ORCID Profile
0000-0002-3740-7758
Current Organisation
Geneva University
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Publisher: Wiley
Date: 15-04-2020
DOI: 10.1002/ECE3.6174
Abstract: While anthropogenic land‐use changes threaten wildlife globally, some species take advantage of such changes and disperse into urban areas. The wildlife in urban areas often promotes conflicts with humans, notably when the animals are associated with the spread of zoonotic diseases. In Israel, current urban invasion of rock hyraxes ( Procavia capensis ) draws public attention, since the species is a reservoir host of cutaneous leishmaniasis, a serious skin disease. The rock hyrax, however, has seldom been studied in densely populated areas, and the drivers for its urban expansion, as well as its abilities to live and spread in core urban areas, are relatively unknown. Here, we explore the rock hyrax expansion to urban areas process by examining the availability, characteristics and use of shelter along an urban gradient. Our findings suggest that a series of factors determines shelter availability and quality for the rock hyrax, which facilitates its dispersion across the urban gradient. We found that rock hyraxes from the Judean Desert expand to the peri‐urban region of Jerusalem by colonizing new rocky shelters formed as by‐products of urban development. With their populations reaching extreme densities in this area and saturating the available shelters, there is some spill over to the adjacent core urban areas where they colonize littered sites, which are made available due to the local socio‐economic conditions and cultural norms of waste disposal and illegal placement of temporary structures. Our work emphasizes the significance of the urban gradient approach for studying the mechanisms promoting wildlife expansion to cities. Our findings suggest that changes in shelter availability and quality due to urban development, and cultural norms promote shifts of the hyrax population by pushing from the already established areas and pulling into new environment across the urban gradient.
Publisher: Public Library of Science (PLoS)
Date: 22-01-2021
DOI: 10.1371/JOURNAL.PNTD.0009047
Abstract: Snakebite causes more than 1.8 million envenoming cases annually and is a major cause of death in the tropics especially for poor farmers. While both social and ecological factors influence the chance encounter between snakes and people, the spatio-temporal processes underlying snakebites remain poorly explored. Previous research has focused on statistical correlates between snakebites and ecological, sociological, or environmental factors, but the human and snake behavioral patterns that drive the spatio-temporal process have not yet been integrated into a single model. Here we use a bottom-up simulation approach using agent-based modelling (ABM) parameterized with datasets from Sri Lanka, a snakebite hotspot, to characterise the mechanisms of snakebite and identify risk factors. Spatio-temporal dynamics of snakebite risks are examined through the model incorporating six snake species and three farmer types (rice, tea, and rubber). We find that snakebites are mainly climatically driven, but the risks also depend on farmer types due to working schedules as well as species present in landscapes. Snake species are differentiated by both distribution and by habitat preference, and farmers are differentiated by working patterns that are climatically driven, and the combination of these factors leads to unique encounter rates for different landcover types as well as locations. Validation using epidemiological studies demonstrated that our model can explain observed patterns, including temporal patterns of snakebite incidence, and relative contribution of bites by each snake species. Our predictions can be used to generate hypotheses and inform future studies and decision makers. Additionally, our model is transferable to other locations with high snakebite burden as well.
Publisher: Elsevier BV
Date: 08-2014
Publisher: Public Library of Science (PLoS)
Date: 12-05-2022
DOI: 10.1371/JOURNAL.PNTD.0009867
Abstract: Snakebite is the only WHO-listed, not infectious neglected tropical disease (NTD), although its eco-epidemiology is similar to that of zoonotic infections: envenoming occurs after a vertebrate host contacts a human. Accordingly, snakebite risk represents the interaction between snake and human factors, but their quantification has been limited by data availability. Models of infectious disease transmission are instrumental for the mitigation of NTDs and zoonoses. Here, we represented snake-human interactions with disease transmission models to approximate geospatial estimates of snakebite incidence in Sri Lanka, a global hotspot. Snakebites and envenomings are described by the product of snake and human abundance, mirroring directly transmitted zoonoses. We found that human-snake contact rates vary according to land cover (surrogate of occupation and socioeconomic status), the impacts of humans and climate on snake abundance, and by snake species. Our findings show that modelling snakebite as zoonosis provides a mechanistic eco-epidemiological basis to understand snakebites, and the possible implications of global environmental and demographic change for the burden of snakebite.
