WorldWideScience

Sample records for modelling bird impacts

  1. Development of a practical modeling framework for estimating the impact of wind technology on bird populations

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, M.L. [California State Univ., Sacramento, CA (United States); Pollock, K.H. [North Carolina State Univ., Raleigh, NC (United States)

    1997-11-01

    One of the most pressing environmental concerns related to wind project development is the potential for avian fatalities caused by the turbines. The goal of this project is to develop a useful, practical modeling framework for evaluating potential wind power plant impacts that can be generalized to most bird species. This modeling framework could be used to get a preliminary understanding of the likelihood of significant impacts to birds, in a cost-effective way. The authors accomplish this by (1) reviewing the major factors that can influence the persistence of a wild population; (2) briefly reviewing various models that can aid in estimating population status and trend, including methods of evaluating model structure and performance; (3) reviewing survivorship and population projections; and (4) developing a framework for using models to evaluate the potential impacts of wind development on birds.

  2. Development of a practical modeling framework for estimating the impact of wind technology on bird populations

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, M.L. [California State Univ., Sacramento, CA (United States); Pollock, K.H. [North Carolina State Univ., Raleigh, NC (United States)

    1997-11-01

    One of the most pressing environmental concerns related to wind project development is the potential for avian fatalities caused by the turbines. The goal of this project is to develop a useful, practical modeling framework for evaluating potential wind power plant impacts that can be generalized to most bird species. This modeling framework could be used to get a preliminary understanding of the likelihood of significant impacts to birds, in a cost-effective way. The authors accomplish this by (1) reviewing the major factors that can influence the persistence of a wild population; (2) briefly reviewing various models that can aid in estimating population status and trend, including methods of evaluating model structure and performance; (3) reviewing survivorship and population projections; and (4) developing a framework for using models to evaluate the potential impacts of wind development on birds.

  3. Bird Avoidance Model

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is an unpublished report on the bird avoidance model to predict bird strike hazards with low flying aircraft. Included is peak periods for different species of...

  4. Life History Traits and Niche Instability Impact Accuracy and Temporal Transferability for Historically Calibrated Distribution Models of North American Birds.

    Science.gov (United States)

    Wogan, Guinevere O U

    2016-01-01

    A primary assumption of environmental niche models (ENMs) is that models are both accurate and transferable across geography or time; however, recent work has shown that models may be accurate but not highly transferable. While some of this is due to modeling technique, individual species ecologies may also underlie this phenomenon. Life history traits certainly influence the accuracy of predictive ENMs, but their impact on model transferability is less understood. This study investigated how life history traits influence the predictive accuracy and transferability of ENMs using historically calibrated models for birds. In this study I used historical occurrence and climate data (1950-1990s) to build models for a sample of birds, and then projected them forward to the 'future' (1960-1990s). The models were then validated against models generated from occurrence data at that 'future' time. Internal and external validation metrics, as well as metrics assessing transferability, and Generalized Linear Models were used to identify life history traits that were significant predictors of accuracy and transferability. This study found that the predictive ability of ENMs differs with regard to life history characteristics such as range, migration, and habitat, and that the rarity versus commonness of a species affects the predicted stability and overlap and hence the transferability of projected models. Projected ENMs with both high accuracy and transferability scores, still sometimes suffered from over- or under- predicted species ranges. Life history traits certainly influenced the accuracy of predictive ENMs for birds, but while aspects of geographic range impact model transferability, the mechanisms underlying this are less understood.

  5. 14 CFR 35.36 - Bird impact.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bird impact. 35.36 Section 35.36... STANDARDS: PROPELLERS Tests and Inspections § 35.36 Bird impact. The applicant must demonstrate, by tests or... 4-pound bird at the critical location(s) and critical flight condition(s) of a typical installation...

  6. Study of Similarity Law for Bird Impact on Structure

    Institute of Scientific and Technical Information of China (English)

    Li Yulong; Zhang Yongkang; Xue Pu

    2008-01-01

    With dimensional analysis and similarity theory, the model similarity law of aircraft structures under bird impact load is investi-gated. Numerical calculations by means of nonlinear dynamic software ANSYS/LS-DYNA are conducted on the finite element models constructed with different scaling factors. The influence of strain rate on the model similarity law is found to be dependent on the swain rate sensitivity of materials and scale factors. Specifically, materials that are not sensitive to strain rate obey the model similarity law in the bird impact process. The conclusions obtained are supposed to provide a theoretical basis for the experimental work of bird impact on aircraft structure.

  7. Linking turbine collision risks with population models to assess cumulative impacts of multiple wind farms on threatened birds

    Energy Technology Data Exchange (ETDEWEB)

    Smales, Ian; Muir, Stuart; Meredith, Charles; Baird, Robert

    2011-07-01

    Full text: Assessment of the effects on birds of wind turbine collisions has generally been focussed on the number of individuals that might be killed at a particular facility. However, this measure, of itself, may have little relevance to evaluating the potential or real effects on conservation status of threatened species. Determination of the overall effect any such mortality may have on the functioning of these populations will provide a better basis for decisions that have a strong foundation in ecology. For species with sufficient demographic information, we have developed and applied an approach combining collision risk modelling for all wind farms within the range of a threatened species with population modelling. This permits population-level evaluation of potential cumulative impacts of multiple wind farms. In Australia, regulatory authorities are increasingly interested in the cumulative risk to threatened species that may be posed by multiple wind energy facilities within a species. range. The approach outlined here has been applied in the pre-construction approval stage using collision risk modelling, and can be applied to operational facilities using data on actual mortalities. Cumulative modelling of risk posed by multiple wind farms requires different approaches for sedentary and migratory species. For sedentary species the cumulative effect will be the sum of the impact experienced by those parts of the population whose range intersects with wind farms. Cumulative impact is derived for migratory species by assessing the probability of birds surviving encounters with one wind farm after another on the migratory route and is thus the product of their survivorship rates for the relevant wind farms. The collision risk modelling used will be outlined along with the method in which it is integrated with a population model. Case studies for a crane (Brolga Grus rubicundus) and a parrot (orange- bellied parrot Neophema chrysogaster) species will be

  8. Bird beaks bear the brunt of bashing impact

    Science.gov (United States)

    Sharker, Saberul Islam; Holekamp, Sean; Fish, Frank; Belden, Jesse; Truscott, Tadd

    2016-11-01

    Seabirds can dive from 30 meters reaching speeds of 24 meters per second as they impact the water reaching depths of 9 meters due to their momentum, and a further 25 meters by active flapping. It is thought that their geometry, particularly the beak, allows them to endure relatively high impact forces that could kill non-diving birds. Acceleration data of simplified models of diving birds agree with simulated data for one species, however, no reliable experimental data with real bird geometries exist for comparison. We experimentally measured the impact accelerations of twelve 3D printed models of diving birds (seven surface diving and five plunge diving) during water-entry at different impact velocities using accelerometers.

  9. Numerical simulation of a rotary engine primary compressor impacted by bird

    Institute of Scientific and Technical Information of China (English)

    Liu Jun; Li Yulong

    2013-01-01

    In order to examine the process of a rotary engine primary compressor impacted by bird,a finite element model of a bird impacted on plate is developed with the explicit code PAM-CRASH.The smooth particles hydrodynamic (SPH) method is used to simulate the bird because of the SPH method showing no signs of instability and correctly modeling the breaking-up of the bird into particles.Good agreement between the simulation results and experimental results indicates that the numerical method of bird strike used in the present paper is reasonable.Then a rotary engine primary compressor impacted by three different configurations bird named straight-ended cylinder bird,quadrangular bird,hemispherical-ended bird are investigated using the numerical simulation method.It is found that the whole process of bird strike sustained about 3.5 ms and the bird is slashed by blade during the strike.The geometry configuration of bird affected the displacement and von Mises stress of some blades severely,just because the breaking bird's mass is affected by the bird's configuration.In the event of bird striking on the site of"up" some blades may develop plastic deformation and it is very adverse for the safety work of the engine.

  10. Predicting the impacts of bioenergy production on farmland birds.

    Science.gov (United States)

    Rivas Casado, Monica; Mead, Andrew; Burgess, Paul J; Howard, David C; Butler, Simon J

    2014-04-01

    Meeting European renewable energy production targets is expected to cause significant changes in land use patterns. With an EU target of obtaining 20% of energy consumption from renewable sources by 2020, national and local policy makers need guidance on the impact of potential delivery strategies on ecosystem goods and services to ensure the targets are met in a sustainable manner. Within agroecosystems, models are available to explore consequences of such policy decisions for food, fuel and fibre production but few can describe the effect on biodiversity. This paper describes the integration and application of a farmland bird population model within a geographical information system (GIS) to explore the consequences of land use changes arising from different strategies to meet renewable energy production targets. Within a 16,000 ha arable dominated case study area in England, the population growth rates of 19 farmland bird species were predicted under baseline land cover, a scenario maximising wheat production for bioethanol, and a scenario focused on mix of bioenergy sources. Both scenarios delivered renewable energy production targets for the region (>12 kWh per person per day) but, despite differences in resultant landscape composition, the response of the farmland bird community as a whole to each scenario was small and broadly similar. However, this similarity in overall response masked significant intra- and inter-specific variations across the study area and between scenarios suggesting contrasting mechanisms of impact and highlighting the need for context dependent, species-level assessment of land use change impacts. This framework provides one of the first systematic attempts to spatially model the effect of policy driven land use change on the population dynamics of a suite of farmland birds. The GIS framework also facilitates its integration with other ecosystem service models to explore wider synergies and trade offs arising from national or local

  11. FE Analysis of Dynamic Response of Aircraft Windshield against Bird Impact

    Directory of Open Access Journals (Sweden)

    Uzair Ahmed Dar

    2013-01-01

    Full Text Available Bird impact poses serious threats to military and civilian aircrafts as they lead to fatal structural damage to critical aircraft components. The exposed aircraft components such as windshields, radomes, leading edges, engine structure, and blades are vulnerable to bird strikes. Windshield is the frontal part of cockpit and more susceptible to bird impact. In the present study, finite element (FE simulations were performed to assess the dynamic response of windshield against high velocity bird impact. Numerical simulations were performed by developing nonlinear FE model in commercially available explicit FE solver AUTODYN. An elastic-plastic material model coupled with maximum principal strain failure criterion was implemented to model the impact response of windshield. Numerical model was validated with published experimental results and further employed to investigate the influence of various parameters on dynamic behavior of windshield. The parameters include the mass, shape, and velocity of bird, angle of impact, and impact location. On the basis of numerical results, the critical bird velocity and failure locations on windshield were also determined. The results show that these parameters have strong influence on impact response of windshield, and bird velocity and impact angle were amongst the most critical factors to be considered in windshield design.

  12. Avian Information Systems: Developing Web-Based Bird Avoidance Models

    Directory of Open Access Journals (Sweden)

    Judy Shamoun-Baranes

    2008-12-01

    Full Text Available Collisions between aircraft and birds, so-called "bird strikes," can result in serious damage to aircraft and even in the loss of lives. Information about the distribution of birds in the air and on the ground can be used to reduce the risk of bird strikes and their impact on operations en route and in and around air fields. Although a wealth of bird distribution and density data is collected by numerous organizations, these data are not readily available nor interpretable by aviation. This paper presents two national efforts, one in the Netherlands and one in the United States, to develop bird avoidance nodels for aviation. These models integrate data and expert knowledge on bird distributions and migratory behavior to provide hazard maps in the form of GIS-enabled Web services. Both models are in operational use for flight planning and flight alteration and for airfield and airfield vicinity management. These models and their presentation on the Internet are examples of the type of service that would be very useful in other fields interested in species distribution and movement information, such as conservation, disease transmission and prevention, or assessment and mitigation of anthropogenic risks to nature. We expect that developments in cyber-technology, a transition toward an open source philosophy, and higher demand for accessible biological data will result in an increase in the number of biological information systems available on the Internet.

  13. Foreign Object Damage to Fan Rotor Blades of Aeroengine Part Ⅱ: Numerical Simulation of Bird Impact

    Institute of Scientific and Technical Information of China (English)

    Guan Yupu; Zhao Zhenhua; Chen Wei; Gao Deping

    2008-01-01

    Bird impact is one of the most dangerous threats to flight safety. The consequences of bird impact can be severe and, therefore, the aircraft components have to be certified for a proven level of bird impact resistance before being put into service. The fan rotor blades of aeroengine are the components being easily impacted by birds. It is necessary to ensure that the fan rotor blades should have adequate resistance against the bird impact, to reduce the flying accidents caused by bird impacts. Using the contacting-impacting algorithm, the numerical simulation is carried out to simulate bird impact. A three-blade computational model is set up for the fan rotor blade having shrouds. The transient response curves of the points corresponding to measured points in experiments, displacements and equivalent stresses on the blades are obtained during the simulation. From the comparison of the transient response curves obtained from numerical simulation with that obtained from experiments, it can be found that the variations in measured points and the corresponding points of simulation are basically the same. The deforming process, the maximum displacements and the maximum equivalent stresses on blades are analyzed. The numerical simulation verifies and complements the experiment results.

  14. Avian information systems: Developing web-based bird avoidance models

    NARCIS (Netherlands)

    Shamoun-Baranes, J.; Bouten, W.; Buurma, L.; DeFusco, R.; Dekker, A.; Sierdsema, H.; Sluiter, F.; van Belle, J.; van Gasteren, H.; van Loon, E.

    2008-01-01

    Collisions between aircraft and birds, so-called "bird strikes," can result in serious damage to aircraft and even in the loss of lives. Information about the distribution of birds in the air and on the ground can be used to reduce the risk of bird strikes and their impact on operations en route and

  15. Impact of estuarine pollution on birds

    Science.gov (United States)

    Blus, L.J.; Wiemeyer, Stanley N.; Kerwin, J.A.; Stendell, R.C.; Ohlendorf, H.M.; Stickel, L.F.

    1977-01-01

    Pollution of estuaries affects bird populations indirectly through changes in habitat and food supply. The multi-factor pollution of Chesapeake Bay has resulted in diminution of submerged aquatic plants and consequent change in food habits of the canvasback duck. Although dredge-spoil operations can improve wildlife habitat, they often result in its demise. Pollution of estuaries also affects birds directly, through chemical toxication, which may result in outright mortality or in reproductive impairment. Lead from industrial sources and roadways enters the estuaries and is accumulated in tissues of birds. Lead pellets deposited in estuaries as a result of hunting are consumed by ducks with sufficient frequency .to result m large annual die-offs from lead poisoning. Fish in certain areas, usually near industrial sources, may contain levels of mercury high enough to be hazardous to birds that consume them. Other heavy metals are present in estuarine birds, but their significance is poorly known. Oil exerts lethal or sublethal effects on birds by oiling their feathers, oiling eggs and young by contaminated parents, and by ingestion of oil-contaminated food. Organochlorine chemicals, of both agricultural and industrial origin, travel through the food chains and reach harmful levels in susceptible species of birds in certain estuarine ecosystems. Both outright mortality and reproductive impairment have occurred.

  16. The impact of West Nile virus on the abundance of selected North American birds.

    Science.gov (United States)

    Foppa, Ivo M; Beard, Raphaelle H; Mendenhall, Ian H

    2011-08-11

    The emergence of West Nile virus (WNV) in North America has been associated with high mortality in the native avifauna and has raised concerns about the long-term impact of WNV on bird populations. Here, we present results from a longitudinal analysis of annual counts of six bird species, using North American Breeding Bird Survey data from ten states (1994 to 2010). We fit overdispersed Poisson models to annual counts. Counts from successive years were linked by an autoregressive process that depended on WNV transmission intensity (annual West Nile neuroinvasive disease reports) and was adjusted by El Niño Southern Oscillation events. These models were fit using a Markov chain Monte Carlo algorithm. Model fit was mostly excellent, especially for American Crows, for which our models explained between 26% and 81% of the observed variance. The impact of WNV on bird populations was quantitatively evaluated by contrasting hypothetical count trajectories (omission of WNV) with observed counts. Populations of American crows were most consistently affected with a substantial cumulative impact in six of ten states. The largest negative impact, almost 60%, was found in Illinois. A regionally substantial decline was also seen for American Robins and House Sparrows, while the other species appeared unaffected. Our results confirm findings from previous studies that single out American Crows as the species most vulnerable to WNV infection. We discuss strengths and limitations of this and other methods for quantifying the impact of WNV on bird populations.

  17. The impact of West Nile virus on the abundance of selected North American birds

    Directory of Open Access Journals (Sweden)

    Beard Raphaelle H

    2011-08-01

    Full Text Available Abstract Background The emergence of West Nile virus (WNV in North America has been associated with high mortality in the native avifauna and has raised concerns about the long-term impact of WNV on bird populations. Here, we present results from a longitudinal analysis of annual counts of six bird species, using North American Breeding Bird Survey data from ten states (1994 to 2010. We fit overdispersed Poisson models to annual counts. Counts from successive years were linked by an autoregressive process that depended on WNV transmission intensity (annual West Nile neuroinvasive disease reports and was adjusted by El Niño Southern Oscillation events. These models were fit using a Markov chain Monte Carlo algorithm. Results Model fit was mostly excellent, especially for American Crows, for which our models explained between 26% and 81% of the observed variance. The impact of WNV on bird populations was quantitatively evaluated by contrasting hypothetical count trajectories (omission of WNV with observed counts. Populations of American crows were most consistently affected with a substantial cumulative impact in six of ten states. The largest negative impact, almost 60%, was found in Illinois. A regionally substantial decline was also seen for American Robins and House Sparrows, while the other species appeared unaffected. Conclusions Our results confirm findings from previous studies that single out American Crows as the species most vulnerable to WNV infection. We discuss strengths and limitations of this and other methods for quantifying the impact of WNV on bird populations.

  18. The impact of hunting on tropical mammal and bird populations

    NARCIS (Netherlands)

    Benítez-López, A.; Alkemade, R.; Schipper, A. M.; Ingram, D. J.; Verweij, P. A.; Eikelboom, J. A. J.; Huijbregts, M. A. J.

    2017-01-01

    As the human population grows and increasingly encroaches on remaining wildlife habitat, hunting threatens many species. Benítez-López et al. conducted a large-scale meta-analysis of hunting trends and impacts across the tropics (see the Perspective by Brashares and Gaynor). Bird and mammal

  19. Recommended protocols for monitoring impacts of wind turbines on birds

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-04-15

    The behaviour of birds in relation to turbine locations are routinely monitored to determine risk factors. Baseline information is typically gathered on birds that reside or migrate through an area to be developed. The purpose of this document was to provide proponents of wind turbine projects with information on the types of protocols likely to be used for baseline studies and follow-up monitoring at proposed wind turbine sites in order to evaluate the impacts of wind turbines on birds. It is intended to facilitate the comparison of data among wind power projects. In order to meet federal environmental assessment requirements, proponents may also be required to follow-up on the actual impact of the installation on birds. This document described methods for collecting field data as well as pre-construction baseline sample methods that might be expected as part of the Environmental Impact Assessment process. Follow-up monitoring should be undertaken during the breeding season, non-breeding season, and at offshore locations. This document also discussed the need to monitor prospective wind turbine sites to determine whether any of the sites present an elevated risk for substantial bat mortality. An overview of post-construction follow-up studies was also provided for carcass searches and collision studies. Details on some of the sampling protocols that are likely to be appropriate for bird monitoring in the context of wind turbine environmental assessment were presented with reference to searches, standardized area searches, distance sampling, behavioural studies, point counts, microphone point counts, playback counts, stopover counts, passage migration counts, acoustic monitoring of migrating birds, radar monitoring, carcass searches, and estimating collisions using other methods. This document also included codes for breeding evidence and a sample data sheet for ten minute point counts. 3 appendices.

  20. Characterization of Bird Impacts on a Rigid Plate: Part 1

    Science.gov (United States)

    1975-01-01

    velocity 40 1. 27cm off center of impact. Prscinng page Madh vii r _ _ AFrFDL-TR-IS-5 LIST OF ILLUSTRATIONS (CON TD ) FIGURE PAGE 21. Impulse...velocity 234 rn/s ! I Shot No. 5190; velocity 129 m/1" B-9 AFFDL-TR-75-S APPENDIX C BIRD IMPACT CINE SEQUENCES AFFDL-TR-75-5 museu. woman nams.UUS Nae womenU

  1. EXPERIMENTAL AND FEM STUDY OF WINDSHIELD SUBJECTED TO HIGH SPEED BIRD IMPACT

    Institute of Scientific and Technical Information of China (English)

    杨嘉陵; 蔡序杰; 武存浩

    2003-01-01

    Both experimental and finite element model (FEM) results are presented for the dynamic strength behavior of windshield subjected to bird impact. The experimental data taken from a series of high speed photographs are compared with the numerical results predicted by using FEM in which the windshield was modeled entirely with solid elements and the bird body was approximately simulated by an elastic-plastic material with failure element behavior. Effective plastic strain and element pressure were adopted as the failure criteria and once the pressure or the effective plastic strain of an element reached the critical value, the element would lose the tensile resistance capability completely. The deflection and stress distribution in the windshield were obtained. It is shown that the result from the finite element analysis agrees with those from the full-scale bird impact test.

  2. 基于SPH方法的LY12-CZ铝合金平板鸟撞模型%Model of bird impact on LY12-CZ aluminum alloy plate based on SPH

    Institute of Scientific and Technical Information of China (English)

    张鼎逆; 上官倩芡; 刘富

    2016-01-01

    To obtain the accurate analysis model of bird impact for aircraft structures,the numerical model of bird impact on LY1 2-CZ aluminum alloy flat plates was established based on the explicit finite element code of PAM-CRASH.Johnson-Cook equation was adopted to describe the constitutive model of LY1 2-CZ aluminum alloy.The stress-strain curves at 4 different strain rates of LY1 2-CZ were measured by dynamic tensile tests using electronic universal testing machine and split Hopkinson tensile bar (SHTB),and four constants in Johnson-Cook equation were fitted.Bird was modeled by smooth particle hydrodynamics (SPH ) method,and Monaghan EOS equation was introduced to simulate the bird material.Two corresponding bird impact experiments were implemented,and the strains of testing points were obtained.The calculation results were compared with the bird impact experimental results.The results show that the good agreement between numerical calculation and experimental results is obtained, which illuminates the bird constitutive model,the aluminum alloy constitutive model and the calculation method for high speed are reasonable and reliable.%为了得到更准确的飞机鸟撞分析模型,基于显式有限元分析程序PAM-CRASH建立了LY12-CZ铝合金平板的鸟撞数值模型.采用Johnson-Cook方程表述LY12-CZ材料的本构.LY12-CZ铝合金在4种不同应变率下的应力应变曲线通过电子万能试验机和分离式霍普金森拉杆(SHTB)拉伸试验获得,对曲线进行拟合得到Johnson-Cook 方程中的4个常数.基于光滑粒子流体动力学(SPH)方法建立了鸟体模型,引入Monaghan EOS 方程来描述鸟体材料.针对所建立的鸟撞数值计算模型,开展相对应的鸟撞试验,获得测试点的应变,并将数值计算结果和试验结果进行对比.结果表明:计算应变与试验测得的应变吻合较好,验证了鸟体、铝合金本构模型以及鸟体高速冲击计算分析模型的合理性、可靠性.

  3. High-Velocity Impact Behaviour of Prestressed Composite Plates under Bird Strike Loading

    Directory of Open Access Journals (Sweden)

    Sebastian Heimbs

    2012-01-01

    Full Text Available An experimental and numerical analysis of the response of laminated composite plates under high-velocity impact loads of soft body gelatine projectiles (artificial birds is presented. The plates are exposed to tensile and compressive preloads before impact in order to cover realistic loading conditions of representative aeronautic structures under foreign object impact. The modelling methodology for the composite material, delamination interfaces, impact projectile, and preload using the commercial finite element code Abaqus are presented in detail. Finally, the influence of prestress and of different delamination modelling approaches on the impact response is discussed and a comparison to experimental test data is given. Tensile and compressive preloading was found to have an influence on the damage pattern. Although this general behaviour could be predicted well by the simulations, further numerical challenges for improved bird strike simulation accuracy are highlighted.

  4. Recommended protocols for monitoring impacts of wind turbines on birds

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-28

    The proponent of a wind-powered generating station may be required to gather baseline information on birds that reside or migrate through the area to be developed. Proponents may also be required follow-up on the actual impact of the installation on the birds in order to fulfil the requirements of a federal environmental assessment. In order to evaluate impacts of wind turbines on birds, information was provided to proponents on the types of protocols likely to be useful for baseline studies and follow-up monitoring at proposed wind turbine sites. Uses of the document, field data collection, and reporting requirements were first discussed, followed by a detailed discussion of pre-construction baseline sample methods that might be expected as part of the Environmental Impact Assessment process. This information was presented according to monitoring during breeding season, non-breeding season, and offshore locations. Monitoring prospective wind turbine sites to determine whether any of the sites present an elevated risk for substantial bat mortality was also discussed. An overview of post-construction follow-up studies was provided for breeding season, non-breeding season, carcass searches and collision studies. The first appendix provided further details on some of the sampling protocols that are likely to be appropriate for bird monitoring in the context of wind turbine environmental assessment. These include area searches, standardized area searches, distance sampling, behavioural studies, point counts, microphone point counts, playback counts, stopover counts, passage migration counts, acoustic monitoring of migrating birds, radar monitoring, carcass searches, and estimating collisions using other methods. Codes for breeding evidence and a sample data sheet for ten minute point counts were also provides in appendices. 3 appendices.

  5. Bird impact at aircraft structure - Damage analysis using Coupled Euler Lagrangian Approach

    Science.gov (United States)

    Smojver, I.; Ivancevic, D.

    2010-06-01

    Numerical bird strike damage prediction procedure has been applied on the very detailed large airplane secondary structure consisting of sandwich, composite and metallic structural items. The impacted inboard flap finite element model is modelled using 3D, shell and continuum shell elements, coupled with appropriate kinematic constraints. The bird has been modelled using Coupled Euler Lagrangian approach, in order to avoid the numerical difficulties connected with mesh distortion. Various failure modes, such as Carbon Fibre Reinforced Plastics (CFRP) face layer rupture, failure of composite matrix, damage initiation / evolution in the sandwich structure Nomex core and elastoplastic failure of a metallic structure have been investigated. Besides, general contact has been applied as to efficiently capture the contact between Eulerian bird material and the structure, as well as large deformations of the different structural components. Compared to the classic Lagrangian modelling of the bird, the analysis has proven to be more stable, and the results, such as damage areas, physically more realistic. The impact has been applied in the area that is the most probably subjected to the impact damage during exploitation.

  6. Assessing impacts of wind turbines on birds through the Canadian environmental impact assessment process

    Energy Technology Data Exchange (ETDEWEB)

    Francis, C.M. [Canadian Wildlife Service, Ottawa, ON (Canada)

    2006-07-01

    While Environment Canada recognizes the benefits of wind power as a source of renewable energy, the adverse impacts of wind turbines on wildlife must be addressed. This presentation discussed the role of the Canadian Wildlife Service (CWS) in developing environmental guidelines for wind energy systems. The CWS is actively involved in the protection of migratory birds protected under the Migratory Bird Treaty Act, as well as species at risk as listed under SARA. In order to aid in federal environmental assessment processes, the CWS is now preparing a guidance document that summarizes the potential impacts of wind turbines on migratory birds and highlights risk factors that should be considered by proponents. The document may be used to determine whether site sensitivity for planned wind farms is high for birds, which include species at risk; large breeding colonies; major concentrations of birds; and important bird areas. High levels of concern will generally anticipate a need for stronger evidence that environmental effects will be minimal. Most wind power projects will require pre-construction monitoring for a one-year period in order to estimate potential adverse impacts and identify possible mitigation measures. Breeding bird surveys may be conducted to determine the presence of species and their relative abundance, as well as to determine the behaviour of birds in relation to the proposed turbine locations. Post-construction monitoring may also be conducted from 1 to 3 years, depending on the risk factors. It was concluded that the recommended protocols for monitoring impacts of wind turbines on birds will also facilitate comparison of data among wind power projects. Targeted research projects are also being conducted by the CWS to improve efficiency of carcass searching, and understanding migration patterns and concentration sites. refs., tabs., figs.

  7. The Netherlands Bird Avoidance Model, Final Report

    NARCIS (Netherlands)

    Shamoun-Baranes, J.; Bouten, W.; Sierdsema, H.; van Belle, J.; van Gasteren, J.R.; van Loon, E.E.

    2006-01-01

    The NL-BAM was developed as a web-based decision support tool to be used by the bird hazard avoidance experts in the ecology unit of the Royal Netherlands Air Force. The NL-BAM will be used together with the ROBIN 4 radar system to provide BirdTAMS, for real time warnings and flight planning and to

  8. Modeling Bird Migration under Climate Change: A Mechanistic Approach

    Science.gov (United States)

    Smith, James A.

    2009-01-01

    How will migrating birds respond to changes in the environment under climate change? What are the implications for migratory success under the various accelerated climate change scenarios as forecast by the Intergovernmental Panel on Climate Change? How will reductions or increased variability in the number or quality of wetland stop-over sites affect migratory bird species? The answers to these questions have important ramifications for conservation biology and wildlife management. Here, we describe the use of continental scale simulation modeling to explore how spatio-temporal changes along migratory flyways affect en-route migration success. We use an individually based, biophysical, mechanistic, bird migration model to simulate the movement of shorebirds in North America as a tool to study how such factors as drought and wetland loss may impact migratory success and modify migration patterns. Our model is driven by remote sensing and climate data and incorporates important landscape variables. The energy budget components of the model include resting, foraging, and flight, but presently predation is ignored. Results/Conclusions We illustrate our model by studying the spring migration of sandpipers through the Great Plains to their Arctic breeding grounds. Why many species of shorebirds have shown significant declines remains a puzzle. Shorebirds are sensitive to stop-over quality and spacing because of their need for frequent refueling stops and their opportunistic feeding patterns. We predict bird "hydrographs that is, stop-over frequency with latitude, that are in agreement with the literature. Mean stop-over durations predicted from our model for nominal cases also are consistent with the limited, but available data. For the shorebird species simulated, our model predicts that shorebirds exhibit significant plasticity and are able to shift their migration patterns in response to changing drought conditions. However, the question remains as to whether this

  9. Modeling Bird Migration under Climate Change: A Mechanistic Approach

    Science.gov (United States)

    Smith, James A.

    2009-01-01

    How will migrating birds respond to changes in the environment under climate change? What are the implications for migratory success under the various accelerated climate change scenarios as forecast by the Intergovernmental Panel on Climate Change? How will reductions or increased variability in the number or quality of wetland stop-over sites affect migratory bird species? The answers to these questions have important ramifications for conservation biology and wildlife management. Here, we describe the use of continental scale simulation modeling to explore how spatio-temporal changes along migratory flyways affect en-route migration success. We use an individually based, biophysical, mechanistic, bird migration model to simulate the movement of shorebirds in North America as a tool to study how such factors as drought and wetland loss may impact migratory success and modify migration patterns. Our model is driven by remote sensing and climate data and incorporates important landscape variables. The energy budget components of the model include resting, foraging, and flight, but presently predation is ignored. Results/Conclusions We illustrate our model by studying the spring migration of sandpipers through the Great Plains to their Arctic breeding grounds. Why many species of shorebirds have shown significant declines remains a puzzle. Shorebirds are sensitive to stop-over quality and spacing because of their need for frequent refueling stops and their opportunistic feeding patterns. We predict bird "hydrographs that is, stop-over frequency with latitude, that are in agreement with the literature. Mean stop-over durations predicted from our model for nominal cases also are consistent with the limited, but available data. For the shorebird species simulated, our model predicts that shorebirds exhibit significant plasticity and are able to shift their migration patterns in response to changing drought conditions. However, the question remains as to whether this

  10. Foreign Object Damage to Fan Rotor Blades of Aeroengine Part Ⅰ: Experimental Study of Bird Impact

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The conditions of experiment for bird impact to blades have been improved. The experiment of bird impact to the fan rotor blades of an aeroengine is carried out. Through analyzing the transient state response of blades impacted by bird and the change of blade profile before and after the impact, the anti-bird impact performance of blades in the first fan rotor is verified. The basis of anti-foreign object damage design for the fan rotor blades of an aeroengine is provided.

  11. Forest fire impact on bird habitat in a mixed oak-pine forest in Puebla, Mexico

    Science.gov (United States)

    Laura P. Ponce-Calderón Ponce-Calderón; Dante A. Rodríguez-Trejo; Beatriz C. Aguilar-Váldez; Elvia. López-Pérez

    2013-01-01

    To assess the impact of different-severity wildfires on bird habitat, habitat quality was determined by analyzing the degree of richness association, abundance and diversity of bird species and vegetation structure (richness, abundance, diversity and coverage). These attributes were quantified with four sampling sites for birds and five for quadrant-centered points...

  12. Assessing the impact of revegetation and weed control on urban sensitive bird species.

    Science.gov (United States)

    Archibald, Carla L; McKinney, Matthew; Mustin, Karen; Shanahan, Danielle F; Possingham, Hugh P

    2017-06-01

    Nature in cities is concentrated in urban green spaces, which are key areas for urban biodiversity and also important areas to connect people with nature. To conserve urban biodiversity within these natural refugia, habitat restoration such as weed control and revegetation is often implemented. These actions are expected to benefit biodiversity, although species known to be affected by urbanization may not be interacting with restoration in the ways we anticipate. In this study, we use a case study to explore how urban restoration activities impact different bird species. Birds were grouped into urban sensitivity categories and species abundance, and richness was then calculated using a hierarchical species community model for individual species responses, with "urban class" used as the hierarchical parameter. We highlight variable responses of birds to revegetation and weed control based on their level of urban sensitivity. Revegetation of open grassy areas delivers significant bird conservation outcomes, but the effects of weed control are neutral or in some cases negative. Specifically, the species most reliant on remnant vegetation in cities seem to remain stable or decline in abundance in areas with weed control, which we suspect is the result of a simplification of the understorey. The literature reports mixed benefits of weed control between taxa and between locations. We recommend, in our case study site, that weed control be implemented in concert with replanting of native vegetation to provide the understory structure preferred by urban sensitive birds. Understanding the impacts of revegetation and weed control on different bird species is important information for practitioners to make restoration decisions about the allocation of funds for conservation action. This new knowledge can be used both for threatened species and invasive species management.

  13. Modeling Extinction Risk of Endemic Birds of Mainland China

    Directory of Open Access Journals (Sweden)

    Youhua Chen

    2013-01-01

    Full Text Available The extinction risk of endemic birds of mainland China was modeled over evolutionary time. Results showed that extinction risk of endemic birds in mainland China always tended to be similar within subclades over the evolutionary time of species divergence, and the overall evolution of extinction risk of species presented a conservatism pattern, as evidenced by the disparity-through-time plot. A constant-rate evolutionary model was the best one to quantify the evolution of extinction risk of endemic birds of mainland China. Thus, there was no rate shifting pattern for the evolution of extinction risk of Chinese endemic birds over time. In a summary, extinction risk of endemic birds of mainland China is systematically quantified under the evolutionary framework in the present work.

  14. Proceedings of the Wind Energy and Birds/Bats Workshop: Understanding and Resolving Bird and Bat Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Susan Savitt (ed.)

    2004-09-01

    Most conservation groups support the development of wind energy in the US as an alternative to fossil and nuclear-fueled power plants to meet growing demand for electrical energy. However, concerns have surfaced over the potential threat to birds, bats, and other wildlife from the construction and operation of wind turbine facilities. Co-sponsored by the American Bird Conservancy (ABC) and the American Wind Energy Association (AWEA), the Wind Energy and Birds/Bats Workshop was convened to examine current research on the impacts of wind energy development on avian and bat species and to discuss the most effective ways to mitigate such impacts. On 18-19 May 2004, 82 representatives from government, non-government organizations, private business, and academia met to (1) review the status of the wind industry and current project development practices, including pre-development risk assessment and post-construction monitoring; (2) learn what is known about direct, indirect (habitat), and cumulative impacts on birds and bats from existing wind projects; about relevant aspects of bat and bird migration ecology; about offshore wind development experience in Europe; and about preventing, minimizing, and mitigating avian and bat impacts; (3) review wind development guidelines developed by the USFWS and the Washington State Department of Fish and Wildlife; and (4) identify topics needing further research and to discuss what can be done to ensure that research is both credible and accessible. These Workshop Proceedings include detailed summaries of the presentations made and the discussions that followed.

  15. The Contribution of Vegetation and Landscape Configuration for Predicting Environmental Change Impacts on Iberian Birds

    Science.gov (United States)

    Triviño, Maria; Thuiller, Wilfried; Cabeza, Mar; Hickler, Thomas; Araújo, Miguel B.

    2011-01-01

    Although climate is known to be one of the key factors determining animal species distributions amongst others, projections of global change impacts on their distributions often rely on bioclimatic envelope models. Vegetation structure and landscape configuration are also key determinants of distributions, but they are rarely considered in such assessments. We explore the consequences of using simulated vegetation structure and composition as well as its associated landscape configuration in models projecting global change effects on Iberian bird species distributions. Both present-day and future distributions were modelled for 168 bird species using two ensemble forecasting methods: Random Forests (RF) and Boosted Regression Trees (BRT). For each species, several models were created, differing in the predictor variables used (climate, vegetation, and landscape configuration). Discrimination ability of each model in the present-day was then tested with four commonly used evaluation methods (AUC, TSS, specificity and sensitivity). The different sets of predictor variables yielded similar spatial patterns for well-modelled species, but the future projections diverged for poorly-modelled species. Models using all predictor variables were not significantly better than models fitted with climate variables alone for ca. 50% of the cases. Moreover, models fitted with climate data were always better than models fitted with landscape configuration variables, and vegetation variables were found to correlate with bird species distributions in 26–40% of the cases with BRT, and in 1–18% of the cases with RF. We conclude that improvements from including vegetation and its landscape configuration variables in comparison with climate only variables might not always be as great as expected for future projections of Iberian bird species. PMID:22216263

  16. A phenomenological model for the collective landing of bird flocks.

    Science.gov (United States)

    Daruka, István

    2009-03-07

    A three-dimensional phenomenological model was developed to describe the collective landing of bird flocks. The employed individual based model included the landscape (as an external field) and a continuous internal variable G, to characterize the landing intent of the birds. The birds' interaction with the landscape was coupled adaptively to their landing intent. During the flight, a sharp crossover is observed in the dynamics of the landing intent, i.e. from the initial, non-landing state (small G) to the landing state (large G) that was terminated by the landing of the flock. In the model, the landing process appears to be a highly concerted, collective motion of the birds, in agreement with the field observations.

  17. An indicator of the impact of climatic change on European bird populations.

    Directory of Open Access Journals (Sweden)

    Richard D Gregory

    Full Text Available Rapid climatic change poses a threat to global biodiversity. There is extensive evidence that recent climatic change has affected animal and plant populations, but no indicators exist that summarise impacts over many species and large areas. We use data on long-term population trends of European birds to develop such an indicator. We find a significant relationship between interspecific variation in population trend and the change in potential range extent between the late 20(th and late 21(st centuries, forecasted by climatic envelope models. Our indicator measures divergence in population trend between bird species predicted by climatic envelope models to be favourably affected by climatic change and those adversely affected. The indicator shows a rapid increase in the past twenty years, coinciding with a period of rapid warming.

  18. The potential for typhoon impact on bird populations on the island of Rota, Northern Mariana

    Directory of Open Access Journals (Sweden)

    Ha, C.

    2012-12-01

    Full Text Available Numerous independent analyses of climate change have suggested that changing weather patterns are resulting in increasing frequency or intensity of hurricanes and typhoons. We explore the relationship between cyclonic event frequency and severity on measures of bird abundance on the island of Rota, in the Northern Mariana Islands to determine if changes in cyclonic event pattern might be related to the local decline of avian species. We developed a database of Rota cyclonic event encounters since 1952 and three primary variables for analysis of cyclonic event behavior were then derived from this data: Time-Between-Typhoon-Encounters, Distance from Rota at closest approach, and Pressure at the center of the cyclonic event at the point of closest approach Three similar smoothed variables were derived relative to each Breeding Bird and Variable Circle Plot census time point. Multivariate general linear models were constructed separately for each bird abundance data set with multiple species as dependent variables and smoothed cyclonic event time-between-encounter, distance-at-closest- point, and central-pressure-at-closest-point as independent variables. Cyclonic event behavior in relation to Rota did not exhibit an increase in frequency, as sometimes perceived, but did show a significant decrease in distance to the island and an increase in intensity as measured by central pressure. Several species abundances showed significant relationships with cyclonic event pressure or distance, including the Mariana Crow, Philippine Turtle Dove, and Rufous Fantail. It appears that changes in cyclonic event “behavior” could be impacting forest-bird populations on Rota. Overall, bird population declines may be due to a combined effect of habitat loss, introduced species pressure, and cyclonic events, where any one of the factors might be enough to tip a species into decline.

  19. Community occupancy before-after-control-impact (CO-BACI) analysis of Hurricane Gudrun on Swedish forest birds.

    Science.gov (United States)

    Russell, James C; Stjernman, Martin; Lindström, Åke; Smith, Henrik G

    2015-04-01

    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.

  20. Functional response models to estimate feeding rates of wading birds

    Science.gov (United States)

    Collazo, J.A.; Gilliam, J.F.; Miranda-Castro, L.

