen-science sightings of the GGOW. This proposed workflow can be applied for quantified inference for any species-habitat model such as typically applied with species distribution models (SDMs). Using Random Forest-an ensemble-type model of Machine Learning following Leo Breiman's approach of inference from predictions-we present a Super SDM for GGOWs in Alaska running on Oracle Cloud Infrastructure (OCI). These Super SDMs were based on best publicly available data (410 occurrences + 1% new assessment sightings) and over 100 environmental GIS habitat predictors ('Big Data'). The compiled global open access data and the associated workflow overcome for the first time the limitations of traditionally used PC and laptops. It breaks new ground and has real-world implications for conservation and land management for GGOW, for Alaska, and for other species worldwide as a 'new' baseline. As this research field remains dynamic, Super SDMs can have limits, are not the ultimate and final statement on species-habitat associations yet, but they summarize all publicly available data and information on a topic in a quantified and testable fashion allowing fine-tuning and improvements as needed. At minimum, they allow for low-cost rapid assessment and a great leap forward to be more ecological and inclusive of all information at-hand. Using GGOWs, here we aim to correct the perception of this species towards a more inclusive, holistic, and scientifically correct assessment of this urban-adapted owl in the Anthropocene, rather than a mysterious wilderness-inhabiting species (aka 'Phantom of the North'). Such a Super SDM was never created for any bird species before and opens new perspectives for impact assessment policy and global sustainability.

6.
Vet Res ; 44: 42, 2013 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-23763792

RESUMO

Avian influenza virus (AIV) is enzootic to wild birds, which are its natural reservoir. The virus exhibits a large degree of genetic diversity and most of the isolated strains are of low pathogenicity to poultry. Although AIV is nearly ubiquitous in wild bird populations, highly pathogenic H5N1 subtypes in poultry have been the focus of most modeling efforts. To better understand viral ecology of AIV, a predictive model should 1) include wild birds, 2) include all isolated subtypes, and 3) cover the host's natural range, unbounded by artificial country borders. As of this writing, there are few large-scale predictive models of AIV in wild birds. We used the Random Forests algorithm, an ensemble data-mining machine-learning method, to develop a global-scale predictive map of AIV, identify important predictors, and describe the environmental niche of AIV in wild bird populations. The model has an accuracy of 0.79 and identified northern areas as having the highest relative predicted risk of outbreak. The primary niche was described as regions of low annual rainfall and low temperatures. This study is the first global-scale model of low-pathogenicity avian influenza in wild birds and underscores the importance of largely unstudied northern regions in the persistence of AIV.


Assuntos
Surtos de Doenças/veterinária , Virus da Influenza A Subtipo H5N1/fisiologia , Influenza Aviária/epidemiologia , Animais , Aves , Ecossistema , Variação Genética , Mapeamento Geográfico , Geografia , Virus da Influenza A Subtipo H5N1/genética , Influenza Aviária/virologia , Modelos Biológicos , Filogenia , Prevalência , Medição de Risco
7.
Am J Primatol ; 75(1): 88-94, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23161483

RESUMO

The Sulawesi black macaque (Macaca nigra) population at Tangkoko Nature Reserve in North Sulawesi, Indonesia has been the focus of periodic study for over 30 years. The population has shown considerable decline during much of that time. Here we present the results of a long-term population survey of the Tangkoko M. nigra, conducted over the past decade, to provide updated information and on-going assessment of the population. Line-transect sampling was conducted annually from 1999 to 2002 and 2005 to 2011 along the same transect during a 2- to 3-week survey period. Although further decline in the population was observed at the outset of the survey, over the subsequent 12-year period we have seen stability in the population parameters with evidence of modest increases in both group and population density. During the 1999-2002 survey periods, there was a mean group density of 3.6 groups/km(2) and a mean population density of 39.8 individuals/km(2) . During 2005-2011, mean group density increased to 3.8 groups/km(2) and mean population density was 51.4 individuals/km(2) . The 2011 survey data indicated an estimated group density of 4.3 groups/km(2) and a population density of 61.5 individuals/km(2) . Given that our transect was located in the core of the Tangkoko reserve, our density estimates should be limited to that area of the reserve. One explanation for the apparent stabilization of the population may be tied to the increasing and sustained number of training and research programs being conducted at the reserve. This collective effort by local and international groups may be helping to reduce illegal activity in the reserve (i.e., hunting and habitat destruction) and generate greater awareness of this critically endangered species. Without the continued vigilance afforded by the existing research and training programs and the support and involvement of the local people, the M. nigra at the Tangkoko Nature Reserve will likely face further decline.