Publisher: Wiley
Date: 13-02-2023
DOI: 10.1002/EAP.2804
Abstract: Extensive land conversion to agriculture in drylands and associated resource use have wide‐ranging impacts on desert ecosystems globally. Incorporating the impacts of human‐social aspects is thus imperative in examining ecological interactions. The provision of agricultural inputs in these resource‐scarce regions supports invasive and pest species, negatively impacting both agricultural productivity and native desert ecosystems. Understanding the spatial dynamics of invasive and pest species requires analyzing both bottom‐up resource availability factors underlying animal distributions and top‐down biological controls. Here, we evaluate the social‐ecological cascading effects of dryland agriculture on vertebrate pest communities in dryland agricultural communities of Israel. Our study region is characterized by 18 agricultural cooperatives with distinct crop regimes due to contrasting social decision‐making and resource allocation schemes (i.e., communal kibbutzim vs. privatized moshavim). Crop choices further affect land management (e.g., enclosed vs. open farm systems) and resource intensity. This system is ideal for studying trophic mechanisms underlying animal assemblages between agricultural regimes. We examine the role of agricultural land‐use practices on pest spatial distributions based on multiyear vertebrate pest observations with agricultural data sets. We use structural equation modeling (SEM) to quantify the relative importance of added agricultural resources underlying bottom‐up and top‐down trophic processes regulating vertebrate pest assemblages. Results reveal that crop choices determine pest distributions through bottom‐up processes directly, while simultaneously driving pest competitive interactions through indirect top‐down cascades impacting pest communities. For ex le, due to the indirect negative effect of wolves on mesopredators (foxes and jackals) mediated by livestock, the total positive effect of livestock on the abundance of mesopredators is reduced. Our study illustrates the social‐ecological cascading effects of agricultural regimes on pest community assemblages mediated by contrasting agricultural land‐use practices. Considering the expansion of dryland agroecological systems globally, understanding the intricate cascading pathways of predator‐ and prey‐pest communities has important implications for agricultural management, biological invasions in drylands, and fragile desert environments.
Publisher: Wiley
Date: 12-06-2018
DOI: 10.1002/FEE.1824
Publisher: Wiley
Date: 17-11-2017
DOI: 10.1111/ECOG.02957
Publisher: Springer Science and Business Media LLC
Date: 12-06-2023
DOI: 10.1038/S41598-023-35452-6
Abstract: A major trade-off of land-use change is the potential for increased risk of infectious diseases, a.o. through impacting disease vector life-cycles. Evaluating the public health implications of land-use conversions requires spatially detailed modelling linking land-use to vector ecology. Here, we estimate the impact of deforestation for oil palm cultivation on the number of life-cycle completions of Aedes albopictus via its impact on local microclimates. We apply a recently developed mechanistic phenology model to a fine-scaled (50-m resolution) microclimate dataset that includes daily temperature, rainfall and evaporation. Results of this combined model indicate that the conversion from lowland rainforest to plantations increases suitability for A. albopictus development by 10.8%, moderated to 4.7% with oil palm growth to maturity. Deforestation followed by typical plantation planting-maturation-clearance-replanting cycles is predicted to create pulses of high development suitability. Our results highlight the need to explore sustainable land-use scenarios that resolve conflicts between agricultural and human health objectives.
Publisher: World Scientific Pub Co Pte Lt
Date: 2000
DOI: 10.1142/S0219525900000273
Abstract: The behaviour of traders in a stock market is influenced by their attitude toward the risk of the security. In this research the internal model of the risk-averse and the risk-loving trader is proposed in the context of the artificial market. This model is based on the ideas of the expected utility hypothesis. It is important to model the difference in subjective value of the same stock because this difference enables market activities. The feature of the proposed model is that this model realizes the dynamic aspect of trader's preference in the risk and the return.