    2010-01-01

    Forager (predator) abundance may mediate feeding rates in wading birds. Yet, when modeled, feeding rates are typically derived from the purely prey-dependent Holling Type II (HoII) functional response model. Estimates of feeding rates are necessary to evaluate wading bird foraging strategies and their role in food webs; thus, models that incorporate predator dependence warrant consideration. Here, data collected in a mangrove swamp in Puerto Rico in 1994 were reanalyzed, reporting feeding rates for mixed-species flocks after comparing fits of the HoII model, as used in the original work, to the Beddington-DeAngelis (BD) and Crowley-Martin (CM) predator-dependent models. Model CM received most support (AIC c wi = 0.44), but models BD and HoII were plausible alternatives (AIC c ??? 2). Results suggested that feeding rates were constrained by predator abundance. Reductions in rates were attributed to interference, which was consistent with the independently observed increase in aggression as flock size increased (P rates. However, inferences derived from the HoII model, as used in the original work, were sound. While Holling's Type II and other purely prey-dependent models have fostered advances in wading bird foraging ecology, evaluating models that incorporate predator dependence could lead to a more adequate description of data and processes of interest. The mechanistic bases used to derive models used here lead to biologically interpretable results and advance understanding of wading bird foraging ecology.

  1. Exploiting Bird Locomotion Kinematics Data for Robotics Modeling

    CERN Document Server

    Hugel, Vincent; Abourachid, Anick

    2008-01-01

    We present here the results of an analysis carried out by biologists and roboticists with the aim of modeling bird locomotion kinematics for robotics purposes. The aim was to develop a bio-inspired kinematic model of the bird leg from biological data. We first acquired and processed kinematic data for sagittal and top views obtained by X-ray radiography of quails walking. Data processing involved filtering and specific data reconstruction in three dimensions, as two-dimensional views cannot be synchronized. We then designed a robotic model of a bird-like leg based on a kinematic analysis of the biological data. Angular velocity vectors were calculated to define the number of degrees of freedom (DOF) at each joint and the orientation of the rotation axes.

  2. The impact of hunting on tropical mammal and bird populations

    NARCIS (Netherlands)

    Benítez-López, A.; Alkemade, R.; Schipper, A.M.; Ingram, D.J.; Verweij, P.A.; Eikelboom, J.A.J.; Huijbregts, M.A.J.

    2017-01-01

    Hunting is a major driver of biodiversity loss, but a systematic large-scale estimate of hunting-induced defaunation is lacking. We synthesized 176 studies to quantify hunting-induced declines of mammal and bird populations across the tropics. Bird and mammal abundances declined by 58% (25 to

  3. Estimation of the impact of prevailing weather conditions on the occurrence of oil-contaminated dead birds on the German North Sea coast

    Energy Technology Data Exchange (ETDEWEB)

    Chrastansky, Alena [GKSS Research Centre, Institute for Coastal Research, Max-Planck-Strasse 1, 21502 Geesthacht (Germany)], E-mail: alena.chrastansky@gkss.de; Callies, Ulrich [GKSS Research Centre, Institute for Coastal Research, Max-Planck-Strasse 1, 21502 Geesthacht (Germany)], E-mail: ulrich.callies@gkss.de; Fleet, David M. [Schleswig-Holstein Agency for Coastal Defence, National Park and Marine Conservation, Schlossgarten 1, 25832 Toenning (Germany)], E-mail: david.fleet@lkn.landsh.de

    2009-01-15

    Chronic oil pollution by illegal oil dumping in the North Sea is difficult to quantify. Beached, oil-contaminated sea birds, however, may be used as an indirect indicator. Reconstructing the drift of oil slicks and sea bird corpses in the southern North Sea for the period 1992-2003 by means of a two-dimensional numerical transport model driven by re-analysed weather data, we show with an example of two common sea bird species that the variability observed within the number of corpses registered during beached bird surveys for the German coast primarily reflects the inter-annual variability of prevailing weather conditions. This should be taken into account when interpreting the data. We propose normalisation of beached bird survey data based on numerical drift simulations to improve the recognition of trends in the level of chronic oil pollution. - Prevailing weather conditions have a significant impact on the occurrence of beached oil-contaminated sea birds.

  4. Using urban forest assessment tools to model bird habitat potential

    Science.gov (United States)

    Lerman, Susannah B.; Nislow, Keith H.; Nowak, David J.; Destefano, Stephen; King, David I.; Jones-Farrand, D. Todd

    2014-01-01

    The alteration of forest cover and the replacement of native vegetation with buildings, roads, exotic vegetation, and other urban features pose one of the greatest threats to global biodiversity. As more land becomes slated for urban development, identifying effective urban forest wildlife management tools becomes paramount to ensure the urban forest provides habitat to sustain bird and other wildlife populations. The primary goal of this study was to integrate wildlife suitability indices to an existing national urban forest assessment tool, i-Tree. We quantified available habitat characteristics of urban forests for ten northeastern U.S. cities, and summarized bird habitat relationships from the literature in terms of variables that were represented in the i-Tree datasets. With these data, we generated habitat suitability equations for nine bird species representing a range of life history traits and conservation status that predicts the habitat suitability based on i-Tree data. We applied these equations to the urban forest datasets to calculate the overall habitat suitability for each city and the habitat suitability for different types of land-use (e.g., residential, commercial, parkland) for each bird species. The proposed habitat models will help guide wildlife managers, urban planners, and landscape designers who require specific information such as desirable habitat conditions within an urban management project to help improve the suitability of urban forests for birds.

  5. Techniques used in reducing oil impact on bird populations

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This paper deals with methods for deterring birds from oil spill areas. This subject has been exhaustively reviewed by Koski and Richardson (1976) and succinctly...

  6. Flying, Feathery and Beaked Objects: Children's Mental Models about Birds

    Science.gov (United States)

    Ahi, Berat

    2016-01-01

    Purpose of this research is to state preschool students' mental model about birds by analyzing their drawing. This is a hermeneutical phenomenology research that is based on social constructivist philosophy. Typical case sampling method has used in order to form working group of this research. Working group consisting of 325 children who are in…

  7. Bird collision impacts at wind turbines in eastern North America

    Energy Technology Data Exchange (ETDEWEB)

    Kerlinger, Paul; Curry, Richard; Guarnaccia, John [Curry and Kerlinger, LLC (United States)

    2011-07-01

    This paper discusses the incidence of bird collisions at wind turbines in Eastern North America. Modern wind turbines are high, with long, tubular towers. Bird fatality is analyzed and references to the relevant studies that have been done are given. 26 sites were investigated for turbine mortality in 2011 and these are shown on a map. 64 turbines were examined in Maple Ridge and it was seen that 4 birds were killed per turbine per year. The results demonstrated that no eagles were killed, there were no endangered species involved and there was no real deviation from site to site. More than 80,000 individual turbines were researched and more than $30 million spent on the study. Around 120,000 birds are killed per year, or an average of over 6 birds per turbine per year, in the United States. It is clear from the extensive research conducted that there are a lot of data on birds and turbines; the data show that songbirds are the most often affected.

  8. Hierarchical models and the analysis of bird survey information

    Science.gov (United States)

    Sauer, J.R.; Link, W.A.

    2003-01-01

    Management of birds often requires analysis of collections of estimates. We describe a hierarchical modeling approach to the analysis of these data, in which parameters associated with the individual species estimates are treated as random variables, and probability statements are made about the species parameters conditioned on the data. A Markov-Chain Monte Carlo (MCMC) procedure is used to fit the hierarchical model. This approach is computer intensive, and is based upon simulation. MCMC allows for estimation both of parameters and of derived statistics. To illustrate the application of this method, we use the case in which we are interested in attributes of a collection of estimates of population change. Using data for 28 species of grassland-breeding birds from the North American Breeding Bird Survey, we estimate the number of species with increasing populations, provide precision-adjusted rankings of species trends, and describe a measure of population stability as the probability that the trend for a species is within a certain interval. Hierarchical models can be applied to a variety of bird survey applications, and we are investigating their use in estimation of population change from survey data.

  9. Impact of Non-Native Birds on Native Ecosystems: A Global Analysis.

    Science.gov (United States)

    Martin-Albarracin, Valeria L; Amico, Guillermo C; Simberloff, Daniel; Nuñez, Martin A

    2015-01-01

    Introduction and naturalization of non-native species is one of the most important threats to global biodiversity. Birds have been widely introduced worldwide, but their impacts on populations, communities, and ecosystems have not received as much attention as those of other groups. This work is a global synthesis of the impact of nonnative birds on native ecosystems to determine (1) what groups, impacts, and locations have been best studied; (2) which taxonomic groups and which impacts have greatest effects on ecosystems, (3) how important are bird impacts at the community and ecosystem levels, and (4) what are the known benefits of nonnative birds to natural ecosystems. We conducted an extensive literature search that yielded 148 articles covering 39 species belonging to 18 families -18% of all known naturalized species. Studies were classified according to where they were conducted: Africa, Asia, Australasia, Europe, North America, South America, Islands of the Indian, of the Pacific, and of the Atlantic Ocean. Seven types of impact on native ecosystems were evaluated: competition, disease transmission, chemical, physical, or structural impact on ecosystem, grazing/ herbivory/ browsing, hybridization, predation, and interaction with other non-native species. Hybridization and disease transmission were the most important impacts, affecting the population and community levels. Ecosystem-level impacts, such as structural and chemical impacts were detected. Seven species were found to have positive impacts aside from negative ones. We provide suggestions for future studies focused on mechanisms of impact, regions, and understudied taxonomic groups.

  10. The contribution of vegetation and landscape configuration for predicting environmental change impacts on Iberian birds

    DEFF Research Database (Denmark)

    Triviño, Maria; Thuiller, Wilfried; Cabeza, Mar

    2011-01-01

    distributions were modelled for 168 bird species using two ensemble forecasting methods: Random Forests (RF) and Boosted Regression Trees (BRT). For each species, several models were created, differing in the predictor variables used (climate, vegetation, and landscape configuration). Discrimination ability...

  11. Comparing determinants of alien bird impacts across two continents: implications for risk assessment and management

    Science.gov (United States)

    Evans, Thomas; Kumschick, Sabrina; Dyer, Ellie; Blackburn, Tim

    2014-01-01

    Invasive alien species can have serious adverse impacts on both the environment and the economy. Being able to predict the impacts of an alien species could assist in preventing or reducing these impacts. This study aimed to establish whether there are any life history traits consistently correlated with the impacts of alien birds across two continents, Europe and Australia, as a first step toward identifying life history traits that may have the potential to be adopted as predictors of alien bird impacts. A recently established impact scoring system was used in combination with a literature review to allocate impact scores to alien bird species with self-sustaining populations in Australia. These scores were then tested for correlation with a series of life history traits. The results were compared to data from a previous study in Europe, undertaken using the same methodology, in order to establish whether there are any life history traits consistently correlated with impact across both continents. Habitat generalism was the only life history trait found to be consistently correlated with impact in both Europe and Australia. This trait shows promise as a potential predictor of alien bird impacts. The results support the findings of previous studies in this field, and could be used to inform decisions regarding the prevention and management of future invasions. PMID:25165531

  12. A review of climate change impacts on birds

    Science.gov (United States)

    Robert W. Butler; William Taylor

    2005-01-01

    Regions of the world with high coastal zone biological productivity often support large numbers of birds. Important sources of this productivity are oceanographic upwelling created by winds and ocean currents, and runoff from the land. It is suggested that climate change effects on winds and ocean currents will potentially affect the timing and magnitude of coastal...

  13. Wind power's impact on birds and bats; Vindkraftens paaverkan paa faaglar och fladdermoess

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-05-15

    Wind turbines can be a danger to birds and bats. Therefore it is important to place the turbines correct. The risks can be minimized with the help of knowledge of birds and bats behavior. It was found in a synthesis report published 2011, where research from Europe and the U.S. are summarized. The report shows which environments should be avoided and the species that are affected in different areas. This popular science brochure is based on the synthesis report 'Wind power's impact on birds and bats'.

  14. Spatiotemporal Distributions of Migratory Birds: Patchy Models with Delay

    Science.gov (United States)

    Gourley, Stephen A.; Liu, Rongsong; Wu, Jianhong

    2010-01-01

    We derive and analyze a mathematical model for the spatiotemporal distribution of a migratory bird species. The birds have specific sites for breeding and winter feeding, and usually several stopover sites along the migration route, and therefore a patch model is the natural choice. However, we also model the journeys of the birds along the flyways, and this is achieved using a continuous space model of reaction-advection type. In this way proper account is taken of flight times and in-flight mortalities which may vary from sector to sector, and this information is featured in the ordinary differential equations for the populations on the patches through the values of the time delays and the model coefficients. The seasonality of the phenomenon is accommodated by having periodic migration and birth rates. The central result of the paper is a very general theorem on the threshold dynamics, obtained using recent results on discrete monotone dynamical systems, for birth functions which are subhomogeneous. For such functions, depending on the spectral radius of a certain operator, either there is a globally attracting periodic solution, or the bird population becomes extinct. Evaluation of the spectral radius is difficult, so we also present, for the particular case of just one stopover site on the migration route, a verifiable sufficient condition for extinction or survival in the form of an attractive periodic solution. This threshold is illustrated numerically using data from the U.S. Geological Survey on the bar-headed goose and its migration to India from its main breeding sites around Lake Qinghai and Mongolia.

  15. New modeling approach for bounding flight in birds.

    Science.gov (United States)

    Sachs, Gottfried; Lenz, Jakob

    2011-12-01

    A new modeling approach is presented which accounts for the unsteady motion features and dynamics characteristics of bounding flight. For this purpose, a realistic mathematical model is developed to describe the flight dynamics of a bird with regard to a motion which comprises flapping and bound phases involving acceleration and deceleration as well as, simultaneously, pull-up and push-down maneuvers. Furthermore, a mathematical optimization method is used for determining that bounding flight mode which yields the minimum energy expenditure per range. Thus, it can be shown to what extent bounding flight is aerodynamically superior to continuous flapping flight, yielding a reduction in the energy expenditure in the speed range practically above the maximum range speed. Moreover, the role of the body lift for the efficiency of bounding flight is identified and quantified. Introducing an appropriate non-dimensionalization of the relations describing the bird's flight dynamics, results of generally valid nature are derived for the addressed items.

  16. Bird interactions with offshore oil and gas platforms: review of impacts and monitoring techniques.

    Science.gov (United States)

    Ronconi, Robert A; Allard, Karel A; Taylor, Philip D

    2015-01-01

    Thousands of oil and gas platforms are currently operating in offshore waters globally, and this industry is expected to expand in coming decades. Although the potential environmental impacts of offshore oil and gas activities are widely recognized, there is limited understanding of their impacts on migratory and resident birds. A literature review identified 24 studies and reports of bird-platform interactions, most being qualitative and half having been peer-reviewed. The most frequently observed effect, for seabirds and landbirds, is attraction and sometimes collisions associated with lights and flares; episodic events have caused the deaths of hundreds or even thousands of birds. Though typically unpredictable, anecdotally, it is known that poor weather, such as fog, precipitation and low cloud cover, can exacerbate the effect of nocturnal attraction to lights, especially when coincidental with bird migrations. Other effects include provision of foraging and roosting opportunities, increased exposure to oil and hazardous environments, increased exposure to predators, or repulsion from feeding sites. Current approaches to monitoring birds at offshore platforms have focused on observer-based methods which can offer species-level bird identification, quantify seasonal patterns of relative abundance and distribution, and document avian mortality events and underlying factors. Observer-based monitoring is time-intensive, limited in spatial and temporal coverage, and suffers without clear protocols and when not conducted by trained, independent observers. These difficulties are exacerbated because deleterious bird-platform interaction is episodic and likely requires the coincidence of multiple factors (e.g., darkness, cloud, fog, rain conditions, occurrence of birds in vicinity). Collectively, these considerations suggest a need to implement supplemental systems for monitoring bird activities around offshore platforms. Instrument-based approaches, such as radar

  17. Session: Non-fatality and habitat impacts on birds from wind energy development

    Energy Technology Data Exchange (ETDEWEB)

    Strickland, Dale

    2004-09-01

    This session at the Wind Energy and Birds/Bats workshop was consisted of one paper presentation followed by a discussion/question and answer period. The session focused on discussion of non-collision impacts of wind energy projects on birds, primarily impacts to habitat. The presentation included information about the impacts of habitat fragmentation, disturbance, and site avoidance from wind turbines, as well as from roads, transmission facilities, and other related construction at wind project sites. Whether birds habituate to the presence of turbines and the influence of regional factors were also addressed. The paper given by Dale Strickland was titled ''Overview of Non-Collision Related Impacts from Wind Projects''.

  18. Avian malaria Plasmodium relictum in native Hawaiian forest birds: epizootiology and demographic impacts on ‵apapane Himatione sanguinea

    Science.gov (United States)

    Atkinson, Carter T.; Samuel, Michael D.

    2010-01-01

    The role of introduced avian malaria Plasmodium relictum in the decline and extinction of native Hawaiian forest birds has become a classic example of the potential effect of invasive diseases on biological diversity of naïve populations. However, empirical evidence describing the impact of avian malaria on fitness of Hawai‵i's endemic forest birds is limited, making it difficult to determine the importance of disease among the suite of potential limiting factors affecting the distribution and abundance of this threatened avifauna. We combined epidemiological force-of-infection with multistate capture––recapture models to evaluate a 7-year longitudinal study of avian malaria in ‵apapane, a relatively common native honeycreeper within mid-elevation Hawaiian forests. We found that malaria transmission was seasonal in this mid-elevation forest; transmission peaked during fall and during some years produced epizootic mortality events. Estimated annual mortality of hatch-year birds typically exceeded 50% and mortality of adults exceeded 25% during epizootics. The substantial impact of avian malaria on this relatively common native species demonstrates the key role this disease has played in the decline and extinction of Hawaiian forest birds.

  19. Woody plants and the prediction of climate-change impacts on bird diversity

    OpenAIRE

    Kissling, W. D.; Field, R.; Korntheuer, H.; Heyder, U.; Böhning-Gaese, K

    2010-01-01

    Current methods of assessing climate-induced shifts of species distributions rarely account for species interactions and usually ignore potential differences in response times of interacting taxa to climate change. Here, we used species-richness data from 1005 breeding bird and 1417 woody plant species in Kenya and employed model-averaged coefficients from regression models and median climatic forecasts assembled across 15 climate-change scenarios to predict bird species richness under climat...

  20. Impact of Spring Bird Migration on the Range Expansion of Ixodes scapularis Tick Population.

    Science.gov (United States)

    Wu, Xiaotian; Röst, Gergely; Zou, Xingfu

    2016-01-01

    Many observational studies suggest that seasonal migratory birds play an important role in spreading Ixodes scapularis, a vector of Lyme disease, along their migratory flyways, and they are believed to be responsible for geographic range expansion of I. scapularis in Canada. However, the interplay between the dynamics of I. scapularis on land and migratory birds in the air is not well understood. In this study, we develop a periodic delay meta-population model which takes into consideration the local landscape for tick reproduction within patches and the times needed for ticks to be transported by birds between patches. Assuming that the tick population is endemic in the source region, we find that bird migration may boost an already established tick population at the subsequent region and thus increase the risk to humans, or bird migration may help ticks to establish in a region where the local landscape is not appropriate for ticks to survive in the absence of bird migration, imposing risks to public health. This theoretical study reveals that bird migration plays an important role in the geographic range expansion of I. scapularis, and therefore our findings may suggest some strategies for Lyme disease prevention and control.

  1. Selecting the right bird model in experimental studies on endocrine disrupting chemicals

    Directory of Open Access Journals (Sweden)

    Veerle L.B. Jaspers

    2015-05-01

    Full Text Available Birds have been used as model species in ecotoxicological research for decades but have only recently been included in toxicity testing schemes. However, the avian fauna is very diverse. Given this diversity the ecology, behavior and reproduction should be considered when selecting the appropriate bird model in ecotoxicological studies. This article focusses on choosing the right bird model species for experimental studies with endocrine disrupting chemicals (EDCs. EDCs have been associated with adverse effects on the reproduction and development in birds and other wildlife. In addition, new EDCs continue to emerge and the concern for potential effects in humans and wildlife is calling for increased toxicity testing and hence appropriate model species. Common bird model species used in ecotoxicological studies investigating EDCs will be reviewed. In addition, considerations for selecting the right bird model, along with potential drawbacks and restrictions on the use of certain species will be discussed.

  2. Quantifying the Detrimental Impacts of Land-Use and Management Change on European Forest Bird Populations

    Science.gov (United States)

    Wade, Amy S. I.; Barov, Boris; Burfield, Ian J.; Gregory, Richard D.; Norris, Ken; Butler, Simon J.

    2013-01-01

    The ecological impacts of changing forest management practices in Europe are poorly understood despite European forests being highly managed. Furthermore, the effects of potential drivers of forest biodiversity decline are rarely considered in concert, thus limiting effective conservation or sustainable forest management. We present a trait-based framework that we use to assess the detrimental impact of multiple land-use and management changes in forests on bird populations across Europe. Major changes to forest habitats occurring in recent decades, and their impact on resource availability for birds were identified. Risk associated with these changes for 52 species of forest birds, defined as the proportion of each species' key resources detrimentally affected through changes in abundance and/or availability, was quantified and compared to their pan-European population growth rates between 1980 and 2009. Relationships between risk and population growth were found to be significantly negative, indicating that resource loss in European forests is an important driver of decline for both resident and migrant birds. Our results demonstrate that coarse quantification of resource use and ecological change can be valuable in understanding causes of biodiversity decline, and thus in informing conservation strategy and policy. Such an approach has good potential to be extended for predictive use in assessing the impact of possible future changes to forest management and to develop more precise indicators of forest health. PMID:23704997

  3. Vegetation moderates impacts of tourism usage on bird communities along roads and hiking trails.

    Science.gov (United States)

    Wolf, Isabelle D; Hagenloh, Gerald; Croft, David B

    2013-11-15

    Bird communities inhabiting ecosystems adjacent to recreational tracks may be adversely affected by disturbance from passing tourism traffic, vehicle-related mortality, habitat alteration and modified biotic relationships such as the increase of strong competitors. This study investigated the effects of tourist usage of roads vs. hiking trails on bird communities in gorges of the Flinders Ranges, a popular South Australian tourist destination in the arid-lands. High tourist usage along roads decreased the individual abundance and species richness of birds relative to low usage trails. The decrease in species richness, though less pronounced, also occurred at high-usage sites along trails. Changes in the species response to recreational disturbance/impacts varied depending on the ecology of the species. Bigger, more competitive birds with a generalist diet were overrepresented at high-usage sites along roads and trails. Species using microhabitats in lower vegetation layers were more sensitive. However, structural and floristic complexity of vegetation was a more important factor influencing bird abundance than tourist usage. Sites with a better developed shrub and tree layer sustained higher species abundance and richer communities. Importantly, vegetation qualities moderated the negative effect of high usage on the individual abundance of birds along roads, to the extent that such an effect was absent at sites with the best developed shrub and tree layer. To protect avifauna along recreational tracks in arid-lands gorges, we recommend the closure of some gorges or sections for vehicle or any access. Further, open space particularly for camping needs to be minimized as it creates areas of high tourist usage with modified habitat that provides birds with little buffer from disturbance. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. TESTS OF PRATT AND WHITNEY MODEL YTF33-P-1 TURBOFAN ENGINE CHARACTERISTICS DURING BIRD INGESTION.

    Science.gov (United States)

    ingestion run regardless of the bird-impact point(s) relative to the engine horizontal axis. This action was attributed to the centrifuging action of...a bird- ingestion incident. Substantial damage was incurred by the first-stage fan rotor blades in the course of the program. Although this damage

  5. The contribution of vegetation and landscape configuration for predicting environmental change impacts on Iberian birds

    DEFF Research Database (Denmark)

    Triviño, Maria; Thuiller, Wilfried; Cabeza, Mar;

    2011-01-01

    distributions were modelled for 168 bird species using two ensemble forecasting methods: Random Forests (RF) and Boosted Regression Trees (BRT). For each species, several models were created, differing in the predictor variables used (climate, vegetation, and landscape configuration). Discrimination ability...... of distributions, but they are rarely considered in such assessments. We explore the consequences of using simulated vegetation structure and composition as well as its associated landscape configuration in models projecting global change effects on Iberian bird species distributions. Both present-day and future...... with bird species distributions in 26-40% of the cases with BRT, and in 1-18% of the cases with RF. We conclude that improvements from including vegetation and its landscape configuration variables in comparison with climate only variables might not always be as great as expected for future projections...

  6. Computational model for vocal tract dynamics in a suboscine bird

    Science.gov (United States)

    Assaneo, M. F.; Trevisan, M. A.

    2010-09-01

    In a recent work, active use of the vocal tract has been reported for singing oscines. The reconfiguration of the vocal tract during song serves to match its resonances to the syringeal fundamental frequency, demonstrating a precise coordination of the two main pieces of the avian vocal system for songbirds characterized by tonal songs. In this work we investigated the Great Kiskadee (Pitangus sulfuratus), a suboscine bird whose calls display a rich harmonic content. Using a recently developed mathematical model for the syrinx and a mobile vocal tract, we set up a computational model that provides a plausible reconstruction of the vocal tract movement using a few spectral features taken from the utterances. Moreover, synthetic calls were generated using the articulated vocal tract that accounts for all the acoustical features observed experimentally.

  7. Halogenated pollutants in terrestrial and aquatic bird eggs: converging patterns of pollutant profiles, and impacts and risks from high levels.

    Science.gov (United States)

    Bouwman, Hindrik; Viljoen, Ignatius M; Quinn, Laura P; Polder, Anuschka

    2013-10-01

    We investigated the presence, levels, relationships, and risks of HCHs, DDTs, chlordanes, mirex, PCBs, and brominated flame retardants (BFRs) in terrestrial and aquatic bird eggs from an area in South Africa where DDT is used for malaria control. We found one of the highest ΣDDT levels reported this century; 13,000 ng/g wm (wet mass) in Grey Heron eggs which exceeds critical levels for reproductive success (3000 ng/g wm) calculated for Brown Pelicans, with a no-effect level estimated at 500 ng/g wm. Even higher ΣDDT levels at 16,000 ng/g wm were found in House Sparrow eggs (possibly the highest ever recorded for sparrows), with a maximum of 24,400 ng/g wm. Significant eggshell thinning in Cattle Egrets (33% between thickest and thinnest) was associated with increased levels of p,p'-DDT and p,p'-DDE. There were indications of unknown use of DDT and lindane. Relative to DDT, PCBs and BFRs levels were quite low. Ordinated data showed that different terrestrial pollutant profiles converged to a homogenised aquatic profile. Converging profiles, high levels of DDT in heron and sparrow eggs, and thinning eggs shells, indicate risk and impacts at release, in the aquatic environment, and in between. If characteristic life-strategies of birds in warm areas (e.g. longer-lived and fewer eggs per clutch) increases the risk compared with similar birds living in colder regions when both experience the same environmental pollutant levels, then malaria control using DDT probably has more significant impacts on biota than previously realised. Therefore, risk assessment and modelling without hard data may miss crucial impacts and risks, as the chemical use patterns and ecologies in Africa and elsewhere may differ from the conditions and assumptions of existing risk assessment and modelling parameters. Consideration of other findings associated with DDT from the same area (intersex in fish and urogental birth defects in baby boys), together with the findings of this study (high

  8. Potential impacts of climatic change upon geographical distributions of birds

    DEFF Research Database (Denmark)

    Huntley, Brian; Collingham, Yvonne C.; Green, Rhys E.

    2006-01-01

    sites, and also potentially increases the distances they must migrate seasonally. Without implementation of new conservation measures, these impacts will be severe and are likely to be exacerbated by land-use change and associated habitat fragmentation. Unless strenuous efforts are made to address...

  9. Phenological model of bird cherry Padus racemosa with data assimilation

    Science.gov (United States)

    Kalvāns, Andis; Sīle, Tija; Kalvāne, Gunta

    2017-07-01

    The accuracy of the operational models can be improved by using observational data to shift the model state in a process called data assimilation. Here, a data assimilation approach using the temperature similarity to control the extent of extrapolation of point-like phenological observations is explored. A degree-day model is used to describe the spring phenology of the bird cherry Padus racemosa in the Baltic region in 2014. The model results are compared to phenological observations that are expressed on a continuous scale based on the BBCH code. The air temperature data are derived from a numerical weather prediction (NWP) model. It is assumed that the phenology at two points with a similar temperature pattern should be similar. The root mean squared difference (RMSD) between the time series of hourly temperature data over a selected time interval are used to measure the temperature similarity of any two points. A sigmoidal function is used to scale the RMSD into a weight factor that determines how the modelled and observed phenophases are combined in the data assimilation. The parameter space for determining the weight of observations is explored. It is found that data assimilation improved the accuracy of the phenological model and that the value of the point-like observations can be increased through using a weighting function based on environmental parameters, such as temperature.

  10. Avian malaria in Hawaiian forest birds: Infection and population impacts across species and elevations

    Science.gov (United States)

    Samuel, Michael D.; Woodworth, Bethany L.; Atkinson, Carter T.; Hart, P. J.; LaPointe, Dennis

    2015-01-01

    Wildlife diseases can present significant threats to ecological systems and biological diversity, as well as domestic animal and human health. However, determining the dynamics of wildlife diseases and understanding the impact on host populations is a significant challenge. In Hawai‘i, there is ample circumstantial evidence that introduced avian malaria (Plasmodium relictum) has played an important role in the decline and extinction of many native forest birds. However, few studies have attempted to estimate disease transmission and mortality, survival, and individual species impacts in this distinctive ecosystem. We combined multi-state capture-recapture (longitudinal) models with cumulative age-prevalence (cross-sectional) models to evaluate these patterns in Apapane, Hawai‘i Amakihi, and Iiwi in low-, mid-, and high-elevation forests on the island of Hawai‘i based on four longitudinal studies of 3–7 years in length. We found species-specific patterns of malaria prevalence, transmission, and mortality rates that varied among elevations, likely in response to ecological factors that drive mosquito abundance. Malaria infection was highest at low elevations, moderate at mid elevations, and limited in high-elevation forests. Infection rates were highest for Iiwi and Apapane, likely contributing to the absence of these species in low-elevation forests. Adult malaria fatality rates were highest for Iiwi, intermediate for Amakihi at mid and high elevations, and lower for Apapane; low-elevation Amakihi had the lowest malaria fatality, providing strong evidence of malaria tolerance in this low-elevation population. Our study indicates that hatch-year birds may have greater malaria infection and/or fatality rates than adults. Our study also found that mosquitoes prefer feeding on Amakihi rather than Apapane, but Apapane are likely a more important reservoir for malaria transmission to mosquitoes. Our approach, based on host abundance and infection rates, may be an

  11. Modelling the spread of innovation in wild birds.

    Science.gov (United States)

    Shultz, Thomas R; Montrey, Marcel; Aplin, Lucy M

    2017-06-01

    We apply three plausible algorithms in agent-based computer simulations to recent experiments on social learning in wild birds. Although some of the phenomena are simulated by all three learning algorithms, several manifestations of social conformity bias are simulated by only the approximate majority (AM) algorithm, which has roots in chemistry, molecular biology and theoretical computer science. The simulations generate testable predictions and provide several explanatory insights into the diffusion of innovation through a population. The AM algorithm's success raises the possibility of its usefulness in studying group dynamics more generally, in several different scientific domains. Our differential-equation model matches simulation results and provides mathematical insights into the dynamics of these algorithms. © 2017 The Author(s).

  12. Malarial birds: modeling infectious human disease in animals.

    Science.gov (United States)

    Slater, Leo B

    2005-01-01

    Through the examination of avian malarias as models of infectious human disease, this paper reveals the kinds of claims that scientists and physicians made on the basis of animal models-biological systems in the laboratory and the field-and what characteristics made for congruence between these models and human malaria. The focus is on the period between 1895 and 1945, and on the genesis and trajectory of certain animal models of malaria within specific locations, such as the Johns Hopkins School of Hygiene and Public Health in Baltimore and Bayer (I. G. Farben) in Elberfeld. These exemplars illustrate a diversity of approaches to malaria-as-disease, and the difficulties of framing aspects of this disease complex within an animal or laboratory system. The diversity and nearness to wild types of the birds, protozoan parasites, and mosquitoes that made up these malaria models contributed a great deal to the complexity of the models. Avian malarias, adopted with enthusiasm, were essential to the success of the U.S. antimalarial program during World War II.

  13. Bird-landscape relations in the Chihuahuan Desert: Coping with uncertainties about predictive models

    Science.gov (United States)

    Gutzwiller, K.J.; Barrow, W.C.

    2001-01-01

    During the springs of 1995-1997, we studied birds and landscapes in the Chihuahuan Desert along part of the Texas-Mexico border. Our objectives were to assess bird-landscape relations and their interannual consistency and to identify ways to cope with associated uncertainties that undermine confidence in using such relations in conservation decision processes. Bird distributions were often significantly associated with landscape features, and many bird-landscape models were valid and useful for predictive purposes. Differences in early spring rainfall appeared to influence bird abundance, but there was no evidence that annual differences in bird abundance affected model consistency. Model consistency for richness (42%) was higher than mean model consistency for 26 focal species (mean 30%, range 0-67%), suggesting that relations involving individual species are, on average, more subject to factors that cause variation than are richness-landscape relations. Consistency of bird-landscape relations may be influenced by such factors as plant succession, exotic species invasion, bird species' tolerances for environmental variation, habitat occupancy patterns, and variation in food density or weather. The low model consistency that we observed for most species indicates the high variation in bird-landscape relations that managers and other decision makers may encounter. The uncertainty of interannual variation in bird-landscape relations can be reduced by using projections of bird distributions from different annual models to determine the likely range of temporal and spatial variation in a species' distribution. Stochastic simulation models can be used to incorporate the uncertainty of random environmental variation into predictions of bird distributions based on bird-landscape relations and to provide probabilistic projections with which managers can weigh the costs and benefits of various decisions, Uncertainty about the true structure of bird-landscape relations

  14. Assessing the impact on birds of prey of nine established wind farms in Thrace, NE Greece

    Energy Technology Data Exchange (ETDEWEB)

    Kret, Elzbieta; Carcamo, Beatriz; Zografou, Christina; Vasilakis, Dimitris

    2011-07-01

    Full text: In this study, we evaluate the impact on birds of prey of nine already established wind farms in Thrace, where a large scale wind farm development project of at least 930 MW is under development. Moreover, the area is acknowledged as of high ornithological interest, used for nesting, wintering and passage by rare territorial birds of prey, including the Near Threatened black vultures that use it for foraging. Finally, ca 50% of the wind farm development project area is covered by Natura 2000 sites. During the monitoring (2008-2010), carcass surveys were carried out in order to estimate mortality. In addition, avian space use surveys were carried out, in order to calculate indexes and to establish comparisons with a previous monitoring study run in 2004-05. In total, 14 birds of prey were found dead (one black vulture, four griffon vultures, one booted eagle, two short-toed eagles, one western marsh harrier, one Eurasian sparrow hawk, three common buzzards, one hawk species). The estimated mortality rate was 0.152 birds of prey (including vultures/turbine/year). Griffon vultures, black vultures and common buzzards comprised more than 50% of observations in the study area. Crossing densities between wind turbines were positively correlated with east exposition and the inclination of the slope, and the length of the wind turbines. gaps, while it was negatively correlated with north exposition. The use of the area was more intensive four years after the initial monitoring, but numbers of common buzzard observations drastically decreased. We suggest that during the planning phase of wind farms it is important to avoid steep slopes, east expositions and to take into account the distance between consecutive wind turbines. Our findings indicate that running a post-construction monitoring during only one year may not be enough to properly assess the impact of wind farms on birds of prey. (Author)

  15. Emergence of long distance bird migrations: a new model integrating global climate changes

    Science.gov (United States)

    Louchart, Antoine

    2008-12-01

    During modern birds history, climatic and environmental conditions have evolved on wide scales. In a continuously changing world, landbirds annual migrations emerged and developed. However, models accounting for the origins of these avian migrations were formulated with static ecogeographic perspectives. Here I reviewed Cenozoic paleoclimatic and paleontological data relative to the palearctic paleotropical long distance (LD) migration system. This led to propose a new model for the origin of LD migrations, the ‘shifting home’ model (SHM). It is based on a dynamic perspective of climate evolution and may apply to the origins of most modern migrations. Non-migrant tropical African bird taxa were present at European latitudes during most of the Cenozoic. Their distribution limits shifted progressively toward modern tropical latitudes during periods of global cooling and increasing seasonality. In parallel, decreasing winter temperatures in the western Palearctic drove shifts of population winter ranges toward the equator. I propose that this induced the emergence of most short distance migrations, and in turn LD migrations. This model reconciliates ecologically tropical ancestry of most LD migrants with predominant winter range shifts, in accordance with requirements for heritable homing. In addition, it is more parsimonious than other non-exclusive models. Greater intrinsic plasticity of winter ranges implied by the SHM is supported by recently observed impacts of the present global warming on migrating birds. This may induce particular threats to some LD migrants. The ancestral, breeding homes of LD migrants were not ‘northern’ or ‘southern’ but shifted across high and middle latitudes while migrations emerged through winter range shifts themselves.

  16. Modeling the distribution of migratory bird stopovers to inform landscape-scale siting of wind development.

    Science.gov (United States)

    Pocewicz, Amy; Estes-Zumpf, Wendy A; Andersen, Mark D; Copeland, Holly E; Keinath, Douglas A; Griscom, Hannah R

    2013-01-01

    Conservation of migratory birds requires understanding the distribution of and potential threats to their migratory habitats. However, although migratory birds are protected under international treaties, few maps have been available to represent migration at a landscape scale useful to target conservation efforts or inform the siting of wind energy developments that may affect migratory birds. To fill this gap, we developed models that predict where four groups of birds concentrate or stopover during their migration through the state of Wyoming, USA: raptors, wetland, riparian and sparse grassland birds. The models were based on existing literature and expert knowledge concerning bird migration behavior and ecology and validated using expert ratings and known occurrences. There was significant agreement between migratory occurrence data and migration models for all groups except raptors, and all models ranked well with experts. We measured the overlap between the migration concentration models and a predictive model of wind energy development to assess the potential exposure of migratory birds to wind development and illustrate the utility of migratory concentration models for landscape-scale planning. Wind development potential is high across 15% of Wyoming, and 73% of this high potential area intersects important migration concentration areas. From 5.2% to 18.8% of each group's important migration areas was represented within this high wind potential area, with the highest exposures for sparse grassland birds and the lowest for riparian birds. Our approach could be replicated elsewhere to fill critical data gaps and better inform conservation priorities and landscape-scale planning for migratory birds.

  17. Woody plants and the prediction of climate-change impacts on bird diversity

    DEFF Research Database (Denmark)

    Kissling, W. Daniel; Field, R.; Korntheuer, H.;

    2010-01-01

    Current methods of assessing climate-induced shifts of species distributions rarely account for species interactions and usually ignore potential differences in response times of interacting taxa to climate change. Here, we used species-richness data from 1005 breeding bird and 1417 woody plant s...... even stronger effects for more specialized plant-animal associations. Given the slow response time of woody plant distributions to climate change, current estimates of future biodiversity of many animal taxa may be both biased and too optimistic.......Current methods of assessing climate-induced shifts of species distributions rarely account for species interactions and usually ignore potential differences in response times of interacting taxa to climate change. Here, we used species-richness data from 1005 breeding bird and 1417 woody plant...... species in Kenya and employed model-averaged coefficients from regression models and median climatic forecasts assembled across 15 climate-change scenarios to predict bird species richness under climate change. Forecasts assuming an instantaneous response of woody plants and birds to climate change...

  18. Danger in the nursery : impact on birds of tar sands oil development in Canada's boreal forest

    Energy Technology Data Exchange (ETDEWEB)

    Wells, J. [Boreal Songbird Initiative, Seattle, WA (United States); Casey-Lefkowitz, S.; Chavarria, G. [Natural Resources Defense Council, New York, NY (United States); Dyer, S. [Pembina Institute, Drayton Valley, AB (Canada)

    2008-07-01

    This report discussed the impacts of tar sands oil development in Canada's boreal forest. The Canadian boreal forest is one of the world's most important breeding areas for migratory birds, with 1 billion to 3 billion individual birds from at least 300 species known to regularly breed there. Approximately 30 per cent of all shorebirds and 30 per cent of all landbirds that breed in the United States and Canada do so within the boreal. The section of the boreal forest that sits over the tar sands region of Alberta is rapidly being fragmented by oil development. As much as 34 to 66 per cent of the Canadian boreal forest, up to 438 million acres, may no longer be intact. In Alberta, 86 per cent of the boreal forest is no longer considered intact, thus putting valuable bird habitat at risk. This report first provided background information on Canada's boreal forest as North America's nesting bird destination. It then reviewed the dangers created by tar sands operations for boreal birds. It noted that tar sands mining destroys boreal bird habitat; tailings ponds trap birds in oil waste; tar sands drilling fragments bird habitat; tar sands water withdrawals harm wetlands and water habitats; and tar sands toxins weaken and kill boreal birds. The impacts of tar sands pipelines and refineries were also discussed along with global warming impacts on boreal birds and the path forward for habitat protection. It was recommended that Alberta should implement a moratorium on new tar sands lease sales, and that Alberta and Canada should halt project approvals until long-term mitigation strategies and conservation measures are in place. refs., tabs., figs.