Assuntos
Macaca/fisiologia , Animais , Indonésia , Densidade Demográfica , Estações do Ano
8.
Vaccines (Basel) ; 11(7)2023 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-37514961

RESUMO

African swine fever (ASF) is a viral disease, endemic to Africa, that causes high mortality when introduced into domestic pig populations. Since the emergence of p72-genotype II African swine fever virus (ASFV) in Georgia in 2007, an ASF epidemic has been spreading across Europe and many countries in Asia. The epidemic first reached Ukraine in 2012. To better understand the dynamics of spread of ASF in Ukraine, we analyzed spatial and temporal outbreak data reported in Ukraine between 2012 and mid-2023. The highest numbers of outbreaks were reported in 2017 (N = 163) and 2018 (N = 145), with overall peak numbers of ASF outbreaks reported in August (domestic pigs) and January (wild boars). While cases were reported from most of Ukraine, we found a directional spread from the eastern and northern borders towards the western and southern regions of Ukraine. Many of the early outbreaks (before 2016) were adjacent to the border, which is again true for more recent outbreaks in wild boar, but not for recent outbreaks in domestic pigs. Outbreaks prior to 2016 also occurred predominantly in areas with a below average domestic pig density. This new analysis suggests that wild boars may have played an important role in the introduction and early spread of ASF in Ukraine. However, in later years, the dynamic suggests human activity as the predominant driver of spread and a separation of ASF epizootics between domestic pigs and in wild boars. The decline in outbreaks since 2019 suggests that the implemented mitigation strategies are effective, even though long-term control or eradication remain challenging and will require continued intensive surveillance of ASF outbreak patterns.

9.
J Trop Med ; 2022: 5942693, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36211623

RESUMO

Rabies is a vaccine-preventable fatal viral disease that is zoonotic in nature. In this article, we provide a justification why the agreement of the World Health Organization (WHO), the Food and Agriculture Organization (FAO), the World Organization for Animal Health (OIE), and Global Alliance for Rabies Control (GARC) on The Global Strategic Plan to End Human Deaths from Dog-mediated Rabies by 2030 should also include a more holistic approach and ecologic views.

10.
Integr Zool ; 17(5): 715-730, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35060680

RESUMO

Tens of thousands of demoiselle cranes' crossing the Himalayas to the Indian subcontinent have been reported for decades, but their exact spring migration route remained a mystery until our previous study found they made a detour in spring along the western edge of the Himalayas and crossed the Mongolian Plateau to their breeding areas based on satellite telemetry of 3 birds. To corroborate the loop migration pattern and explore whether demoiselle crane's loop migration route is shaped by time- and energy-minimization strategies in spring and autumn and how the temporal and spatial variation of environmental conditions contribute to crane's selection of migration routes, we tracked 11 satellite-tagged demoiselle cranes from their breeding area in China and Russia, simulated 2 pseudo migration routes, and then compared the environmental conditions, time, and energy cost between true and pseudo routes in the same season. Results show that demoiselles' spring migration obeyed time-minimization hypothesis, avoiding the colder Qinghai-Tibet Plateau, benefited by abundant food and higher thermal and orographic uplift along the route; autumn migration follows energy-minimization hypothesis with the shorter route. Our research will contribute to uncover the mechanical reasons why demoiselle crane avoids crossing the giant barrier of the Himalayas in spring, and shapes a loop migration route.