Publisher: Public Library of Science (PLoS)
Date: 06-2021
DOI: 10.1371/JOURNAL.PNTD.0009447
Abstract: Snakebite incidence shows both spatial and temporal variation. However, no study has evaluated spatiotemporal patterns of snakebites across a country or region in detail. We used a nationally representative population s le to evaluate spatiotemporal patterns of snakebite in Sri Lanka. We conducted a community-based cross-sectional survey representing all nine provinces of Sri Lanka. We interviewed 165 665 people (0.8% of the national population), and snakebite events reported by the respondents were recorded. Sri Lanka is an agricultural country its central, southern and western parts receive rain mainly from Southwest monsoon (May to September) and northern and eastern parts receive rain mainly from Northeast monsoon (November to February). We developed spatiotemporal models using multivariate Poisson process modelling to explain monthly snakebite and envenoming incidences in the country. These models were developed at the provincial level to explain local spatiotemporal patterns. Snakebites and envenomings showed clear spatiotemporal patterns. Snakebite hotspots were found in North-Central, North-West, South-West and Eastern Sri Lanka. They exhibited biannual seasonal patterns except in South-Western inlands, which showed triannual seasonality. Envenoming hotspots were confined to North-Central, East and South-West parts of the country. Hotspots in North-Central regions showed triannual seasonal patterns and South-West regions had annual patterns. Hotspots remained persistent throughout the year in Eastern regions. The overall monthly snakebite and envenoming incidences in Sri Lanka were 39 (95%CI: 38–40) and 19 (95%CI: 13–30) per 100 000, respectively, translating into 110 000 (95%CI: 107 500–112 500) snakebites and 45 000 (95%CI: 32 000–73 000) envenomings in a calendar year. This study provides information on community-based monthly incidence of snakebites and envenomings over the whole country. Thus, it provides useful insights into healthcare decision-making, such as, prioritizing locations to establish specialized centres for snakebite management and allocating resources based on risk assessments which take into account both location and season.
Publisher: Elsevier BV
Date: 09-2021
Publisher: Elsevier BV
Date: 08-2016
Publisher: Springer Science and Business Media LLC
Date: 06-02-2023
Publisher: Elsevier BV
Date: 07-2021
Publisher: Public Library of Science (PLoS)
Date: 30-11-2010
Publisher: Wiley
Date: 03-2023
DOI: 10.1002/ECE3.9915
Abstract: Geology plays a fundamental role in establishing species' habitats, determining both physical (e.g., landscape morphology, soil texture) and chemical (e.g., mineral composition, water availability) properties. In the current Anthropocene epoch, human activity is transforming Earth's geology and ecosystems. Yet to date, there have been almost no studies incorporating geology when examining the effect of such land‐use changes on species distribution. This study seeks to uncover how specific land‐use changes interact with geology, in order to explain the recent and rapid expansion of the rock hyrax ( Procavia capensis ) across the mountains of central Israel and the West Bank. Hyraxes are dependent on rock mounds for their habitat, and their expansion seems to be correlated with increasing infrastructure construction. However, their expansion patterns differ among locations, even when the human land‐use is similar. To explain the patterns of hyrax distribution observed over the past 46 years, we converted geological data into ecological data, which present the probability of the local bedrock breaking into boulders, whether due to either natural or anthropogenic weathering processes. We applied species distribution models (SDMs) and found that the expansion of rock hyrax populations was facilitated by means of the interaction of specific geological units with land‐use practices (e.g., roads and construction), which resulted in the accumulation of large boulders, creating novel habitats and stepping stones in previously unsuitable areas for hyraxes. Since rock hyraxes are major hosts of the leishmaniasis pathogen, the findings from this study offer important insights into the progression and potential outbreaks of the disease in human populations. Understanding the role that geology plays in shaping a species' niche is expected to prove useful in studying the distribution of other wildlife species and is fundamental in studies seeking to predict the potential ecological impacts on local bio ersity associated with land‐use change.