  19. Impacts of Traffic Noise and Traffic Volume on Birds of Roadside Habitats

    Directory of Open Access Journals (Sweden)

    Kirsten M. Parris

    2009-06-01

    Full Text Available Roadside habitats are important for a range of taxa including plants, insects, mammals, and birds, particularly in developed countries in which large expanses of native vegetation have been cleared for agriculture or urban development. Although roadside vegetation may provide suitable habitat for many species, resident animals can be exposed to high levels of traffic noise, visual disturbance from passing vehicles, and the risk of collision with cars and trucks. Traffic noise can reduce the distance over which acoustic signals such as song can be detected, an effect known as acoustic interference or masking. Studies from the northern hemisphere show that the singing behavior of birds changes in the presence of traffic noise. We investigated the impact of traffic noise and traffic volume on two species of birds, the Grey Shrike-thrush (Colluricincla harmonica and the Grey Fantail (Rhipidura fuliginosa, at 58 roadside sites on the Mornington Peninsula, southeastern Australia. The lower singing Grey Shrike-thrush sang at a higher frequency in the presence of traffic noise, with a predicted increase in dominant frequency of 5.8 Hz/dB of traffic noise, and a total effect size of 209 Hz. In contrast, the higher singing Grey Fantail did not appear to change its song in traffic noise. The probability of detecting each species on a visit to a site declined substantially with increasing traffic noise and traffic volume, with several lines of evidence supporting a larger effect of traffic noise. Traffic noise could hamper detection of song by conspecifics, making it more difficult for birds to establish and maintain territories, attract mates and maintain pair bonds, and possibly leading to reduced breeding success in noisy roadside habitats. Closing key roads during the breeding season is a potential, but untested, management strategy to protect threatened bird species from traffic noise and collision with vehicles at the time of year when they are most

  20. A numerical model for bird strike on sidewall structure of an aircraft nose

    Directory of Open Access Journals (Sweden)

    Liu Jun

    2014-06-01

    Full Text Available In order to examine the potential of using the coupled smooth particles hydrodynamic (SPH and finite element (FE method to predict the dynamic responses of aircraft structures in bird strike events, bird-strike tests on the sidewall structure of an aircraft nose are carried out and numerically simulated. The bird is modeled with SPH and described by the Murnaghan equation of state, while the structure is modeled with finite elements. A coupled SPH–FE method is developed to simulate the bird-strike tests and a numerical model is established using a commercial software PAM-CRASH. The bird model shows no signs of instability and correctly modeled the break-up of the bird into particles. Finally the dynamic response such as strains in the skin is simulated and compared with test results, and the simulated deformation and fracture process of the sidewall structure is compared with images recorded by a high speed camera. Good agreement between the simulation results and test data indicates that the coupled SPH–FE method can provide a very powerful tool in predicting the dynamic responses of aircraft structures in events of bird strike.

  1. A numerical model for bird strike on sidewall structure of an aircraft nose

    Institute of Scientific and Technical Information of China (English)

    Liu Jun; Li Yulong; Gao Xiaosheng; Yu Xiancheng

    2014-01-01

    In order to examine the potential of using the coupled smooth particles hydrodynamic (SPH) and finite element (FE) method to predict the dynamic responses of aircraft structures in bird strike events, bird-strike tests on the sidewall structure of an aircraft nose are carried out and numerically simulated. The bird is modeled with SPH and described by the Murnaghan equation of state, while the structure is modeled with finite elements. A coupled SPH-FE method is developed to simulate the bird-strike tests and a numerical model is established using a commercial software PAM-CRASH. The bird model shows no signs of instability and correctly modeled the break-up of the bird into particles. Finally the dynamic response such as strains in the skin is simulated and compared with test results, and the simulated deformation and fracture process of the sidewall structure is compared with images recorded by a high speed camera. Good agreement between the simulation results and test data indicates that the coupled SPH-FE method can provide a very powerful tool in predicting the dynamic responses of aircraft structures in events of bird strike.

  2. Population Trends of Central European Montane Birds Provide Evidence for Adverse Impacts of Climate Change on High-Altitude Species.

    Directory of Open Access Journals (Sweden)

    Jiří Flousek

    Full Text Available Climate change is among the most important global threats to biodiversity and mountain areas are supposed to be under especially high pressure. Although recent modelling studies suggest considerable future range contractions of montane species accompanied with increased extinction risk, data allowing to test actual population consequences of the observed climate changes and identifying traits associated to their adverse impacts are very scarce. To fill this knowledge gap, we estimated long-term population trends of montane birds from 1984 to 2011 in a central European mountain range, the Giant Mountains (Krkonoše, where significant warming occurred over this period. We then related the population trends to several species' traits related to the climate change effects. We found that the species breeding in various habitats at higher altitudes had more negative trends than species breeding at lower altitudes. We also found that the species moved upwards as a response to warming climate, and these altitudinal range shifts were associated with more positive population trends at lower altitudes than at higher altitudes. Moreover, long-distance migrants declined more than residents or species migrating for shorter distances. Taken together, these results indicate that the climate change, besides other possible environmental changes, already influences populations of montane birds with particularly adverse impacts on high-altitude species such as water pipit (Anthus spinoletta. It is evident that the alpine species, predicted to undergo serious climatically induced range contractions due to warming climate in the future, already started moving along this trajectory.

  3. Population Trends of Central European Montane Birds Provide Evidence for Adverse Impacts of Climate Change on High-Altitude Species.

    Science.gov (United States)

    Flousek, Jiří; Telenský, Tomáš; Hanzelka, Jan; Reif, Jiří

    2015-01-01

    Climate change is among the most important global threats to biodiversity and mountain areas are supposed to be under especially high pressure. Although recent modelling studies suggest considerable future range contractions of montane species accompanied with increased extinction risk, data allowing to test actual population consequences of the observed climate changes and identifying traits associated to their adverse impacts are very scarce. To fill this knowledge gap, we estimated long-term population trends of montane birds from 1984 to 2011 in a central European mountain range, the Giant Mountains (Krkonoše), where significant warming occurred over this period. We then related the population trends to several species' traits related to the climate change effects. We found that the species breeding in various habitats at higher altitudes had more negative trends than species breeding at lower altitudes. We also found that the species moved upwards as a response to warming climate, and these altitudinal range shifts were associated with more positive population trends at lower altitudes than at higher altitudes. Moreover, long-distance migrants declined more than residents or species migrating for shorter distances. Taken together, these results indicate that the climate change, besides other possible environmental changes, already influences populations of montane birds with particularly adverse impacts on high-altitude species such as water pipit (Anthus spinoletta). It is evident that the alpine species, predicted to undergo serious climatically induced range contractions due to warming climate in the future, already started moving along this trajectory.

  4. Terror birds on the run: a mechanical model to estimate its maximum running speed

    Science.gov (United States)

    Blanco, R. Ernesto; Jones, Washington W

    2005-01-01

    ‘Terror bird’ is a common name for the family Phorusrhacidae. These large terrestrial birds were probably the dominant carnivores on the South American continent from the Middle Palaeocene to the Pliocene–Pleistocene limit. Here we use a mechanical model based on tibiotarsal strength to estimate maximum running speeds of three species of terror birds: Mesembriornis milneedwardsi, Patagornis marshi and a specimen of Phorusrhacinae gen. The model is proved on three living large terrestrial bird species. On the basis of the tibiotarsal strength we propose that Mesembriornis could have used its legs to break long bones and access their marrow. PMID:16096087

  5. Impacts of transmission lines on birds in flight: proceedings of a workshop

    Science.gov (United States)

    Avery, Michael L.

    1978-01-01

    Progress to alleviate the national and world energy problem will come as individual issues are identified and acceptable solutions implemented. One of the specific issues to emerge in the last few years in the United States is the impact of electric power transmission lines on birds in flight. Therefore, the National Power Plant Team, Office of Biological Services, U.S. Fish and Wildlife Service, requested Oak Ridge Associated Universities (ORAU) to organized and convene a workshop of knowledgeable experts to examine this issue and options for dealing with it. The participants are listed at the end of this report.

  6. Numerical Simulation of Bird Impact on the Helicopter Blade by Fluid-structure Coupling Method%采用流固耦合方法的直升机桨叶鸟撞数值模拟

    Institute of Scientific and Technical Information of China (English)

    林长亮; 王浩文; 陈仁良; 尚晓冬

    2012-01-01

    During the process of bird impact on helicopter blades, the relative speed is quite fast and the bird presents the fluid characteristic. So the impact between the bird and helicopter blade is a typical transient fluid-structure coupling dynamics. Firstly, to verify the calculation method and the bird model, the bird impact on aluminum plate test in the literature is analyzed by adopting ALE fluid-solid coupling method. Then numerical simulation of bird impact on the blades is conducted. The numerical simulation results show that the ALE method can accurately simulate and be applied to the process of bird impact on helicopter blade. The detailed analysis to the calculation result such as stress, displacement and impact pressure provides a reference to anti-bird impact on helicopter rotor design.%在鸟撞直升机桨叶过程中,鸟体与桨叶撞击相对速度很大,呈现出流体特性,属于典型的流固耦合瞬态冲击动力学问题.首先针对文献中的鸟撞铝板试验采用ALE流固耦合方法进行了分析,对计算方法与鸟体模型进行了验证.然后进行了桨叶鸟撞数值模拟.数值模拟结果表明ALE方法能够准确模拟鸟撞过程,适用于直升机桨叶鸟撞分析.通过应力、位移以及撞击压力等计算结果的详细分析,对直升机旋翼抗鸟撞设计具有一定的参考价值.

  7. 民机典型前缘结构抗鸟撞分析研究%Study of Bird Impact Resistance for Typical Civil Aircraft Leading Edge Structure

    Institute of Scientific and Technical Information of China (English)

    何瑞

    2013-01-01

    为保障飞行安全,CCAR25部对民机结构抗鸟撞性能提出了严格的指令性要求,须对机翼前缘、平尾前缘和垂尾前缘等典型前缘结构进行鸟撞分析。鸟撞分析涉及到结构的动力学分析、鸟体的本构关系模拟、材料的高速非线性效应以及结构大变形等多方面因素的影响,相关的计算复杂,会耗费结构设计人员大量的精力和时间。通过采用经验公式和仿真分析方法对前缘结构抗鸟撞性能进行快速的分析,可达到对结构的抗鸟撞能力进行快速预估并从而指导设计的目的。%For flying safety, leading edge structures include wing leading edge horizontal leading edge and vertical leading edge, which are very typical structures in civil aircraft. Bird impact analysis has relations with the structure dynamic analysis the physical model of bird the high speed non-linear influences of material and the structure large displacements. It will cost many energies and much time to accurately analyze bird impact resistance's properties of the structure, and will reduce the work efficiency. In the paper, experienced formula and simulation to quickly an-alyze the bird impact resistance of the aircraft leading edge is employed, then according to the analysis estimates the structure's bird impact resistance, finally depending on the estimation we can quickly revise the design to achieve the aim at the analysis guiding design.

  8. Potential Impacts of Extended Winter Navigation upon Migratory Birds of the Upper U.S. Great Lakes. Great Lakes-St. Lawrence Seaway Navigation Season Extension Program

    Science.gov (United States)

    1982-09-01

    Biological Services Program OBS-82i51 SEPTEMBER 1982 POTENTIAL IMPACTS OF EXTENDED WINTER ’It NAVIGATION UPON MIGRATORY BIRDS OF THE UPPER N"j U.S...Security Classification) Potential Impacts of Extended Winter Navigation Upon Migratory Birds of the Upper U.S. Great Lakes 12. PERSONAL AUTHOR(S) Davis...PAGE Unclassified Potential Impacts of Extended Winter Navigation upon Migratory Birds of the Upper U.S. Great Lakes ERRATA SHEET Page XVII, item F6

  9. The Distribution and Abundance of Bird Species: Towards a Satellite, Data Driven Avian Energetics and Species Richness Model

    Science.gov (United States)

    Smith, James A.

    2003-01-01

    This paper addresses the fundamental question of why birds occur where and when they do, i.e., what are the causative factors that determine the spatio-temporal distributions, abundance, or richness of bird species? In this paper we outline the first steps toward building a satellite, data-driven model of avian energetics and species richness based on individual bird physiology, morphology, and interaction with the spatio-temporal habitat. To evaluate our model, we will use the North American Breeding Bird Survey and Christmas Bird Count data for species richness, wintering and breeding range. Long term and current satellite data series include AVHRR, Landsat, and MODIS.

  10. Shades of green: A bird's eye view of wind energy; L'energie eolienne et son impact sur les oiseaux

    Energy Technology Data Exchange (ETDEWEB)

    Whittam, B.; Kingsley, A.

    2003-03-31

    The issue of birds being killed by wind turbines is discussed. The substance of the argument is that contrary to beliefs held primarily by those opposed to wind turbine developments, when correctly sited, wind turbines appear to have relatively little impact on birds. Historically, 'bird-kill' was a significant factor in the 1980s when a significant number of raptors were killed by wind turbines and their associated power lines in California, Tennessee, Spain and the Netherlands, where many turbines were located on major bird migration routes. Based on experiences learned from these occurrences, several countries have produced bird-focused guidelines for the siting of wind turbines. In Canada, Bird Studies Canada was recently contracted by Environment Canada to produce guidelines for the environmental assessment of wind turbine projects related to birds. The objective of the guidelines is to help prevent adverse impacts on birds, whether the impact is related to habitat disturbance or collision. Based on American studies, it is estimated that 2.19 birds are killed annually at each wind turbine in California; the estimated fatality rate elsewhere in the United States is 1.83. That works out to 33,000 dead birds (based on 15,000 wind turbines), a large number, but relatively small when compared with the millions of birds that travel over windfarms each year, or when compared to the many millions of birds that die annually due to collisions with transmission lines, vehicles, buildings and communication towers. Nevertheless, there is room for concern. Bird Studies Canada is particularly concerned about the growing offshore wind industry and its potential to disrupt songbird migration, waterfowl staging areas and the prey base of seabirds. In general, Bird Studies Canada advises against siting large wind facilities in areas heavily travelled by birds, and is firmly opposed to placing wind turbines in areas known to provide critical habitat for Species At Risk

  11. Impact of wild herbivorous mammals and birds on the altitudinal and northern treeline ecotones

    Directory of Open Access Journals (Sweden)

    Friedrich-Karl Holtmeier

    2012-10-01

    Full Text Available Wild herbivorous mammals may damage treeline vegetation an cause soil erosion at a local scale. In many high mountain areas of Europe and North America, large numbers of red deer have become a threat to the maintenance of high-elevation forests and attempts to restore the climatic treeline. In northern Fennoscandia, overgrazing by reindeer in combination with mass outbreaks of the autumnal moth are influencing treeline dynamics. Moose are also increasingly involved damaging treeline forest. In the Alps, the re-introduction of ibex is causing local damage to subalpine forests and tree establishment above the forest limit as well as aggravating soil erosion. High-elevation forests and treeline in Europe are susceptible to the deleterious impact of wild ungulate populations because of former extensive pastoral use. Rodents may damage tree seedlings and saplings by girdling, root cutting, bark stripping and burrowing. Hares damage young trees by gnawing. Large numbers of small rodents may occasionally impede tree regeneration by depleting the seed sources. Rodents do not contribute to forest expansion beyond the current treeline. Among birds, nutcrackers are highly effective in influencing tree distribution patterns and treeline dynamics. Without the nutcracker caching of stone pine seeds any upward advance of the trees in response to climatic warming would be impossible. Some bird species such as black grouse, willow grouse and ptarmigan can impair tree growth by feeding on buds, catkins and fresh terminal shoots.

  12. Model-based evaluation of highly and low pathogenic avian influenza dynamics in wild birds.

    Directory of Open Access Journals (Sweden)

    Viviane Hénaux

    Full Text Available There is growing interest in avian influenza (AI epidemiology to predict disease risk in wild and domestic birds, and prevent transmission to humans. However, understanding the epidemic dynamics of highly pathogenic (HPAI viruses remains challenging because they have rarely been detected in wild birds. We used modeling to integrate available scientific information from laboratory and field studies, evaluate AI dynamics in individual hosts and waterfowl populations, and identify key areas for future research. We developed a Susceptible-Exposed-Infectious-Recovered (SEIR model and used published laboratory challenge studies to estimate epidemiological parameters (rate of infection, latency period, recovery and mortality rates, considering the importance of age classes, and virus pathogenicity. Infectious contact leads to infection and virus shedding within 1-2 days, followed by relatively slower period for recovery or mortality. We found a shorter infectious period for HPAI than low pathogenic (LP AI, which may explain that HPAI has been much harder to detect than LPAI during surveillance programs. Our model predicted a rapid LPAI epidemic curve, with a median duration of infection of 50-60 days and no fatalities. In contrast, HPAI dynamics had lower prevalence and higher mortality, especially in young birds. Based on field data from LPAI studies, our model suggests to increase surveillance for HPAI in post-breeding areas, because the presence of immunologically naïve young birds is predicted to cause higher HPAI prevalence and bird losses during this season. Our results indicate a better understanding of the transmission, infection, and immunity-related processes is required to refine predictions of AI risk and spread, improve surveillance for HPAI in wild birds, and develop disease control strategies to reduce potential transmission to domestic birds and/or humans.

  13. Barcoding Neotropical birds: assessing the impact of nonmonophyly in a highly diverse group.

    Science.gov (United States)

    Chaves, Bárbara R N; Chaves, Anderson V; Nascimento, Augusto C A; Chevitarese, Juliana; Vasconcelos, Marcelo F; Santos, Fabrício R

    2015-07-01

    In this study, we verified the power of DNA barcodes to discriminate Neotropical birds using Bayesian tree reconstructions of a total of 7404 COI sequences from 1521 species, including 55 Brazilian species with no previous barcode data. We found that 10.4% of species were nonmonophyletic, most likely due to inaccurate taxonomy, incomplete lineage sorting or hybridization. At least 0.5% of the sequences (2.5% of the sampled species) retrieved from GenBank were associated with database errors (poor-quality sequences, NuMTs, misidentification or unnoticed hybridization). Paraphyletic species (5.8% of the total) can be related to rapid speciation events leading to nonreciprocal monophyly between recently diverged sister species, or to absence of synapomorphies in the small COI region analysed. We also performed two series of genetic distance calculations under the K2P model for intraspecific and interspecific comparisons: the first included all COI sequences, and the second included only monophyletic taxa observed in the Bayesian trees. As expected, the mean and median pairwise distances were smaller for intraspecific than for interspecific comparisons. However, there was no precise 'barcode gap', which was shown to be larger in the monophyletic taxon data set than for the data from all species, as expected. Our results indicated that although database errors may explain some of the difficulties in the species discrimination of Neotropical birds, distance-based barcode assignment may also be compromised because of the high diversity of bird species and more complex speciation events in the Neotropics. © 2014 John Wiley & Sons Ltd.

  14. Wired: impacts of increasing power line use by a growing bird population

    Science.gov (United States)

    Moreira, Francisco; Encarnação, Vitor; Rosa, Gonçalo; Gilbert, Nathalie; Infante, Samuel; Costa, Julieta; D’Amico, Marcello; Martins, Ricardo C.; Catry, Inês

    2017-02-01

    Power lines are increasingly widespread across many regions of the planet. Although these linear infrastructures are known for their negative impacts on bird populations, through collision and electrocution, some species take advantage of electricity pylons for nesting. In this case, estimation of the net impact of these infrastructures at the population level requires an assessment of trade-offs between positive and negative impacts. We compiled historical information (1958–2014) of the Portuguese white stork Ciconia ciconia population to analyze long-term changes in numbers, distribution range and use of nesting structures. White stork population size increased 660% up to 12000 breeding pairs between 1984 and 2014. In the same period, the proportion of nests on electricity pylons increased from 1% to 25%, likely facilitated by the 60% increase in the length of the very high tension power line grid (holding the majority of the nests) in the stork’s distribution range. No differences in breeding success were registered for storks nesting on electricity pylons versus other structures, but a high risk of mortality by collision and electrocution with power lines was estimated. We discuss the implications of this behavioral change, and of the management responses by power line companies, both for stork populations and for managers.

  15. Conceptual ecological model for management of breeding shrubland birds in the Mid-Atlantic Region

    Science.gov (United States)

    Peterjohn, Bruce G.

    2006-01-01

    communities. This project involved parks within three NPS Inventory and Monitoring Program (I&M) networks, Mid-Atlantic, National Capital, and Eastern Rivers and Mountains. Five parks were selected for the initial focus of this study, all of which maintain open landscapes for interpreting historic events. Most parks were selected because they contain the most extensive grassland habitats within their networks, although some also support shrubby successional habitats. The five parks included in this study are Antietam National Battlefield, Fort Necessity National Battlefield, Gettysburg National Battlefield, Manassas National Battlefield, and Monocacy National Battlefield. This conceptual ecological model is one product of this project. The information presented below allows NPS network coordinators to understand which factors should be considered when making decisions concerning shrubland management within their networks. This model provides park resource managers with information on shrubland ecology in the Mid-Atlantic Region, the ecological requirements of shrubland birds likely to occur in their parks, and management issues influencing whether significant breeding populations can occupy shrublands created and maintained in the parks. Resource managers can then make informed decisions concerning their ability to create and maintain shrubland habitats. The emphasis of this conceptual model is restricted to management of breeding shrubland birds. Additional species occur during migration and winter, and habitat requirements of shrubland birds during nonbreeding seasons may differ from those described for the breeding season.

  16. Impacts of changing rainfall regime on the demography of tropical birds

    Science.gov (United States)

    Brawn, Jeffrey D.; Benson, Thomas J.; Stager, Maria; Sly, Nicholas D.; Tarwater, Corey E.

    2016-12-01

    Biodiversity in tropical regions is particularly high and may be highly sensitive to climate change. Unfortunately, a lack of long-term data hampers understanding of how tropical species, especially animals, may react to projected environmental changes. The amount and timing of rainfall is key to the function of tropical ecosystems and, although specific model predictions differ, there is general agreement that rainfall regimes will change over large areas of the tropics. Here, we estimate associations between dry season length (DSL) and the population biology of 20 bird species sampled in central Panama over a 33-year period. Longer dry seasons decreased the population growth rates and viability of nearly one-third of the species sampled. Simulations with modest increases in DSL suggest that consistently longer dry seasons will change the structure of tropical bird communities. Such change may occur even without direct loss of habitat--a finding with fundamental implications for conservation planning. Systematic changes in rainfall regime may threaten some populations and communities of tropical animals even in large tracts of protected habitat. These findings suggest the need for collaboration between climate scientists and conservation biologists to identify areas where rainfall regimes will be able to plausibly maintain wildlife populations.

  17. Modelling effects of chemical exposure on birds wintering in agricultural landscapes: The western burrowing owl (Athene cunicularia hypugaea) as a case study

    Science.gov (United States)

    Engelman, C.A.; Grant, W.E.; Mora, M.A.; Woodin, M.

    2012-01-01

    We describe an ecotoxicological model that simulates the sublethal and lethal effects of chronic, low-level, chemical exposure on birds wintering in agricultural landscapes. Previous models estimating the impact on wildlife of chemicals used in agro-ecosystems typically have not included the variety of pathways, including both dermal and oral, by which individuals are exposed. The present model contains four submodels simulating (1) foraging behavior of individual birds, (2) chemical applications to crops, (3) transfers of chemicals among soil, insects, and small mammals, and (4) transfers of chemicals to birds via ingestion and dermal exposure. We demonstrate use of the model by simulating the impacts of a variety of commonly used herbicides, insecticides, growth regulators, and defoliants on western burrowing owls (Athene cunicularia hypugaea) that winter in agricultural landscapes in southern Texas, United States. The model generated reasonable movement patterns for each chemical through soil, water, insects, and rodents, as well as into the owl via consumption and dermal absorption. Sensitivity analysis suggested model predictions were sensitive to uncertainty associated with estimates of chemical half-lives in birds, soil, and prey, sensitive to parameters associated with estimating dermal exposure, and relatively insensitive to uncertainty associated with details of chemical application procedures (timing of application, amount of drift). Nonetheless, the general trends in chemical accumulations and the relative impacts of the various chemicals were robust to these parameter changes. Simulation results suggested that insecticides posed a greater potential risk to owls of both sublethal and lethal effects than do herbicides, defoliants, and growth regulators under crop scenarios typical of southern Texas, and that use of multiple indicators, or endpoints provided a more accurate assessment of risk due to agricultural chemical exposure. The model should prove

  18. Modelling effects of chemical exposure on birds wintering in agricultural landscapes: The western burrowing owl (Athene cunicularia hypugaea) as a case study

    Science.gov (United States)

    Engelman, Catherine A.; Grant, William E.; Mora, Miguel A.; Woodin, Marc

    2012-01-01

    We describe an ecotoxicological model that simulates the sublethal and lethal effects of chronic, low-level, chemical exposure on birds wintering in agricultural landscapes. Previous models estimating the impact on wildlife of chemicals used in agro-ecosystems typically have not included the variety of pathways, including both dermal and oral, by which individuals are exposed. The present model contains four submodels simulating (1) foraging behavior of individual birds, (2) chemical applications to crops, (3) transfers of chemicals among soil, insects, and small mammals, and (4) transfers of chemicals to birds via ingestion and dermal exposure. We demonstrate use of the model by simulating the impacts of a variety of commonly used herbicides, insecticides, growth regulators, and defoliants on western burrowing owls (Athene cunicularia hypugaea) that winter in agricultural landscapes in southern Texas, United States. The model generated reasonable movement patterns for each chemical through soil, water, insects, and rodents, as well as into the owl via consumption and dermal absorption. Sensitivity analysis suggested model predictions were sensitive to uncertainty associated with estimates of chemical half-lives in birds, soil, and prey, sensitive to parameters associated with estimating dermal exposure, and relatively insensitive to uncertainty associated with details of chemical application procedures (timing of application, amount of drift). Nonetheless, the general trends in chemical accumulations and the relative impacts of the various chemicals were robust to these parameter changes. Simulation results suggested that insecticides posed a greater potential risk to owls of both sublethal and lethal effects than do herbicides, defoliants, and growth regulators under crop scenarios typical of southern Texas, and that use of multiple indicators, or endpoints provided a more accurate assessment of risk due to agricultural chemical exposure. The model should prove

  19. Wind power's impacts on birds and bats - Synthesis report; Vindkraftens paaverkan paa faaglar och fladdermoess - Syntesrapport

    Energy Technology Data Exchange (ETDEWEB)

    Rydell, Jens; Hedenstroem, Anders; Green, Martin (Biologiska institutionen, Lunds universitet (Sweden)); Engstroem, Henri (Sveriges Ornitologiska Foerening/ Evolutionsbiologiskt Centrum, Uppsala Universitet (Sweden)); Kyed Larsen, Jesper (Vattenfall Wind Power, Fredericia (Denmark)); Pettersson, Jan (JP Faagelvind, Faerjestaden (Sweden))

    2011-11-15

    Wind power is apparently facing a major expansion and it is probably inevitable that birds and bats will be killed or otherwise adversely affected by wind turbines in the future. However, we believe that the planning framework (30 TWh in 2020) does not conflict with that viable populations of birds and bats are preserved. The risks of negative impacts can be limited significantly by planning and co-operation and using the knowledge that already exists. There are on the other hand also significant knowledge gaps to be filled in order to further reduce uncertainty at future wind projects

  20. Model to Track Wild Birds for Avian Influenza by Means of Population Dynamics and Surveillance Information

    Science.gov (United States)

    Alba, Anna; Bicout, Dominique J.; Vidal, Francesc; Curcó, Antoni; Allepuz, Alberto; Napp, Sebastián; García-Bocanegra, Ignacio; Costa, Taiana; Casal, Jordi

    2012-01-01

    Design, sampling and data interpretation constitute an important challenge for wildlife surveillance of avian influenza viruses (AIV). The aim of this study was to construct a model to improve and enhance identification in both different periods and locations of avian species likely at high risk of contact with AIV in a specific wetland. This study presents an individual-based stochastic model for the Ebre Delta as an example of this appliance. Based on the Monte-Carlo method, the model simulates the dynamics of the spread of AIV among wild birds in a natural park following introduction of an infected bird. Data on wild bird species population, apparent AIV prevalence recorded in wild birds during the period of study, and ecological information on factors such as behaviour, contact rates or patterns of movements of waterfowl were incorporated as inputs of the model. From these inputs, the model predicted those species that would introduce most of AIV in different periods and those species and areas that would be at high risk as a consequence of the spread of these AIV incursions. This method can serve as a complementary tool to previous studies to optimize the allocation of the limited AI surveillance resources in a local complex ecosystem. However, this study indicates that in order to predict the evolution of the spread of AIV at the local scale, there is a need for further research on the identification of host factors involved in the interspecies transmission of AIV. PMID:22952962

  1. Model to track wild birds for avian influenza by means of population dynamics and surveillance information.

    Directory of Open Access Journals (Sweden)

    Anna Alba

    Full Text Available Design, sampling and data interpretation constitute an important challenge for wildlife surveillance of avian influenza viruses (AIV. The aim of this study was to construct a model to improve and enhance identification in both different periods and locations of avian species likely at high risk of contact with AIV in a specific wetland. This study presents an individual-based stochastic model for the Ebre Delta as an example of this appliance. Based on the Monte-Carlo method, the model simulates the dynamics of the spread of AIV among wild birds in a natural park following introduction of an infected bird. Data on wild bird species population, apparent AIV prevalence recorded in wild birds during the period of study, and ecological information on factors such as behaviour, contact rates or patterns of movements of waterfowl were incorporated as inputs of the model. From these inputs, the model predicted those species that would introduce most of AIV in different periods and those species and areas that would be at high risk as a consequence of the spread of these AIV incursions. This method can serve as a complementary tool to previous studies to optimize the allocation of the limited AI surveillance resources in a local complex ecosystem. However, this study indicates that in order to predict the evolution of the spread of AIV at the local scale, there is a need for further research on the identification of host factors involved in the interspecies transmission of AIV.

  2. Model study on the clinical signs and residue concentrations of sublethal carbofuran poisoning in birds.

    Science.gov (United States)

    Lehel, J; Laczay, P; Déri, J; Darin, E G; Budai, P

    2010-10-01

    The incidence of fatal poisoning of birds of prey caused by carbofuran has increased markedly in Hungary since 2007. An experimental model with broiler chickens was used to study clinical signs of sublethal carbofuran poisoning in birds and to measure the residue concentrations of carbamate in tissues after exposure. Eight chickens were treated with a carbofuran-containing insecticide orally by gastric tube at a single dose of 2.5 mg/kg body weight, and clinical signs of poisoning were observed. Gas chromatography was used to determine carbofuran concentrations in the blood, muscle, and liver samples, and in stomach contents. Poisoning was characterized by typical muscarinic and nicotinic clinical signs without mortality. Carbofuran in the stomach and edible tissues of acutely poisoned birds may lead to secondary poisoning of predators and may also present risks to human health.

  3. Three-dimensional numerical simulation of a bird model in unsteady flight

    Science.gov (United States)

    Lin-Lin, Zhu; Hui, Guan; Chui-Jie, Wu

    2016-07-01

    In this paper, a type of numerical simulation of a three-dimensional (3D) bionic bird with flapping wings in a viscous flow is studied. The model is a self-propelled flying bird capable of free rotation and translation whose flying motion follows the laws of conservation of momentum and angular momentum. The bird is propelled and lifted through flapping and rotating wings and most of thrust force and lift force are exerted on both wings. Both the vortex structures and the flight characteristics are also presented. The relationship between both wings' movement and the vortex structures as well as that between both wings' movement and flight characteristics are also analyzed in this paper. The study uses a 3D computational fluid dynamics package that includes the combined immersed boundary method, volume of fluid method, adaptive multigrid finite volume method, and control strategy for swimming and flying.

  4. Using regional bird density distribution models to evaluate protected area networks and inform conservation planning

    Science.gov (United States)

    John D. Alexander; Jaime L. Stephens; Sam Veloz; Leo Salas; Josée S. Rousseau; C. John Ralph; Daniel A. Sarr

    2017-01-01

    As data about populations of indicator species become available, proactive strategies that improve representation of biological diversity within protected area networks should consider finer-scaled evaluations, especially in regions identified as important through course-scale analyses. We use density distribution models derived from a robust regional bird...

  5. Theoretical analysis of an iron mineral-based magnetoreceptor model in birds

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Greiner, Walter

    2007-01-01

    involves two types of iron minerals (magnetite and maghemite) that were found in subcellular compartments within sensory dendrites of the upper beak of several bird species. But so far a quantitative evaluation of the proposed receptor is missing. In this article, we develop a theoretical model...

  6. Balance between climate change mitigation benefits and land use impacts of bioenergy: conservation implications for European birds.

    Science.gov (United States)

    Meller, Laura; Thuiller, Wilfried; Pironon, Samuel; Barbet-Massin, Morgane; Hof, Andries; Cabeza, Mar

    2015-07-01

    Both climate change and habitat modification exert serious pressure on biodiversity. Although climate change mitigation has been identified as an important strategy for biodiversity conservation, bioenergy remains a controversial mitigation action due to its potential negative ecological and socio-economic impacts which arise through habitat modification by land-use change. While the debate continues, the separate or simultaneous impacts of both climate change and bioenergy on biodiversity have not yet been compared. We assess projected range shifts of 156 European bird species by 2050 under two alternative climate change trajectories: a baseline scenario, where the global mean temperature increases by 4°C by the end of the century, and a 2 degrees scenario, where global concerted effort limits the temperature increase to below 2°C. For the latter scenario, we also quantify the pressure exerted by increased cultivation of energy biomass as modelled by IMAGE2.4, an integrated land-use model. The global bioenergy use in this scenario is in the lower end of the range of previously estimated sustainable potential. Under the assumptions of these scenarios, we find that the magnitude of range shifts due to climate change is far greater than the impact of land conversion to woody bioenergy plantations within the European Union, and that mitigation of climate change reduces the exposure experienced by species. However, we identified potential for local conservation conflict between priority areas for conservation and bioenergy production. These conflicts must be addressed by strict bioenergy sustainability criteria that acknowledge biodiversity conservation needs beyond existing protected areas and apply also to biomass imported from outside the European Union.

  7. A resource-based modelling framework to assess habitat suitability for steppe birds in semiarid Mediterranean agricultural systems.

    Directory of Open Access Journals (Sweden)

    Laura Cardador

    Full Text Available European agriculture is undergoing widespread changes that are likely to have profound impacts on farmland biodiversity. The development of tools that allow an assessment of the potential biodiversity effects of different land-use alternatives before changes occur is fundamental to guiding management decisions. In this study, we develop a resource-based model framework to estimate habitat suitability for target species, according to simple information on species' key resource requirements (diet, foraging habitat and nesting site, and examine whether it can be used to link land-use and local species' distribution. We take as a study case four steppe bird species in a lowland area of the north-eastern Iberian Peninsula. We also compare the performance of our resource-based approach to that obtained through habitat-based models relating species' occurrence and land-cover variables. Further, we use our resource-based approach to predict the effects that change in farming systems can have on farmland bird habitat suitability and compare these predictions with those obtained using the habitat-based models. Habitat suitability estimates generated by our resource-based models performed similarly (and better for one study species than habitat based-models when predicting current species distribution. Moderate prediction success was achieved for three out of four species considered by resource-based models and for two of four by habitat-based models. Although, there is potential for improving the performance of resource-based models, they provide a structure for using available knowledge of the functional links between agricultural practices, provision of key resources and the response of organisms to predict potential effects of changing land-uses in a variety of context or the impacts of changes such as altered management practices that are not easily incorporated into habitat-based models.

  8. The Impact of Wild Birds and Farm Management on Salmonella and Campylobacter in Small Ruminants

    Science.gov (United States)

    Wild-birds are potential sources of enteric disease infections in farm animals. This study was designed to evaluate the potential pathways and control of foodborne pathogen transmission between wild-birds and farm animals. At two farms, a total of 14 one-acre pastures were fenced to each host 12 sh...

  9. Long-term climate impacts on breeding bird phenology in Pennsylvania, USA.

    Science.gov (United States)

    McDermott, Molly E; DeGroote, Lucas W

    2016-10-01

    Climate change is influencing bird phenology worldwide, but we still lack information on how many species are responding over long temporal periods. We assessed how climate affected passerine reproductive timing and productivity at a constant effort mist-netting station in western Pennsylvania using a model comparison approach. Several lines of evidence point to the sensitivity of 21 breeding passerines to climate change over five decades. The trends for temperature and precipitation over 53 years were slightly positive due to intraseasonal variation, with the greatest temperature increases and precipitation declines in early spring. Regardless of broodedness, migration distance, or breeding season, 13 species hatched young earlier over time with most advancing >3 days per decade. Warm springs were associated with earlier captures of juveniles for 14 species, ranging from 1- to 3-day advancement for every 1 °C increase. This timing was less likely to be influenced by spring precipitation; nevertheless, higher rainfall was usually associated with later appearance of juveniles and breeding condition in females. Temperature and precipitation were positively related to productivity for seven and eleven species, respectively, with negative relations evident for six and eight species. We found that birds fledged young earlier with increasing spring temperatures, potentially benefiting some multibrooded species. Indeed, some extended the duration of breeding in these warm years. Yet, a few species fledged fewer juveniles in warmer and wetter seasons, indicating that expected future increases could be detrimental to locally breeding populations. Although there were no clear relationships between life history traits and breeding phenology, species-specific responses to climate found in our study provide novel insights into phenological flexibility in songbirds. Our research underscores the value of long-term monitoring studies and the importance of continuing constant

  10. Detection of bird nests during mechanical weeding by incremental background modeling and visual saliency.

    Science.gov (United States)

    Steen, Kim Arild; Therkildsen, Ole Roland; Green, Ole; Karstoft, Henrik

    2015-03-02

    Mechanical weeding is an important tool in organic farming. However, the use of mechanical weeding in conventional agriculture is increasing, due to public demands to lower the use of pesticides and an increased number of pesticide-resistant weeds. Ground nesting birds are highly susceptible to farming operations, like mechanical weeding, which may destroy the nests and reduce the survival of chicks and incubating females. This problem has limited focus within agricultural engineering. However, when the number of machines increases, destruction of nests will have an impact on various species. It is therefore necessary to explore and develop new technology in order to avoid these negative ethical consequences. This paper presents a vision-based approach to automated ground nest detection. The algorithm is based on the fusion of visual saliency, which mimics human attention, and incremental background modeling, which enables foreground detection with moving cameras. The algorithm achieves a good detection rate, as it detects 28 of 30 nests at an average distance of 3.8 m, with a true positive rate of 0.75.

  11. Impact of commercial afforestation on bird populations in Mpumalanga Province, South Africa - Insights from bird-atlas data

    CSIR Research Space (South Africa)

    Allan, DG

    1997-02-01

    Full Text Available are negatively impacted by commercial afforestation, through the loss of the open grassland habitats on which they are reliant Species References Southern bald ibis Collar & Stuart (1985) Lesser kestrel Wattled crane Blue crane... & Stuart (1985) Tarboton et al. (1987) Johnson (1992) Collar et al. (1994) Taylor (1994) Taylor (1994) Tarboton (1989) Johnson (1992) Hockey et al. (1988) Collar et al. (1994) Allan et al. (1983) Snell (1979, 1988) Brooke...

  12. BIRDS AS A MODEL TO STUDY ADULT NEUROGENESIS: BRIDGING EVOLUTIONARY, COMPARATIVE AND NEUROETHOLOGICAL APPROCHES

    Science.gov (United States)

    BARNEA, ANAT; PRAVOSUDOV, VLADIMIR

    2011-01-01

    During the last few decades evidence has demonstrated that adult neurogenesis is a well-preserved feature throughout the animal kingdom. In birds, ongoing neuronal addition occurs rather broadly, to a number of brain regions. This review describes adult avian neurogenesis and neuronal recruitment, discusses factors that regulate these processes, and touches upon the question of their genetic control. Several attributes make birds an extremely advantageous model to study neurogenesis. First, song learning exhibits seasonal variation that is associated with seasonal variation in neuronal turnover in some song control brain nuclei, which seems to be regulated via adult neurogenesis. Second, food-caching birds naturally use memory-dependent behavior in learning locations of thousands of food caches scattered over their home ranges. In comparison with other birds, food-caching species have relatively enlarged hippocampi with more neurons and intense neurogenesis, which appears to be related to spatial learning. Finally, migratory behavior and naturally occurring social systems in birds also provide opportunities to investigate neurogenesis. Such diversity of naturally-occurring memory-based behaviors, combined with the fact that birds can be studied both in the wild and in the laboratory, make them ideal for investigation of neural processes underlying learning. This can be done by using various approaches, from evolutionary and comparative to neuroethological and molecular. Finally, we connect the avian arena to a broader view by providing a brief comparative and evolutionary overview of adult neurogenesis and by discussing the possible functional role of the new neurons. We conclude by indicating future directions and possible medical applications. PMID:21929623

  13. Modeling Bird Migration in Changing Habitats: Space-based Ornithology using Satellites and GIS

    Science.gov (United States)

    Smith, James A.; Deppe, Jill L.