Assuntos
Migração Animal , Aves , Animais , China , Estações do Ano , Telemetria
11.
Sci Total Environ ; 845: 157140, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-35803416

RESUMO

Rangeland ecosystems are changing worldwide with the abandonment of extensive pastoralism practices and greater interest for species coexistence. However, the lack of compiled data on current changes in the abundance and distribution of herbivores challenges rangeland management decisions. Here we gathered and made available for the first time the most extensive set of occurrence data for rangeland herbivores in Iceland in an Open Access framework for transparent and repeatable science-based decisions. We mapped fine scale species distribution overlap to identify areas at risk for wildlife-livestock conflict and overgrazing. Nationwide and long term (1861-2021) occurrence data from 8 independent datasets were used alongside 11 predictor raster layers ("Big Data") to data mine and map the distribution of the domestic sheep (Ovis aries), feral reindeer (Rangifer tarandus tarandus), pink-footed geese (Anser brachyrhynchus), and rock ptarmigan (Lagopus muta islandorum) over the country during the summer. Using algorithms of Maxent in R, RandomForest, TreeNet (stochastic gradient boosting) and MARS (Splines) in Minitab-SPM 8.3, we computed 1 km pixel predictions from machine learning-based ensemble models. Our high-resolution models were tested with alternative datasets, and Area Under the Curve (AUC) values that indicated good (reindeer: 0.8817 and rock ptarmigan: 0.8844) to high model accuracy (sheep: 0.9708 and pink-footed goose: 0.9143). Whenever possible, source data and models are made available online and described with ISO-compliant metadata. Our results illustrate that sheep and pink-footed geese have the greatest overlap in distribution with potential implication for wildlife-livestock conflicts and continued ecosystem degradation even under diminishing livestock abundance at higher elevation. These nationwide models and data are a global asset and a first step in making available the best data for science-based sustainable decision-making about national herbivores affecting species coexistence and environmental management.


Assuntos
Ecossistema , Rena , Animais , Gansos , Herbivoria , Islândia , Gado , Ovinos
12.
PeerJ ; 9: e11830, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34611502

RESUMO

American red squirrels (Tamiasciurus hudsonicus) are small mammals that are abundantly distributed throughout North America. Urbanization in the Anthropocene is now a global process, and squirrels live in affected landscapes. This leads to squirrels adjusting to human developments. Not much is known about the distribution of squirrels and squirrel middens near humans, especially not in the subarctic and sub-urbanized regions. Although this species is hunted, there are no real publicly available distribution and abundance estimates nor management plans and bag limits for squirrels in Alaska or in the United States known by us, except the endangered Mt. Graham squirrel. In general, insufficient squirrel conservation research is carried out; they are underrepresented in research and its literature. To further the science-based management for such species, this study aims to generate the first digital open access workflow as a generic research template for small mammal work including the latest machine learning of open source and high-resolution LIDAR data in an Open Source Geographic Information System (QGIS) and ArcGIS. Machine learning has proven to be less modeler biased and improve accuracy of the analysis outcome, therefore it is the preferred approach. This template is designed to be rapid, simple, robust, generic and effective for being used by a global audience. As a unique showcase, here a squirrel midden survey was carried out for two years (2016 and 2017). These squirrel middens were detected in a research area of 45,5 hectares (0,455 km2) in downtown Fairbanks, interior boreal forest of Alaska, U.S. Transect distances were geo-referenced with a GPS and adjusted to the visual conditions to count all squirrel middens within the survey area. Different layers of proximity to humans and habitat characteristics were assembled using aerial imagery and LIDAR data (3D data needed for an arboreal species like the red squirrels) consisting of a 3 × 3 m resolution. The layer data was used to train a predictive distribution model for red squirrel middens with machine learning. The model showed the relative index of occurrence (RIO) in a map and identified canopy height, distance to trails, canopy density and the distance to a lake, together, as the strongest predictors for squirrel midden distribution whereas open landscape and disturbed areas are avoided. It is concluded that squirrels select for high and dense forests for middens while avoiding human disturbance. This study is able to present a machine learning template to easily and rapidly produce an accurate abundance prediction which can be used for management implications.