Publisher: No publisher found
Date: 2019
DOI: 10.1111/CONL.12586
Publisher: The Royal Society
Date: 07-06-2015
Abstract: Implementation of adaptation actions to protect bio ersity is limited by uncertainty about the future. One reason for this is the fear of making the wrong decisions caused by the myriad future scenarios presented to decision-makers. We propose an adaptive management (AM) method for optimally managing a population under uncertain and changing habitat conditions. Our approach incorporates multiple future scenarios and continually learns the best management strategy from observations, even as conditions change. We demonstrate the performance of our AM approach by applying it to the spatial management of migratory shorebird habitats on the East Asian–Australasian flyway, predicted to be severely impacted by future sea-level rise. By accounting for non-stationary dynamics, our solution protects 25 000 more birds per year than the current best stationary approach. Our approach can be applied to many ecological systems that require efficient adaptation strategies for an uncertain future.
Publisher: Wiley
Date: 03-2016
DOI: 10.1002/FEE.1203
Publisher: Elsevier BV
Date: 02-2023
Publisher: American Association for the Advancement of Science (AAAS)
Date: 04-12-2009
Abstract: A model shows that REDD (reducing emissions from deforestation and degradation) can be extended to bio ersity conservation.
Publisher: Wiley
Date: 15-12-2023
DOI: 10.1111/COBI.14031
Abstract: Bio ersity offsets aim to counterbalance the residual impacts of development on species and ecosystems. Guidance documents explicitly recommend that bio ersity offset actions be located close to the location of impact because of higher potential for similar ecological conditions, but allowing greater spatial flexibility has been proposed. We examined the circumstances under which offsets distant from the impact location could be more likely to achieve no net loss or provide better ecological outcomes than offsets close to the impact area. We applied a graphical model for migratory shorebirds in the East Asian–Australasian Flyway as a case study to explore the problems that arise when incorporating spatial flexibility into offset planning. Spatially flexible offsets may alleviate impacts more effectively than local offsets however, the risks involved can be substantial. For our case study, there were inadequate data to make robust conclusions about the effectiveness and equivalence of distant habitat‐based offsets for migratory shorebirds. Decisions around offset placement should be driven by the potential to achieve equivalent ecological outcomes however, when considering more distant offsets, there is a need to evaluate the likely increased risks alongside the potential benefits. Although spatially flexible offsets have the potential to provide more cost‐effective bio ersity outcomes and more cobenefits, our case study showed the difficulty of demonstrating these benefits in practice and the potential risks that need to be considered to ensure effective offset placement.
Publisher: Springer Science and Business Media LLC
Date: 15-09-2013
DOI: 10.1038/NCLIMATE2007
Publisher: Cold Spring Harbor Laboratory
Date: 04-10-2021
DOI: 10.1101/2021.10.01.21264438
Abstract: Snakebite is the only WHO-listed, not infectious neglected tropical disease (NTD), although its eco-epidemiology is similar to that of zoonotic infections: envenoming occurs after a vertebrate host contacts a human. Accordingly, snakebite risk represents the interaction between snake and human factors, but their quantification has been limited by data availability. Models of infectious disease transmission are instrumental for the mitigation of NTDs and zoonoses. Here, we represented snake-human interactions with disease transmission models to approximate geospatial estimates of snakebite incidence in Sri Lanka, a global hotspot. Snakebites and envenomings are described by the product of snake and human abundance, mirroring directly transmitted zoonoses. We found that human-snake contact rates vary according to land cover (surrogate of occupation and socioeconomic status), the impacts of humans and climate on snake abundance, and by snake species. Our findings show that redefining snakebite as zoonosis provides a mechanistic eco-epidemiological basis to understand snakebites, and the possible implications of global environmental and demographic change for the burden of snakebite.