    2008-01-01

    Understanding bird migration and avian biodiversity is one of the most compelling and challenging problems of modern biology with major implications for human health and conservation biology. Migration and conservation efforts cross national boundaries and are subject to numerous international agreements and treaties presenting challenges in both geographic space and time. Space based technology, coupled with geographic information systems, yields new opportunities to shed light on the distribution and movement of organisms on the planet and their sensitivity to human disturbances and environmental changes. At NASA, we are creating ecological forecasting tools for science and application users to address the consequences of loss of wetlands, flooding, drought or other natural disasters such as hurricanes on avian biodiversity and bird migration. In our work, we use individual organism biophysical models and drive these models with satellite observations and numerical weather predictions of the spatio-temporal gradients in climate and habitat. Geographic information system technology comprises one component of our overall simulation framework, especially for characterizing the changing habitats and conditions encountered by en-route migratory birds. Simulation provides a tool for studying bird migration across multiple scales and can be linked to mechanistic processes describing the time and energy budget states of migrating birds. Such models yield an understanding of how a migratory flyway and its component habitats function as a whole and link stop-over ecology with biological conservation and management. We present examples of our simulation of shorebirds, principally, pectoral sandpipers, along the central flyways of the United States and Canada from the Gulf of Mexico to Alaska.

  14. Modeling Bird Migration in Changing Habitats: Space-based Ornithology using Satellites and GIS

    Science.gov (United States)

    Smith, James A.; Deppe, Jill L.

    2008-01-01

    Understanding bird migration and avian biodiversity is one of the most compelling and challenging problems of modern biology with major implications for human health and conservation biology. Migration and conservation efforts cross national boundaries and are subject to numerous international agreements and treaties presenting challenges in both geographic space and time. Space based technology, coupled with geographic information systems, yields new opportunities to shed light on the distribution and movement of organisms on the planet and their sensitivity to human disturbances and environmental changes. At NASA, we are creating ecological forecasting tools for science and application users to address the consequences of loss of wetlands, flooding, drought or other natural disasters such as hurricanes on avian biodiversity and bird migration. In our work, we use individual organism biophysical models and drive these models with satellite observations and numerical weather predictions of the spatio-temporal gradients in climate and habitat. Geographic information system technology comprises one component of our overall simulation framework, especially for characterizing the changing habitats and conditions encountered by en-route migratory birds. Simulation provides a tool for studying bird migration across multiple scales and can be linked to mechanistic processes describing the time and energy budget states of migrating birds. Such models yield an understanding of how a migratory flyway and its component habitats function as a whole and link stop-over ecology with biological conservation and management. We present examples of our simulation of shorebirds, principally, pectoral sandpipers, along the central flyways of the United States and Canada from the Gulf of Mexico to Alaska.

  15. Modeling the Geography of Migratory Pathways and Stopover Habitats for Neotropical Migratory Birds

    OpenAIRE

    Roger Tankersley, Jr.; Kenneth Orvis

    2003-01-01

    Intact migratory routes are critical for the stability of forest-dwelling, neotropical, migratory bird populations, and mortality along migratory pathways may be significant. Yet we know almost nothing about the geography of available stopovers or the possible migratory pathways that connect optimal stopovers. We undertake a spatial analysis of stopover habitat availability and then model potential migratory pathways between optimal stopovers in the eastern United States. Using models of fixe...

  16. Frequency-dependent selection by wild birds promotes polymorphism in model salamanders

    Directory of Open Access Journals (Sweden)

    Shook Kim

    2009-05-01

    Full Text Available Abstract Background Co-occurrence of distinct colour forms is a classic paradox in evolutionary ecology because both selection and drift tend to remove variation from populations. Apostatic selection, the primary hypothesis for maintenance of colour polymorphism in cryptic animals, proposes that visual predators focus on common forms of prey, resulting in higher survival of rare forms. Empirical tests of this frequency-dependent foraging hypothesis are rare, and the link between predator behaviour and maintenance of variation in prey has been difficult to confirm. Here, we show that predatory birds can act as agents of frequency-dependent selection on terrestrial salamanders. Polymorphism for presence/absence of a dorsal stripe is widespread in many salamander species and its maintenance is a long-standing mystery. Results We used realistic food-bearing model salamanders to test whether selection by wild birds maintains a stripe/no-stripe polymorphism. In experimental manipulations, whichever form was most common was most likely to be attacked by ground-foraging birds, resulting in a survival advantage for the rare form. Conclusion This experiment demonstrates that frequency-dependent foraging by wild birds can maintain colour polymorphism in cryptic prey.

  17. Conceptual ecological model for management of breeding grassland birds in the Mid-Atlantic Region

    Science.gov (United States)

    Peterjohn, Bruce G.

    2006-01-01

    this study are: Antietam National Battlefield, Fort Necessity National Battlefield, Gettysburg National Battlefield, Manassas National Battlefield, and Monocacy National Battlefield. This conceptual ecological model is one product of this project. The information presented below allows NPS Network Coordinators to understand the factors to consider when making decisions concerning grassland management within their networks. This model provides park Resource Managers with information on grassland ecology in the Mid-Atlantic Region, the ecological requirements of grassland birds likely to occur in their parks, and management issues that influence whether significant breeding populations can be expected to occupy grasslands created and maintained in the parks. The Resource Managers can then make informed decisions concerning their ability to create and maintain grassland habitats. The emphasis of this conceptual model is restricted to management of breeding grassland birds. Additional species may occur in this region during migration and winter, while habitat requirements of all grassland birds during nonbreeding seasons will differ from those described for the breeding season.

  18. Impacts of the 1986 San Joaquin Valley crude oil spill on marine birds in central California

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A total of 10577 birds of at least 26 species were estimated to have been debilitated or killed by the spill. The totals for major groups were estimated as: 276...

  19. Bird Flight as a Model for a Course in Unsteady Aerodynamics

    Science.gov (United States)

    Jacob, Jamey; Mitchell, Jonathan; Puopolo, Michael

    2014-11-01

    Traditional unsteady aerodynamics courses at the graduate level focus on theoretical formulations of oscillating airfoil behavior. Aerodynamics students with a vision for understanding bird-flight and small unmanned aircraft dynamics desire to move beyond traditional flow models towards new and creative ways of appreciating the motion of agile flight systems. High-speed videos are used to record kinematics of bird flight, particularly barred owls and red-shouldered hawks during perching maneuvers, and compared with model aircraft performing similar maneuvers. Development of a perching glider and associated control laws to model the dynamics are used as a class project. Observations are used to determine what different species and sizes of birds share in their methods to approach a perch under similar conditions. Using fundamental flight dynamics, simplified models capable of predicting position, attitude, and velocity of the flier are developed and compared with the observations. By comparing the measured data from the videos and predicted and measured motions from the glider models, it is hoped that the students gain a better understanding of the complexity of unsteady aerodynamics and aeronautics and an appreciation for the beauty of avian flight.

  20. Virginia ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, pelagic birds, passerine birds, and gulls...

  1. Assessing risk to birds from industrial wind energy development via paired resource selection models.

    Science.gov (United States)

    Miller, Tricia A; Brooks, Robert P; Lanzone, Michael; Brandes, David; Cooper, Jeff; O'Malley, Kieran; Maisonneuve, Charles; Tremblay, Junior; Duerr, Adam; Katzner, Todd

    2014-06-01

    When wildlife habitat overlaps with industrial development animals may be harmed. Because wildlife and people select resources to maximize biological fitness and economic return, respectively, we estimated risk, the probability of eagles encountering and being affected by turbines, by overlaying models of resource selection for each entity. This conceptual framework can be applied across multiple spatial scales to understand and mitigate impacts of industry on wildlife. We estimated risk to Golden Eagles (Aquila chrysaetos) from wind energy development in 3 topographically distinct regions of the central Appalachian Mountains of Pennsylvania (United States) based on models of resource selection of wind facilities (n = 43) and of northbound migrating eagles (n = 30). Risk to eagles from wind energy was greatest in the Ridge and Valley region; all 24 eagles that passed through that region used the highest risk landscapes at least once during low altitude flight. In contrast, only half of the birds that entered the Allegheny Plateau region used highest risk landscapes and none did in the Allegheny Mountains. Likewise, in the Allegheny Mountains, the majority of wind turbines (56%) were situated in poor eagle habitat; thus, risk to eagles is lower there than in the Ridge and Valley, where only 1% of turbines are in poor eagle habitat. Risk within individual facilities was extremely variable; on average, facilities had 11% (SD 23; range = 0-100%) of turbines in highest risk landscapes and 26% (SD 30; range = 0-85%) of turbines in the lowest risk landscapes. Our results provide a mechanism for relocating high-risk turbines, and they show the feasibility of this novel and highly adaptable framework for managing risk of harm to wildlife from industrial development.

  2. IMPACT fragmentation model developments

    Science.gov (United States)

    Sorge, Marlon E.; Mains, Deanna L.

    2016-09-01

    The IMPACT fragmentation model has been used by The Aerospace Corporation for more than 25 years to analyze orbital altitude explosions and hypervelocity collisions. The model is semi-empirical, combining mass, energy and momentum conservation laws with empirically derived relationships for fragment characteristics such as number, mass, area-to-mass ratio, and spreading velocity as well as event energy distribution. Model results are used for several types of analysis including assessment of short-term risks to satellites from orbital altitude fragmentations, prediction of the long-term evolution of the orbital debris environment and forensic assessments of breakup events. A new version of IMPACT, version 6, has been completed and incorporates a number of advancements enabled by a multi-year long effort to characterize more than 11,000 debris fragments from more than three dozen historical on-orbit breakup events. These events involved a wide range of causes, energies, and fragmenting objects. Special focus was placed on the explosion model, as the majority of events examined were explosions. Revisions were made to the mass distribution used for explosion events, increasing the number of smaller fragments generated. The algorithm for modeling upper stage large fragment generation was updated. A momentum conserving asymmetric spreading velocity distribution algorithm was implemented to better represent sub-catastrophic events. An approach was developed for modeling sub-catastrophic explosions, those where the majority of the parent object remains intact, based on estimated event energy. Finally, significant modifications were made to the area-to-mass ratio distribution to incorporate the tendencies of different materials to fragment into different shapes. This ability enabled better matches between the observed area-to-mass ratios and those generated by the model. It also opened up additional possibilities for post-event analysis of breakups. The paper will discuss

  3. Population trends for North American winter birds based on hierarchical models

    Science.gov (United States)

    Soykan, Candan U.; Sauer, John; Schuetz, Justin G.; LeBaron, Geoffrey S.; Dale, Kathy; Langham, Gary M.

    2016-01-01

    Managing widespread and persistent threats to birds requires knowledge of population dynamics at large spatial and temporal scales. For over 100 yrs, the Audubon Christmas Bird Count (CBC) has enlisted volunteers in bird monitoring efforts that span the Americas, especially southern Canada and the United States. We employed a Bayesian hierarchical model to control for variation in survey effort among CBC circles and, using CBC data from 1966 to 2013, generated early-winter population trend estimates for 551 species of birds. Selecting a subset of species that do not frequent bird feeders and have ≥25% range overlap with the distribution of CBC circles (228 species) we further estimated aggregate (i.e., across species) trends for the entire study region and at the level of states/provinces, Bird Conservation Regions, and Landscape Conservation Cooperatives. Moreover, we examined the relationship between ten biological traits—range size, population size, migratory strategy, habitat affiliation, body size, diet, number of eggs per clutch, age at sexual maturity, lifespan, and tolerance of urban/suburban settings—and CBC trend estimates. Our results indicate that 68% of the 551 species had increasing trends within the study area over the interval 1966–2013. When trends were examined across the subset of 228 species, the median population trend for the group was 0.9% per year at the continental level. At the regional level, aggregate trends were positive in all but a few areas. Negative population trends were evident in lower latitudes, whereas the largest increases were at higher latitudes, a pattern consistent with range shifts due to climate change. Nine of 10 biological traits were significantly associated with median population trend; however, none of the traits explained >34% of the deviance in the data, reflecting the indirect relationships between population trend estimates and species traits. Trend estimates based on the CBC are broadly congruent with

  4. Preliminary methodology to assess the national and regional impact of U.S. wind energy development on birds and bats

    Science.gov (United States)

    Diffendorfer, James E.; Beston, Julie A.; Merrill, Matthew D.; Stanton, Jessica C.; Corum, Margo D.; Loss, Scott R.; Thogmartin, Wayne E.; Johnson, Douglas H.; Erickson, Richard A.; Heist, Kevin W.

    2015-01-01

    The U.S. Geological Survey has developed a methodology to assess the impacts of wind energy development on wildlife; it is a probabilistic, quantitative assessment methodology that can communicate to decision makers and the public the magnitude of these effects on species populations. The methodology is currently applicable to birds and bats, focuses primarily on the effects of collisions, and can be applied to any species that breeds in, migrates through, or otherwise uses any part of the United States. The methodology is intended to assess species at the national scale and is fundamentally different from existing methods focusing on impacts at individual facilities.

  5. Models of 'obesity' in large animals and birds.

    Science.gov (United States)

    Clarke, Iain J

    2008-01-01

    Most laboratory-based research on obesity is carried out in rodents, but there are a number of other interesting models in the animal kingdom that are instructive. This includes domesticated animal species such as pigs and sheep, as well as wild, migrating and hibernating species. Larger animals allow particular experimental manipulations that are not possible in smaller animals and especially useful models have been developed to address issues such as manipulation of fetal development. Although some of the most well-studied models are ruminants, with metabolic control that differs from monogastrics, the general principles of metabolic regulation still pertain. It is possible to obtain much more accurate endocrine profiles in larger animals and this has provided important data in relation to leptin and ghrelin physiology. Genetic models have been created in domesticated animals through selection and these complement those of the laboratory rodent. This short review highlights particular areas of research in domesticated and wild species that expand our knowledge of systems that are important for our understanding of obesity and metabolism.

  6. Research priorities in modeling the transmission risks of H7N9 bird flu

    OpenAIRE

    Wiwanitkit, Viroj; Shi, Benyun; Xia, Shang; Yang, Guo-Jing; Zhou, Xiao-Nong; Liu, Jiming

    2013-01-01

    The epidemic of H7N9 bird flu in eastern China in early 2013 has caused much attention from researchers as well as public health workers. The issue on modeling the transmission risks is very interesting topic. In this article, this issue is debated and discussed in order to promote further researches on prediction and prevention of avian influenza viruses supported by better interdisciplinary datasets from the surveillance and response system.

  7. Integrated Climate Change and Threatened Bird Population Modeling to Mitigate Operations Risks on Florida Military Installations

    Science.gov (United States)

    2013-01-01

    The integrated modeling and management framework developed in this study can be generalized to other coastal facilities and environmental... Nourishment , Exclosures, and Predator Management) have benefits worthy of investigation. In the following section we introduce the location of study , bird...m SLR as well as the No Action and Beach Nourishment scenarios. For this measure, cells throughout the study site with a habitat suitability equal

  8. Research priorities in modeling the transmission risks of H7N9 bird flu.

    Science.gov (United States)

    Wiwanitkit, Viroj; Shi, Benyun; Xia, Shang; Yang, Guo-Jing; Zhou, Xiao-Nong; Liu, Jiming

    2013-08-08

    The epidemic of H7N9 bird flu in eastern China in early 2013 has caused much attention from researchers as well as public health workers. The issue on modeling the transmission risks is very interesting topic. In this article, this issue is debated and discussed in order to promote further researches on prediction and prevention of avian influenza viruses supported by better interdisciplinary datasets from the surveillance and response system.

  9. Session: What have studies of communications towers suggested regarding the impact of guy wires and lights on birds and bats

    Energy Technology Data Exchange (ETDEWEB)

    Kerlinger, Paul

    2004-09-01

    This session at the Wind Energy and Birds/Bats workshop consisted of one presentation followed by a discussion/question and answer period. The paper ''Wind turbines and Avian Risk: Lessons from Communications Towers'' was given by Paul Kerlinger. The presenter outlined lessons that have been learned from research on communications (not cell) towers and about the impacts of guy wires and lights on birds and bats and how they could be useful to wind energy developers. The paper also provided specific information about a large 'fatality' event that occurred at the Mountaineer, WC wind energy site in May 2003, and a table of Night Migrant Carcass search findings for various wind sites in the US.

  10. Avian collision risk models for wind energy impact assessments

    Energy Technology Data Exchange (ETDEWEB)

    Masden, E.A., E-mail: elizabeth.masden@uhi.ac.uk [Environmental Research Institute, North Highland College-UHI, University of the Highlands and Islands, Ormlie Road, Thurso, Caithness KW14 7EE (United Kingdom); Cook, A.S.C.P. [British Trust for Ornithology, The Nunnery, Thetford IP24 2PU (United Kingdom)

    2016-01-15

    With the increasing global development of wind energy, collision risk models (CRMs) are routinely used to assess the potential impacts of wind turbines on birds. We reviewed and compared the avian collision risk models currently available in the scientific literature, exploring aspects such as the calculation of a collision probability, inclusion of stationary components e.g. the tower, angle of approach and uncertainty. 10 models were cited in the literature and of these, all included a probability of collision of a single bird colliding with a wind turbine during passage through the rotor swept area, and the majority included a measure of the number of birds at risk. 7 out of the 10 models calculated the probability of birds colliding, whilst the remainder used a constant. We identified four approaches to calculate the probability of collision and these were used by others. 6 of the 10 models were deterministic and included the most frequently used models in the UK, with only 4 including variation or uncertainty in some way, the most recent using Bayesian methods. Despite their appeal, CRMs have their limitations and can be ‘data hungry’ as well as assuming much about bird movement and behaviour. As data become available, these assumptions should be tested to ensure that CRMs are functioning to adequately answer the questions posed by the wind energy sector. - Highlights: • We highlighted ten models available to assess avian collision risk. • Only 4 of the models included variability or uncertainty. • Collision risk models have limitations and can be ‘data hungry’. • It is vital that the most appropriate model is used for a given task.

  11. Estimation of Muscle Mass by Ultrasonography Differs between Observers and Life States of Models in Small Birds.

    Science.gov (United States)

    Royer-Boutin, Pascal; Cortés, Pablo A; Milbergue, Myriam; Petit, Magali; Vézina, François

    2015-01-01

    Ultrasonography has proven to be a valuable noninvasive method of measure of muscle size in birds, but validation of its use in birds as small as black-capped chickadees (Poecile atricapillus; 11 g) is scarce. The effect of observers and life state (dead or alive) of models used for calibration on measurement quality is also poorly documented. Using 31 dead and 22 live chickadees, linear regressions between ultrasound and dissection measurements of pectoral and thigh muscles were fitted and compared between five different observers. R(2) values varied greatly between observers and were generally weaker in live birds, ranging between 0.02 and 0.59, despite high repeatability of measurement. Using equations calculated from dead birds to estimate muscle mass of live birds yielded much higher measurement errors (9%-18%) than when using equations calculated from live birds (5%-8%). Our results suggest that with careful training and using only calibration from live birds, ultrasonography can be a useful but limited tool to estimate muscle size of birds as small as the black-capped chickadee.

  12. Estimating bat and bird mortality occurring at wind energy turbines from covariates and carcass searches using mixture models.

    Science.gov (United States)

    Korner-Nievergelt, Fränzi; Brinkmann, Robert; Niermann, Ivo; Behr, Oliver

    2013-01-01

    Environmental impacts of wind energy facilities increasingly cause concern, a central issue being bats and birds killed by rotor blades. Two approaches have been employed to assess collision rates: carcass searches and surveys of animals prone to collisions. Carcass searches can provide an estimate for the actual number of animals being killed but they offer little information on the relation between collision rates and, for example, weather parameters due to the time of death not being precisely known. In contrast, a density index of animals exposed to collision is sufficient to analyse the parameters influencing the collision rate. However, quantification of the collision rate from animal density indices (e.g. acoustic bat activity or bird migration traffic rates) remains difficult. We combine carcass search data with animal density indices in a mixture model to investigate collision rates. In a simulation study we show that the collision rates estimated by our model were at least as precise as conventional estimates based solely on carcass search data. Furthermore, if certain conditions are met, the model can be used to predict the collision rate from density indices alone, without data from carcass searches. This can reduce the time and effort required to estimate collision rates. We applied the model to bat carcass search data obtained at 30 wind turbines in 15 wind facilities in Germany. We used acoustic bat activity and wind speed as predictors for the collision rate. The model estimates correlated well with conventional estimators. Our model can be used to predict the average collision rate. It enables an analysis of the effect of parameters such as rotor diameter or turbine type on the collision rate. The model can also be used in turbine-specific curtailment algorithms that predict the collision rate and reduce this rate with a minimal loss of energy production.

  13. Estimating bat and bird mortality occurring at wind energy turbines from covariates and carcass searches using mixture models.

    Directory of Open Access Journals (Sweden)

    Fränzi Korner-Nievergelt

    Full Text Available Environmental impacts of wind energy facilities increasingly cause concern, a central issue being bats and birds killed by rotor blades. Two approaches have been employed to assess collision rates: carcass searches and surveys of animals prone to collisions. Carcass searches can provide an estimate for the actual number of animals being killed but they offer little information on the relation between collision rates and, for example, weather parameters due to the time of death not being precisely known. In contrast, a density index of animals exposed to collision is sufficient to analyse the parameters influencing the collision rate. However, quantification of the collision rate from animal density indices (e.g. acoustic bat activity or bird migration traffic rates remains difficult. We combine carcass search data with animal density indices in a mixture model to investigate collision rates. In a simulation study we show that the collision rates estimated by our model were at least as precise as conventional estimates based solely on carcass search data. Furthermore, if certain conditions are met, the model can be used to predict the collision rate from density indices alone, without data from carcass searches. This can reduce the time and effort required to estimate collision rates. We applied the model to bat carcass search data obtained at 30 wind turbines in 15 wind facilities in Germany. We used acoustic bat activity and wind speed as predictors for the collision rate. The model estimates correlated well with conventional estimators. Our model can be used to predict the average collision rate. It enables an analysis of the effect of parameters such as rotor diameter or turbine type on the collision rate. The model can also be used in turbine-specific curtailment algorithms that predict the collision rate and reduce this rate with a minimal loss of energy production.

  14. Impact of the implementation of rest days in live bird markets on the dynamics of H5N1 highly pathogenic avian influenza.

    Science.gov (United States)

    Fournié, G; Guitian, F J; Mangtani, P; Ghani, A C

    2011-08-01

    Live bird markets (LBMs) act as a network 'hub' and potential reservoir of infection for domestic poultry. They may therefore be responsible for sustaining H5N1 highly pathogenic avian influenza (HPAI) virus circulation within the poultry sector, and thus a suitable target for implementing control strategies. We developed a stochastic transmission model to understand how market functioning impacts on the transmission dynamics. We then investigated the potential for rest days-periods during which markets are emptied and disinfected-to modulate the dynamics of H5N1 HPAI within the poultry sector using a stochastic meta-population model. Our results suggest that under plausible parameter scenarios, HPAI H5N1 could be sustained silently within LBMs with the time spent by poultry in markets and the frequency of introduction of new susceptible birds' dominant factors determining sustained silent spread. Compared with interventions applied in farms (i.e. stamping out, vaccination), our model shows that frequent rest days are an effective means to reduce HPAI transmission. Furthermore, our model predicts that full market closure would be only slightly more effective than rest days to reduce transmission. Strategies applied within markets could thus help to control transmission of the disease.

  15. Model selection for the North American Breeding Bird Survey: A comparison of methods

    Science.gov (United States)

    Link, William; Sauer, John; Niven, Daniel

    2017-01-01

    The North American Breeding Bird Survey (BBS) provides data for >420 bird species at multiple geographic scales over 5 decades. Modern computational methods have facilitated the fitting of complex hierarchical models to these data. It is easy to propose and fit new models, but little attention has been given to model selection. Here, we discuss and illustrate model selection using leave-one-out cross validation, and the Bayesian Predictive Information Criterion (BPIC). Cross-validation is enormously computationally intensive; we thus evaluate the performance of the Watanabe-Akaike Information Criterion (WAIC) as a computationally efficient approximation to the BPIC. Our evaluation is based on analyses of 4 models as applied to 20 species covered by the BBS. Model selection based on BPIC provided no strong evidence of one model being consistently superior to the others; for 14/20 species, none of the models emerged as superior. For the remaining 6 species, a first-difference model of population trajectory was always among the best fitting. Our results show that WAIC is not reliable as a surrogate for BPIC. Development of appropriate model sets and their evaluation using BPIC is an important innovation for the analysis of BBS data.

  16. Decision Support Tool: Modeling the Distribution and Abundance of Birds on the Alaska Peninsula: A Synthesis of Recent Survey Data

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This progress report for the Modeling the Distribution and Abundance of Birds on the Alaska Peninsula project covers activities during FY2015. The goal of this...

  17. Diving birds

    Science.gov (United States)

    Clanet, Christophe; Masson, Lucien; McKinley, Gareth; Cohen, Robert; Ecole polytechnique Collaboration; MIT Collaboration

    2015-11-01

    Many seabirds (gannets, pelicans, gulls, albatrosses) dive into water at high speeds (25 m/s) in order to capture underwater preys. Diving depths of 20 body lengths are reported in the literature. This value is much larger than the one achieved by men, which is of the order of 5. We study this difference by comparing the impact of slender vs bluff bodies. We show that, contrary to bluff bodies, the penetration depth of slender bodies presents a maximum value for a specific impact velocity that we connect to the velocity of diving birds.

  18. Public support for conserving bird species runs counter to climate change impacts on their distributions

    DEFF Research Database (Denmark)

    Lundhede, Thomas; Jacobsen, Jette Bredahl; Hanley, Nick

    2014-01-01

    There is increasing evidence that global climate change will alter the spatiotemporal occurrences and abundances of many species at continental scales. This will have implications for efficient conservation of biodiversity. We investigate if the general public in Denmark are willing to pay...... for the preservation of birds potentially immigrating and establishing breeding populations due to climate change to the same extent that they are for native species populations currently breeding in Denmark, but potentially emigrating due to climate change. We find that Danish citizens are willing to pay much more...... for the conservation of birds currently native to Denmark, than for bird species moving into the country – even when they are informed about the potential range shifts associated with climate change. The only exception is when immigrating species populations are under pressure at European level. Furthermore, people...

  19. A mechanical model of wing and theoretical estimate of taper factor for three gliding birds

    Indian Academy of Sciences (India)

    Moosarreza Shamsyeh Zahedi; Mir Yaseen Ali Khan

    2007-03-01

    We tested a mechanical model of wing, which was constructed using the measurements of wingspan and wing area taken from three species of gliding birds. In this model, we estimated the taper factors of the wings for jackdaw (Corrus monedula), Harris’ hawk (Parabuteo unicinctas) and Lagger falcon (Falco jugger) as 1.8, 1.5 and 1.8, respectively. Likewise, by using the data linear regression and curve estimation method, as well as estimating the taper factors and the angle between the humerus and the body, we calculated the relationship between wingspan, wing area and the speed necessary to meet the aerodynamic requirements of sustained flight. In addition, we calculated the relationship between the speed, wing area and wingspan for a specific angle between the humerus and the body over the range of stall speed to maximum speed of gliding flight. We then compared the results for these three species of gliding birds. These comparisons suggest that the aerodynamic characteristics of Harris’ hawk wings are similar to those of the falcon but different from those of the jackdaw. This paper also presents two simple equations to estimate the minimum angle between the humerus and the body as well as the minimum span ratio of a bird in gliding flight.

  20. A mechanical model of wing and theoretical estimate of taper factor for three gliding birds.

    Science.gov (United States)

    Zahedi, Moosarreza Shamsyeh; Khan, Mir Yaseen Ali

    2007-03-01

    We tested a mechanical model of wing,which was constructed using the measurements of wingspan and wing area taken from three species of gliding birds.In this model,we estimated the taper factors of the wings for jackdaw (Corrus monedula), Harris' hawk (Parabuteo unicinctas) and Lagger falcon (Falco jugger) as 1.8, 1.5 and 1.8,respectively. Likewise, by using the data linear regression and curve estimation method,as well as estimating the taper factors and the angle between the humerus and the body, we calculated the relationship between wingspan,wing area and the speed necessary to meet the aerodynamic requirements of sustained flight.In addition,we calculated the relationship between the speed,wing area and wingspan for a specific angle between the humerus and the body over the range of stall speed to maximum speed of gliding flight.We then compared the results for these three species of gliding birds. These comparisons suggest that the aerodynamic characteristics of Harris' hawk wings are similar to those of the falcon but different from those of the jackdaw.This paper also presents two simple equations to estimate the minimum angle between the humerus and the body as well as the minimum span ratio of a bird in gliding flight.

  1. Birds in an Australian Rainforest: Their Attraction for Visitors and Visitor's Ecological Impacts

    OpenAIRE

    Tisdell, Clement A.; Wilson, Clevo

    2004-01-01

    Lamington National Park in Queensland, Australia is noted for its rainforest and is part of the World Heritage listed property but prior to this work, no systematic study has been done of the importance of birds to its visitors. This study is based on data from survey forms handed to visitors at an important site in the park and completed by visitors following their visit. It yielded 622 useable responses. These enabled us to establish the comparative importance of birds as an attraction to t...

  2. 民用飞机鸟撞研究现状%Investigation of the Present Status of Research on Bird Impacting on Commercial Airplanes

    Institute of Scientific and Technical Information of China (English)

    李玉龙; 石霄鹏

    2012-01-01

    Bird impact accidents pose one of the biggest risks to civil aviation, which consequently become one of the focuses of research. An investigation of the status of bird impacting on commercial airplanes is presented in this paper. The losses caused by bird impact accidents in recent years are enumerated and the regulations about bird impacting on commercial airplanes in different countries are reviewed. The three aspects of theoretical investigation,numerical simulation and experimental study for bird impact are introduced in detail and a number of designs of aeronautical structures against bird impact accidents in recent years are presented. Finally, prospects in future bird impact research are proposed.%鸟撞事故是近年来对民用航空威胁较大的事故之一,民用飞机鸟撞研究已经渐渐成为各国学者研究的新热点.本文详细介绍了民用飞机鸟撞研究的现状.总结了近年来鸟撞事故所造成的损失,列举了一些航空大国的航空管理部门针对鸟撞作出的适航管理规定.对于鸟撞问题的研究,从鸟撞过程的理论分析研究、数值模拟研究和试验研究3个方面进行了综述.对于近些年国内外的飞机抗鸟撞设计,主要包括新材料的运用以及新的结构形式的运用,进行了详细介绍.最后,对未来民用飞机抗鸟撞研究的发展作了展望.

  3. Impact of power lines on bird mortality in a subalpine area

    Directory of Open Access Journals (Sweden)

    Bevanger, K.

    2004-12-01

    Full Text Available Four sections of power lines, amounting to 4,000 km, in a subalpine area of southern Norway were patrolled from April 1989 to June 1995 to record birds killed when colliding with the overhead wires. A total of 399 dead birds and bird remains were identified as collision victims. At least 24 species were identified among the victims, the majority only represented by a few individuals. Ptarmigan (Lagopus spp., particularly Willow ptarmigan (Lagopus lagopus, made up 80% of the victims. Season, power-line section and ptarmigan abundance affected the collision rate of this species. The highest rate was found in winter, marginally higher than in spring. Few collided with the power lines in autumn, and none were identified as victims in summer. On average, the annual minimum ptarmigan collision rate was found to be 5.3 birds/km power line. The only parameter with a predictable effect on the probability of ptarmigan collisions was the height of the trees, as collision spots tended to be in places with low trees. Mortality due to power lines was, on average at least 2.4 times higher than the annual ptarmigan hunting bag in the area during this 6-year study.

  4. The impact of wild birds and farm management on Campylobacter and Salmonella in small ruminants

    Science.gov (United States)

    This study was designed to evaluate the potential pathways and control of foodborne pathogen transmission between wild-birds and farm animals. At two farms, a total of 14 one-acre pastures were fenced to each host 12 sheep and 12 goats. For the control group, pastures were set-up with open water tub...

  5. The impacts of roads and other infrastructure on mammal and bird populations: A meta-analysis

    NARCIS (Netherlands)

    Benítez-López, A.; Alkemade, R.; Verweij, P.A.

    2010-01-01

    Biodiversity is being lost at an increased rate as a result of human activities. One of the major threats to biodiversity is infrastructural development. We used meta-analyses to study the effects of infrastructure proximity on mammal and bird populations. Data were gathered from 49 studies on 234 m

  6. Assessment of the Impacts of Green Mountain Power Corporation's Wind Power Facility on Breeding and Migrating Birds in Searsburg, Vermont: July 1996--July 1998

    Energy Technology Data Exchange (ETDEWEB)

    Kerlinger, P.

    2002-03-01

    A 6-megawatt, 11 turbine wind power development was constructed by Green Mountain Power Corporation in Searsburg, southern Vermont, in 1996. To determine whether birds were impacted, a series of modified BA (Before, After) studies was conducted before construction (1993-1996), during (1996), and after (1997) construction on the project site. The studies were designed to monitor changes in breeding bird community (species composition and abundance) on the site, examine the behavior and numbers of songbirds migrating at night over the site and hawks migrating over the site in daylight, and search for carcasses of birds that might have collided with the turbines.

  7. Alabama ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, seabirds, passerine birds, gulls, and terns...

  8. Maryland ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, seabirds, passerine birds, and gulls and...

  9. Estimation of the impact of prevailing weather conditions on the occurrence of oil-contaminated dead birds on the German North Sea coast.

    Science.gov (United States)

    Chrastansky, Alena; Callies, Ulrich; Fleet, David M

    2009-01-01

    Chronic oil pollution by illegal oil dumping in the North Sea is difficult to quantify. Beached, oil-contaminated sea birds, however, may be used as an indirect indicator. Reconstructing the drift of oil slicks and sea bird corpses in the southern North Sea for the period 1992-2003 by means of a two-dimensional numerical transport model driven by re-analysed weather data, we show with an example of two common sea bird species that the variability observed within the number of corpses registered during beached bird surveys for the German coast primarily reflects the inter-annual variability of prevailing weather conditions. This should be taken into account when interpreting the data. We propose normalisation of beached bird survey data based on numerical drift simulations to improve the recognition of trends in the level of chronic oil pollution.

  10. Human Impacts Flatten Rainforest-Savanna Gradient and Reduce Adaptive Diversity in a Rainforest Bird

    OpenAIRE

    Freedman, Adam H.; Wolfgang Buermann; Mitchard, Edward T A; DeFries, Ruth S.; Smith, Thomas B

    2010-01-01

    Ecological gradients have long been recognized as important regions for diversification and speciation. However, little attention has been paid to the evolutionary consequences or conservation implications of human activities that fundamentally change the environmental features of such gradients. Here we show that recent deforestation in West Africa has homogenized the rainforest-savanna gradient, causing a loss of adaptive phenotypic diversity in a common rainforest bird, the little greenbul...

  11. Modeling the Geography of Migratory Pathways and Stopover Habitats for Neotropical Migratory Birds

    Directory of Open Access Journals (Sweden)

    Roger Tankersley, Jr.

    2003-07-01

    Full Text Available Intact migratory routes are critical for the stability of forest-dwelling, neotropical, migratory bird populations, and mortality along migratory pathways may be significant. Yet we know almost nothing about the geography of available stopovers or the possible migratory pathways that connect optimal stopovers. We undertake a spatial analysis of stopover habitat availability and then model potential migratory pathways between optimal stopovers in the eastern United States. Using models of fixed orientation and fixed nightly flight distance between stopovers during spring migration, we explore whether a simple endogenous migratory program is sufficient to ensure successful migration across the modern landscape. Our model runs suggest that the modern distribution of optimum stopovers in the eastern United States can be adequately exploited by birds following migratory pathways defined by fixed-orientation and fixed-distance nightly flights. Longer flight distances may increase the chances of success by enabling migrants to bypass locales offering little habitat. Our results also suggest that most southwest-northeast migratory pathways through the Appalachian mountains are intact. Lack of optimal habitat at key locations in the Southeast causes many modeled pathways to fail. We present a speculative view of regional migration patterns implied by predominant ideas found in stopover ecology literature, and demonstrate the need for broad-scale migration research, in the hope that our approach will foster other continental- and regional-scale projects.

  12. Multilevel spatial semantic model for urban house information extraction automatically from QuickBird imagery

    Science.gov (United States)

    Guan, Li; Wang, Ping; Liu, Xiangnan

    2006-10-01

    Based on the introduction to the characters and constructing flow of space semantic model, the feature space and context of house information in high resolution remote sensing image are analyzed, and the house semantic network model of Quick Bird image is also constructed. Furthermore, the accuracy and practicability of space semantic model are checked up through extracting house information automatically from Quick Bird image after extracting candidate semantic nodes to the image by taking advantage of grey division method, window threshold value method and Hough transformation. Sample result indicates that its type coherence, shape coherence and area coherence are 96.75%, 89.5 % and 88 % respectively. Thereinto the effect of the extraction of the houses with rectangular roof is the best and that with herringbone and the polygonal roofs is just ideal. However, the effect of the extraction of the houses with round roof is not satisfied and thus they need the further perfection to the semantic model to make them own higher applied value.

  13. Using occupancy models of forest breeding birds to prioritize conservation planning

    Science.gov (United States)

    De Wan, A. A.; Sullivan, P.J.; Lembo, A.J.; Smith, C.R.; Maerz, J.C.; Lassoie, J.P.; Richmond, M.E.

    2009-01-01

    As urban development continues to encroach on the natural and rural landscape, land-use planners struggle to identify high priority conservation areas for protection. Although knowing where urban-sensitive species may be occurring on the landscape would facilitate conservation planning, research efforts are often not sufficiently designed to make quality predictions at unknown locations. Recent advances in occupancy modeling allow for more precise estimates of occupancy by accounting for differences in detectability. We applied these techniques to produce robust estimates of habitat occupancy for a subset of forest breeding birds, a group that has been shown to be sensitive to urbanization, in a rapidly urbanizing yet biological diverse region of New York State. We found that detection probability ranged widely across species, from 0.05 to 0.8. Our models suggest that detection probability declined with increasing forest fragmentation. We also found that the probability of occupancy of forest breeding birds is negatively influenced by increasing perimeter-area ratio of forest fragments and urbanization in the surrounding habitat matrix. We capitalized on our random sampling design to produce spatially explicit models that predict high priority conservation areas across the entire region, where interior-species were most likely to occur. Finally, we use our predictive maps to demonstrate how a strict sampling design coupled with occupancy modeling can be a valuable tool for prioritizing biodiversity conservation in land-use planning. ?? 2009 Elsevier Ltd.

  14. Social Impact, a Theoretical Model

    Directory of Open Access Journals (Sweden)

    Jenny Onyx

    2014-01-01

    Full Text Available This paper constructs a theoretical model of social impact as it applies to civil society organisations. It does so by drawing on the recent literature on the topic as well as recently completed empirical studies. First, the relationship between impact and evaluation is examined. This is followed by an exploration of the capitals, notably social, human, and cultural capital and their interrelationships, as a theoretical base for the explication of social impact. A formal model of social impact is then identified together with a set of basic principles that may be said to define social impact. Finally the implications of the model are discussed for social policy and organisational management.

  15. Predicting continental-scale patterns of bird species richness with spatially explicit models

    DEFF Research Database (Denmark)

    Rahbek, Carsten; Gotelli, Nicholas J; Colwell, Robert K

    2007-01-01

    The causes of global variation in species richness have been debated for nearly two centuries with no clear resolution in sight. Competing hypotheses have typically been evaluated with correlative models that do not explicitly incorporate the mechanisms responsible for biotic diversity gradients....... Here, we employ a fundamentally different approach that uses spatially explicit Monte Carlo models of the placement of cohesive geographical ranges in an environmentally heterogeneous landscape. These models predict species richness of endemic South American birds (2248 species) measured...... the extraordinary diversity of avian species in the montane tropics, the most species-rich region on Earth. Our findings imply that correlative climatic models substantially underestimate the importance of historical factors and small-scale niche-driven assembly processes in shaping contemporary species...

  16. Mechanistic modeling of insecticide risks to breeding birds in North American agroecosystems.

    Science.gov (United States)

    Etterson, Matthew; Garber, Kristina; Odenkirchen, Edward

    2017-01-01

    Insecticide usage in the United States is ubiquitous in urban, suburban, and rural environments. There is accumulating evidence that insecticides adversely affect non-target wildlife species, including birds, causing mortality, reproductive impairment, and indirect effects through loss of prey base, and the type and magnitude of such effects differs by chemical class, or mode of action. In evaluating data for an insecticide registration application and for registration review, scientists at the United States Environmental Protection Agency (USEPA) assess the fate of the insecticide and the risk the insecticide poses to the environment and non-target wildlife. Current USEPA risk assessments for pesticides generally rely on endpoints from laboratory based toxicity studies focused on groups of individuals and do not directly assess population-level endpoints. In this paper, we present a mechanistic model, which allows risk assessors to estimate the effects of insecticide exposure on the survival and seasonal productivity of birds known to forage in agricultural fields during their breeding season. This model relies on individual-based toxicity data and translates effects into endpoints meaningful at the population level (i.e., magnitude of mortality and reproductive impairment). The model was created from two existing USEPA avian risk assessment models, the Terrestrial Investigation Model (TIM v.3.0) and the Markov Chain Nest Productivity model (MCnest). The integrated TIM/MCnest model was used to assess the relative risk of 12 insecticides applied via aerial spray to control corn pests on a suite of 31 avian species known to forage in cornfields in agroecosystems of the Midwest, USA. We found extensive differences in risk to birds among insecticides, with chlorpyrifos and malathion (organophosphates) generally posing the greatest risk, and bifenthrin and λ-cyhalothrin (pyrethroids) posing the least risk. Comparative sensitivity analysis across the 31 species showed

  17. Three-dimensional computer modeling of birds proepicardium on different stages of embryogenesis

    Directory of Open Access Journals (Sweden)

    Pototskaya O.Yu.