13.
Zoonoses Public Health ; 68(6): 677-683, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33955689

RESUMO

The ecology of rabies in the circumpolar North is still not well understood. We use machine learning, a geographic information system and data explicit in time and space obtained for reported rabies cases and predictors in Canada to develop an ecological niche model for the distribution of reported rabies cases in the American north (Alaska and Canada). The ecological niche model based on reported rabies cases in Canada predicted reported rabies cases in Alaska, suggesting a rather robust inference and even similar drivers on a continental scale. As found in Alaska, proximity to human infrastructure-specifically along the coast-was a strong predictor in the detection of rabies cases in Canada. Also, this finding highlights the need for a more systematic landscape sampling for rabies infection model predictions to better understand and tackle the ecology of this important zoonotic disease on a landscape scale at some distance from human infrastructure in wilderness areas.


Assuntos
Animais Selvagens , Gado , Modelos Biológicos , Animais de Estimação , Raiva/veterinária , Alaska/epidemiologia , Animais , Canadá/epidemiologia , Demografia , Ecossistema , Sistemas de Informação Geográfica , Humanos , Raiva/epidemiologia , Zoonoses Virais
14.
Sci Total Environ ; 777: 146093, 2021 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-33684761

RESUMO

The Anthropocene causes many massive and novel impacts, e.g., on migratory birds and their habitats. Many species of migratory birds have been declining on the Palearctic-African flyway in recent decades. To investigate possible impacts on a continental scale, we used 18 predictors extracted from 16 publicly available GIS layers in combination with machine learning methods on the sub-Saharan distributions of 64 passerine migrant species. These bird species were categorized as having experienced a 'Large Decline' (n = 12), a 'Moderate Decline' (n = 6) or 'No Decline' (n = 46) based on European census data from 1970 to 1990. Therefore, we present the first study for these species which uses publically available Open Access GIS-data and a multivariate (n = 18) and multi-species (n = 64) machine learning approach to deduce possible past impacts. We furthermore modelled likely future human population change and climate change impacts. We identified three predictor themes related to the distributions and declines of these migratory birds: (I) locations, represented by African ecosystems, countries, and soil types; (II) human population pressures and land-use intensities, the latter represented by land-use categories, habitat area, and cropland proportion; and (III) climatic predictors. This is the first study to relate migratory bird declines to human population pressures and land-use intensities using this type of analysis. We also identified areas of conservation concern, such as the Sahel region. Our models also predict that the declining trends of migratory birds will continue into the foreseeable future across much of Africa. We then briefly discuss some wider conservation implications in the light of the increasing drivers of biodiversity change associated with the Anthropocene as well as some possible solutions. We argue that only comprehensive systemic change can mitigate the impacts on the migratory birds and their habitats.


Assuntos
Ecossistema , Passeriformes , África , África do Norte , Migração Animal , Animais , Mudança Climática , Sistemas de Informação Geográfica , Humanos , Aprendizado de Máquina , Estações do Ano
15.
Sci Rep ; 11(1): 22051, 2021 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-34764401