Publisher: Elsevier BV
Date: 11-2007
Publisher: Wiley
Date: 27-06-2014
DOI: 10.1111/COBI.12319
Abstract: Every year, millions of migratory shorebirds fly through the East Asian-Australasian Flyway between their arctic breeding grounds and Australasia. This flyway includes numerous coastal wetlands in Asia and the Pacific that are used as stopover sites where birds rest and feed. Loss of a few important stopover sites through sea-level rise (SLR) could cause sudden population declines. We formulated and solved mathematically the problem of how to identify the most important stopover sites to minimize losses of bird populations across flyways by conserving land that facilitates upshore shifts of tidal flats in response to SLR. To guide conservation investment that minimizes losses of migratory bird populations during migration, we developed a spatially explicit flyway model coupled with a maximum flow algorithm. Migratory routes of 10 shorebird taxa were modeled in a graph theoretic framework by representing clusters of important wetlands as nodes and the number of birds flying between 2 nodes as edges. We also evaluated several resource allocation algorithms that required only partial information on flyway connectivity (node strategy, based on the impacts of SLR at nodes habitat strategy, based on habitat change at sites population strategy, based on population change at sites and random investment). The resource allocation algorithms based on flyway information performed on average 15% better than simpler allocations based on patterns of habitat loss or local bird counts. The Yellow Sea region stood out as the most important priority for effective conservation of migratory shorebirds, but investment in this area alone will not ensure the persistence of species across the flyway. The spatial distribution of conservation investments differed enormously according to the severity of SLR and whether information about flyway connectivity was used to guide the prioritizations. With the rapid ongoing loss of coastal wetlands globally, our method provides insight into efficient conservation planning for migratory species.
Publisher: Public Library of Science (PLoS)
Date: 24-06-2014
Publisher: The Royal Society
Date: 22-06-2013
Abstract: Sea-level rise (SLR) will greatly alter littoral ecosystems, causing habitat change and loss for coastal species. Habitat loss is widely used as a measurement of the risk of extinction, but because many coastal species are migratory, the impact of habitat loss will depend not only on its extent, but also on where it occurs. Here, we develop a novel graph-theoretic approach to measure the vulnerability of a migratory network to the impact of habitat loss from SLR based on population flow through the network. We show that reductions in population flow far exceed the proportion of habitat lost for 10 long-distance migrant shorebirds using the East Asian–Australasian Flyway. We estimate that SLR will inundate 23–40% of intertidal habitat area along their migration routes, but cause a reduction in population flow of up to 72 per cent across the taxa. This magnifying effect was particularly strong for taxa whose migration routes contain bottlenecks—sites through which a large fraction of the population travels. We develop the bottleneck index , a new network metric that positively correlates with the predicted impacts of habitat loss on overall population flow. Our results indicate that migratory species are at greater risk than previously realized.
Publisher: Royal Zoological Society of New South Wales
Date: 2018
DOI: 10.7882/AZ.2017.042
Publisher: Elsevier BV
Date: 10-2013
Publisher: Public Library of Science (PLoS)
Date: 03-10-2019
Publisher: Springer Science and Business Media LLC
Date: 04-03-2021
DOI: 10.1038/S41598-021-83793-X
Abstract: The rapid pace of current global warming lead to the advancement of spring migration in the majority of long-distance migratory bird species. While data on arrival timing to breeding grounds in Europe is plentiful, information from the African departure sites are scarce. Here we analysed changes in arrival timing at a stopover site in Israel and any links to Enhanced Vegetation Index (EVI) on the species-specific African non-breeding range in three migratory passerines between 2000–2017. Differences in wing length between early and late arriving in iduals were also examined as a proxy for migration distance. We found that male redstart, but not females, advanced arrival to stopover site, but interestingly, not as a response to EVI phenology. Blackcap and barred warbler did not shift arrival timing significantly, although the arrival of blackcap was dependent on EVI. Barred warbler from the early arrival phase had longer wings, suggesting different populations. Our study further supports the existence species-specific migration decisions and inter-sexual differences, which may be triggered by both exogenous (local vegetation condition) and endogenous cues. Given rapid rate of changes in environmental conditions at higher latitudes, some migrants may experience difficulty in the race to match global changes to ensure their survival.