    2009-01-01

    Full Text Available As the proepicardium is the source of many cell populations of the mature heart, including cell components of coronary vessels, its investigation became actual last time. It is known, that there are some differences between birds and mammalian proepicardium; one of them consists in the way, in which they contact to myocardium: mammalian proepicardium produce vesicles, which contact to atrioventricular groove, wile in birds there is no vesicles and whole protrusions of proepicardium attach to the heart. But, recent years it became evident, that in rat proepicardium there are no vesicles during all stages of its existence, and in birds there is a proepicardium-like structure producing vesicles, which attach to the heart. Thus, the goal of our research was to characterize changes in the shape of proepicardium during bird’s embryogenesis. We used Cobb 500 chick embryos as a material; on the basis of pictures of proepicardium serial sections, with the help of Photoshop CS2, Amira for microscopy 5.0, 3ds max 8.0 computer programs, we made three-dimensional models of proepicardium on 15, 16, 17, 18, 21 stages of development by V.Hamburger, H.Hamilton, 1951. The most important changes in proepicardium shape observed from 14 to 20 stages of development. During this period proepicardium appeared on the right horn of sinus venous, enlarged and formed several crests, which contacted to atrioventricular groove. Coalescence of these crests led to dorsal mesocardium formation. From 21 to 27 stages of development there were no significant changes in proepicardium shape; the area of its contact to sinus venous was grown downwards while the area of contact to the heart enlarged. No vesicles, no “finger-like protrusions” were observed on any stage of bird’s development.

  18. Non-linear Numerical Simulation of Bird Impact on Aircraft Windshield%鸟撞飞机风挡非线性数值分析

    Institute of Scientific and Technical Information of China (English)

    朱书华; 王跃全; 郭亮; 张立圣; 童明波

    2011-01-01

    采用非线性有限元法,基于ABAQUS/Explicit软件平台及内嵌的材料用户定义子程序(VUMAT),建立了鸟撞飞机风挡的力学分析模型.比较了有限元模型中玻璃骨架、弧框和橡胶垫片对风挡动响应分析结果的影响,并与全尺寸风挡鸟撞试验数据进行了对比.对比结果表明,考虑了玻璃骨架、弧框和橡胶垫片的有限元模型所计算得到的位移、应变曲线与试验实测曲线的一致性有了改善.最后,探讨了玻璃骨架、橡胶垫片的厚度和弹性模量对风挡抗鸟撞能力的影响规律,为风挡的抗鸟撞设计及改型提供参考.%A finite element model (FEM) of bird impact on the windshield is established via the nonlinear finite element method, combined with the user-defined materials subroutine (VUMAT) of the ABAQUS/Explicit software. The dynamic response of bird strike on aircraft windshield is analyzed in two different configurations, with and without the surrounding structure frame, skin and rubber layer. By comparing the simulation results and the full-scale experiment data, the results of FEM with the surrounding structure have a better agreement with the experiments in the instantaneous deformation of bird and windshield, the damage modes of the windshield, the displacement curves and the strain curves of the measured points on the windshield. In addition, the sensitivities of the design parameters of aircraft windshield, including skin thickness, skin elastic modulus, rubber thickness, and rubber elastic modulus are discussed on the windshield capability against bird-strike comprehensively.

  19. Predicting the offshore distribution and abundance of marine birds with a hierarchical community distance sampling model.

    Science.gov (United States)

    Goyert, Holly F; Gardner, Beth; Sollmann, Rahel; Veit, Richard R; Gilbert, Andrew T; Connelly, Emily E; Williams, Kathryn A

    2016-09-01

    Proposed offshore wind energy development on the Atlantic Outer Continental Shelf has brought attention to the need for baseline studies of the distribution and abundance of marine birds. We compiled line transect data from 15 shipboard surveys (June 2012-April 2014), along with associated remotely sensed habitat data, in the lower Mid-Atlantic Bight off the coast of Delaware, Maryland, and Virginia, USA. We implemented a recently developed hierarchical community distance sampling model to estimate the seasonal abundance of 40 observed marine bird species. Treating each season separately, we included six oceanographic parameters to estimate seabird abundance: three static (distance to shore, slope, sediment grain size) and three dynamic covariates (sea surface temperature [SST], salinity, primary productivity). We expected that avian bottom-feeders would respond primarily to static covariates that characterize seafloor variability, and that surface-feeders would respond more to dynamic covariates that quantify surface productivity. We compared the variation in species-specific and community-level responses to these habitat features, including for rare species, and we predicted species abundance across the study area. While several protected species used the study area in summer during their breeding season, estimated abundance and observed diversity were highest for nonbreeding species in winter. Distance to shore was the most common significant predictor of abundance, and thus useful in estimating the potential exposure of marine birds to offshore development. In many cases, our expectations based on feeding ecology were confirmed, such as in the first winter season, when bottom-feeders associated significantly with the three static covariates (distance to shore, slope, and sediment grain size), and surface-feeders associated significantly with two dynamic covariates (SST, primary productivity). However, other cases revealed significant relationships between

  20. Understanding how birds navigate

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Schulten, Klaus

    2009-01-01

    A proposed model for migrating birds' magnetic sense can withstand moderate orientational disorder of a key protein in the eye.......A proposed model for migrating birds' magnetic sense can withstand moderate orientational disorder of a key protein in the eye....

  1. Quaternary history of an endemic passerine bird on Corsica Island: Glacial refugium and impact of recent forest regression

    Science.gov (United States)

    Thibault, Jean-Claude; Cibois, Alice; Prodon, Roger; Pasquet, Eric

    2016-03-01

    Molecular studies support the hypothesis that Corsica Island was a glacial refugium for a number of forest birds during the Pleistocene. We focused on the Corsican nuthatch (Sitta whiteheadi), an endemic passerine strongly associated with the laricio pine (Pinus nigra laricio). The range of laricio pine has been impacted by the Pleistocene glacial periods and forest has been recently fragmented by cutting and fires. Using both molecular (mitochondrial and nuclear) and morphological characters, we assessed the variation within the nuthatch population. Our results are consistent with the hypothesis that the Corsican nuthatch endured through the late Pleistocene and Holocene climatic variations, and sustained the subsequent cycles of forests reduction/expansion. The results also suggest that the recent anthropization of the landscape resulted in the isolation of a cluster of populations in the northern part of the island. The fragmentation of the habitat of the nuthatch may impede the future of the bird by creating isolated population units between which the gene flow is reduced.

  2. Growth curve analysis of birds: the Richards model and procedural problems. [Tachycineta bicolor

    Energy Technology Data Exchange (ETDEWEB)

    Zach, R.; Liner, Y.; Rigby, G.L.; Mayoh, K.R.

    1984-01-01

    Four sigmoid growth curve models for birds were compared using the daily body masses and primary-feather lengths of 35 nestling tree swallows (Tachycineta bicolor). The Richards model was superior to the von Bertalanffy, Gompertz, and logistic models for body mass, but not for primary-feather length. The latter models have fixed growth forms and are special cases of the flexible Richards model. Owing to parameter correlations, the Richards model was very sensitive to the starting parameter values for the numerical computer fitting routines. The lack of data leading up to the asymptote made it difficult to calculate good starting values for primary-feather length. None of the models tested was completely satisfactory for primary-feather length, as indicated by nonrandomly distributed residuals over time. The log transformation was appropriate for body mass. It homogenized the residual variances and increased the explained percentage of variation. The explained percentage of variation was a useful selection criterion for the best-fitting model, especially since it was directly related to randomness in the distribution of the residuals and homogeneity of residual variances. However, even percentages of variation exceeding 99.5%, did not necessarily indicate an excellent fit. The Richards model did not yield more model parameters for growth curve analysis, because the shape parameter and the growth rate constant were almost perfectly correlated.

  3. Biological exposure models for oil spill impact analysis

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The oil spill impact analysis (OSIA) software system has been developed to supply a tool for comprehensive, quantitative environmental impact assessments resulting from oil spills. In the system, a biological component evaluates potential effects on exposed organisms based on results from a physico-chemieal fates component, including the extent and characteristics of the surface slick, and dissolved and total concentrations of hydrocarbons in the water column. The component includes a particle-based exposure model for migratory adult fish populations, a particle-based exposure model for spawning planktonic organisms (eggs and larvae), and an exposure model for wildlife species (sea birds or marine mammals). The exposure model for migratory adult fish populations simulates the migration behaviors of fish populations migrating to or staying in their feeding areas, over-wintering areas or spawning areas, and determines the acute effects (mortality) and chronic accumulation (body burdens) from the dissolved contaminant. The exposure model for spawning planktonic organisms simulates the release of eggs and larvae, also as particles, from specific spawning areas during the spawning period, and determines their potential exposure to contaminants in the water or sediment. The exposure model for wild species calculates the exposure to surrace oil of wildlife (bird and marine mammal ) categories inhabiting the contaminated area. Compared with the earlier models in which all kinds of organisms are assumed evenly and randomly distributed, the updated biological exposure models can more realistically estimate potential effects on marine ecological system from oil spill pollution events.

  4. New health risks and sociocultural contexts: bird flu impacts on consumers and poultry businesses in Lao PDR.

    Science.gov (United States)

    Suder, Gabriele; Inthavong, Saynakhone

    2008-02-01

    Avian flu has been identified as one of the most challenging new risks, global in impact due to the "highly interconnected and integrated world economy along with other unpredictable events such as the Asian financial crisis and global terrorism." We have chosen the case of Lao PDR to shed light on an area in which local people consume chicken as one of their staple foods. Our research analyzes consumer behavior, poultry business modification patterns in a high-risk country, and government reaction for business resilience. The geographic choice is motivated by the 2006 EIU report on Catastrophe Risk Management that indicated that Asian-Pacific companies are better prepared for such risks as bird flu than European business is, despite the many cases found in both regions.

  5. Understanding interaction effects of climate change and fire management on bird distributions through combined process and habitat models

    Science.gov (United States)

    White, Joseph D.; Gutzwiller, Kevin J.; Barrow, Wylie C.; Johnson-Randall, Lori; Zygo, Lisa; Swint, Pamela

    2011-01-01

    Avian conservation efforts must account for changes in vegetation composition and structure associated with climate change. We modeled vegetation change and the probability of occurrence of birds to project changes in winter bird distributions associated with climate change and fire management in the northern Chihuahuan Desert (southwestern U.S.A.). We simulated vegetation change in a process-based model (Landscape and Fire Simulator) in which anticipated climate change was associated with doubling of current atmospheric carbon dioxide over the next 50 years. We estimated the relative probability of bird occurrence on the basis of statistical models derived from field observations of birds and data on vegetation type, topography, and roads. We selected 3 focal species, Scaled Quail (Callipepla squamata), Loggerhead Shrike (Lanius ludovicianus), and Rock Wren (Salpinctes obsoletus), that had a range of probabilities of occurrence for our study area. Our simulations projected increases in relative probability of bird occurrence in shrubland and decreases in grassland and Yucca spp. and ocotillo (Fouquieria splendens) vegetation. Generally, the relative probability of occurrence of all 3 species was highest in shrubland because leaf-area index values were lower in shrubland. This high probability of occurrence likely is related to the species' use of open vegetation for foraging. Fire suppression had little effect on projected vegetation composition because as climate changed there was less fuel and burned area. Our results show that if future water limits on plant type are considered, models that incorporate spatial data may suggest how and where different species of birds may respond to vegetation changes.

  6. Understanding interaction effects of climate change and fire management on bird distributions through combined process and habitat models.

    Science.gov (United States)

    White, Joseph D; Gutzwiller, Kevin J; Barrow, Wylie C; Johnson-Randall, Lori; Zygo, Lisa; Swint, Pamela

    2011-06-01

    Avian conservation efforts must account for changes in vegetation composition and structure associated with climate change. We modeled vegetation change and the probability of occurrence of birds to project changes in winter bird distributions associated with climate change and fire management in the northern Chihuahuan Desert (southwestern U.S.A.). We simulated vegetation change in a process-based model (Landscape and Fire Simulator) in which anticipated climate change was associated with doubling of current atmospheric carbon dioxide over the next 50 years. We estimated the relative probability of bird occurrence on the basis of statistical models derived from field observations of birds and data on vegetation type, topography, and roads. We selected 3 focal species, Scaled Quail (Callipepla squamata), Loggerhead Shrike (Lanius ludovicianus), and Rock Wren (Salpinctes obsoletus), that had a range of probabilities of occurrence for our study area. Our simulations projected increases in relative probability of bird occurrence in shrubland and decreases in grassland and Yucca spp. and ocotillo (Fouquieria splendens) vegetation. Generally, the relative probability of occurrence of all 3 species was highest in shrubland because leaf-area index values were lower in shrubland. This high probability of occurrence likely is related to the species' use of open vegetation for foraging. Fire suppression had little effect on projected vegetation composition because as climate changed there was less fuel and burned area. Our results show that if future water limits on plant type are considered, models that incorporate spatial data may suggest how and where different species of birds may respond to vegetation changes.

  7. Screamy Bird

    DEFF Research Database (Denmark)

    Tarby, Sara; Cermak, Daniel

    2016-01-01

    Sara Tarby, Daniel Cermak-Sassenrath. Screamy Bird. Digital game. Kulturnatten 2016, Danish Science Ministry, Copenhagen, DK, Oct 14, 2016.......Sara Tarby, Daniel Cermak-Sassenrath. Screamy Bird. Digital game. Kulturnatten 2016, Danish Science Ministry, Copenhagen, DK, Oct 14, 2016....

  8. Modeling pellet impact drilling process

    OpenAIRE

    Kovalev, Artem Vladimirovich; Ryabchikov, Sergey Yakovlevich; Isaev, Evgeniy Dmitrievich; Ulyanova, Oksana Sergeevna

    2016-01-01

    The paper describes pellet impact drilling which could be used to increase the drilling speed and the rate of penetration when drilling hard rocks. Pellet impact drilling implies rock destruction by metal pellets with high kinetic energy in the immediate vicinity of the earth formation encountered. The pellets are circulated in the bottom hole by a high velocity fluid jet, which is the principle component of the ejector pellet impact drill bit. The experiments conducted has allowed modeling t...

  9. Estimating indices of range shifts in birds using dynamic models when detection is imperfect

    Science.gov (United States)

    Clement, Matthew J.; Hines, James E.; Nichols, James D.; Pardieck, Keith L.; Ziolkowski, David J.

    2016-01-01

    There is intense interest in basic and applied ecology about the effect of global change on current and future species distributions. Projections based on widely used static modeling methods implicitly assume that species are in equilibrium with the environment and that detection during surveys is perfect. We used multiseason correlated detection occupancy models, which avoid these assumptions, to relate climate data to distributional shifts of Louisiana Waterthrush in the North American Breeding Bird Survey (BBS) data. We summarized these shifts with indices of range size and position and compared them to the same indices obtained using more basic modeling approaches. Detection rates during point counts in BBS surveys were low, and models that ignored imperfect detection severely underestimated the proportion of area occupied and slightly overestimated mean latitude. Static models indicated Louisiana Waterthrush distribution was most closely associated with moderate temperatures, while dynamic occupancy models indicated that initial occupancy was associated with diurnal temperature ranges and colonization of sites was associated with moderate precipitation. Overall, the proportion of area occupied and mean latitude changed little during the 1997–2013 study period. Near-term forecasts of species distribution generated by dynamic models were more similar to subsequently observed distributions than forecasts from static models. Occupancy models incorporating a finite mixture model on detection – a new extension to correlated detection occupancy models – were better supported and may reduce bias associated with detection heterogeneity. We argue that replacing phenomenological static models with more mechanistic dynamic models can improve projections of future species distributions. In turn, better projections can improve biodiversity forecasts, management decisions, and understanding of global change biology.

  10. 直升机桨叶鸟撞试验方法的数值模拟%Numerical simulation of bird impact on helicopter blade

    Institute of Scientific and Technical Information of China (English)

    林长亮; 王浩文; 陈仁良

    2012-01-01

    由于直升机旋翼的工作特点,使得全尺寸旋翼鸟撞试验很难进行,而在飞行器结构抗鸟撞的设计过程中,鸟撞试验是最终、最有效的检验方法,因此开展直升机桨叶鸟撞试验研究十分必要.采用Arbitrary Lagrangian Eulerian (ALE)流固耦合方法分别对旋转状态的桨叶鸟撞以及端部受集中载荷作用的静止状态桨叶鸟撞进行了数值模拟,通过数值模拟结果对比,发现两种状态下桨叶的动态响应结果很接近,说明采用集中载荷替代离心载荷的静态鸟撞试验可以较好地模拟旋转状态下桨叶鸟撞试验,从而为直升机动部件鸟撞试验研究提供理论依据.%The bird impact test for full-size rotor is difficult because of working characteristics of the helicopter rotor. However, in the design process of crashworthy aircraft structure, bird impact test is the ultimate and the most effective verification method. Therefore it is quite necessary to study the test method for bird impact on helicopter blade. Arbitrary Lagrangian Eulerian (ALE) fluid-solid coupling method was adopted to simulate bird impact on rotating blade as well as on stationary one whose end was under concentrated loads, respectively. After comparison of numerical simulation results, it was found that dynamic response of blade under the above two states is quite approximate. This shows that static bird impact test adopting centralized loads instead of centrifugal ones can better simulate the test of bird impact on rotating blade, thus providing a reference method for research of bird impact on helicopter rotor.

  11. Cardio-respiratory development in bird embryos: new insights from a venerable animal model

    Directory of Open Access Journals (Sweden)

    Warren W. Burggren

    Full Text Available ABSTRACT The avian embryo is a time-honored animal model for understanding vertebrate development. A key area of extensive study using bird embryos centers on developmental phenotypic plasticity of the cardio-respiratory system and how its normal development can be affected by abiotic factors such as temperature and oxygen availability. Through the investigation of the plasticity of development, we gain a better understanding of both the regulation of the developmental process and the embryo's capacity for self-repair. Additionally, experiments with abiotic and biotic stressors during development have helped delineate not just critical windows for avian cardio-respiratory development, but the general characteristics (e.g., timing and dose-dependence of critical windows in all developing vertebrates. Avian embryos are useful in exploring fetal programming, in which early developmental experiences have implications (usually negative later in life. The ability to experimentally manipulate the avian embryo without the interference of maternal behavior or physiology makes it particularly useful in future studies of fetal programming. The bird embryo is also a key participant in studies of transgenerational epigenetics, whether by egg provisioning or effects on the germline that are transmitted to the F1 generation (or beyond. Finally, the avian embryo is heavily exploited in toxicology, in which both toxicological testing of potential consumer products as well as the consequences of exposure to anthropogenic pollutants are routinely carried out in the avian embryo. The avian embryo thus proves useful on numerous experimental fronts as an animal model that is concurrently both of adequate complexity and sufficient simplicity for probing vertebrate cardio-respiratory development.

  12. Hawaiian forest bird trends: using log-linear models to assess long-term trends is supported by model diagnostics and assumptions (reply to Freed and Cann 2013)

    Science.gov (United States)

    Camp, Richard J.; Pratt, Thane K.; Gorresen, P. Marcos; Woodworth, Bethany L.; Jeffrey, John J.

    2014-01-01

    Freed and Cann (2013) criticized our use of linear models to assess trends in the status of Hawaiian forest birds through time (Camp et al. 2009a, 2009b, 2010) by questioning our sampling scheme, whether we met model assumptions, and whether we ignored short-term changes in the population time series. In the present paper, we address these concerns and reiterate that our results do not support the position of Freed and Cann (2013) that the forest birds in the Hakalau Forest National Wildlife Refuge (NWR) are declining, or that the federally listed endangered birds are showing signs of imminent collapse. On the contrary, our data indicate that the 21-year long-term trends for native birds in Hakalau Forest NWR are stable to increasing, especially in areas that have received active management.

  13. Quantification of bird-to-bird and bird-to-human infections during 2013 novel H7N9 avian influenza outbreak in China.

    Directory of Open Access Journals (Sweden)

    Ying-Hen Hsieh

    Full Text Available From February to May, 2013, 132 human avian influenza H7N9 cases were identified in China resulting in 37 deaths. We developed a novel, simple and effective compartmental modeling framework for transmissions among (wild and domestic birds as well as from birds to human, to infer important epidemiological quantifiers, such as basic reproduction number for bird epidemic, bird-to-human infection rate and turning points of the epidemics, for the epidemic via human H7N9 case onset data and to acquire useful information regarding the bird-to-human transmission dynamics. Estimated basic reproduction number for infections among birds is 4.10 and the mean daily number of human infections per infected bird is 3.16*10-5 [3.08*10-5, 3.23*10-5]. The turning point of 2013 H7N9 epidemic is pinpointed at April 16 for bird infections and at April 9 for bird-to-human transmissions. Our result reveals very low level of bird-to-human infections, thus indicating minimal risk of widespread bird-to-human infections of H7N9 virus during the outbreak. Moreover, the turning point of the human epidemic, pinpointed at shortly after the implementation of full-scale control and intervention measures initiated in early April, further highlights the impact of timely actions on ending the outbreak. This is the first study where both the bird and human components of an avian influenza epidemic can be quantified using only the human case data.

  14. Quantification of bird-to-bird and bird-to-human infections during 2013 novel H7N9 avian influenza outbreak in China.

    Science.gov (United States)

    Hsieh, Ying-Hen; Wu, Jianhong; Fang, Jian; Yang, Yong; Lou, Jie

    2014-01-01

    From February to May, 2013, 132 human avian influenza H7N9 cases were identified in China resulting in 37 deaths. We developed a novel, simple and effective compartmental modeling framework for transmissions among (wild and domestic) birds as well as from birds to human, to infer important epidemiological quantifiers, such as basic reproduction number for bird epidemic, bird-to-human infection rate and turning points of the epidemics, for the epidemic via human H7N9 case onset data and to acquire useful information regarding the bird-to-human transmission dynamics. Estimated basic reproduction number for infections among birds is 4.10 and the mean daily number of human infections per infected bird is 3.16*10-5 [3.08*10-5, 3.23*10-5]. The turning point of 2013 H7N9 epidemic is pinpointed at April 16 for bird infections and at April 9 for bird-to-human transmissions. Our result reveals very low level of bird-to-human infections, thus indicating minimal risk of widespread bird-to-human infections of H7N9 virus during the outbreak. Moreover, the turning point of the human epidemic, pinpointed at shortly after the implementation of full-scale control and intervention measures initiated in early April, further highlights the impact of timely actions on ending the outbreak. This is the first study where both the bird and human components of an avian influenza epidemic can be quantified using only the human case data.

  15. Human impacts flatten rainforest-savanna gradient and reduce adaptive diversity in a rainforest bird.

    Directory of Open Access Journals (Sweden)

    Adam H Freedman

    Full Text Available Ecological gradients have long been recognized as important regions for diversification and speciation. However, little attention has been paid to the evolutionary consequences or conservation implications of human activities that fundamentally change the environmental features of such gradients. Here we show that recent deforestation in West Africa has homogenized the rainforest-savanna gradient, causing a loss of adaptive phenotypic diversity in a common rainforest bird, the little greenbul (Andropadus virens. Previously, this species was shown to exhibit morphological and song divergence along this gradient in Central Africa. Using satellite-based estimates of forest cover, recent morphological data, and historical data from museum specimens collected prior to widespread deforestation, we show that the gradient has become shallower in West Africa and that A. virens populations there have lost morphological variation in traits important to fitness. In contrast, we find no loss of morphological variation in Central Africa where there has been less deforestation and gradients have remained more intact. While rainforest deforestation is a leading cause of species extinction, the potential of deforestation to flatten gradients and inhibit rainforest diversification has not been previously recognized. More deforestation will likely lead to further flattening of the gradient and loss of diversity, and may limit the ability of species to persist under future environmental conditions.

  16. Human impacts flatten rainforest-savanna gradient and reduce adaptive diversity in a rainforest bird.

    Science.gov (United States)

    Freedman, Adam H; Buermann, Wolfgang; Mitchard, Edward T A; Defries, Ruth S; Smith, Thomas B

    2010-09-30

    Ecological gradients have long been recognized as important regions for diversification and speciation. However, little attention has been paid to the evolutionary consequences or conservation implications of human activities that fundamentally change the environmental features of such gradients. Here we show that recent deforestation in West Africa has homogenized the rainforest-savanna gradient, causing a loss of adaptive phenotypic diversity in a common rainforest bird, the little greenbul (Andropadus virens). Previously, this species was shown to exhibit morphological and song divergence along this gradient in Central Africa. Using satellite-based estimates of forest cover, recent morphological data, and historical data from museum specimens collected prior to widespread deforestation, we show that the gradient has become shallower in West Africa and that A. virens populations there have lost morphological variation in traits important to fitness. In contrast, we find no loss of morphological variation in Central Africa where there has been less deforestation and gradients have remained more intact. While rainforest deforestation is a leading cause of species extinction, the potential of deforestation to flatten gradients and inhibit rainforest diversification has not been previously recognized. More deforestation will likely lead to further flattening of the gradient and loss of diversity, and may limit the ability of species to persist under future environmental conditions.

  17. 大型民用飞机风挡鸟撞的适航分析与数值仿真%Airworthiness Analysis and Numerical Simulation of Bird Impact on Large Civil Aircraft Windshield

    Institute of Scientific and Technical Information of China (English)

    陈佳慧; 胡宇群; 陈川

    2016-01-01

    鸟撞一直都是航空安全的隐患,对此需要有相应的适航条款来表明民用飞机相关部件的抗鸟撞性能符合要求。针对风挡鸟撞问题现状,分析了目前民用飞机鸟撞适航验证的方法和手段,对比研究了不同鸟撞数值模型,通过计算机辅助设计软件建立了某型民用飞机风挡三维几何模型,采用显式非线性数值分析软件ANSYS/LS-DYNA进行风挡鸟撞过程的数值仿真分析,以期为大型民机风挡鸟撞适航验证提供更有效的方法和手段,提高适航验证工作效率,降低工作成本。%Bird strike is a major threat to aircraft windshields and need a certification requirement for a proven level of impact resistance. Apart from costly bird strike experiments, explicit numerical modeling techniques have been employed. This paper summarized the current airworthiness verification methods of bird strike,compared the different bird strike analysis models. With the help of Computer Aided Design software,established a three-dimensional geometric model of a certain type of civil aircraft windshield,and the simulation of the dynamic process of bird impacting windshield is run using the nonlinear explicit finite element code ANSYS/LS-DYNA. The solution of analysis presents the theoretical basis for the airworthi-ness certification methods of bird strike windshield,in hope of improving the efficiency of airworthiness ver-ification work and reducing the cost.

  18. Interactive modeling of storm impact

    Science.gov (United States)

    van Rooijen, A.; Baart, F.; Roelvink, J. A.; Donchyts, G.; Scheel, F.; de Boer, W.

    2014-12-01

    In the past decades the impact of storms on the coastal zone has increasingly drawn the attention of policy makers and coastal planners, engineers and researchers. The mean reason for this interest is the high density of the world's population living near the ocean, in combination with climate change. Due to sea level rise and extremer weather conditions, many of the world's coastlines are becoming more vulnerable to the potential of flooding. Currently it is common practice to predict storm impact using physics-based numerical models. The numerical model utilizes several inputs (e.g. bathymetry, waves, surge) to calculate the impact on the coastline. Traditionally, the numerical modeller takes the following three steps: schematization/model setup, running and post-processing. This process generally has a total feedback time in the order of hours to days, and is suitable for so-called confirmatory modelling.However, often models are applied as an exploratory tool, in which the effect of e.g. different hydraulic conditions, or measures is investigated. The above described traditional work flow is not the most efficient method for exploratory modelling. Interactive modelling lets users adjust a simulation while running. For models typically used for storm impact studies (e.g. XBeach, Delft3D, D-Flow FM), the user can for instance change the storm surge level, wave conditions, or add a measure such as a nourishment or a seawall. The model will take the adjustments into account immediately, and will directly compute the effect. Using this method, tools can be developed in which stakeholders (e.g. coastal planners, policy makers) are in control and together evaluate ideas by interacting with the model. Here we will show initial results for interactive modelling with a storm impact model.

  19. Climate change and the increasing impact of polar bears on bird populations

    Directory of Open Access Journals (Sweden)

    Jouke eProp

    2015-03-01

    Full Text Available The Arctic is becoming warmer at a high rate, and contractions in the extent of sea ice are currently changing the habitats of marine top-predators dependent on ice. Polar bears (Ursus maritimus depend on sea ice for hunting seals. For these top-predators, longer ice-free seasons are hypothesized to force the bears to hunt for alternative terrestrial food, such as eggs from colonial breeding birds. We analyzed time-series of polar bear observations at four locations on Spitsbergen (Svalbard and one in east Greenland. Summer occurrence of polar bears, measured as the probability of encountering bears and the number of days with bear presence, has increased significantly from the 1970/80s to the present. The shifts in polar bear occurrence coincided with trends for shorter sea ice seasons and less sea ice during the spring in the study area. This resulted in a strong inverse relationship between the probability of bear encounters on land and the length of the sea ice season. Within ten years after their first appearance on land, polar bears had advanced their arrival dates by almost 30 days. Direct observations of nest predation showed that polar bears may severely affect reproductive success of the barnacle goose (Branta leucopsis, common eider (Somateria mollissima and glaucous gull (Larus hyperboreus. Nest predation was strongest in years when the polar bears arrived well before hatch, with more than 90% of all nests being predated. The results are similar to findings from Canada, and large-scale processes, such as climate and subsequent habitat changes, are pinpointed as the most likely drivers in various parts of the Arctic. We suggest that the increasing, earlier appearance of bears on land in summer reflects behavioral adaptations by a small segment of the population to cope with a reduced hunting range on sea ice. This exemplifies how behavioral adaptations may contribute to the cascading effects of climate change.

  20. Dynamic response of scale models subjected to impact loading

    Science.gov (United States)

    Hillsdon, Graham K.

    1997-05-01

    Presented with the problem of possible failure of large structures due to dynamic loading, and the cost of staging full scale tests. The Oxford University's Department of Engineering Science, supported by British Gas and Rolls Royce, has been scale modeling these events experimentally. The paper looks at two areas of research: (1) The structural integrity of a particular type of Liquified Natural Gas Storage Tank, and its vulnerability to blast loading. (2) The ability of Large Aero Engine Fan blades to withstand impacts associated with birds, stones, ice etc.

  1. Scaling of organ subunits in adult mammals and birds: a model.

    Science.gov (United States)

    Prothero, J

    1996-02-01

    Members of one class of organs--including kidney and lung--consist chiefly of repeating units, or subunits, similar in size and shape. Across species, both the number and size of repeating units may increase with increasing organ size. A simple model is proposed, relating the scaling of unit-size and unit-number to that of organ volume. The model makes three structural assumptions, the crucial one, biologically speaking, being that the numerical density of repeating units scales as does organ surface-to-volume ratio. Data were collected from the literature bearing on the number, diameter, total surface area and total volume of such repeating units (i.e., alveoli, air capillaries, renal tubules and glomeruli), for avian and mammalian lung and for mammalian kidney, each as a function of organ size. These data, after log-log transformation, were submitted to standard linear least squares regression analysis. The resultant slopes for nine different regression lines are in good agreement with the model predictions. This finding suggests, surprisingly, that organ scale-up, at least for selected organs, expressed in terms of repeating units, as a function of organ volume, in mammals and birds, and conceivably in other phyla, may be based on a small number of elementary structural principles.

  2. Interleukin-17A and Neutrophils in a Murine Model of Bird-Related Hypersensitivity Pneumonitis.

    Directory of Open Access Journals (Sweden)

    Masahiro Ishizuka

    Full Text Available Hypersensitivity pneumonitis (HP is an immune mediated lung disease induced by the repeated inhalation of a wide variety of antigens. Bird-related hypersensitivity pneumonitis (BRHP is one of the most common forms of HP in human and results from the inhalation of avian antigens. The findings of a recent clinical analysis suggest that in addition to Th1 factors, the levels of interleukin(IL-17 and IL-17-associated transcripts are increased in the setting of HP, and that both IL-17A and neutrophils are crucial for the development of pulmonary inflammation in murine models of HP. Our objectives were to investigate the roles of IL-17A and neutrophils in granuloma-forming inflammation in an acute HP model. We developed a mouse model of acute BRHP using pigeon dropping extract. We evaluated the process of granuloma formation and the roles of both IL-17A and neutrophils in a model. We found that the neutralization of IL-17A by the antibody attenuated granuloma formation and the recruitment of neutrophils, and also decreased the expression level of chemokine(C-X-C motif ligand 5 (CXCL5 in the acute HP model. We confirmed that most of the neutrophils in the acute HP model exhibited immunoreactivity to the anti-IL-17 antibody. We have identified the central roles of both IL-17A and neutrophils in the pathogenesis of granuloma formation in acute HP. We have also assumed that neutrophils are an important source of IL-17A in an acute HP model, and that the IL-17A-CXCL5 pathway may be responsible for the recruitment of neutrophils.

  3. The impact of nature-based tourism on bird communities: a case study in Pallas-Yllästunturi National Park.

    Science.gov (United States)

    Huhta, Esa; Sulkava, Pekka

    2014-05-01

    Nature-based tourism and recreation within and close to protected areas may have negative environmental impacts on biodiversity due to urban development, landscape fragmentation, and increased disturbance. We conducted a 3-year study of disturbances of birds induced by nature-based tourism over a recreational gradient in the Pallas-Yllästunturi National Park and its surroundings in northern Finland. Bird assemblages were studied in highly disturbed areas close to the park (a ski resort, villages, and accommodation areas) and in campfire sites, along hiking routes (recreational areas) and in a forest (control area) within the park. Compared with the forest, the disturbed urbanized areas had higher abundances of human-associated species, corvid species, cavity and building nesters, and edge species. The abundances of managed forest species were higher in campfire sites than in the forest. Hiking trails and campfire sites did not have a negative impact on open-nesting bird species. The most likely reason for this outcome is that most campfire sites were situated at forest edges; this species group prefers managed forests and forest edge as a breeding habitat. The abundances of virgin forest species did not differ among the areas studied. The results of the study suggest that the current recreation pressure has not caused substantial changes in the forest bird communities within the National Park. We suggest that the abundances of urban exploiter species could be used as indicators to monitor the level and changes of urbanization and recreational pressure at tourist destinations.

  4. The Impact of Nature-Based Tourism on Bird Communities: A Case Study in Pallas-Yllästunturi National Park

    Science.gov (United States)

    Huhta, Esa; Sulkava, Pekka

    2014-05-01

    Nature-based tourism and recreation within and close to protected areas may have negative environmental impacts on biodiversity due to urban development, landscape fragmentation, and increased disturbance. We conducted a 3-year study of disturbances of birds induced by nature-based tourism over a recreational gradient in the Pallas-Yllästunturi National Park and its surroundings in northern Finland. Bird assemblages were studied in highly disturbed areas close to the park (a ski resort, villages, and accommodation areas) and in campfire sites, along hiking routes (recreational areas) and in a forest (control area) within the park. Compared with the forest, the disturbed urbanized areas had higher abundances of human-associated species, corvid species, cavity and building nesters, and edge species. The abundances of managed forest species were higher in campfire sites than in the forest. Hiking trails and campfire sites did not have a negative impact on open-nesting bird species. The most likely reason for this outcome is that most campfire sites were situated at forest edges; this species group prefers managed forests and forest edge as a breeding habitat. The abundances of virgin forest species did not differ among the areas studied. The results of the study suggest that the current recreation pressure has not caused substantial changes in the forest bird communities within the National Park. We suggest that the abundances of urban exploiter species could be used as indicators to monitor the level and changes of urbanization and recreational pressure at tourist destinations.

  5. BPMN Impact on Process Modeling

    OpenAIRE

    Polak, Przemyslaw

    2013-01-01

    Recent years have seen huge rise in popularity of BPMN in the area of business process modeling, especially among business analysts. This notation has characteristics that distinguish it significantly from the previously popular process modeling notations, such as EPC. The article contains the analysis of some important characteristics of BPMN and provides author’s conclusions on the impact that the popularity and specificity of BPMN can have on the practice of process modeling. Author's obse...

  6. Modeling participation duration, with application to the North American Breeding Bird Survey

    Science.gov (United States)

    Link, William; Sauer, John

    2014-01-01

    We consider “participation histories,” binary sequences consisting of alternating finite sequences of 1s and 0s, ending with an infinite sequence of 0s. Our work is motivated by a study of observer tenure in the North American Breeding Bird Survey (BBS). In our analysis, j indexes an observer’s years of service and Xj is an indicator of participation in the survey; 0s interspersed among 1s correspond to years when observers did not participate, but subsequently returned to service. Of interest is the observer’s duration D = max {j: Xj = 1}. Because observed records X = (X1, X2,..., Xn)1 are of finite length, all that we can directly infer about duration is that D ⩾ max {j ⩽n: Xj = 1}; model-based analysis is required for inference about D. We propose models in which lengths of 0s and 1s sequences have distributions determined by the index j at which they begin; 0s sequences are infinite with positive probability, an estimable parameter. We found that BBS observers’ lengths of service vary greatly, with 25.3% participating for only a single year, 49.5% serving for 4 or fewer years, and an average duration of 8.7 years, producing an average of 7.7 counts.

  7. Modelling Perception of Structure and Affect in Music: Spectral Centroid and Wishart's Red Bird

    Directory of Open Access Journals (Sweden)

    Roger T. Dean

    2011-12-01

    Full Text Available Pearce (2011 provides a positive and interesting response to our article on time series analysis of the influences of acoustic properties on real-time perception of structure and affect in a section of Trevor Wishart’s Red Bird (Dean & Bailes, 2010. We address the following topics raised in the response and our paper. First, we analyse in depth the possible influence of spectral centroid, a timbral feature of the acoustic stream distinct from the high level general parameter we used initially, spectral flatness. We find that spectral centroid, like spectral flatness, is not a powerful predictor of real-time responses, though it does show some features that encourage its continued consideration. Second, we discuss further the issue of studying both individual responses, and as in our paper, group averaged responses. We show that a multivariate Vector Autoregression model handles the grand average series quite similarly to those of individual members of our participant groups, and we analyse this in greater detail with a wide range of approaches in work which is in press and continuing. Lastly, we discuss the nature and intent of computational modelling of cognition using acoustic and music- or information theoretic data streams as predictors, and how the music- or information theoretic approaches may be applied to electroacoustic music, which is ‘sound-based’ rather than note-centred like Western classical music.

  8. Impact of climate change effecting Decline on Migration Birds of Bhadalwadi Lake Indapur Taluka M.S India

    Directory of Open Access Journals (Sweden)

    U.S .Gantaloo

    2016-08-01

    Full Text Available Environmental changes are now a day’s happening regularly day to day increase in temperature ,Scarcity of rainfall ,Drying of lakes have strong implication on Biodiversity . .Global warming has set in motion and is affecting the timing of migration of birds .Birds are reliable indicator of environment change for centuries and their arrival indicate start of winter and departure summer in study area .There are many example of the effect of climate change on birds from all around the world which taken together provide compelling evidence that climate change is already affecting birds in diverse ways. The study was carried out for two years considering the changes occurring in climate parameters like Air Temperature, Rainfall were taken into facts .Keen observation with the help camera photography were taken to study. The effect on migrating Birds which measure international status on wet lands and lakes. Hence in the present study the data on biodiversity ,migratory birds have been collected to understand How climate change supported the dwelling of avian fauna in this area . This paper opens a review on migration of birds on the eve of 14th&15th May of world Bird migratory day.

  9. The Verification of the Simulation Methods to Bird Impact Resistance Design of Wing Leading Edge%机翼前缘抗鸟撞设计仿真方法验证

    Institute of Scientific and Technical Information of China (English)

    李京菁; 赵美英; 王文智

    2011-01-01

    This article used experimental method and finite element method (FEM) to study bird impact resistance for two types of aircraft wing leading-edge structure, in which the slanting supporting plate structure and corrugated panel structure were included. And the feasibility of the numerical simulation method to analyzing bird impact performance of complex structures has been verified. The simulation model of slanting supporting plate structure was validated by comparison with the experimental results, and its good bird impact resistance was demonstrated; however, the simulation results with the initial model of corrugated panel structure did not match the experimental ones without considering the joint strength between the skin and corrugated panel. The corrected simulation model of cor- rugated panel was finally built up.%分别利用实验方法和有限元分析方法研究了斜支板和波纹板前缘结构的抗鸟撞性能进行分析计算,验证了数值模拟方法在复杂结构的抗鸟撞性能分析中应用的可行性。通过与实验结果对比,验证了斜支板结构模型的正确性,肯定了其具有良好的抗鸟撞特性;波纹板结构初始模型的计算结果与实验结果存在较大差异,主要原因是未考虑蒙皮与波纹板的连接强度,造成了波纹板结构抗鸟撞失效。针对波纹板模型进行了改进,最终得到与实验结果相符的有限元模型。

  10. "Birds of a Feather": Does User Homophily Impact Information Diffusion in Social Media?

    CERN Document Server

    De Choudhury, Munmun; John, Ajita; Seligmann, Doree Duncan; Kelliher, Aisling

    2010-01-01

    This article investigates the impact of user homophily on the social process of information diffusion in online social media. Over several decades, social scientists have been interested in the idea that similarity breeds connection: precisely known as "homophily". Homophily has been extensively studied in the social sciences and refers to the idea that users in a social system tend to bond more with ones who are similar to them than to ones who are dissimilar. The key observation is that homophily structures the ego-networks of individuals and impacts their communication behavior. It is therefore likely to effect the mechanisms in which information propagates among them. To this effect, we investigate the interplay between homophily along diverse user attributes and the information diffusion process on social media. In our approach, we first extract diffusion characteristics---corresponding to the baseline social graph as well as graphs filtered on different user attributes (e.g. location, activity). Second,...

