9 research outputs found

    Pollen metabarcoding reveals broad and species-specific resource use by urban bees

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    Bee populations are currently undergoing severe global declines driven by the interactive effects of a number of factors. Ongoing urbanisation has the potential to exacerbate bee declines, unless steps are taken to ensure appropriate floral resources are available. Sown wildflower strips are one way in which floral resources can be provided to urban bees. However, the use of these strips by pollinators in urban environments remains little studied. Here, we employ pollen metabarcoding of the rbcL gene to compare the foraging patterns of different bee species observed using urban sown wildflower strips in July 2016, with a goal of identifying which plant species are most important for bees. We also demonstrate the use of a non-destructive method of pollen collection. Bees were found to forage on a wide variety of plant genera and families, including a diverse range of plants from outside the wildflower plots, suggesting that foragers visiting sown wildflower strips also utilize other urban habitats. Particular plants within the wildflower strips dominated metabarcoding data, particularly Papaver rhoeas and Phacelia tanacetifolia. Overall, we demonstrate that pollinators observed in sown wildflower strips use certain sown foodplants as part of a larger urban matrix

    Increased vigilance of paired males in sexually dimorphic species: distinguishing between alternative explanations in wintering Eurasian wigeon

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    In animal pairs, males are often more vigilant than females. This is generally assumed to result from mate guarding (either against predators or other males). However, when males have conspicuous secondary sexual characteristics, they could be constrained to be more vigilant because of a higher predation risk than females. We attempted to distinguish between the "male constraint hypothesis" and two variations of the mate-guarding hypothesis by studying the vigilance behavior of the sexually dimorphic wigeon during early winter, when some males are in breeding plumage and some are not and when not all males are paired. The proportion of time spent vigilant by paired males in breeding plumage was five times higher than any other category of males or females. We found no significant differences between the vigilance levels of unpaired male wigeon in cryptic and in breeding plumage and therefore rejected the male constraint hypothesis. As vigilance levels of paired and unpaired females did not differ either, we rejected the hypothesis that paired males invest in vigilance to reduce their mate's need to be vigilant to predation risks. Paired females interacted less frequently with other wigeon than unpaired ones, and it is probably to protect their female from other males that paired male wigeon increase their vigilance times. Copyright 2003.

    Techniques for evaluating the spatial behaviour of river fish

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    Radio-tagging is widely used for studies of movements, resource use and demography of land vertebrates, with potential to combine such data for predictive modelling of populations from individuals. Such modelling requires standard measures of individual space use, for combination with data on resources, survival, dispersal and breeding. This paper describes how protocols for efficient collection of space-use data can be developed during a pilot study, and reviews the ways in which such data can be used for space-use indices that help answer biological questions, with examples from a study of riverine pike (Esox lucius). Analyses of diurnal activity and spatio-temporal correlation were used to assess when to record locations, and analyses of home range increments were used to define the number of location records necessary to assess seasonal ranges. We stress the importance of developing protocols that use minimal numbers of locations from each individual, so that analyses can be based on samples of many individuals. The efficacy of link-distance (e.g. cluster analysis) and location density (e.g. contouring) techniques for spatial analysis for river fish were compared, and the utility of clipping off areas to river banks was assessed. In addition, a new automated analysis was used to estimate distances along river mid-lines. These techniques made it possible to quantify interactions between individuals and their habitat: including a significant increase in core range size during floods, significant preference for deep pools, and a lack of exclusive territories

    Using clinical research networks to assess severity of an emerging influenza pandemic

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    BACKGROUND: Early clinical severity assessments during the 2009 influenza A H1N1 pandemic (pH1N1) overestimated clinical severity due to selection bias and other factors. We retrospectively investigated how to use data from the International Network for Strategic Initiatives in Global HIV Trials, a global clinical influenza research network, to make more accurate case fatality ratio (CFR) estimates early in a future pandemic, an essential part of pandemic response. METHODS: We estimated the CFR of medically attended influenza (CFRMA) as the product of probability of hospitalization given confirmed outpatient influenza and the probability of death given hospitalization with confirmed influenza for the pandemic (2009-2011) and post-pandemic (2012-2015) periods. We used literature survey results on health-seeking behavior to convert that estimate to CFR among all infected persons (CFRAR). RESULTS: During the pandemic period, 5.0% (3.1%-6.9%) of 561 pH1N1-positive outpatients were hospitalized. Of 282 pH1N1-positive inpatients, 8.5% (5.7%-12.6%) died. CFRMA for pH1N1 was 0.4% (0.2%-0.6%) in the pandemic period 2009-2011 but declined 5-fold in young adults during the post-pandemic period compared to the level of seasonal influenza in the post-pandemic period 2012-2015. CFR for influenza-negative patients did not change over time. We estimated the 2009 pandemic CFRAR to be 0.025%, 16-fold lower than CFRMA. CONCLUSIONS: Data from a clinical research network yielded accurate pandemic severity estimates, including increased severity among younger people. Going forward, clinical research networks with a global presence and standardized protocols would substantially aid rapid assessment of clinical severity

    Containment measures

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    OBSOLETE (project finished) - Description of containment measures during COVID'19 lockdown, in the context of SIlent Cities project. Please request access to Silent Cities if neede

    Archived - General Information (DO NOT USE)

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    DO NOT USE - The goal of this component was to document the data collection process of the Silent Cities Dataset. This component is just left for archive
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