Publisher: Springer Science and Business Media LLC
Date: 05-2020
DOI: 10.1038/S41467-020-16010-4
Abstract: Vector-borne diseases remain a major contributor to the global burden of disease, while climate change is expected to exacerbate their risk. Characterising vector development rate and its spatio-temporal variation under climate change is central to assessing the changing basis of human disease risk. We develop a mechanistic phenology model and apply it to Aedes aegypti , an invasive mosquito vector for arboviruses (e.g. dengue, zika and yellow fever). The model predicts the number of life-cycle completions (LCC) for a given location per unit time based on empirically derived biophysical responses to environmental conditions. Results suggest that the world became ~1.5% more suitable per decade for the development of Ae. aegypti during 1950–2000, while this trend is predicted to accelerate to 3.2–4.4% per decade by 2050. Invasion fronts in North America and China are projected to accelerate from ~2 to 6 km/yr by 2050. An increase in peak LCC combined with extended periods suitable for mosquito development is simulated to accelerate the vector’s global invasion potential.
Publisher: Springer Science and Business Media LLC
Date: 14-05-2023
Publisher: Wiley
Date: 18-07-2017
DOI: 10.1111/COBI.13060
Publisher: American Association for the Advancement of Science (AAAS)
Date: 19-03-2010
Publisher: Wiley
Date: 19-11-2021
Abstract: Despite important implications for human health, distribution, abundance and behaviour of most medically relevant snakes remain poorly understood. Such data deficiencies h er efforts to characterise the causal pathways of snakebite envenoming and to prioritise management options in the areas at greatest risk. We estimated the spatial patterns of abundance of seven medically relevant snake species from Sri Lanka, a snakebite hotspot, and combined them with indices of species' relative abundance, aggressiveness and envenoming severity obtained from an expert opinion survey, to test whether these fundamental ecological traits could explain spatial patterns of snakebite and envenoming incidence. The spatial intensity of snake occurrence records in relation to independent environmental factors (fundamental niches and land cover) was analysed with point process models. Then, with the estimated patterns of abundance, we tested which species' abundances added together, with and without weightings for aggressiveness, envenoming severity and relative abundance, best correlate with per capita geographic incidence patterns of snakebite and envenoming. We found that weighting abundance patterns by species' traits increased correlation with incidence. The best performing combination had three species weighted by aggressiveness and abundance, with a correlation of r = 0.47 ( p 0.01) with snakebite incidence. An envenoming severity and relative abundance‐weighted combination of two species was the most strongly associated with envenoming incidence ( r = 0.46, p = 0). Synthesis and applications . We show that snakebite risk is explained by abundance, aggressiveness and envenoming severity of the snake species most frequently involved in envenoming cases. Incorporating causality via ecological information of key snake species is critical for snakebite risk mapping, helping to tailor preventive measures for dominant snake species and deploying the necessary antivenom therapies.
Publisher: Elsevier BV
Date: 02-2015
Publisher: Springer Science and Business Media LLC
Date: 18-01-2023
Publisher: Elsevier BV
Date: 2020
Publisher: Proceedings of the National Academy of Sciences
Date: 12-08-2008
Abstract: Global bio ersity priority setting underpins the strategic allocation of conservation funds. In identifying the first comprehensive set of global priority areas for mammals, Ceballos et al. [Ceballos G, Ehrlich PR, Soberón J, Salazar I, Fay JP (2005) Science 309:603–607] found much potential for conflict between conservation and agricultural human activity. This is not surprising because, like other global priority-setting approaches, they set priorities without socioeconomic objectives. Here we present a priority-setting framework that seeks to minimize the conflicts and opportunity costs of meeting conservation goals. We use it to derive a new set of priority areas for investment in mammal conservation based on ( i ) agricultural opportunity cost and bio ersity importance, ( ii ) current levels of international funding, and ( iii ) degree of threat. Our approach achieves the same bio ersity outcomes as Ceballos et al.' s while reducing the opportunity costs and conflicts with agricultural human activity by up to 50%. We uncover shortfalls in the allocation of conservation funds in many threatened priority areas, highlighting a global conservation challenge.
No related grants have been discovered for Takuya Iwamura.