  11. Effects on birds of an offshore wind park at Horns Rev: Environmental impact assessment

    Energy Technology Data Exchange (ETDEWEB)

    Noer, H.; Kjaer Christensen, T.; Clausager, I.; Krag Petersen, I. [DMU, Dept. of Coastal Zone Ecology (Denmark)

    2000-07-01

    This report presents the technical background to the ornithological environmental impact assessment for the construction of an offshore windpark at Horns Rev, 14 km west-south-west of Blaevandshuk, Denmark. Construction of the park is planned to commence in 2001. The park will consist of c. 80 wind turbines, each of at least 1.8 MW, and cover an area of 27.5 km{sup 2} (including the 200 m exclusion zone around the park). (au)

  12. Estimating the surface area of birds: using the homing pigeon (Columba livia as a model

    Directory of Open Access Journals (Sweden)

    Cristina R. Perez

    2014-05-01

    Full Text Available Estimation of the surface area of the avian body is valuable for thermoregulation and metabolism studies as well as for assessing exposure to oil and other surface-active organic pollutants from a spill. The use of frozen carcasses for surface area estimations prevents the ability to modify the posture of the bird. The surface area of six live homing pigeons in the fully extended flight position was estimated using a noninvasive method. An equation was derived to estimate the total surface area of a pigeon based on its body weight. A pigeon's surface area in the fully extended flight position is approximately 4 times larger than the surface area of a pigeon in the perching position. The surface area of a bird is dependent on its physical position, and, therefore, the fully extended flight position exhibits the maximum area of a bird and should be considered the true surface area of a bird.

  13. Estimating the surface area of birds: using the homing pigeon (Columba livia) as a model.

    Science.gov (United States)

    Perez, Cristina R; Moye, John K; Pritsos, Chris A

    2014-05-08

    Estimation of the surface area of the avian body is valuable for thermoregulation and metabolism studies as well as for assessing exposure to oil and other surface-active organic pollutants from a spill. The use of frozen carcasses for surface area estimations prevents the ability to modify the posture of the bird. The surface area of six live homing pigeons in the fully extended flight position was estimated using a noninvasive method. An equation was derived to estimate the total surface area of a pigeon based on its body weight. A pigeon's surface area in the fully extended flight position is approximately 4 times larger than the surface area of a pigeon in the perching position. The surface area of a bird is dependent on its physical position, and, therefore, the fully extended flight position exhibits the maximum area of a bird and should be considered the true surface area of a bird.

  14. Prosthetic Avian Vocal Organ Controlled by a Freely Behaving Bird Based on a Low Dimensional Model of the Biomechanical Periphery

    Science.gov (United States)

    Arneodo, Ezequiel M.; Perl, Yonatan Sanz; Goller, Franz; Mindlin, Gabriel B.

    2012-01-01

    Because of the parallels found with human language production and acquisition, birdsong is an ideal animal model to study general mechanisms underlying complex, learned motor behavior. The rich and diverse vocalizations of songbirds emerge as a result of the interaction between a pattern generator in the brain and a highly nontrivial nonlinear periphery. Much of the complexity of this vocal behavior has been understood by studying the physics of the avian vocal organ, particularly the syrinx. A mathematical model describing the complex periphery as a nonlinear dynamical system leads to the conclusion that nontrivial behavior emerges even when the organ is commanded by simple motor instructions: smooth paths in a low dimensional parameter space. An analysis of the model provides insight into which parameters are responsible for generating a rich variety of diverse vocalizations, and what the physiological meaning of these parameters is. By recording the physiological motor instructions elicited by a spontaneously singing muted bird and computing the model on a Digital Signal Processor in real-time, we produce realistic synthetic vocalizations that replace the bird's own auditory feedback. In this way, we build a bio-prosthetic avian vocal organ driven by a freely behaving bird via its physiologically coded motor commands. Since it is based on a low-dimensional nonlinear mathematical model of the peripheral effector, the emulation of the motor behavior requires light computation, in such a way that our bio-prosthetic device can be implemented on a portable platform. PMID:22761555

  15. Prosthetic avian vocal organ controlled by a freely behaving bird based on a low dimensional model of the biomechanical periphery.

    Directory of Open Access Journals (Sweden)

    Ezequiel M Arneodo

    Full Text Available Because of the parallels found with human language production and acquisition, birdsong is an ideal animal model to study general mechanisms underlying complex, learned motor behavior. The rich and diverse vocalizations of songbirds emerge as a result of the interaction between a pattern generator in the brain and a highly nontrivial nonlinear periphery. Much of the complexity of this vocal behavior has been understood by studying the physics of the avian vocal organ, particularly the syrinx. A mathematical model describing the complex periphery as a nonlinear dynamical system leads to the conclusion that nontrivial behavior emerges even when the organ is commanded by simple motor instructions: smooth paths in a low dimensional parameter space. An analysis of the model provides insight into which parameters are responsible for generating a rich variety of diverse vocalizations, and what the physiological meaning of these parameters is. By recording the physiological motor instructions elicited by a spontaneously singing muted bird and computing the model on a Digital Signal Processor in real-time, we produce realistic synthetic vocalizations that replace the bird's own auditory feedback. In this way, we build a bio-prosthetic avian vocal organ driven by a freely behaving bird via its physiologically coded motor commands. Since it is based on a low-dimensional nonlinear mathematical model of the peripheral effector, the emulation of the motor behavior requires light computation, in such a way that our bio-prosthetic device can be implemented on a portable platform.

  16. Through the eyes of a bird: modelling visually guided obstacle flight.

    Science.gov (United States)

    Lin, Huai-Ti; Ros, Ivo G; Biewener, Andrew A

    2014-07-01

    Various flight navigation strategies for birds have been identified at the large spatial scales of migratory and homing behaviours. However, relatively little is known about close-range obstacle negotiation through cluttered environments. To examine obstacle flight guidance, we tracked pigeons (Columba livia) flying through an artificial forest of vertical poles. Interestingly, pigeons adjusted their flight path only approximately 1.5 m from the forest entry, suggesting a reactive mode of path planning. Combining flight trajectories with obstacle pole positions, we reconstructed the visual experience of the pigeons throughout obstacle flights. Assuming proportional-derivative control with a constant delay, we searched the relevant parameter space of steering gains and visuomotor delays that best explained the observed steering. We found that a pigeon's steering resembles proportional control driven by the error angle between the flight direction and the desired opening, or gap, between obstacles. Using this pigeon steering controller, we simulated obstacle flights and showed that pigeons do not simply steer to the nearest opening in the direction of flight or destination. Pigeons bias their flight direction towards larger visual gaps when making fast steering decisions. The proposed behavioural modelling method converts the obstacle avoidance behaviour into a (piecewise) target-aiming behaviour, which is better defined and understood. This study demonstrates how such an approach decomposes open-loop free-flight behaviours into components that can be independently evaluated.

  17. Simulating Aircraft's Asymmetrical Windshield Subjected to Bird Impact%飞机前风挡非对称结构的鸟撞数值模拟

    Institute of Scientific and Technical Information of China (English)

    王猛; 黄德武; 罗荣梅

    2012-01-01

    We employ the ANSYS/LS-DYNA nonlinear dynamic analysis software to simulate the dynamic response of the asymmetrical windshield subjected to bird impact and calculate the maximum principal stress,strain and displacement of its internal units,thus obtaining their distribution results.The principal stress at the fringe of the asymmetrical windshield subjected to bird impact is as high as nearly 0.8σmax but lasts only a short time and does not cause any damage to the asymmetrical windshield.This design of asymmetrical windshield does not reduce its critical velocity when it is under bird impact.Besides,the dispersion for the position of bird impact has some effect on the critical velocity of the asymmetrical windshield.%利用ANSYS/LS-DYNA非线性动力分析程序,对一种非对称结构飞机前风挡的鸟撞动态响应进行了三维数值模拟。计算得到非对称结构风挡内部单元的最大主应力、位移、应变等分布规律。与完整对称风挡相比,尽管撞击过程中非对称边缘处首先产生较高的应力值,接近0.8σmax,但持续时间短,并未造成材料破坏;这种非对称结构设计并不使鸟撞风挡临界速度产生明显的降低。另外,撞击点位置偏差对风挡鸟撞临界速度也有较大影响。

  18. Bird guard

    Science.gov (United States)

    Fairchild, Dana M.

    2010-03-02

    The bird guard provides a device to protect electrical insulators comprising a central shaft; a clamp attached to an end of the shaft to secure the device to a transmission tower; a top and bottom cover to shield transmission tower insulators; and bearings to allow the guard to rotate in order to frighten birds away from the insulators.

  19. Bird guard

    Science.gov (United States)

    Fairchild, Dana M.

    2010-03-02

    The bird guard provides a device to protect electrical insulators comprising a central shaft; a clamp attached to an end of the shaft to secure the device to a transmission tower; a top and bottom cover to shield transmission tower insulators; and bearings to allow the guard to rotate in order to frighten birds away from the insulators.

  20. Numerical Simulation for Arc Windshields of Aircrafts Subjected to Bird Impact

    Institute of Scientific and Technical Information of China (English)

    Yao Xiaohu; Zhao Longmao; Liu Xiaoming

    2004-01-01

    A finite element model including full-scale circular arc windshield glass and the relative parts of the military plane is established in this paper. The model is analyzed by using an explicit element code LS-DYNA3D for analyzing the nonlinear dynamic response of structures. The data in aspects of displacement, strain, stress and contact force in the process of deformation are obtained. The deformation and failure mechanism of circular arc windshield glass are discussed. The possible location at which failure may take place is given. The valuable data are provided for designing,researching and producing new windshields with high crashworthiness.

  1. Impact of antigenic diversity on laboratory diagnosis of Avian bornavirus infections in birds.

    Science.gov (United States)

    Zimmermann, Vanessa; Rinder, Monika; Kaspers, Bernd; Staeheli, Peter; Rubbenstroth, Dennis

    2014-11-01

    Avian bornaviruses (ABVs) are a group of genetically diverse viruses within the Bornaviridae family that can infect numerous avian species and represent the causative agents of proventricular dilatation disease, an often fatal disease that is widely distributed in captive populations of parrots and related species. The current study was designed to assess the antigenic variability of the family Bornaviridae and to determine its impact on ABV diagnosis by employing fluorescent antibody assays. It was shown that polyclonal rabbit sera directed against recombinant bornavirus nucleoprotein, X protein, phosphoprotein, and matrix protein provided sufficient cross-reactivity for the detection of viral antigen from a broad range of bornavirus genotypes grown in cell culture. In contrast, a rabbit anti-glycoprotein serum and 2 monoclonal antibodies directed against nucleoprotein and phosphoprotein proteins reacted more specifically. Antibodies were readily detected in sera from avian patients infected with known ABV genotypes if cells persistently infected with a variety of different bornavirus genotypes were used for analysis. For all sera, calculated antibody titers were highest when the homologous or a closely related target virus was used for the assay. Cross-reactivity with more distantly related genotypes of other phylogenetic groups was usually reduced, resulting in titer reduction of up to 3 log units. The presented results contribute to a better understanding of the antigenic diversity of family Bornaviridae and further emphasize the importance of choosing appropriate diagnostic tools for sensitive detection of ABV infections. © 2014 The Author(s).

  2. Impacts of logging and conversion of rainforest to oil palm on the functional diversity of birds in Sundaland

    National Research Council Canada - National Science Library

    Edwards, Felicity A; Edwards, David P; Hamer, Keith C; Davies, Richard G; Lens, Luc

    2013-01-01

    .... We calculated FD for birds across a gradient of disturbance from primary forest through intensively logged forest to oil palm plantations on previously forested land in B orneo, S outheast A sia...

  3. A global analysis of the impacts of urbanization on bird and plant diversity reveals key anthropogenic drivers

    Science.gov (United States)

    Aronson, Myla F. J.; La Sorte, Frank A.; Nilon, Charles H.; Katti, Madhusudan; Goddard, Mark A.; Lepczyk, Christopher A.; Warren, Paige S.; Williams, Nicholas S. G.; Cilliers, Sarel; Clarkson, Bruce; Dobbs, Cynnamon; Dolan, Rebecca; Hedblom, Marcus; Klotz, Stefan; Kooijmans, Jip Louwe; Kühn, Ingolf; MacGregor-Fors, Ian; McDonnell, Mark; Mörtberg, Ulla; Pyšek, Petr; Siebert, Stefan; Sushinsky, Jessica; Werner, Peter; Winter, Marten

    2014-01-01

    Urbanization contributes to the loss of the world's biodiversity and the homogenization of its biota. However, comparative studies of urban biodiversity leading to robust generalities of the status and drivers of biodiversity in cities at the global scale are lacking. Here, we compiled the largest global dataset to date of two diverse taxa in cities: birds (54 cities) and plants (110 cities). We found that the majority of urban bird and plant species are native in the world's cities. Few plants and birds are cosmopolitan, the most common being Columba livia and Poa annua. The density of bird and plant species (the number of species per km2) has declined substantially: only 8% of native bird and 25% of native plant species are currently present compared with estimates of non-urban density of species. The current density of species in cities and the loss in density of species was best explained by anthropogenic features (landcover, city age) rather than by non-anthropogenic factors (geography, climate, topography). As urbanization continues to expand, efforts directed towards the conservation of intact vegetation within urban landscapes could support higher concentrations of both bird and plant species. Despite declines in the density of species, cities still retain endemic native species, thus providing opportunities for regional and global biodiversity conservation, restoration and education. PMID:24523278

  4. Predicting impacts of future human population growth and development on occupancy rates of forest-dependent birds

    Science.gov (United States)

    Brown, Michelle L.; Donovan, Therese; Schwenk, W. Scott; Theobald, David M.

    2014-01-01

    Forest loss and fragmentation are among the largest threats to forest-dwelling wildlife species today, and projected increases in human population growth are expected to increase these threats in the next century. We combined spatially-explicit growth models with wildlife distribution models to predict the effects of human development on 5 forest-dependent bird species in Vermont, New Hampshire, and Massachusetts, USA. We used single-species occupancy models to derive the probability of occupancy for each species across the study area in the years 2000 and 2050. Over half a million new housing units were predicted to be added to the landscape. The maximum change in housing density was nearly 30 houses per hectare; however, 30% of the towns in the study area were projected to add less than 1 housing unit per hectare. In the face of predicted human growth, the overall occupancy of each species decreased by as much as 38% (ranging from 19% to 38% declines in the worst-case scenario) in the year 2050. These declines were greater outside of protected areas than within protected lands. Ninety-seven percent of towns experienced some decline in species occupancy within their borders, highlighting the value of spatially-explicit models. The mean decrease in occupancy probability within towns ranged from 3% for hairy woodpecker to 8% for ovenbird and hermit thrush. Reductions in occupancy probability occurred on the perimeters of cities and towns where exurban development is predicted to increase in the study area. This spatial approach to wildlife planning provides data to evaluate trade-offs between development scenarios and forest-dependent wildlife species.

  5. The impact of climate change on birds: a review%气候变化对鸟类影响的研究进展

    Institute of Scientific and Technical Information of China (English)

    吴伟伟; 徐海根; 吴军; 曹铭昌

    2012-01-01

    The impact of climate change on biodiversity has become a hot issue. This paper reviews the effects of climate change on avian distribution, phenology and population dynamics according to the results of the latest research. Due to climate change, bird distributions have shifted towards high-latitude and high-altitude areas, which is changing more quickly than before. However, the breeding area which bird lived was changed different from the non-breedings. In addition, the ranges of many species have decreased, the timing of oviposition and migration have become more variable, and populations of many species have declined. We also summarize the major methods used to forecast the effects of future climate scenarios on birds, and discuss how evolution, biotic interactions and dispersal ability affect the results of predictions. We found that more and more scientists using the integrated models than the single ones nowadays, a new advice using the mechanistic models has been proved well, and evolution has become a big problem for the prediction from the latest researches. The suggestions are as follows: (1) a system of avian protection should be established as soon as possible in China. (2) people should devise and evaluate some models in research work.%气候变化对生物多样性的影响已成为热点问题.本文以鸟类为研究对象,根据鸟类受气候变化影响的最新研究成果,综述了气候变化对鸟类的分布、物候和种群等方面的影响.结果表明,在气候变化影响下,鸟类分布向高纬度或高海拔区移动,速度比以往加快,繁殖地和非繁殖地的分布移动变化并不相同,并且多数分布范围缩小,物候期发生复杂变化,种群数量下降明显.文章还讨论了该领域主要的预测和评估方法,以及进化适应等生物因素对气候变化预测结果的影响,除了以往单一的相关性模型外,目前应用最多的是集成模型,而未来最具发展潜力的是机理模型.进化

  6. Experimental test of postfire management in pine forests: impact of salvage logging versus partial cutting and nonintervention on bird-species assemblages.

    Science.gov (United States)

    Castro, Jorge; Moreno-Rueda, Gregorio; Hódar, José A

    2010-06-01

    There is an intense debate about the effects of postfire salvage logging versus nonintervention policies on regeneration of forest communities, but scant information from experimental studies is available. We manipulated a burned forest area on a Mediterranean mountain to experimentally analyze the effect of salvage logging on bird-species abundance, diversity, and assemblage composition. We used a randomized block design with three plots of approximately 25 ha each, established along an elevational gradient in a recently burned area in Sierra Nevada Natural and National Park (southeastern Spain). Three replicates of three treatments differing in postfire burned wood management were established per plot: salvage logging, nonintervention, and an intermediate degree of intervention (felling and lopping most of the trees but leaving all the biomass). Starting 1 year after the fire, we used point sampling to monitor bird abundance in each treatment for 2 consecutive years during the breeding and winter seasons (720 censuses total). Postfire burned-wood management altered species assemblages. Salvage logged areas had species typical of open- and early-successional habitats. Bird species that inhabit forests were still present in the unsalvaged treatments even though trees were burned, but were almost absent in salvage-logged areas. Indeed, the main dispersers of mid- and late-successional shrubs and trees, such as thrushes (Turdus spp.) and the European Jay (Garrulus glandarius) were almost restricted to unsalvaged treatments. Salvage logging might thus hamper the natural regeneration of the forest through its impact on assemblages of bird species. Moreover, salvage logging reduced species abundance by 50% and richness by 40%, approximately. The highest diversity at the landscape level (gamma diversity) resulted from a combination of all treatments. Salvage logging may be positive for bird conservation if combined in a mosaic with other, less-aggressive postfire

  7. Talking Birds

    Institute of Scientific and Technical Information of China (English)

    海文

    2005-01-01

    Many students of Englishthink thatlearning a new languageis very difficult.N ow think howdifficultitis to learn English whenyour brain is only the size of abird's brain。That is what som ebirds can do.M any different kinds of birdscan copy the sounds of lan-guage.A frican gray parrots are thebirds bestknown for this.Every D ecem ber in London,the N ationalCage and A viary BirdShow tries to find the best“talkbird in the world.O ne bird nam edPrudle stood outam ong the“talk-ing birds by winning this prizeevery...

  8. Assessing impacts to birds from the Buffalo Ridge, Minnesota windplant development

    Energy Technology Data Exchange (ETDEWEB)

    Strickland, M.D.; Johnson, G.D.; Erickson, W.P. [WEST Inc., Cheyenne, WY (United States)] [and others

    1997-12-31

    Northern States Power (NSP) plans development of a 425 MW windpowered electrical generation facility within the Buffalo Ridge Wind Resource Area (WRA) in southwestern Minnesota. In 1996, Western EcoSystems Technology (WEST, Inc.) was contracted by NSP to develop an avian monitoring protocol for the Buffalo Ridge windplant. This protocol was developed and peer-reviewed by numerous individuals representing the wind energy industry, U.S. Fish and Wildlife Service, Minnesota Department of Natural Resources, and conservation groups prior to finalization. The WRA currently consists of three phases of development. Phase I, constructed by Kenetech in 1994, consists of 73 Model 33 M-VS turbines and related facilities, including distribution lines, meteorological towers, communication systems, transformers, substations, roads, and operations and maintenance facilities in the approximate center of the WRA, and generates 25 MW of electricity. Phase II, consisting of 143 turbines and related facilities sufficient to generate 100 MW of electricity, will be constructed by Zond Systems, Inc. beginning in the spring of 1997. Phase II will be located in the northwestern portion of the WRA. Phase III facilities capable of generating an additional 100 MW are planned for the southeast portion of the WRA. Plans call for the eventual production of 425 MW of electricity within the WRA. Studies were conducted in these three areas and a permanent reference area not scheduled for windpower development located along Buffalo Ridge northwest of the WRA in Brooking County South Dakota.

  9. Birds and wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Langston, Rowena

    2011-07-01

    Full text: Climate change, perhaps more accurately described as climate disruption, is considered to be a major long-term threat to biodiversity, with a high probability that the underlying cause is due to anthropogenic greenhouse gas emissions. Renewable energy is an important component of a programme of measures to combat further climate change, to include improved energy efficiency and demand management. Wind energy is the most advanced renewable energy source and is a global industry onshore and, increasingly, offshore. However, as with any form of energy generation, wind energy also has potential environmental costs which have to be balanced against benefits. The environmental impacts on birds derive from the following: collision risk, in particular from the moving rotor blades; displacement arising from disturbance during construction, operation or decommissioning; habitat loss or change leading to alteration of food availability; barrier effects leading to deviation of long distance migratory flights or disruption of local flights between feeding, nesting, and roosting/loafing locations. Not all species of birds, or individuals within a species, are equally susceptible to negative interactions with wind turbines, and neither are the population consequences of impacts equivalent. Of greatest concern are bird species of conservation concern that exhibit behaviours that place them at risk of an adverse impact, notably when that impact leads to a reduction in population size that is unlikely to be compensated for. In particular, cumulative impacts arising from multiple wind farms or wind farms in combination with other developments are of concern. There has been a welcome increase in research effort and peer-reviewed publications on the subject of birds and wind energy in recent years. Increasing our understanding of impacts is essential to delivering possible solutions and this paper reviews current knowledge for birds. (Author)

  10. 14 CFR 29.631 - Bird strike.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bird strike. 29.631 Section 29.631... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction General § 29.631 Bird strike. The... safe landing (for Category B) after impact with a 2.2-lb (1.0 kg) bird when the velocity of...

  11. Parameters Inversion on Bird Constitutive Model Part Ⅰ:Study on Experiment of Bird Striking on Plate%鸟体本构模型参数反演I:鸟撞平板试验研究

    Institute of Scientific and Technical Information of China (English)

    刘军; 李玉龙; 郭伟国; 石霄鹏; 彭刚; 叶彪

    2011-01-01

    为了结合数值模拟得到鸟撞过程中的鸟体本构模型参数,对鸟撞平板进行了试验研究.鸟体质量分别为1.8kg和3.6 kg,平板材料采用厚度为10 mm和14 mm的LYl2铝合金和厚度为4.5 mm和8.0 mm的45#钢,鸟体撞击速度为70、120、170 m/s,共进行了16组鸟撞试验.采用动态数据采集系统获得了鸟撞过程中平板的位移和应变及撞击支反力等物理量的时间历程数据,运用高速摄像系统记录了鸟撞平板动响应变形的全过程.试验结果表明:每组两次试验从撞击速度到试验结果重复性均很好;鸟撞作用时间为ms量级,属冲击动力学行为,且鸟体与平板之间存在强烈的耦合作用;平板变形较大,中心点最大位移是平板厚度的7.9倍;撞击速度越高,鸟体的流体特性越明显.%In order to obtain the mechanical parameters of the bird during the process of bird striking, numerical simulations and experiments of bird striking on plate are studied in the paper. The bird mass is 1.8 kg and 3. 6 kg respectively, and the plate is made by LY12 aluminium alloy with the thickness of 10 mm and 14 mm and 45# steel with the thickness of 4.5 mm and 8.0 mm. Sixteen groups of experiments are performed in the present paper with the bird velocity at 70,120,170 m/s,respectively. The histories of displacement-time and strain-time of plate as well as the force-time are measured by the dynamic data acquisition system, and the whole process of dynamic response during bird striking on plate is recorded by highspeed camera system. The results of the experiments indicate that the repeatability of the impacting velocities and the measured results for twice experiments in one group are very good. The reaction time of bird striking is millisecond, so its behavior belongs to impact dynamics; there exists strong coupling between the bird and the plate. The deformation of the plate is very big and the ratio of the plate displacement at the center point to the

  12. Hawaii ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for endangered waterbirds and passerine birds, migratory shorebirds and waterfowl, gulls and terns,...

  13. The Terrestrial Investigation Model: A probabilistic risk assessment model for birds exposed to pesticides

    Science.gov (United States)

    One of the major recommendations of the National Academy of Science to the USEPA, NMFS and USFWS was to utilize probabilistic methods when assessing the risks of pesticides to federally listed endangered and threatened species. The Terrestrial Investigation Model (TIM, version 3....

  14. Recreation-induced changes in boreal bird communities in protected areas.

    Science.gov (United States)

    Kangas, K; Luoto, M; Ihantola, A; Tomppo, E; Siikamäki, P

    2010-09-01

    The impacts of human-induced disturbance on birds have been studied in growing extent, but there are relatively few studies about the effects of recreation on forest bird communities in protected areas. In this paper, the relative importance of recreation as well as environmental variables on bird communities in Oulanka National Park, in northeastern Finland, was investigated using general additive models (GAM). Bird data collected using the line transect method along hiking trails and in undisturbed control areas were related to number of visits, area of tourism infrastructure, and habitat variables. We further examined the impact of spatial autocorrelation by calculating an autocovariate term for GAMs. Our results indicate that number of visits affects the occurrence and composition of bird communities, but it had no impact on total species richness. Open-cup nesters breeding on the ground showed strongest negative response to visitor pressure, whereas the open-cup nesters nesting in trees and shrubs were more tolerant. For cavity-nesting species, recreation had no significant impact. The contribution of the number of visits was generally low also in models in which it was selected, and the occurrence of birds was mainly determined by habitat characteristics of the area. However, our results show that the recreation-induced disturbance with relatively low visitor pressure can have negative impacts on some bird species and groups of species and should be considered in management of protected areas with recreational activities.

  15. Optical techniques as validation tools for finite element modeling of biomechanical structures, demonstrated in bird ear research

    Science.gov (United States)

    Muyshondt, Pieter; De Greef, Daniël; Soons, Joris; Dirckx, Joris J. J.

    2014-05-01

    In this paper we demonstrate the potential of stroboscopic digital holography and laser vibrometry as tools to gather vibration data and validate modelling results in complex biomechanical systems, in this case the avian middle ear. Whereas the middle ear of all mammal species contains three ossicles, birds only feature one ossicle, the columella. Despite this far simpler design, the hearing range of most birds is comparable to mammals, and is adapted to operate under very diverse atmospheric circumstances. This makes the investigation of the avian middle ear potentially very meaningful, since it could provide knowledge that can improve the design of prosthetic ossicle replacements in humans such as a TORP (Total Ossicle Replacement Prosthesis). In order to better understand the mechanics of the bird's hearing, we developed a finite element model that simulates the transmission of an incident acoustic wave on the eardrum via the middle ear structures to the fluid of the inner ear. The model is based on geometry extracted from stained μCT data and is validated using results from stroboscopic digital holography measurements on the eardrum and LDV measurements on the columella footplate. This technique uses very short high-power laser pulses that are synchronized to the membrane's vibration phase to measure the dynamic response of the bird's eardrum to an incident acoustic stimulus. Vibration magnitude as well as phase relative to the sound wave can be deduced from the results, the latter being of great importance in the elastic characterization of the tympanic membrane. In this work, the setup and results from the optical measurements, as well as the properties and optimization of the finite element model are presented. Observed phase variations across the eardrum's surface on the holography results strongly suggest the presence of internal energy losses in the membrane due to damping. Therefore, a viscoelastic characterisation of the model based on a complex

  16. Model for vocalization by a bird with distensible vocal cavity and open beak.

    Science.gov (United States)

    Fletcher, Neville H; Riede, Tobias; Suthers, Roderick A

    2006-02-01

    Some birds make use of a distensible oral cavity to produce nearly pure-tone song. Songbirds such as the Northern cardinal (Cardinalis cardinalis) have a muscularly distended oropharyngeal-esophageal cavity between the top of the trachea and the open beak. The present paper analyzes the acoustics of this vocal system. It is shown that the resonance of the oropharyngeal-esophageal cavity, vented through the beak, introduces a dominant peak in the radiation efficiency, the frequency of which can be adjusted by varying the volume of the cavity, the beak gape, and perhaps the position of the tongue in the mouth. To produce nearly pure-tone song, the bird adjusts the frequency of this peak to coincide with the fundamental of the syringeal oscillation. The present paper provides the acoustical analysis underlying this behavior.

  17. The 60-dB rule for birds: An example of the application of a weighting function in environmental impact mitigation

    Science.gov (United States)

    Bowles, Ann E.; Wisdom, Sheyna

    2005-09-01

    Over the last decade U.S. Fish and Wildlife Service managers in California have required millions of dollars in added expenditure for NEPA consultation, mitigation barriers, and project delays to reduce the effects of noise from construction activities on endangered passerine birds when the hourly A-weighted Leq is expected to exceed 60 dB. The rule was originally intended to prevent masking of species-typical songs of endangered birds such as the Coastal California Gnatcatcher. However, no research is available to demonstrate the effectiveness of the rule for any noise-related impact. Although A-weighting is probably a conservative estimator of bird exposure in the range from 125 Hz to 8 kHz, it may underestimate exposure at very low frequencies. Its utility as a weighting function has not been tested against other possible weighting procedures, such as use of the species-typical auditory threshold function. Additionally, where sources are intense but intermittent, Leq is unlikely to be a useful metric. These issues should receive more technical scrutiny before the 60-dB rule becomes entrenched in law. It is in widespread use for NEPA consultations, and is already being extended to other species, including large mammals.

  18. Modelling Perception of Structure and Affect in Music: Spectral Centroid and Wishart's Red Bird

    OpenAIRE

    Dean, Roger T.; Freya Bailes

    2011-01-01

    Pearce (2011) provides a positive and interesting response to our article on time series analysis of the influences of acoustic properties on real-time perception of structure and affect in a section of Trevor Wishart’s Red Bird (Dean & Bailes, 2010). We address the following topics raised in the response and our paper. First, we analyse in depth the possible influence of spectral centroid, a timbral feature of the acoustic stream distinct from the high level general parameter we used initial...

  19. Numerical Study of Bird Impact on the Aircraft Windshield Structure with Composite Material%民机机头复合材料风挡结构鸟撞分析

    Institute of Scientific and Technical Information of China (English)

    简成文; 李书

    2015-01-01

    The relative velocity is always very large when the bird impacting on the aircraft windshield, and the body of the bird will present the property of fluid. This kind of problem belongs to the category of fluid dynamics. At first, this paper analyzed a numerical simulation of bird impacting on aluminum plate with the method of ALE, and the result of simulation and the test data are compared. Then a full scale model which contains windshield, framework and the skin is set up. The framework and the skin are made of composite materials. Numerical study of bird strike on this model is done and the result proves that the structure meets the design requirements. At present, a full scale framework of aircraft windshield with composite materials has not been applied to the civil aircraft yet, so the study of this windshield structure with composite materials is of great significance.%在鸟体撞击风挡结构过程中,鸟体与风挡结构撞击相对速度很大,呈现出流体特性,属于典型的流固耦合瞬态冲击动力学问题。首先针对文献中的鸟撞铝板试验采用任意的拉格朗日-欧拉( ALE )流固耦合方法进行了分析,对计算方法与鸟体模型进行了验证。然后建立了包括风挡玻璃、风挡骨架以及蒙皮在内的民机全尺寸风挡结构抗鸟撞动响应分析的有限元模型,进行了鸟撞数值模拟,其中风挡骨架与蒙皮采用复合材料。全尺寸的复合材料风挡骨架目前还没有应用到民机上,因此,对复合材料风挡结构的研究是很有意义的。

  20. Epigenetics and phenotypic variability: some interesting insights from birds.

    Science.gov (United States)

    Frésard, Laure; Morisson, Mireille; Brun, Jean-Michel; Collin, Anne; Pain, Bertrand; Minvielle, Francis; Pitel, Frédérique

    2013-06-11

    Little is known about epigenetic mechanisms in birds with the exception of the phenomenon of dosage compensation of sex chromosomes, although such mechanisms could be involved in the phenotypic variability of birds, as in several livestock species. This paper reviews the literature on epigenetic mechanisms that could contribute significantly to trait variability in birds, and compares the results to the existing knowledge of epigenetic mechanisms in mammals. The main issues addressed in this paper are: (1) Does genomic imprinting exist in birds? (2) How does the embryonic environment influence the adult phenotype in avian species? (3) Does the embryonic environment have an impact on phenotypic variability across several successive generations? The potential for epigenetic studies to improve the performance of individual animals through the implementation of limited changes in breeding conditions or the addition of new parameters in selection models is still an open question.

  1. The Identification of Military Installations as Important Migratory Bird Stopover Sites and the Development of Bird Migration Forecast Models: A Radar Ornithology Approach

    Science.gov (United States)

    2012-08-01

    30. Moore, F. R. 1994. Resumption of feeding under risk of predation: effect of migratory condition. Animal Behaviour 48:975-977. Moore, F. R. 1999...can be used to map geographical areas of high bird activity (e.g., stopover, roosting and feeding , and colonial breeding areas). It also provides... Raptors Unknown Abert’s Towhee American Avocet Broad-winged Hawk Unknown Accipiter Anna’s Hummingbird American Bittern Mississippi Kite Unknown

  2. Columbia River ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, diving birds, seabirds, passerine birds, gulls, and terns in...

  3. Western Alaska ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, seabirds, passerine birds, and gulls and...

  4. Aging in Birds.

    Science.gov (United States)

    Travin, D Y; Feniouk, B A

    2016-12-01

    Rodents are the most commonly used model organisms in studies of aging in vertebrates. However, there are species that may suit this role much better. Most birds (Aves), having higher rate of metabolism, live two-to-three times longer than mammals of the same size. This mini-review briefly covers several evolutionary, ecological, and physiological aspects that may contribute to the phenomenon of birds' longevity. The role of different molecular mechanisms known to take part in the process of aging according to various existing theories, e.g. telomere shortening, protection against reactive oxygen species, and formation of advanced glycation end-products is discussed. We also address some features of birds' aging that make this group unique and perspective model organisms in longevity studies.

  5. Tracking migrating birds

    DEFF Research Database (Denmark)

    Willemoes, Mikkel

    Migratory movements of birds has always fascinated man and led to many questions concerning the ecological drivers behind, the necessary adaptations and the navigational abilities required. However, especially for the long-distance migrants, basic descriptions of their movements are still lacking...... and a forest reserve. In the degraded habitat all species used more space, although the consequence on bird density is less clear. Two manuscripts relate the migratory movements of a long-distance migrant with models of navigation. One compares model predictions obtained by simulation with actual movements...... in when and where the bird compensated for the displacement. The last paper investigates effects of habitat shading on the performance of light-level based geolocation and compares experimental data with data from real tracking studies. This illustrates some of the potential problems and limitations...

  6. Birds as predators in tropical agroforestry systems.

    Science.gov (United States)

    Van Bael, Sunshine A; Philpott, Stacy M; Greenberg, Russell; Bichier, Peter; Barber, Nicholas A; Mooney, Kailen A; Gruner, Daniel S

    2008-04-01

    Insectivorous birds reduce arthropod abundances and their damage to plants in some, but not all, studies where predation by birds has been assessed. The variation in bird effects may be due to characteristics such as plant productivity or quality, habitat complexity, and/or species diversity of predator and prey assemblages. Since agroforestry systems vary in such characteristics, these systems provide a good starting point for understanding when and where we can expect predation by birds to be important. We analyze data from bird exclosure studies in forests and agroforestry systems to ask whether birds consistently reduce their arthropod prey base and whether bird predation differs between forests and agroforestry systems. Further, we focus on agroforestry systems to ask whether the magnitude of bird predation (1) differs between canopy trees and understory plants, (2) differs when migratory birds are present or absent, and (3) correlates with bird abundance and diversity. We found that, across all studies, birds reduce all arthropods, herbivores, carnivores, and plant damage. We observed no difference in the magnitude of bird effects between agroforestry systems and forests despite simplified habitat structure and plant diversity in agroforests. Within agroforestry systems, bird reduction of arthropods was greater in the canopy than the crop layer. Top-down effects of bird predation were especially strong during censuses when migratory birds were present in agroforestry systems. Importantly, the diversity of the predator assemblage correlated with the magnitude of predator effects; where the diversity of birds, especially migratory birds, was greater, birds reduced arthropod densities to a greater extent. We outline potential mechanisms for relationships between bird predator, insect prey, and habitat characteristics, and we suggest future studies using tropical agroforests as a model system to further test these areas of ecological theory.

  7. Bayesian cross-validation for model evaluation and selection, with application to the North American Breeding Bird Survey

    Science.gov (United States)

    Link, William; Sauer, John R.

    2016-01-01

    The analysis of ecological data has changed in two important ways over the last 15 years. The development and easy availability of Bayesian computational methods has allowed and encouraged the fitting of complex hierarchical models. At the same time, there has been increasing emphasis on acknowledging and accounting for model uncertainty. Unfortunately, the ability to fit complex models has outstripped the development of tools for model selection and model evaluation: familiar model selection tools such as Akaike's information criterion and the deviance information criterion are widely known to be inadequate for hierarchical models. In addition, little attention has been paid to the evaluation of model adequacy in context of hierarchical modeling, i.e., to the evaluation of fit for a single model. In this paper, we describe Bayesian cross-validation, which provides tools for model selection and evaluation. We describe the Bayesian predictive information criterion and a Bayesian approximation to the BPIC known as the Watanabe-Akaike information criterion. We illustrate the use of these tools for model selection, and the use of Bayesian cross-validation as a tool for model evaluation, using three large data sets from the North American Breeding Bird Survey.

  8. Bayesian cross-validation for model evaluation and selection, with application to the North American Breeding Bird Survey.

    Science.gov (United States)

    Link, William A; Sauer, John R

    2016-07-01

    The analysis of ecological data has changed in two important ways over the last 15 years. The development and easy availability of Bayesian computational methods has allowed and encouraged the fitting of complex hierarchical models. At the same time, there has been increasing emphasis on acknowledging and accounting for model uncertainty. Unfortunately, the ability to fit complex models has outstripped the development of tools for model selection and model evaluation: familiar model selection tools such as Akaike's information criterion and the deviance information criterion are widely known to be inadequate for hierarchical models. In addition, little attention has been paid to the evaluation of model adequacy in context of hierarchical modeling, i.e., to the evaluation of fit for a single model. In this paper, we describe Bayesian cross-validation, which provides tools for model selection and evaluation. We describe the Bayesian predictive information criterion and a Bayesian approximation to the BPIC known as the Watanabe-Akaike information criterion. We illustrate the use of these tools for model selection, and the use of Bayesian cross-validation as a tool for model evaluation, using three large data sets from the North American Breeding Bird Survey.

  9. Dynamics Model for Bird Strike Accident Early Warning%飞机抗鸟撞的预警动力学模型

    Institute of Scientific and Technical Information of China (English)

    刘双燕; 邓琼; 陈春林

    2012-01-01

    为预防鸟撞事故,根据事故发生过程和开放系统的熵演变过程有很大相似性这一特点,采用信息熵理论解释事故发生过程,进而建立鸟撞事故发生和预警的动力学模型,揭示引发事故的主要原因和预防事故的对策.在此基础上,采用基于熵的综合评价方法,对造成事故的多个因素进行对比分析和综合评价,得出鸟撞事故中飞行时间(季节和昼夜2个因素)、飞行高度、飞机的结构、遭遇的鸟类和发生区域等5大类共6个因素的熵值.结果表明,飞鸟种类的熵值最大,为0.4106;其次是飞机结构因素.因此,预防鸟撞事故应该从飞鸟控制和飞机结构设计着手.%A system dynamics model for bird strike' s occurrence was introduced to study the Bird Strike disaster on airplane. The process of bird strike' s occurrence was explained by information entropy theory based on similarity of the process of bird strike' s occurrence to the evolution of the entropy of an open system. Main causes of the bird strike accident and the countermeasures for preventing it were revealed. U-sing the comprehensive evaluation method based on information entropy, entropy values of the 6 factors causing the accident ( including kind of birds, the timing of the flight, the height of the flight, the structure of aircraft and the area of bird strike' s occurrence) were calculated. The result shows that the kind of birds is the most important factor in bird strike accident, of which entropy value is 0. 410 6, followed by the aircraft structure factor. In a word, bird strike accident prevention should start from the bird control and aircraft structural design.

  10. Success factors for avian influenza vaccine use in poultry and potential impact at the wild bird-agricultural interface.