RESUMO

Many polar species and habitats are now affected by man-made global climate change and underlying infrastructure. These anthropogenic forces have resulted in clear implications and many significant changes in the arctic, leading to the emergence of new climate, habitats and other issues including digital online infrastructure representing a 'New Artic'. Arctic grazers, like Eastern Russian migratory populations of Tundra Bean Goose Anser fabalis and Greater White-fronted Goose A. albifrons, are representative examples and they are affected along the entire flyway in East Asia, namely China, Japan and Korea. Here we present the best publicly-available long-term (24 years) digitized geographic information system (GIS) data for the breeding study area (East Yakutia and Chukotka) and its habitats with ISO-compliant metadata. Further, we used seven publicly available compiled Open Access GIS predictor layers to predict the distribution for these two species within the tundra habitats. Using BIG DATA we are able to improve on the ecological niche prediction inference for both species by focusing for the first time specifically on biological relevant population cohorts: post-breeding moulting non-breeders, as well as post-breeding parent birds with broods. To assure inference with certainty, we assessed it with 4 lines of evidence including alternative best-available open access field data from GBIF.org as well as occurrence data compiled from the literature. Despite incomplete data, we found a good model accuracy in support of our evidence for a robust inference of the species distributions. Our predictions indicate a strong publicly best-available relative index of occurrence (RIO). These results are based on the quantified ecological niche showing more realistic gradual occurrence patterns but which are not fully in agreement with the current strictly applied parsimonious flyway and species delineations. While our predictions are to be improved further, e.g. when synergetic data are made freely available, here we offer within data caveats the first open access model platform for fine-tuning and future predictions for this otherwise poorly represented region in times of a rapid changing industrialized 'New Arctic' with global repercussions.


Assuntos
Gansos/fisiologia , Distribuição Animal , Migração Animal , Animais , Regiões Árticas , Mudança Climática , Ecossistema , Modelos Biológicos , Muda , Reprodução
16.
J Anim Ecol ; 79(2): 471-82, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20002863

RESUMO

1. Climate is an important factor influencing the population dynamics of large herbivores operating directly on individuals or through its effect on forage characteristics. However, the seasonal effect of climate may differ between forage- and predator-limited populations because of a climatic influence on predation rates. The influence of climate on predator-limited large herbivores is less well known than on forage-limited populations. Further, the effect of Pacific-based climate on large herbivore populations has been rarely assessed. 2. We investigated the effect of the Pacific Decadal Oscillation (PDO), across different seasons, on recruitment in 10 populations (herds) of mountain-dwelling caribou Rangifer tarandus caribou L. in the Yukon Territory, Canada. These low-density populations occur in highly seasonal environments and are considered predator-limited with high neonatal calf mortality. Hence, in most years females do not spend resources through lactational support during the summer and resource intake is devoted to self-maintenance. We predicted that climate affecting environmental conditions at calving would have a strong effect on recruitment via its influence on predation rates. We also predicted that climatic conditions prior to conception could have an effect on recruitment through its influence on female fecundity. We modelled recruitment (n = 165) by seasonal PDO values using generalized linear mixed-effects models with herd-varying coefficients. 3. We found that recruitment variability was best explained by variation in winter climate (beta = 0.110, SE = 0.007) prior to birth (in utero) and May climate (beta = 0.013, SE = 0.006) at calving. There was little support for a pre-conception climate effect influencing female body condition and hence fecundity. These results confirm that recruitment in these populations is limited by predation and that forage-limitation is not a significant factor in their population dynamics. There was considerable variability in herd-specific relationships between the PDO and recruitment. Incorporating herd-specific characteristics, such as variable predator densities or terrain characteristics within a herd range, may shed greater light on the complex relationship between climate and ungulate population dynamics.


Assuntos
Clima , Ecossistema , Rena/fisiologia , Estações do Ano , Animais , Feminino , Masculino , Modelos Biológicos , Dinâmica Populacional , Lobos/fisiologia , Yukon
17.
Sci Rep ; 10(1): 16817, 2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-33033298