    Science.gov (United States)

    Swayne, David E; Spackman, Erica; Pantin-Jackwood, Mary

    2014-01-01

    Thirty-two epizootics of high pathogenicity avian influenza (HPAI) have been reported in poultry and other birds since 1959. The ongoing H5N1 HPAI epizootic that began in 1996 has also spilled over to infect wild birds. Traditional stamping-out programs in poultry have resulted in eradication of most HPAI epizootics. However, vaccination of poultry was added as a control tool in 1995 and has been used during five epizootics. Over 113 billion doses of AI vaccine have been used in poultry from 2002 to 2010 as oil-emulsified, inactivated whole AIV vaccines (95.5%) and live vectored vaccines (4.5%). Over 99% of the vaccine has been used in the four H5N1 HPAI enzootic countries: China including Hong Kong (91%), Egypt (4.7%), Indonesia (2.3%), and Vietnam (1.4%) where vaccination programs have been nationwide and routine to all poultry. Ten other countries used vaccine in poultry in a focused, risk-based manner but this accounted for less than 1% of the vaccine used. Most vaccine "failures" have resulted from problems in the vaccination process; i.e., failure to adequately administer the vaccine to at-risk poultry resulting in lack of population immunity, while fewer failures have resulted from antigenic drift of field viruses away from the vaccine viruses. It is currently not feasible to vaccinate wild birds against H5N1 HPAI, but naturally occurring infections with H5 low pathogenicity avian influenza viruses may generate cross-protective immunity against H5N1 HPAI. The most feasible method to prevent and control H5N1 HPAI in wild birds is through control of the disease in poultry with use of vaccine to reduce environmental burden of H5N1 HPAIV, and eventual eradication of the virus in domestic poultry, especially in domestic ducks which are raised in enzootic countries on range or in other outdoor systems having contact with wild aquatic and periurban terrestrial birds.

  11. Tuberculosis in wild birds: implications for captive birds

    Science.gov (United States)

    Converse, K. A.; Dein, F. J.

    1990-01-01

    The geographic distribution of avian tuberculosis is widespread but the lack of visible epizootics makes assessment of its impact on wild birds difficult. Generally a low prevalence, widely-scattered, individual animal disease, avian tuberculosis is caused by the same agent in wild and domestic birds. Thus there exists the potential for disease transfer between these two groups in situations that result in direct contact such as wild animals newly captured or transferred from rehabilitation centers, and wild and captive animals intermingling in exhibit areas. During the past 7 yr, tuberculosis caused by Mycobacterium avium, was diagnosed in 64 birds submitted to the National Wildlife Health Research Center from 16 states; avian tuberculosis was the primary diagnosis in 52 of the 64 birds, while the remaining 12 isolates were incidental findings. Twenty-eight of these birds were picked up during epizootics caused by other disease agents including avian cholera, botulism type C, and lead, organophosphorus compound, and cyanide poisoning. Twelve birds were found incidental to birds collected during disease monitoring programs and research projects, and 10 birds were collected by hunters or found sick and euthanatized. Tuberculosis lesions occurred (in order of decreasing frequency) in the liver, intestine, spleen, lung, and air sacs. Several unusual morphological presentations were observed in the gizzard, shoulder joint, jugular vein, face, nares and bill, ureter and bone marrow. Infected birds were collected during all 12 mo of the yr from a variety of species in the Anseriformes, Podicipediformes, Gruiformes, and Falconiformes. Nine of the 46 known age birds were immature indicating that lesions can develop during the first year.

  12. Automated recognition of bird song elements from continuous recordings using dynamic time warping and hidden Markov models: a comparative study.

    Science.gov (United States)

    Kogan, J A; Margoliash, D

    1998-04-01

    The performance of two techniques is compared for automated recognition of bird song units from continuous recordings. The advantages and limitations of dynamic time warping (DTW) and hidden Markov models (HMMs) are evaluated on a large database of male songs of zebra finches (Taeniopygia guttata) and indigo buntings (Passerina cyanea), which have different types of vocalizations and have been recorded under different laboratory conditions. Depending on the quality of recordings and complexity of song, the DTW-based technique gives excellent to satisfactory performance. Under challenging conditions such as noisy recordings or presence of confusing short-duration calls, good performance of the DTW-based technique requires careful selection of templates that may demand expert knowledge. Because HMMs are trained, equivalent or even better performance of HMMs can be achieved based only on segmentation and labeling of constituent vocalizations, albeit with many more training examples than DTW templates. One weakness in HMM performance is the misclassification of short-duration vocalizations or song units with more variable structure (e.g., some calls, and syllables of plastic songs). To address these and other limitations, new approaches for analyzing bird vocalizations are discussed.

  13. Testing bird response to roads on a rural environment: A case study from Central Italy

    Science.gov (United States)

    Morelli, Federico; Jerzak, Leszek; Pruscini, Fabio; Santolini, Riccardo; Benedetti, Yanina; Tryjanowski, Piotr

    2015-11-01

    The construction of roads is currently well spread in many parts of our world and impacts strongly on wildlife distribution. Some bird species avoid, while other prefer to be in the vicinity of these human structures. However, studies on roads effects on birds, in terms of strength or direction of these effects, are scarce. Therefore, in a study carried out in Central Italy we tested the responses of different bird species to roads at a local spatial scale, using generalized linear models (GLM). Analysis were conducted on a large dataset (more than 1400 sampled sites, mainly on rural environments). Both positive and negative effects of roads on birds were found for bird species of close or semi-close environments, while the negative effects of roads were negligible for bird species of open and semi-open environments. This fact suggest that roads can be a source of "functional heterogeneity" on semi-open environments, providing marginal habitats, hedgerows and residual vegetation typical of roadsides, offering breeding and feeding habitat for some bird species. The proposed methodology provide a useful explorative tool, in order to develop conservation policies to preserve the biodiversity, mainly in rural landscapes. The outputs of GLM can be used as inputs in ecological planning: direction and strength of the effects of roads on bird species are adequate to estimate the response of bird community, up front to the presence of new structures, or identifying which of them should be mitigated to reduce negative effects on the biodiversity.

  14. Automatic identification of bird targets with radar via patterns produced by wing flapping.

    Science.gov (United States)

    Zaugg, Serge; Saporta, Gilbert; van Loon, Emiel; Schmaljohann, Heiko; Liechti, Felix

    2008-09-01

    Bird identification with radar is important for bird migration research, environmental impact assessments (e.g. wind farms), aircraft security and radar meteorology. In a study on bird migration, radar signals from birds, insects and ground clutter were recorded. Signals from birds show a typical pattern due to wing flapping. The data were labelled by experts into the four classes BIRD, INSECT, CLUTTER and UFO (unidentifiable signals). We present a classification algorithm aimed at automatic recognition of bird targets. Variables related to signal intensity and wing flapping pattern were extracted (via continuous wavelet transform). We used support vector classifiers to build predictive models. We estimated classification performance via cross validation on four datasets. When data from the same dataset were used for training and testing the classifier, the classification performance was extremely to moderately high. When data from one dataset were used for training and the three remaining datasets were used as test sets, the performance was lower but still extremely to moderately high. This shows that the method generalizes well across different locations or times. Our method provides a substantial gain of time when birds must be identified in large collections of radar signals and it represents the first substantial step in developing a real time bird identification radar system. We provide some guidelines and ideas for future research.

  15. Business model elements impacting cloud computing adoption

    DEFF Research Database (Denmark)

    Bogataj, Kristina; Pucihar, Andreja; Sudzina, Frantisek

    The paper presents a proposed research framework for identification of business model elements impacting Cloud Computing Adoption. We provide a definition of main Cloud Computing characteristics, discuss previous findings on factors impacting Cloud Computing Adoption, and investigate technology...... adoption theories, such as Diffusion of Innovations, Technology Acceptance Model, Unified Theory of Acceptance and Use of Technology. Further on, at research model for identification of Cloud Computing Adoption factors from a business model perspective is presented. The following business model building...

  16. Business model elements impacting cloud computing adoption

    DEFF Research Database (Denmark)

    Bogataj, Kristina; Pucihar, Andreja; Sudzina, Frantisek

    adoption theories, such as Diffusion of Innovations, Technology Acceptance Model, Unified Theory of Acceptance and Use of Technology. Further on, at research model for identification of Cloud Computing Adoption factors from a business model perspective is presented. The following business model building......The paper presents a proposed research framework for identification of business model elements impacting Cloud Computing Adoption. We provide a definition of main Cloud Computing characteristics, discuss previous findings on factors impacting Cloud Computing Adoption, and investigate technology...

  17. Contrasting impacts of pollen and seed dispersal on spatial genetic structure in the bird-pollinated Banksia hookeriana.

    Science.gov (United States)

    Krauss, S L; He, T; Barrett, L G; Lamont, B B; Enright, N J; Miller, B P; Hanley, M E

    2009-03-01

    In plants, pollen- and seed-dispersal distributions are characteristically leptokurtic, with significant consequences for spatial genetic structure and nearest-neighbour mating. However, most studies to date have been on wind- or insect-pollinated species. Here, we assigned paternity to quantify effective pollen dispersal over 9 years of mating, contrasted this to seed dispersal and examined their effects on fine-scale spatial genetic structure, within the bird-pollinated shrub Banksia hookeriana (Proteaceae). We used 163 polymorphic amplified fragment length polymorphism markers to assess genetic structure and pollen dispersal in a spatially discrete population of 112 plants covering 0.56 ha. Spatial autocorrelation analysis detected spatial genetic structure in the smallest distance class of 0-5 m (r=0.025), with no significant structure beyond 8 m. Experimentally quantified seed-dispersal distances for 337 seedlings showed a leptokurtic distribution around a median of 5 m, reaching a distance of 36 m. In marked contrast, patterns of pollen dispersal for 274 seeds departed strikingly from typical near-neighbour pollination, with a distribution largely corresponding to the spatial distribution of plants. We found very high multiple paternity, very low correlated paternity and an equal probability of siring for the 50 closest potential mates. Extensive pollen carryover was demonstrated by multiple siring in 83 of 86 (96.5%) two-seeded fruits. Highly mobile nectar-feeding birds facilitate this promiscuity through observed movements that were effectively random. As the incidence of bird-pollination is markedly greater in the Southwest Australian Floristic Region than elsewhere, our results have broad and novel significance for the evolution and conservation for many species in Gondwanan lineages.

  18. Epidemiologic characterization of Colorado backyard bird flocks.

    Science.gov (United States)

    Smith, Emily I; Reif, John S; Hill, Ashley E; Slota, Katharine E; Miller, Ryan S; Bjork, Kathe E; Pabilonia, Kristy L

    2012-06-01

    Backyard gallinaceous bird flocks may play an important role in the spread of infectious diseases within poultry populations as well as the transmission of zoonotic diseases to humans. An epidemiologic characterization was conducted of Colorado backyard flocks to gather information on general flock characteristics, human movement of birds, human-bird interaction, biosecurity practices, and flock health. Our results suggest that backyard poultry flocks in Colorado are small-sized flocks (68.6% of flocks had backyard flock environment may promote bird-to-bird transmission as well as bird-to-human transmission of infectious disease. Birds are primarily housed with free access to the outside (96.85%), and many are moved from the home premises (46.06% within 1 yr). Human contact with backyard flocks is high, biosecurity practices are minimal, and bird health is negatively impacted by increased movement events. Increased knowledge of backyard bird characteristics and associated management practices can provide guidelines for the development of measures to decrease disease transmission between bird populations, decrease disease transmission from birds to humans, and increase the overall health of backyard birds.

  19. The impact of rise of the Andes and Amazon landscape evolution on diversification of lowland terra-firme forest birds

    Science.gov (United States)

    Aleixo, A.; Wilkinson, M. J.

    2011-12-01

    Since the 19th Century, the unmatched biological diversity of Amazonia has stimulated a diverse set of hypotheses accounting for patterns of species diversity and distribution in mega-diverse tropical environments. Unfortunately, the evidence supporting particular hypotheses to date is at best described as ambiguous, and no generalizations have emerged yet, mostly due to the lack of comprehensive comparative phylogeographic studies with thorough trans-Amazonian sampling of lineages. Here we report on spatial and temporal patterns of diversification estimated from mitochondrial gene trees for 31 lineages of birds associated with upland terra-firme forest, the dominant habitat in modern lowland Amazonia. The results confirm the pervasive role of Amazonian rivers as primary barriers separating sister lineages of birds, and a protracted spatio-temporal pattern of diversification, with a gradual reduction of earlier (1st and 2nd) and older (> 2 mya) splits associated with each lineage in an eastward direction (the easternmost tributaries of the Amazon, the Xingu and Tocantins Rivers, are not associated with any splits older than > 2 mya). This "younging-eastward" pattern may have an abiotic explanation related to landscape evolution. Triggered by a new pulse of Andean uplift, it has been proposed that modern Amazon basin landscapes may have evolved successively eastward, away from the mountain chain, starting ~10 mya. This process was likely based on the deposition of vast fluvial sediment masses, known as megafans, which apparently extended in series progressively eastward from Andean sources. The effects on drainage patterns are apparent from the location of axial rivers such as the Negro / Orinoco and Madeira which lie at the distal ends of major megafan ramparts at cratonic margins furthest from the Andes. Megafan extension plausibly explains the progressive extinction of the original Pebas wetland of west-central Amazonia by the present fluvial landsurfaces where

  20. Modelling of the spring phenological phases of the Silver birch Betula pendula and Bird cherry Padus racemosa in Baltic region

    Science.gov (United States)

    Kalvāns, Andis; Kalvāne, Gunta; Bitāne, Māra; Cepīte-Frišfelde, Daiga; Sīle, Tija; Seņņikovs, Juris

    2014-05-01

    The air temperature is the strongest driving factor of the plant development during spring time in moderate climate conditions. However other factors such as the air temperature during the dormancy period and light conditions can play a role as well. The full potential of the recent and historical phenological observation data can be utilised by modelling tools. We have calibrated seven phenological models described in scientific literature to calculate the likely dates leaf unfolding and start of flowering of the Silver birch Betula pendula and bird cherry Padus racemosa (Kalvāns at al, accepted). Phenological observations are derived from voluntary observation network for period 1960-2009 in Latvia. The number of used observations for each phase range from 149 to 172. Air temperature data measured in meteorological stations closest to the corresponding phenological observation sites are obtained from Latvian Environment, Geology and Meteorology Centre. We used 33 random data subsamples for model calibration to produce a range of model coefficients enabling the estimation of the phenological model uncertainty. It is found that the best reproduction of the observational data are obtained using a simple linear degree day model considering daily minimum and maximum temperature and more complex sigmoidal model honouring the need for low temperatures for dormancy release (UniChill, Chuine, 2000). The median calibration base temperature in the degree day model for the silver birch leaf unfolding is 5.6°C and for start of the flowering 6.7°C; for the bird cherry the corresponding base temperatures are 3.2°C and 3.4°C. The calibrated models and air temperature archive data derived from the Danish Meteorological Institute is used to simulate the respective phase onset in the Estonia, Latvia and Lithuania in 2009. Significant regional differences between modelled phase onset times are observed. There is a wide regional variation of the model uncertainty as well

  1. BIRD FLU (AVIAN INFLUENZA)

    OpenAIRE

    Ali ACAR; Bulent BESIRBELLIOÐLU

    2005-01-01

    Avian influenza (bird flu) is a contagious disease of animals caused by influenza A viruses. These flu viruses occur naturally among birds. Actually, humans are not infected by bird flu viruses.. However, during an outbreak of bird flu among poultry, there is a possible risk to people who have contact infect birds or surface that have been contaminated with excreations from infected birds. Symptoms of bird flu in humans have ranged from typical flu-like symptoms to eye infections, pneumonia, ...

  2. Intraspecific correlations of basal and maximal metabolic rates in birds and the aerobic capacity model for the evolution of endothermy.

    Directory of Open Access Journals (Sweden)

    David L Swanson

    Full Text Available The underlying assumption of the aerobic capacity model for the evolution of endothermy is that basal (BMR and maximal aerobic metabolic rates are phenotypically linked. However, because BMR is largely a function of central organs whereas maximal metabolic output is largely a function of skeletal muscles, the mechanistic underpinnings for their linkage are not obvious. Interspecific studies in birds generally support a phenotypic correlation between BMR and maximal metabolic output. If the aerobic capacity model is valid, these phenotypic correlations should also extend to intraspecific comparisons. We measured BMR, M(sum (maximum thermoregulatory metabolic rate and MMR (maximum exercise metabolic rate in a hop-flutter chamber in winter for dark-eyed juncos (Junco hyemalis, American goldfinches (Carduelis tristis; M(sum and MMR only, and black-capped chickadees (Poecile atricapillus; BMR and M(sum only and examined correlations among these variables. We also measured BMR and M(sum in individual house sparrows (Passer domesticus in both summer, winter and spring. For both raw metabolic rates and residuals from allometric regressions, BMR was not significantly correlated with either M(sum or MMR in juncos. Moreover, no significant correlation between M(sum and MMR or their mass-independent residuals occurred for juncos or goldfinches. Raw BMR and M(sum were significantly positively correlated for black-capped chickadees and house sparrows, but mass-independent residuals of BMR and M(sum were not. These data suggest that central organ and exercise organ metabolic levels are not inextricably linked and that muscular capacities for exercise and shivering do not necessarily vary in tandem in individual birds. Why intraspecific and interspecific avian studies show differing results and the significance of these differences to the aerobic capacity model are unknown, and resolution of these questions will require additional studies of potential

  3. Affinity for natal environments by dispersers impacts reproduction and explains geographical structure of a highly mobile bird.

    Science.gov (United States)

    Fletcher, Robert J; Robertson, Ellen P; Wilcox, Rebecca C; Reichert, Brian E; Austin, James D; Kitchens, Wiley M

    2015-09-07

    Understanding dispersal and habitat selection behaviours is central to many problems in ecology, evolution and conservation. One factor often hypothesized to influence habitat selection by dispersers is the natal environment experienced by juveniles. Nonetheless, evidence for the effect of natal environment on dispersing, wild vertebrates remains limited. Using 18 years of nesting and mark-resight data across an entire North American geographical range of an endangered bird, the snail kite (Rostrhamus sociabilis), we tested for natal effects on breeding-site selection by dispersers and its consequences for reproductive success and population structure. Dispersing snail kites were more likely to nest in wetlands of the same habitat type (lacustrine or palustrine) as their natal wetland, independent of dispersal distance, but this preference declined with age and if individuals were born during droughts. Importantly, dispersing kites that bred in natal-like habitats had lower nest success and productivity than kites that did not. These behaviours help explain recently described population connectivity and spatial structure across their geographical range and reveal that assortative breeding is occurring, where birds are more likely to breed with individuals born in the same wetland type as their natal habitat. Natal environments can thus have long-term and large-scale effects on populations in nature, even in highly mobile animals.

  4. The Impact of Rise of the Andes and Amazon Landscape Evolution on Diversification of Lowland terra-firme Forest Birds

    Science.gov (United States)

    Aleixo, Alexandre; Wilkinson, M. Justin

    2011-01-01

    Since the 19th Century, the unmatched biological diversity of Amazonia has stimulated a diverse set of hypotheses accounting for patterns of species diversity and distribution in mega-diverse tropical environments. Unfortunately, the evidence supporting particular hypotheses to date is at best described as ambiguous, and no generalizations have emerged yet, mostly due to the lack of comprehensive comparative phylogeographic studies with thorough trans-Amazonian sampling of lineages. Here we report on spatial and temporal patterns of diversification estimated from mitochondrial gene trees for 31 lineages of birds associated with upland terra-firme forest, the dominant habitat in modern lowland Amazonia. The results confirm the pervasive role of Amazonian rivers as primary barriers separating sister lineages of birds, and a protracted spatio-temporal pattern of diversification, with a gradual reduction of earlier (1st and 2nd) and older (> 2 mya) splits associated with each lineage in an eastward direction. (The easternmost tributaries of the Amazon, the Xingu and Tocantins Rivers, are not associated with any splits older than > 2 mya). For the suboscine passerines, maximum-likelihood estimates of rates of diversification point to an overall constant rate over the past 5 my (up to a significant downturn at 300,000 y ago). This "younging-eastward" pattern may have an abiotic explanation related to landscape evolution. Triggered by a new pulse of Andean uplift, it has been proposed that modern Amazon basin landscapes may have evolved successively eastward, away from the mountain chain, starting approximately 10 mya. This process was likely based on the deposition of vast fluvial sediment masses, known as megafans, that may have extended progressively and in series eastward from Andean sources. This process plausibly explains the progressive extinction of original Pebas wetland of western-central Amazonia by the present fluvial landsurfaces of a more terra-firme type

  5. Green Light for Nocturnally Migrating Birds

    Directory of Open Access Journals (Sweden)

    Hanneke Poot

    2008-12-01

    Laboratory experiments have shown the magnetic compass to be wavelength dependent: migratory birds require light from the blue-green part of the spectrum for magnetic compass orientation, whereas red light (visible long-wavelength disrupts magnetic orientation. We designed a field study to test if and how changing light color influenced migrating birds under field conditions. We found that nocturnally migrating birds were disoriented and attracted by red and white light (containing visible long-wavelength radiation, whereas they were clearly less disoriented by blue and green light (containing less or no visible long-wavelength radiation. This was especially the case on overcast nights. Our results clearly open perspective for the development of bird-friendly artificial lighting by manipulating wavelength characteristics. Preliminary results with an experimentally developed bird-friendly light source on an offshore platform are promising. What needs to be investigated is the impact of bird-friendly light on other organisms than birds.

  6. Impact Behaviour of Soft Body Projectiles

    Science.gov (United States)

    Kalam, Sayyad Abdul; Rayavarapu, Vijaya Kumar; Ginka, Ranga Janardhana

    2017-04-01

    Bird strike analysis is a common type of analysis done during the design and analysis of primary structures such as engine cowlings or fuselage panels. These simulations are done in order to predict whether various designs will pass the necessary certification tests. Composite materials are increasingly being used in aerospace industry and bird strike is a major threat which may lead to serious structural damage of those materials. Such phenomenon may arise from numerous impact scenarios. The focus of current study is on the finite element modeling for composite structures and simulation of high velocity impact loads from soft body projectiles with an explicit dynamics code AUTODYN. This paper investigates the methodology which can be utilized to certify an aircraft for bird strike resistance using computational technique by first demonstrating the accuracy of the method for bird impact on rigid target modeling and then applies the developed model to a more complex problem. The model developed for bird strike threat assessment incorporates parameters of bird number (bird density), bird body mass, equation of state (EOS) and bird path during impact.

  7. Weighing the relative potential impacts of climate change and land-use change on an endangered bird.

    Science.gov (United States)

    Bancroft, Betsy A; Lawler, Joshua J; Schumaker, Nathan H

    2016-07-01

    Climate change and land-use change are projected to be the two greatest drivers of biodiversity loss over the coming century. Land-use change has resulted in extensive habitat loss for many species. Likewise, climate change has affected many species resulting in range shifts, changes in phenology, and altered interactions. We used a spatially explicit, individual-based model to explore the effects of land-use change and climate change on a population of the endangered Red-cockaded Woodpecker (RCW; Picoides borealis). We modeled the effects of land-use change using multiple scenarios representing different spatial arrangements of new training areas for troops across Fort Benning. We used projected climate-driven changes in habitat and changes in reproductive output to explore the potential effects of climate change. We summarized potential changes in habitat based on the output of the dynamic vegetation model LPJ-GUESS, run for multiple climate change scenarios through the year 2100. We projected potential changes in reproduction based on an empirical relationship between spring precipitation and the mean number of successful fledglings produced per nest attempt. As modeled in our study, climate change had virtually no effect on the RCW population. Conversely, simulated effects of land-use change resulted in the loss of up to 28 breeding pairs by 2100. However, the simulated impacts of development depended on where the development occurred and could be completely avoided if the new training areas were placed in poor-quality habitat. Our results demonstrate the flexibility inherent in many systems that allows seemingly incompatible human land uses, such as development, and conservation actions to exist side by side.

  8. Automatic identification of bird targets with radar via patterns produced by wing flapping

    NARCIS (Netherlands)

    Zaugg, S.; Saporta, G.; van Loon, E.; Schmaljohann, H.; Liechti, F.

    2008-01-01

    Bird identification with radar is important for bird migration research, environmental impact assessments (e.g. wind farms), aircraft security and radar meteorology. In a study on bird migration, radar signals from birds, insects and ground clutter were recorded. Signals from birds show a typical

  9. Automatic identification of bird targets with radar via patterns produced by wing flapping

    NARCIS (Netherlands)

    Zaugg, S.; Saporta, G.; van Loon, E.; Schmaljohann, H.; Liechti, F.

    2008-01-01

    Bird identification with radar is important for bird migration research, environmental impact assessments (e.g. wind farms), aircraft security and radar meteorology. In a study on bird migration, radar signals from birds, insects and ground clutter were recorded. Signals from birds show a typical pa

  10. Game Birds of Colorado.

    Science.gov (United States)

    Colorado State Div. of Wildlife, Denver.

    This booklet is intended to familiarize the reader with game birds typical of Colorado. Discussions in English and Spanish are presented. Discussions cover the management of game birds, individual game bird species, and endangered species of birds related to game birds. (RE)

  11. An analytical hierarchical model explaining the robustness and flaw-tolerance of the interlocking barb-barbule structure of bird feathers

    Science.gov (United States)

    Chen, Qiang; Gorb, Stanislav; Kovalev, Alexander; Li, Zhiyong; Pugno, Nicola

    2016-10-01

    Feathers can fulfill their aerodynamic function only if the pennaceous vane forms an airfoil stabilized by robust interlocking between barbules. Thus, revealing the robustness of the interlocking mechanical behavior of the barbules is very important to understand the function and long-term resilience of bird feathers. This paper, basing on the small- and large-beam deflection solutions, presents a hierarchical mechanical model for deriving the critical delamination conditions of the interlocking barbules between two adjacent barbs in bird feathers. The results indicate a high robustness and flaw-tolerant design of the structure. This work contributes to the understanding of the mechanical behavior of the robust interlocking barb-barbule structure of the bird feather, and provides a basis for design of feather-inspired materials with robust interlocking mechanism, such as advanced bio-inspired micro-zipping devices.

  12. Impact modeling with Smooth Particle Hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Stellingwerf, R.F.; Wingate, C.A.

    1993-07-01

    Smooth Particle Hydrodynamics (SPH) can be used to model hypervelocity impact phenomena via the addition of a strength of materials treatment. SPH is the only technique that can model such problems efficiently due to the combination of 3-dimensional geometry, large translations of material, large deformations, and large void fractions for most problems of interest. This makes SPH an ideal candidate for modeling of asteroid impact, spacecraft shield modeling, and planetary accretion. In this paper we describe the derivation of the strength equations in SPH, show several basic code tests, and present several impact test cases with experimental comparisons.

  13. Impact of different monochromatic LED light colours and bird age on the behavioural output and fear response in ducks

    Directory of Open Access Journals (Sweden)

    Shabiha Sultana

    2013-12-01

    Full Text Available This study was performed to observe the effect of monochromatic light emitting diode (LED light colour and bird age on the behaviour and fear response of ducks. A total of 200 1-day-old ducklings were used in the experiment (two replications, 25 ducklings/pen, and lighting was set up as follows: white (W, control, 400-770 nm, yellow (Y, 600 nm, green (G, 520 nm and blue (B, 460 nm LED lights. Ducks were subjected to 23L: 1D h lighting with 0.1 Watt/m2 light intensity. Video was recorded twice per day (2 h in the morning and 2 h in the afternoon and observed five consecutive days per week. Duration of feeding, drinking, sitting, walking, standing, preening, wing flapping, wing stretching, tail wagging, head shaking, body shaking, ground pecking, peck object, and social interaction behaviour were recorded. At 3 and 6 weeks of age, 10 birds per treatment were subjected to the tonic immobility (TI test (three times/duck. Ducks reared in Y and W light were more active, as expressed by more walking, ground pecking, drinking and social interaction activities than those of ducks under the B light treatment (P<0.05. Ducks showed more time sitting, standing, and preening under B light (P<0.05. Feeding, sitting, standing and drinking behaviours increased, and walking and social interaction behaviours decreased with age of the ducks (P<0.05. Differences in behaviours among different light colours were observed. In addition, the TI test results indicated that B and G light reduced the fear response of the ducks.

  14. Mississippi River Flood of 2011 and the Activation of the Birds Point-New Madrid Floodway: Observations and Modeling of a Levee Breach

    Science.gov (United States)

    Holmes, R. R.; Koenig, T. A.; McDonald, R. R.; Nelson, J. M.; Simoes, F. J.

    2011-12-01

    During 2011, record flooding has occurred in many parts of the central United States. As the flooding reached record levels for the Mississippi-Ohio River confluence at Cairo, Illinois, the 61 kilometer long and 8 kilometer wide Birds Point-New Madrid Floodway (Floodway) was activated to provide a lowering of upstream water levels through a controlled demolition of approximately 3,300 meters of levee at 10:00 PM on May 2, 2011. Prior to activation of the Floodway, the U.S. Geological Survey (USGS) deployed 38 self-contained stage sensors throughout the Floodway to capture the change in water elevation through time at various locations. From April 29, 2011 to May 24, 2011, daily streamflow measurements were made upstream of the confluence of the Ohio and Mississippi Rivers, within the Floodway opening and outlets, and on the Mississippi River downstream of the Floodway opening. Additionally, velocity and bathymetric data were collected immediately downstream of the Floodway opening at Birds Point to characterize scour in the Floodway. The data provide a unique look at the impact of a controlled levee breach on river flows and hydraulics. The activation of the Floodway lowered the water level at Cairo, Illinois by 0.44 meters in the first 14 hours, while increasing the streamflow of the Mississippi and Ohio Rivers in vicinity of Cairo, Illinois by 9,200 cubic meters per second. On May 2, prior to the activation of the Floodway, the measured combined streamflow of the upper Mississippi and Ohio Rivers at Cairo, Illinois was 52,900 cubic meters per second with the Ohio River contributing 27,700 cubic meters per second. Following the controlled breach of the Birds Point levee (immediately downstream of Cairo, Illinois on the right descending bank) the night of May 2, 2011, the measured combined streamflow at Cairo, Illinois on May 3, 2011 increased to 62,100 cubic meters per second with the Ohio River increasing to 38,100 cubic meters per second, an increase of 10

  15. JEDI: Jobs and Economic Development Impact Model

    Energy Technology Data Exchange (ETDEWEB)

    2017-06-13

    The Jobs and Economic Development Impact (JEDI) models are user-friendly tools that estimate the economic impacts of constructing and operating power generation and biofuel plants at the local (usually state) level. First developed by NREL's researchers to model wind energy jobs and impacts, JEDI has been expanded to also estimate the economic impacts of biofuels, coal, conventional hydro, concentrating solar power, geothermal, marine and hydrokinetic power, natural gas, photovoltaics, and transmission lines. This fact sheet focuses on JEDI for wind energy projects and is revised with 2017 figures.

  16. Sparkling feather reflections of a bird-of-paradise explained by finite-difference time-domain modeling

    NARCIS (Netherlands)

    Wilts, Bodo D; Michielsen, Kristel; De Raedt, Hans; Stavenga, Doekele G

    2014-01-01

    Birds-of-paradise are nature's prime examples of the evolution of color by sexual selection. Their brilliant, structurally colored feathers play a principal role in mating displays. The structural coloration of both the occipital and breast feathers of the bird-of-paradise Lawes' parotia is produced

  17. Assessing allowable take of migratory birds

    Science.gov (United States)

    Runge, M.C.; Sauer, J.R.; Avery, M.L.; Blackwell, B.F.; Koneff, M.D.

    2009-01-01

    Legal removal of migratory birds from the wild occurs for several reasons, including subsistence, sport harvest, damage control, and the pet trade. We argue that harvest theory provides the basis for assessing the impact of authorized take, advance a simplified rendering of harvest theory known as potential biological removal as a useful starting point for assessing take, and demonstrate this approach with a case study of depredation control of black vultures (Coragyps atratus) in Virginia, USA. Based on data from the North American Breeding Bird Survey and other sources, we estimated that the black vulture population in Virginia was 91,190 (95% credible interval = 44,520?212,100) in 2006. Using a simple population model and available estimates of life-history parameters, we estimated the intrinsic rate of growth (rmax) to be in the range 7?14%, with 10.6% a plausible point estimate. For a take program to seek an equilibrium population size on the conservative side of the yield curve, the rate of take needs to be less than that which achieves a maximum sustained yield (0.5 x rmax). Based on the point estimate for rmax and using the lower 60% credible interval for population size to account for uncertainty, these conditions would be met if the take of black vultures in Virginia in 2006 was <3,533 birds. Based on regular monitoring data, allowable harvest should be adjusted annually to reflect changes in population size. To initiate discussion about how this assessment framework could be related to the laws and regulations that govern authorization of such take, we suggest that the Migratory Bird Treaty Act requires only that take of native migratory birds be sustainable in the long-term, that is, sustained harvest rate should be

  18. Use of multispecies occupancy models to evaluate the response of bird communities to forest degradation associated with logging.

    Science.gov (United States)

    Carrillo-Rubio, Eduardo; Kéry, Marc; Morreale, Stephen J; Sullivan, Patrick J; Gardner, Beth; Cooch, Evan G; Lassoie, James P

    2014-08-01

    Forest degradation is arguably the greatest threat to biodiversity, ecosystem services, and rural livelihoods. Therefore, increasing understanding of how organisms respond to degradation is essential for management and conservation planning. We were motivated by the need for rapid and practical analytical tools to assess the influence of management and degradation on biodiversity and system state in areas subject to rapid environmental change. We compared bird community composition and size in managed (ejido, i.e., communally owned lands) and unmanaged (national park) forests in the Sierra Tarahumara region, Mexico, using multispecies occupancy models and data from a 2-year breeding bird survey. Unmanaged sites had on average higher species occupancy and richness than managed sites. Most species were present in low numbers as indicated by lower values of detection and occupancy associated with logging-induced degradation. Less than 10% of species had occupancy probabilities >0.5, and degradation had no positive effects on occupancy. The estimated metacommunity size of 125 exceeded previous estimates for the region, and sites with mature trees and uneven-aged forest stand characteristics contained the highest species richness. Higher estimation uncertainty and decreases in richness and occupancy for all species, including habitat generalists, were associated with degraded young, even-aged stands. Our findings show that multispecies occupancy methods provide tractable measures of biodiversity and system state and valuable decision support for landholders and managers. These techniques can be used to rapidly address gaps in biodiversity information, threats to biodiversity, and vulnerabilities of species of interest on a landscape level, even in degraded or fast-changing environments. Moreover, such tools may be particularly relevant in the assessment of species richness and distribution in a wide array of habitats.

  19. Heterogeneous movement of insectivorous Amazonian birds through primary and secondary forest: A case study using multistate models with radiotelemetry data

    Science.gov (United States)

    Hines, James; Powell, Luke L.; Wolfe, Jared D.; Johnson, Erik l.; Nichols, James D.; Stouffer, Phillip C.

    2015-01-01

    Given rates of deforestation, disturbance, and secondary forest accumulation in tropical rainforests, there is a great need to quantify habitat use and movement among different habitats. This need is particularly pronounced for animals most sensitive to disturbance, such as insectivorous understory birds. Here we use multistate capture–recapture models with radiotelemetry data to determine the successional stage at which within-day movement probabilities of Amazonian birds in secondary forest are similar to those in primary forest. We radio-tracked three common understory insectivore species in primary and secondary forest at the Biological Dynamics of Forest Fragments project near Manaus, Brazil: two woodcreepers, Glyphorynchus spirurus (n = 19) andXiphorhynchus pardalotus (n = 18), and the terrestrial antthrush Formicarius colma(n = 19). Forest age was a strong predictor of fidelity to a given habitat. All three species showed greater fidelity to primary forest than to 8–14-year-old secondary forest, indicating the latter’s relatively poor quality. The two woodcreeper species used 12–18-year-old secondary forest in a manner comparable to continuous forest, but F. colmaavoided moving even to 27–31-year-old secondary forest—the oldest at our site. Our results suggest that managers concerned with less sensitive species can assume that forest reserves connected by 12–18-year-old secondary forest corridors are effectively connected. On the other hand, >30 years are required after land abandonment before secondary forest serves as a primary forest-like conduit for movement by F. colma; more sensitive terrestrial insectivores may take longer still.

  20. Bird Flu (Avian Influenza)

    Science.gov (United States)

    ... for the treatment of H7N9 bird flu. Bird flu vaccine The Food and Drug Administration has approved one ... continue to work on other types of bird flu vaccines. Recommendations for travelers If you're traveling to ...

  1. Migration of birds

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers the migration of birds. Topics covered include why birds migrate, when birds migrate, speed, altitude, courses, distance, major flyways and...

  2. Magnitude and correlates of bird collisions at glass bus shelters in an urban landscape.

    Science.gov (United States)

    Barton, Christine M; Riding, Corey S; Loss, Scott R

    2017-01-01

    Wildlife residing in urban landscapes face many human-related threats to their survival. For birds, collision with glass on manmade structures has been identified as a major hazard, causing hundreds of millions of avian fatalities in North America every year. Although research has investigated factors associated with bird-glass collision mortality at buildings, no prior studies have focused on bird fatalities at glass-walled bus shelters. Our objectives in this study were to describe the magnitude of bird-bus shelter collisions in the city of Stillwater, Oklahoma and assess potential predictors of collision risk, including characteristics of shelters (glass area) and surrounding land cover (e.g., vegetative features). We surveyed for bird carcasses and indirect collision evidence at 18 bus shelters over a five-month period. Linear regression and model selection results revealed that the amount of glass on shelters and the area of lawn within 50 m of shelters were both positively related to fatal bird collisions; glass area was also positively associated with observations of collision evidence on glass surfaces. After accounting for scavenger removal of carcasses, we estimate that a minimum of 34 birds are killed each year between May and September by collision with the 36 bus shelters in the city of Stillwater. While our study provides an initial look at bird fatalities at bus shelters, additional research is needed to generate a large-scale estimate of collision mortality and to assess species composition of fatalities at a national scale. Designing new bus shelters to include less glass and retrofitting existing shelters to increase visibility of glass to birds will likely reduce fatal bird collisions at bus shelters and thus reduce the cumulative magnitude of anthropogenic impacts to birds in cities.

  3. How displaced migratory birds could use volatile atmospheric compounds to find their migratory corridor? A test using a particle dispersion model.

    Directory of Open Access Journals (Sweden)

    Kamran Safi

    2016-10-01

    Full Text Available Olfaction represents an important sensory modality for navigation of both homing pigeons and wild birds. Experimental evidence in homing pigeons showed that airborne volatile compounds carried by the winds at the home area are learned in association with wind directions. When displaced, pigeons obtain information on the direction of their displacement using local odours at the release site. Recently, the role of olfactory cues in navigation has been reported also for wild birds during migration. However, the question whether wild birds develop an olfactory navigational map similar to that described in homing pigeons or, alternatively, exploit the distribution of volatile compounds in different manners for reaching the goal is still an open question. Using an interdisciplinary approach, we evaluate the possibilities of reconstructing spatio-temporally explicit aerosol dispersion at large spatial scales using the particle dispersion model FLEXPART. By combining atmospheric information with particle dispersion models, atmospheric scientists predict the dispersion of pollutants for example, after nuclear fallouts or volcanic eruptions or wildfires, or in retrospect reconstruct the origin of emissions such as aerosols. Using simple assumptions, we reconstructed the putative origin of aerosols traveling to the location of migrating birds. We use the model to test whether the putative odour plume could have originated from an important stopover site. If the migrating birds knew this site and the associated plume from previous journeys, the odour could contribut to the reorientation towards the migratory corridor, as suggested for the model scenario in displaced Lesser black-backed gulls migrating from Northern Europe into Africa.

  4. Effects of bird-feeding activities on the health of wild birds.

    Science.gov (United States)

    Wilcoxen, Travis E; Horn, David J; Hogan, Brianna M; Hubble, Cody N; Huber, Sarah J; Flamm, Joseph; Knott, Madeline; Lundstrom, Lisa; Salik, Faaria; Wassenhove, Samantha J; Wrobel, Elizabeth R

    2015-01-01

    Among the most popular reasons that people feed wild birds is that they want to help birds. The extent to which supplemental food helps birds, however, is not well established. From spring 2011 to spring 2014, we examined how feeding of wild birds influences the health of individual birds at forested sites in central Illinois, USA. Specifically, we compared three forested sites where we provided supplemental food with three forested sites for which no supplemental food was available and monitored changes in the individual health of birds. In addition, we determined whether any changes in bird health had occurred after feeders had been removed from sites 10 months before. Generally, the individual health of birds improved with supplemental feeding, including increased antioxidant levels, reduced stress (heterophil-to-lymphocyte ratio) and more rapid feather growth. In some species, we also found improved body condition index scores and innate immune defense. The difference among sites was not present 10 months after feeders were removed, suggesting that the impact on health was indeed related to supplemental feeding. Potential negative effects of supplemental feeding were also found, including an increase in infectious disease prevalence among individual birds at forested sites where supplemental food was offered. Birds with clear signs of pathology showed deficits in most of the physiological metrics in which birds at feeder sites typically showed improved health condition. At the peak of prevalence of infectious disease, 8.3% of all birds at feeders exhibited symptoms of conjunctivitis, pox, dermal disease or cloacal disease. We found both positive and negative impacts of wild bird feeding, and that, in general, birds that had access to supplemental food were in better physiological condition. Moreover, the negative effects we found may be mitigated by hobbyists engaging in safer bird-feeding practices.

  5. A Probabilistic Asteroid Impact Risk Model

    Science.gov (United States)

    Mathias, Donovan L.; Wheeler, Lorien F.; Dotson, Jessie L.