RESUMO

Avian Influenza (AI) is a complex but still poorly understood disease; specifically when it comes to reservoirs, co-infections, connectedness and wider landscape perspectives. Low pathogenic (Low-path LP) AI in chickens caused by less virulent strains of AI viruses (AIVs)-when compared with highly pathogenic AIVs (HPAIVs)-are not even well-described yet or known how they contribute to wider AI and immune system issues. Co-circulation of LPAIVs with HPAIVs suggests their interactions in their ecological aspects. Here we show for the Pacific Rim an international approach how to data mine and model-predict LP AI and its ecological niche with machine learning and open access data sets and geographic information systems (GIS) on a 5 km pixel size for best-possible inference. This is based on the best-available data on the issue (~ 40,827 records of lab-analyzed field data from Japan, Russia, Vietnam, Mongolia, Alaska and Influenza Research Database (IRD) and U.S. Department of Agriculture (USDA) database sets, as well as 19 GIS data layers). We sampled 157 hosts and 110 low-path AIVs with 32 species as drivers. The prevalence across low-path AIV subtypes is dominated by Muscovy ducks, Mallards, Whistling Swans and gulls also emphasizing industrial impacts for the human-dominated wildlife contact zone. This investigation sets a good precedent for the study of reservoirs, big data mining, predictions and subsequent outbreaks of HPAI and other pandemics.


Assuntos
Aves/virologia , Mineração de Dados , Reservatórios de Doenças , Influenza Aviária/epidemiologia , Animais , Galinhas/virologia , Mineração de Dados/métodos , Conjuntos de Dados como Assunto , Reservatórios de Doenças/estatística & dados numéricos , Reservatórios de Doenças/virologia , Patos/virologia , Previsões , Influenza Aviária/virologia , Modelos Estatísticos , Orthomyxoviridae/patogenicidade , Oceano Pacífico , Prevalência
18.
MethodsX ; 6: 2281-2292, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31667128

RESUMO

Random forests (RF) is a powerful species distribution model (SDM) algorithm. This ensemble model by default can produce categorical and numerical species distribution maps based on its classification tree (CT) and regression tree (RT) algorithms, respectively. The CT algorithm can also produce numerical predictions (class probability). Here, we present a detailed procedure involving the use of the CT and RT algorithms using the RF method with presence-only data to model the distribution of species. CT and RT are used to generate numerical prediction maps, and then numerical predictions are converted to binary predictions through objective threshold-setting methods. We also applied simple methods to deal with collinearity of predictor variables and spatial autocorrelation of species occurrence data. A geographically stratified sampling method was employed for generating pseudo-absences. The detailed procedural framework is meant to be a generic method to be applied to virtually any SDM prediction question using presence-only data. •How to use RF as a standard method for generic species distributions with presence-only data•How to choose RF (CT or RT) methods for the distribution modeling of species•A general and detailed procedure for any SDM prediction question.

20.
Ecol Evol ; 8(19): 9712-9727, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30386569

RESUMO

Phylogenetic niche conservatism implies that sister taxa will have similar niches, although the niches of disjunct subspecies may evolve differently. This study uses Macaca assamensis, subspecies assamensis and pelops, to investigate the similarities of realized climatic niches of two disjunct subspecies (separated by the Brahmaputra River) along with a similarity analysis of their respective regions' climate. Modeled distributions were used to quantify their potential distribution under current and future climate scenarios. The climatic similarity between regions of each subspecies was tested with principal component analysis (PCA), and the realized climatic niche overlap between two subspecies was tested with a multivariate analysis of variance (MANOVA) on a subset of the least correlated variables out of 24 publicly available topo-bioclimatic variables. Tukey's honest significance difference (HSD) was used to test the range differences (on all 24 variables) between subspecies. The potential distribution of both taxa in the current climate and projected future climate was model-predicted using MaxEnt and Random Forest. We found significantly different climatic ranges for 21 predictors (HSD; p < 0.05) for the two subspecies, significantly different climatic conditions for their regions (using PCA; p < 0.001), and significantly different realized climatic niches for the two subspecies (MANOVA; p < 0.001). The distribution models generated a larger potential area than the currently known distributions. Although literature show that the Brahmaputra River is an effective dispersal barrier, we found some of the neighboring geographic range for both subspecies appears to be potentially suitable for the other taxon. The projected future potential areas indicate that some parts of the currently occupied geography, mostly southern parts, may become climatically unsuitable, whereas other new geographical areas may become suitable. Most of these new potential areas will be toward the north where higher and fragmented mountains, which has conservation implications.

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