    2016-01-01

    Asteroid threat assessment requires the quantification of both the impact likelihood and resulting consequence across the range of possible events. This paper presents a probabilistic asteroid impact risk (PAIR) assessment model developed for this purpose. The model incorporates published impact frequency rates with state-of-the-art consequence assessment tools, applied within a Monte Carlo framework that generates sets of impact scenarios from uncertain parameter distributions. Explicit treatment of atmospheric entry is included to produce energy deposition rates that account for the effects of thermal ablation and object fragmentation. These energy deposition rates are used to model the resulting ground damage, and affected populations are computed for the sampled impact locations. The results for each scenario are aggregated into a distribution of potential outcomes that reflect the range of uncertain impact parameters, population densities, and strike probabilities. As an illustration of the utility of the PAIR model, the results are used to address the question of what minimum size asteroid constitutes a threat to the population. To answer this question, complete distributions of results are combined with a hypothetical risk tolerance posture to provide the minimum size, given sets of initial assumptions. Model outputs demonstrate how such questions can be answered and provide a means for interpreting the effect that input assumptions and uncertainty can have on final risk-based decisions. Model results can be used to prioritize investments to gain knowledge in critical areas or, conversely, to identify areas where additional data has little effect on the metrics of interest.

  6. Climate-driven diversification and Pleistocene refugia in Philippine birds: evidence from phylogeographic structure and paleoenvironmental niche modeling.

    Science.gov (United States)

    Hosner, Peter A; Sánchez-González, Luis A; Peterson, A Townsend; Moyle, Robert G

    2014-09-01

    Avian diversification in oceanic archipelagos is largely attributed to isolation across marine barriers. During glacial maxima, lowered sea levels resulted in repeated land connections between islands joined by shallow seas. Consequently, such islands are not expected to show endemism. However, if climate fluctuations simultaneously caused shifts in suitable environmental conditions, limiting populations to refugia, then occurrence on and dispersal across periodic land bridges are not tenable. To assess the degree to which paleoclimate barriers, rather than marine barriers, drove avian diversification in the Philippine Archipelago, we produced ecological niche models for current-day, glacial maxima, and interglacial climate scenarios to infer potential Pleistocene distributions and paleoclimate barriers. We then tested marine and paleoclimate barriers for correspondence to geographic patterns of population divergence, inferred from DNA sequences from eight codistributed bird species. In all species, deep-water channels corresponded to zones of genetic differentiation, but six species exhibited deeper divergence associated with a periodic land bridge in the southern Philippines. Ecological niche models for these species identified a common paleoclimate barrier that coincided with deep genetic structure among populations. Although dry land connections joined southern Philippine islands during low sea level stands, unfavorable environmental conditions limited populations within landmasses, resulting in long-term isolation and genetic differentiation. These results highlight the complex nature of diversification in archipelagos: marine barriers, changes in connectivity due to sea level change, and climate-induced refugia acted in concert to produce great species diversity and endemism in the Philippines.

  7. Factors influencing phototaxis in nocturnal migrating birds.

    Science.gov (United States)

    Zhao, Xuebing; Chen, Mingyan; Wu, Zhaolu; Wang, Zijiang

    2014-12-01

    Many migratory bird species fly during the night (nocturnal migrants) and have been shown to display some phototaxis to artificial light. During 2006 to 2009, we investigated phototaxis in nocturnal migrants at Jinshan Yakou in Xinping County (N23°56', E101°30'; 2400 m above sea-level), and at the Niaowang Mountain in Funing County (N23°30', E105°35'; 1400 m above sea-level), both in the Yunnan Province of Southwest China. A total of 5069 birds, representing 129 species, were captured by mist-netting and artificial light. The extent of phototaxis effect on bird migration was examined during all four seasons, three phases of the moon, and under two weather conditions (mist and wind). Data were statistically analyzed to determine the extent to which these factors may impact phototaxis of nocturnal migrants. The results point to phototaxis in birds migrating in the spring and autumn, especially in the autumn. Furthermore, migrating birds were more readily attracted to artificial lights during nights with little moonlight, mist, and a headwind. Regardless of the initial orientation in which birds flew, either following the wind or against the wind, birds would always fly against the wind when flying towards the light. This study broadens our understanding of the nocturnal bird migration, potentially resulting in improved bird ringing practices, increased awareness, and better policies regarding bird protection.

  8. Addressing complexity and uncertainty: conceptual models and expert judgments applied to migratory birds in the oil sands of Canada

    Directory of Open Access Journals (Sweden)

    Marc A. Nelitz

    2015-12-01

    Full Text Available Complexity and uncertainty are inherent in social-ecological systems. Although they can create challenges for scientists and decision makers, they cannot be a reason for delaying decision making. Two strategies have matured in recent decades to address these challenges. Systems thinking, as embodied by conceptual modeling, is a holistic approach in which a system can be better understood by examining it as a whole. Expert elicitation represents a second strategy that enables a greater diversity of inputs to understand complex systems. We explored the use of conceptual models and expert judgments to inform expansion of monitoring around oil sands development in northern Alberta, Canada, particularly related to migratory forest birds. This study area is a complex social-ecological system for which there is an abundance of specific information, but a relatively weak understanding about system behavior. Multiple conceptual models were developed to represent complexity and provide a more fulsome view of influences across the landscape. A hierarchical approach proved useful, and a mechanistic structure of the models clarified the cumulative and interactive nature of factors within and outside the study area. To address gaps in understanding, expert judgments were integrated using a series of structured exercises to derive "weightings" of importance of different components in the conceptual models, specifically pairwise comparisons, Likert scaling, and a maximum difference conjoint approach. These exercises were helpful for discriminating the importance of different influences and illuminating the competing beliefs of experts. Various supporting tools helped us engage a group of experts from across North America, which included a virtual meeting, online polling, desktop sharing, web survey, and financial incentive. This combination of techniques was innovative and proved useful for addressing complexity and uncertainty in a specific natural resource

  9. Human-induced contaminant impacts on migratory birds: lessons from the North American eared grebe (Podiceps nigricollis)

    Science.gov (United States)

    Sladky, Kurt K.; Quist, Charlotte; Ramirez, Pedro; Hill, David; Dein, F. Joshua

    2003-01-01

    The effects of aquatic contaminants generated by soda ash mining processes on the North American eared grebe (Podiceps nigricollis) population illustrates important issues associated with human-induced habitat degradation on the health of migratory species. Eared grebes have been extensively studied in their staging and breeding habitats, but little is known about their 2- to 3-day migratory periods. During migration, few bodies of water are available to the birds for refuge between freshwater breeding areas in Canada and hypersaline lakes (e.g., Great Salt Lake in Utah or Mono Lake in California) to which they migrate. One geographic refuge area includes a series of "tailings" ponds associated with soda ash mining operations in southwestern Wyoming. The ponds range from 100-1200 acres, with water containing high concentrations of sodium decahydrate (Na2CO3•10H2O). At cool temperatures (generally companies have developed hazing strategies and rehabilitation programs in order to minimize mortality. In order to determine causes of grebe mortality and devise strategies to reduce mortality, a field epidemiologic investigation was developed with the following objectives: 1) to determine whether eared grebes have quantifiable physiologic abnormalities associated with exposure to soda ash mine pond water; 2) to evaluate physical effects of sodium decahydrate crystallization on grebe survival; 3) to establish cause of death based on necropsy of deceased grebes; 4) to determine long-term survivability of eared grebes after exposure to the pond water; and 5) to evaluate water quality and determine whether aquatic invertebrates are present in the ponds as a possible food source.

  10. Landscape-based population viability models demonstrate importance of strategic conservation planning for birds

    Science.gov (United States)

    Thomas W. Bonnot; Frank R. Thompson; Joshua J. Millspaugh; D. Todd. Jones-Farland

    2013-01-01

    Efforts to conserve regional biodiversity in the face of global climate change, habitat loss and fragmentation will depend on approaches that consider population processes at multiple scales. By combining habitat and demographic modeling, landscape-based population viability models effectively relate small-scale habitat and landscape patterns to regional population...

  11. Towards a new generation of breeding bird Atlases: annual Atlases based on site-occupancy models

    NARCIS (Netherlands)

    van Strien, A.; van Turnhout, C.; Soldaat, L.

    2010-01-01

    Site-occupancy models which take into account detection probability of species have promising applications for Atlas work. These models enable to estimate the ‘true’ state of occupancy in sites even if sites differ in observation effort. Data collected with different field methods and opportunistic

  12. A Thankful Bird

    Institute of Scientific and Technical Information of China (English)

    颜巧玲

    2002-01-01

    One day, I was playing in the woods when I saw a bird standing on a tree branch in the rain. “Poor bird, I thought, ”He has no home. “When I got home, I set down to make a house for the bird so that the bird would not catch rain any longer.

  13. Birds Kept as Pets

    Science.gov (United States)

    ... Bird Importation website . Choosing a bird Match a bird's attitude, temperament, size, and activity level with your family, ... 2009;135:68-77 Compendium of Measures To Control Chlamydophila psittaci ... Pet Birds (Avian Chlamydiosis), 2010 [PDF – 17 pages] National Association ...

  14. [Ecological benefit evaluation of urban forests in Shenyang City based on QuickBird image and CITYgreen model].

    Science.gov (United States)

    Liu, Chang-Fu; He, Xing-Yuan; Chen, Wei; Zhao, Gui-Ling; Li, Ling; Xu, Wen-Duo

    2008-09-01

    Based on the urban forest coverage data interpreted from QuickBird image (2006) and the CITYgreen model, the benefits of Shenyang urban forest types with different canopy closure in carbon fixation and pollutant removal were investigated by means of sampling strategy. The results showed that the total amount of carbon storage, annual carbon sequestration, annual air pollutant removal, and their corresponding values were 0.51 Tg, 6858.20 Mg x a-1), 556.04 Mg x a(-1) 1.26 x 10(8) Yuan, 1.72 x 10(6) Yuan, and 0.22 x 10(8) Yuan, respectively. Among the urban forest types in Shenyang City, ecological and public welfare forest (E) contributed most to the carbon fixation and air pollutant removal. The carbon density decreased in the order of S (subordinated forest) > L (landscape and relaxation forest) > P (production and management forest) > E > R (road forest), annual carbon sequestration was in the order of P > L > E > S > R, and annual air pollutant removal was in the order of P > L > S > E > R. The carbon density of different urban forest types was closely related to their structural complexity. For the forests with high canopy closure, both the annual carbon sequestration and the annual pollutant removal were high; while for those with lower canopy closure, these two characteristics were dependent on the structural complexity of the forests.

  15. A review of climate change effects on terrestrial rangeland birds

    Science.gov (United States)

    D. M. Finch; K. E. Bagne; M. M. Friggens; D. M. Smith; K. M. Brodhead

    2011-01-01

    We evaluated existing literature on predicted and known climate change effects on terrestrial rangeland birds. We asked the following questions: 1) How does climate change affect birds? 2) How will birds respond to climate change? 3) Are species already responding? 4) How will habitats be impacted?

  16. Risk Considerations of Bird Strikes to Space Launch Vehicles

    Science.gov (United States)

    Hales, Christy; Ring, Robert

    2016-01-01

    Within seconds after liftoff of the Space Shuttle during mission STS-114, a turkey vulture impacted the vehicle's external tank. The contact caused no apparent damage to the Shuttle, but the incident led NASA to consider the potential consequences of bird strikes during a Shuttle launch. The environment at Kennedy Space Center provides unique bird strike challenges due to the Merritt Island National Wildlife Refuge and the Atlantic Flyway bird migration routes. NASA is currently refining risk assessment estimates for the probability of bird strike to space launch vehicles. This paper presents an approach for analyzing the risks of bird strikes to space launch vehicles and presents an example. The migration routes, types of birds present, altitudes of those birds, exposed area of the launch vehicle, and its capability to withstand impacts affect the risk due to bird strike. A summary of significant risk contributors is discussed.

  17. Testing the environmental Kuznets curve hypothesis with bird populations as habitat-specific environmental indicators: evidence from Canada.

    Science.gov (United States)

    Lantz, Van; Martínez-Espiñeira, Roberto

    2008-04-01

    The traditional environmental Kuznets curve (EKC) hypothesis postulates that environmental degradation follows an inverted U-shaped relationship with gross domestic product (GDP) per capita. We tested the EKC hypothesis with bird populations in 5 different habitats as environmental quality indicators. Because birds are considered environmental goods, for them the EKC hypothesis would instead be associated with a U-shaped relationship between bird populations and GDP per capita. In keeping with the literature, we included other variables in the analysis-namely, human population density and time index variables (the latter variable captured the impact of persistent and exogenous climate and/or policy changes on bird populations over time). Using data from 9 Canadian provinces gathered over 37 years, we used a generalized least-squares regression for each bird habitat type, which accounted for the panel structure of the data, the cross-sectional dependence across provinces in the residuals, heteroskedasticity, and fixed- or random-effect specifications of the models. We found evidence that supports the EKC hypothesis for 3 of the 5 bird population habitat types. In addition, the relationship between human population density and the different bird populations varied, which emphasizes the complex nature of the impact that human populations have on the environment. The relationship between the time-index variable and the different bird populations also varied, which indicates there are other persistent and significant influences on bird populations over time. Overall our EKC results were consistent with those found for threatened bird species, indicating that economic prosperity does indeed act to benefit some bird populations.

  18. 基于DOE参数筛选的SPH鸟体参数反演%Parameter Inversion of SPH Bird Model Based on DOE Parameter Selection

    Institute of Scientific and Technical Information of China (English)

    罗军; 刘长虹; 洪清泉; 鞠锋; 丁敏

    2012-01-01

    鸟体参数的准确性对鸟撞仿真精度有重大影响,参数反演可以克服人工试凑法的局限生,搜寻出合理的鸟体参数,提高鸟撞仿真精度.在Hyper Study多学科优化平台下,先采用正交实验设计方法挑选出对位移结果敏感的鸟体参数,以简化优化问题的复杂性和计算量,然后采用自适应响应面法进行鸟体的参数反演的多目标优化,优化目标为最小化鸟撞位置处仿真位移和实验位移的平方差.RADIOSS的求解结果表明,采用优化后的鸟体参数的鸟体模型的仿真曲线与实验曲线拟合效果大大提高.%The accuracy of the bird model parameters has a significant effect on bird strike simulation, and the inversion of physical parameters can overcome the limitations of artificial trial method finding out reasonable bird model parameters and improving the accuracy of bird strike simulation. Based on the Hyper Study,a multidisciplinary optimization platform,orthogonal design of experimental(DOE)method is introduced to identify the model parameters which are sensitive to displacement, to simplify the complexity of optimization and to reduce the computation.Then those parameters are optimized based on adaptive response surface method (ARSM),and the optimization objective is to minimize the squared differences of simulation displacement and experimental displacement on the bird strike points.The results solved by RADIOSS demonstrate that when bird model adoptes the optimized parameters ,the simulation curve and experimental curve fit better.

  19. Inactivation of various influenza strains to model avian influenza (Bird Flu) with various disinfectant chemistries.

    Energy Technology Data Exchange (ETDEWEB)

    Oberst, R. D.; Bieker, Jill Marie; Souza, Caroline Ann

    2005-12-01

    Due to the grave public health implications and economic impact possible with the emergence of the highly pathogenic avian influenza A isolate, H5N1, currently circulating in Asia we have evaluated the efficacy of various disinfectant chemistries against surrogate influenza A strains. Chemistries included in the tests were household bleach, ethanol, Virkon S{reg_sign}, and a modified version of the Sandia National Laboratories developed DF-200 (DF-200d, a diluted version of the standard DF-200 formulation). Validation efforts followed EPA guidelines for evaluating chemical disinfectants against viruses. The efficacy of the various chemistries was determined by infectivity, quantitative RNA, and qualitative protein assays. Additionally, organic challenges using combined poultry feces and litter material were included in the experiments to simulate environments in which decontamination and remediation will likely occur. In all assays, 10% bleach and Sandia DF-200d were the most efficacious treatments against two influenza A isolates (mammalian and avian) as they provided the most rapid and complete inactivation of influenza A viruses.

  20. Impact of pest control strategies on the arthropodofauna living in bird nests built in nestboxes in pear and apple orchards.

    Science.gov (United States)

    Roy, Lise; Bouvier, Jean-Charles; Lavigne, Claire; Galès, Mathieu; Buronfosse, Thierry

    2013-08-01

    Pesticide applications have a strong impact on biodiversity in agroecosystems. The present study aimed to assess the impact of pest control strategies on the arthropodofauna of Parus major nests built within nestboxes installed in orchards. Unlike many studied groups, these arthropod communities are not in direct contact with pesticide sprays (on account of their being sheltered by nestboxes) and are also unable to move away from the treated area. In this pilot study, we estimated the prevalence and the taxonomic and ecological diversities of arthropodofauna sampled in the nests and assessed the extent to which the whole and nest-specific arthropodofauna were affected by pest control strategies. Sixteen different insect and arachnid Primary Taxonomic Groups (PTGs, order level or below) were found in nests. The best represented PTGs (≥10% occurrence in years 2007 and 2008) were Psocoptera (Insecta, detritivorous/saprophagous), detritivorous/saprophagous Astigmata (Acari) and hematophagous Mesostigmata (Acari). Pest control strategies had a large impact on the prevalence of arthropods in nests, with higher proportions of nests hosting arthropods in organic orchards than in conventional orchards and with intermediate proportions in nests in Integrated Pest Management orchards. In contrast, pest control strategies had no significant effect on the composition of the arthropod communities when only nests hosting nidicolous arthropods were considered.

  1. Refugia, colonization and diversification of an arid-adapted bird: coincident patterns between genetic data and ecological niche modelling.

    Science.gov (United States)

    Barrientos, Rafael; Kvist, Laura; Barbosa, Andrés; Valera, Francisco; Khoury, Fares; Varela, Sara; Moreno, Eulalia

    2014-02-01

    Phylogeographical studies are common in boreal and temperate species from the Palaearctic, but scarce in arid-adapted species. We used nuclear and mitochondrial markers to investigate phylogeography and to estimate chronology of colonization events of the trumpeter finch Bucanetes githagineus, an arid-adapted bird. We used 271 samples from 16 populations, most of which were fresh samples but including some museum specimens. Microsatellite data showed no clear grouping according to the sampling locations. Microsatellite and mitochondrial data showed the clearest differentiation between Maghreb and Canary Islands and between Maghreb and Western Sahara. Mitochondrial data suggest differentiation between different Maghreb populations and among Maghreb and Near East populations, between Iberian Peninsula and Canary Islands, as well as between Western Sahara and Maghreb. Our coalescence analyses indicate that the trumpeter finch colonized North Africa during the humid Marine Isotope Stage 5 (MIS5) period of the Sahara region 125 000 years ago. We constructed an ecological niche model (ENM) to estimate the geographical distribution of climatically suitable habitats for the trumpeter finch. We tested whether changes in the species range in relation to glacial-interglacial cycles could be responsible for observed patterns of genetic diversity and structure. Modelling results matched with those from genetic data as the species' potential range increases in interglacial scenarios (in the present climatic scenario and during MIS5) and decreases in glacial climates (during the last glacial maximum, LGM, 21 000 years ago). Our results suggest that the trumpeter finch responded to Pleistocene climatic changes by expanding and contracting its range.

  2. 基于可靠性的飞机风挡抗鸟撞优化设计%Reliability-Based Optimization Design of Aircraft Windshield for Resisting Bird Impact

    Institute of Scientific and Technical Information of China (English)

    于明; 刘永寿; 李磊; 岳珠峰

    2012-01-01

    传统的飞机风挡设计通常在确定的工况下进行,未能充分考虑实际鸟撞风挡过程中不确定性因素的影响,导致飞机鸟撞风挡的故障多发.综合考虑鸟撞飞机风挡过程中鸟体材料参数、质量、撞击速度等不确定因素的影响,以飞机风挡抗鸟撞的可靠度为约束,风挡质量为目标,基于双循环方法和近似技术建立了风挡抗鸟撞可靠性优化设计系统,利用一阶矩法进行可靠性分析,对某飞机风挡进行了基于可靠性的优化设计.实例分析证明所建风挡抗鸟撞可靠性优化设计系统可行有效.%Traditional methods for aircraft windshield design are carried out based on determinate work condition. The effect of uncertainty factors during the process of windihield impacted by bird are not fully considered, so this result in low reliability of windshield performance. The effects of uncertainty factors into as bird body material parameters, mass and inpact velocity during the process of windshield impacted by bird are considered. Reliability-based optimization design of windshield for resisting bird impact is set up according to the reliability of aircraft windshield for resisting bird impact and the windshield quality based on the double loop strategy and the approximation technique. The reliatility analysis is carried out by using the first-order reliability method. The reliability -based optimization design of aircraft wind shield for resinting bird impact is made. It is proved that this optimization design is feasible.

  3. Impacts of Model Building Energy Codes

    Energy Technology Data Exchange (ETDEWEB)

    Athalye, Rahul A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sivaraman, Deepak [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Elliott, Douglas B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Liu, Bing [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bartlett, Rosemarie [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-10-31

    The U.S. Department of Energy (DOE) Building Energy Codes Program (BECP) periodically evaluates national and state-level impacts associated with energy codes in residential and commercial buildings. Pacific Northwest National Laboratory (PNNL), funded by DOE, conducted an assessment of the prospective impacts of national model building energy codes from 2010 through 2040. A previous PNNL study evaluated the impact of the Building Energy Codes Program; this study looked more broadly at overall code impacts. This report describes the methodology used for the assessment and presents the impacts in terms of energy savings, consumer cost savings, and reduced CO2 emissions at the state level and at aggregated levels. This analysis does not represent all potential savings from energy codes in the U.S. because it excludes several states which have codes which are fundamentally different from the national model energy codes or which do not have state-wide codes. Energy codes follow a three-phase cycle that starts with the development of a new model code, proceeds with the adoption of the new code by states and local jurisdictions, and finishes when buildings comply with the code. The development of new model code editions creates the potential for increased energy savings. After a new model code is adopted, potential savings are realized in the field when new buildings (or additions and alterations) are constructed to comply with the new code. Delayed adoption of a model code and incomplete compliance with the code’s requirements erode potential savings. The contributions of all three phases are crucial to the overall impact of codes, and are considered in this assessment.

  4. Mosaic-level inference of the impact of land cover changes in agricultural landscapes on biodiversity: a case-study with a threatened grassland bird.

    Science.gov (United States)

    Moreira, Francisco; Silva, João P; Estanque, Beatriz; Palmeirim, Jorge M; Lecoq, Miguel; Pinto, Márcia; Leitão, Domingos; Alonso, Ivan; Pedroso, Rui; Santos, Eduardo; Catry, Teresa; Silva, Patricia; Henriques, Inês; Delgado, Ana

    2012-01-01

    Changes in land use/land cover are a major driver of biodiversity change in the Mediterranean region. Understanding how animal populations respond to these landscape changes often requires using landscape mosaics as the unit of investigation, but few previous studies have measured both response and explanatory variables at the land mosaic level. Here, we used a "whole-landscape" approach to assess the influence of regional variation in the land cover composition of 81 farmland mosaics (mean area of 2900 ha) on the population density of a threatened bird, the little bustard (Tetrax tetrax), in southern Portugal. Results showed that ca. 50% of the regional variability in the density of little bustards could be explained by three variables summarising the land cover composition and diversity in the studied mosaics. Little bustard breeding males attained higher population density in land mosaics with a low land cover diversity, with less forests, and dominated by grasslands. Land mosaic composition gradients showed that agricultural intensification was not reflected in a loss of land cover diversity, as in many other regions of Europe. On the contrary, it led to the introduction of new land cover types in homogenous farmland, which increased land cover diversity but reduced overall landscape suitability for the species. Based on these results, the impact of recent land cover changes in Europe on the little bustard populations is evaluated.

  5. INVESTIGATION OF TURBOPROP ENGINE CHARACTERISTICS DURING BIRD INGESTION.

    Science.gov (United States)

    TURBOPROP ENGINES, * INGESTION (ENGINES), *BIRDS, * INGESTION (ENGINES), PERFORMANCE(ENGINEERING), RECOVERY, STABILIZATION, TURBOJET INLETS, FLAMEOUT, DAMAGE, INLET GUIDE VANES, IMPACT, AVIATION SAFETY.

  6. Of bugs and birds: Markov Chain Monte Carlo for hierarchical modeling in wildlife research

    Science.gov (United States)

    Link, W.A.; Cam, E.; Nichols, J.D.; Cooch, E.G.

    2002-01-01

    Markov chain Monte Carlo (MCMC) is a statistical innovation that allows researchers to fit far more complex models to data than is feasible using conventional methods. Despite its widespread use in a variety of scientific fields, MCMC appears to be underutilized in wildlife applications. This may be due to a misconception that MCMC requires the adoption of a subjective Bayesian analysis, or perhaps simply to its lack of familiarity among wildlife researchers. We introduce the basic ideas of MCMC and software BUGS (Bayesian inference using Gibbs sampling), stressing that a simple and satisfactory intuition for MCMC does not require extraordinary mathematical sophistication. We illustrate the use of MCMC with an analysis of the association between latent factors governing individual heterogeneity in breeding and survival rates of kittiwakes (Rissa tridactyla). We conclude with a discussion of the importance of individual heterogeneity for understanding population dynamics and designing management plans.

  7. Experimental comparison of models for ultrafast impact ionization is silicon

    DEFF Research Database (Denmark)

    Tarekegne, Abebe Tilahun; Iwaszczuk, Krzysztof; Jepsen, Peter Uhd

    2016-01-01

    We compare experimentally the exponential and quadratic (Keldysh formula) impact ionization models using THz induced impact ionization in silicon. We demonstrate that the exponential model offers the best description of impact ionization process for ultrashort electric filed pulses.......We compare experimentally the exponential and quadratic (Keldysh formula) impact ionization models using THz induced impact ionization in silicon. We demonstrate that the exponential model offers the best description of impact ionization process for ultrashort electric filed pulses....

  8. Flood Progression Modelling and Impact Analysis

    DEFF Research Database (Denmark)

    Mioc, Darka; Anton, François; Nickerson, B.

    People living in the lower valley of the St. John River, New Brunswick, Canada, frequently experience flooding when the river overflows its banks during spring ice melt and rain. To better prepare the population of New Brunswick for extreme flooding, we developed a new flood prediction model...... that computes floodplain polygons before the flood occurs. This allows emergency managers to access the impact of the flood before it occurs and make the early decisions for evacuation of the population and flood rescue. This research shows that the use of GIS and LiDAR technologies combined with hydrological...... modelling can significantly improve the decision making and visualization of flood impact needed for emergency planning and flood rescue. Furthermore, the 3D GIS application we developed for modelling flooded buildings and infrastructure provides a better platform for modelling and visualizing flood...

  9. The Lund Model at Nonzero Impact Parameter

    CERN Document Server

    Janik, R A; Janik, Romuald A.; Peschanski, Robi

    2003-01-01

    We extend the formulation of the longitudinal 1+1 dimensional Lund model to nonzero impact parameter using the minimal area assumption. Complete formulae for the string breaking probability and the momenta of the produced mesons are derived using the string worldsheet Minkowskian helicoid geometry. For strings stretched into the transverse dimension, we find probability distribution with slope linear in m_T similar to the statistical models but without any thermalization assumptions.

  10. Effects of immune supplementation and immune challenge on oxidative status and physiology in a model bird: implications for ecologists

    NARCIS (Netherlands)

    Crommenacker, van de J.; Horrocks, N.P.C.; Versteegh, M.A.; Tieleman, B.I.; Komdeur, J.; Matson, K.D.

    2010-01-01

    One route to gain insight into the causes and consequences of ecological differentiation is to understand the underlying physiological mechanisms. We explored the relationships between immunological and oxidative status and investigated how birds cope physiologically with the effects of immune-deriv

  11. Ecological niche modeling as a new paradigm for large-scale investigations of diversity and distribution of birds

    Science.gov (United States)

    A. Townsend Peterson; Daniel A. Kluza

    2005-01-01

    Large-scale assessments of the distribution and diversity of birds have been challenged by the need for a robust methodology for summarizing or predicting species' geographic distributions (e.g. Beard et al. 1999, Manel et al. 1999, Saveraid et al. 2001). Methodologies used in such studies have at times been inappropriate, or even more frequently limited in their...

  12. Trade-offs between pasture production and farmland bird conservation: exploration of options using a dynamic farm model

    NARCIS (Netherlands)

    Sabatier, R.; Teillard, F.; Rossing, W.A.H.; Doyen, L.; Tichit, M.

    2015-01-01

    In European grassland landscapes, grazing and mowing play a key role for the maintenance of high-quality habitats that host important bird populations. As grasslands are also key resources for cattle feeding, there is a need to develop management strategies that achieve the double objective of produ

  13. BIRD FLU (AVIAN INFLUENZA

    Directory of Open Access Journals (Sweden)

    Ali ACAR

    2005-12-01

    Full Text Available Avian influenza (bird flu is a contagious disease of animals caused by influenza A viruses. These flu viruses occur naturally among birds. Actually, humans are not infected by bird flu viruses.. However, during an outbreak of bird flu among poultry, there is a possible risk to people who have contact infect birds or surface that have been contaminated with excreations from infected birds. Symptoms of bird flu in humans have ranged from typical flu-like symptoms to eye infections, pneumonia, severe respiratory diseases and other severe and life-threatening complications. In such situation, people should avoid contact with infected birds or contaminated surface, and should be careful when handling and cooking poultry. [TAF Prev Med Bull 2005; 4(6.000: 345-353

  14. Flood Impact Modelling and Natural Flood Management

    Science.gov (United States)

    Owen, Gareth; Quinn, Paul; ODonnell, Greg

    2016-04-01

    Local implementation of Natural Flood Management methods are now being proposed in many flood schemes. In principal it offers a cost effective solution to a number of catchment based problem as NFM tackles both flood risk and WFD issues. However within larger catchments there is the issue of which subcatchments to target first and how much NFM to implement. If each catchment has its own configuration of subcatchment and rivers how can the issues of flood synchronisation and strategic investment be addressed? In this study we will show two key aspects to resolving these issues. Firstly, a multi-scale network water level recorder is placed throughout the system to capture the flow concentration and travel time operating in the catchment being studied. The second is a Flood Impact Model (FIM), which is a subcatchment based model that can generate runoff in any location using any hydrological model. The key aspect to the model is that it has a function to represent the impact of NFM in any subcatchment and the ability to route that flood wave to the outfall. This function allows a realistic representation of the synchronisation issues for that catchment. By running the model in interactive mode the user can define an appropriate scheme that minimises or removes the risk of synchornisation and gives confidence that the NFM investment is having a good level of impact downstream in large flood events.

  15. Frictional Impact Modeling of a Cereal Thresher

    Directory of Open Access Journals (Sweden)

    Christian O. Osueke

    2011-01-01

    Full Text Available Problem statement: There is no point producing cereal threshing models that cannot replicate its performance on the field. The frictional impact that occurs between the crop surface and threshing cylinder has been often neglected by most researchers in cereal threshing. Approach: Study proffers a solution to this issue by developing a model for threshing which in-cooperate friction. This was done by analyzing the crop/threshing cylinder behavior, hence establishing mathematical sub-models to characterize the performance of this model. Results: The model was further packaged with computer aided software based on visual basic programming language and finally applied. Conclusion: Upon application, it was discovered that at a moisture content of 15% v = 9 m sec-1, Q = 0.18 kg sec-1 the model yielded performance characteristics as Eff = 88.22%, TNL = 11.78% and CAPTH = 211.52 kg h-1.

  16. Generational change in fasting glucose and insulin among children at ages 5-16y: Modelled on the EarlyBird study (2015) and UK growth standards (1990) (EarlyBird 69).

    Science.gov (United States)

    Mostazir, Mohammod; Jeffery, Alison; Voss, Linda; Wilkin, Terence

    2017-01-01

    Pre-diabetes is a state of beta-cell stress caused by excess demand for insulin. Body mass is an important determinant of insulin demand, and BMI has risen substantially over recent time. We sought to model changes in the parameters of glucose control against rising BMI over the past 25years. Using random coefficient mixed models, we established the correlations between HbA1C, fasting glucose, fasting insulin, HOMA2-IR and BMI in contemporary (2015) children (N=307) at ages 5-16y from the EarlyBird study, and modelled their corresponding values 25years ago according to the distribution of BMI in the UK Growth Standards (1990). There was little change in HbA1C or fasting glucose over the 25y period at any age or in either gender. On the other hand, the estimates for fasting insulin and HOMA2-IR were substantially higher in both genders in 2015 compared with 1990. Insofar as it is determined by body mass, there has been a substantial rise in beta cell demand among children over the past 25years. The change could be detected by fasting insulin and HOMA2-IR, but not by fasting glucose or HbA1C. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  17. Audubon Bird Study Program.

    Science.gov (United States)

    National Audubon Society, New York, NY.

    Included are a student reader, "The Story of Birds," a leaders' guide, a large colored Audubon bird chart, and a separate guide for the chart. The student reader is divided into eleven sections which relate to the various physical and behavioral features of birds such as feathers, feeding habits as related to the shape of bills and feet, nests,…

  18. A Clever Bird

    Institute of Scientific and Technical Information of China (English)

    张仰清

    2000-01-01

    A man in Australia had a wonderful bird. There was no other bird like it . It was very,very clever. The bird could say any word --except one. It could not say the name of the town where it was born. The name of that town was Catano.

  19. Archaeopteryx: Dinosaur or Bird?

    Institute of Scientific and Technical Information of China (English)

    SONG Jianlan

    2011-01-01

    @@ An Archaeopteryx-like theropod dinosaur newly found from western Liaoning Province in northeastern China would make an unusual, if not unwelcome, gift for the 150th birthday of Archaeopteryx, the oldest bird as long-believed by paleontologists: Named as Xiaotingia zhengiis, the new species carries some critical traits suggesting that Archaeopteryx might have actually been a dinosaur.Naturally this breaking news stirred intense controversies.Was "The Oldest Bird" a bird? If not, what makes a bird? With these questions in mind, the author joined an exploration in search of "the real first bird" along with the paleontologists at the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) under CAS.

  20. Identification, documentation and delineation of coastal migratory bird habitat in Alaska. II, Feeding habits of birds in the Beaufort Sea: Partial final report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The impact of oil and gas development on bird populations is usually thought of in terms of spilled oil directly oiling birds and causing mortality. Far more...

  1. Identification, documentation and delineation of coastal migratory bird habitat in Alaska. II, Feeding habits of birds in the Beaufort Sea: Partial final report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The impact of oil and gas development on bird populations is usually thought of in terms of spilled oil directly oiling birds and causing mortality. Far more...

  2. Impact of numerical models on fragmentation processes

    Science.gov (United States)

    Renouf, Mathieu; Gezahengn, Belien; Abbas, Micheline; Bourgeois, Florent

    2013-06-01

    Simulated fragmentation process in granular assemblies is a challenging problem which date back the beginning of the 90'. If first approaches have focus on the fragmentation on a single particle, with the development of robust, fast numerical method is is possible today to simulated such process in a large collection of particles. But the question of the fragmentation problem is still open: should the fragmentation be done dynamically (one particle becoming two fragments) and according which criterion or should the fragment paths be defined initially and which is the impact of the discretization and the model of fragments? The present contribution proposes to investigate the second aspect i.e. the impact of fragment modeling on the fragmentation processes. First to perform such an analysis, the geometry of fragments (disks/sphere or polygon/polyhedra), their behavior (rigid/deformable) and the law governing their interactions are investigated. Then such model will be used in a grinding application where the evolution of fragments and impact on the behavior of the whole packing are investigate.

  3. Scope and profoundness of environmental assessments. A study in the frame of environmental impact assessments. Strategic environmental assessment and FFH (fauna-flora-habitat) impact assessment under specific consideration of the conflict wind energy - bird protection; Untersuchungsumfang und Ermittlungstiefe in Umweltpruefungen. Eine Untersuchung im Rahmen von Umweltvertraeglichkeitspruefung, strategischer Umweltpruefung und FFH-Vertraeglichkeitspruefung unter besonderer Beruecksichtigung des Konfliktfelds Windenergie - Vogelschutz

    Energy Technology Data Exchange (ETDEWEB)

    Erb, Mareen

    2013-07-01

    The legal background of environmental impact assessments and the principle regulations and guidelines for this assessment are shortly summarized. The following Issues are discussed in detail: fundamentals of environmental assessments, profoundness and scope in environmental assessments; the conflict wind energy parks and birds.

  4. Proventricular dilatation syndrome in large psittacine birds.

    Science.gov (United States)

    Clark, F D

    1984-01-01

    Proventricular dilatation was diagnosed in 16 psittacine birds. Signs included anorexia, lethargy, weight loss, and intermittent vomiting. The proventriculus in all birds was thin-walled and impacted with ingesta and occupied most of the body cavity. Microscopic changes in the proventriculus varied from none to an infiltration of lymphocytes, macrophages, and heterophils. There was no evidence of viral or bacterial infection or lead toxicity.

  5. From a Bird's Eye View: An Interdisciplinary Approach to Migration

    Science.gov (United States)

    Benson, Juliann

    2007-01-01

    Inspiring students to learn about birds can be a daunting task--students see birds just about every day and often don't think twice about them. The activity described here is designed to excite students to "become" birds. Students are asked to create a model and tell the life story of a bird by mapping its migration pattern. (Contains 6 figures, 6…

  6. Modelling climate impacts on the aviation sector

    Science.gov (United States)

    Williams, Paul

    2017-04-01

    The climate is changing, not just where we live at ground level, but also where we fly at 35,000 feet. We have long known that air travel contributes to climate change through its emissions. However, we have only recently become aware that climate change could have significant consequences for air travel. This presentation will give an overview of the possible impacts of climate change on the aviation sector. The presentation will describe how the impacts are modelled and how their social and economic costs are estimated. The impacts are discussed in the International Civil Aviation Organization's (ICAO's) latest Environmental Report (Puempel and Williams 2016). Some of the possible impacts are as follows. Rising sea levels and storm surges threaten coastal airports, such as La Guardia in New York, which was flooded by the remnants of Hurricane Sandy in 2012. Warmer air at ground level reduces the lift force and makes it more difficult for planes to take-off (Coffel and Horton 2015). More extreme weather may cause flight disruptions and delays. Clear-air turbulence is expected to become up to 40% stronger and twice as common (Williams and Joshi 2013). Transatlantic flights may collectively be airborne for an extra 2,000 hours each year because of changes to the jet stream, burning an extra 7.2 million gallons of jet fuel at a cost of US 22 million, and emitting an extra 70 million kg of carbon dioxide (Williams 2016). These modelled impacts provide further evidence of the two-way interaction between aviation and climate change. References Coffel E and Horton R (2015) Climate change and the impact of extreme temperatures on aviation. Weather, Climate, and Society, 7, 94-102. http://dx.doi.org/10.1175/WCAS-D-14-00026.1 Puempel H and Williams PD (2016) The impacts of climate change on aviation: Scientific challenges and adaptation pathways. ICAO Environmental Report 2016: On Board A Sustainable Future, pp 205-207. http

  7. Exotic birds increase generalization and compensate for native bird decline in plant-frugivore assemblages.

    Science.gov (United States)

    García, Daniel; Martínez, Daniel; Stouffer, Daniel B; Tylianakis, Jason M

    2014-11-01

    Exotic species are thought to alter the structure of natural communities and disrupt ecosystem functioning through invasion. Nevertheless, exotic species may also provide ecological insurance when they contribute to maintain ecosystem functions after the decline of native species following anthropogenic disturbance. Here, this hypothesis is tested with the assemblage of frugivorous birds and fleshy-fruited plants of New Zealand, which has suffered strong historical declines in native birds while simultaneously gaining new frugivores introduced by European settlers. We studied the plant-frugivore assemblage from measures of fruit and bird abundances and fruit consumption in nine forest patches, and tested how this changed across a gradient of relative abundance of exotic birds. We then examined how each bird species' role in the assemblage (the proportion of fruits and the number of plant species consumed) varied with their relative abundance, body size and native/exotic status. The more abundant and, to a lesser extent, larger birds species consumed a higher proportion of fruits from more plant species. Exotic birds consumed fruits less selectively and more proportionate to the local availability than did native species. Interaction networks in which exotic birds had a stronger role as frugivores had higher generalization, higher nestedness and higher redundancy of plants. Exotic birds maintained frugivory when native birds became rarer, and diversified the local spectrum of frugivores for co-occurring native plants. These effects seemed related to the fact that species abundances, rather than trait-matching constraints, ultimately determined the patterns of interactions between birds and plants. By altering the structure of plant-frugivore assemblages, exotic birds likely enhance the stability of the community-wide seed dispersal in the face of continued anthropogenic impact.

  8. American Samoa ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for seabirds, wading birds, shorebirds, waterfowl, and gulls and terns in American Samoa. Vector polygons...

  9. A comparative analysis of the influence of weather on the flight altitudes of birds

    NARCIS (Netherlands)

    Shamoun-Baranes, J.; van Loon, E.; van Gasteren, H.; van Belle, J.; Bouten, W.; Buurma, L.

    2006-01-01

    Birds pose a serious risk to flight safety worldwide. A Bird Avoidance Model (BAM) is being developed in the Netherlands to reduce the risk of bird-aircraft collisions. In order to develop a temporally and spatially dynamic model of bird densities, data are needed on the flight-altitude distribution

  10. A new model to simulate impact breakup

    Science.gov (United States)

    Cordelli, Alessandro; Farinella, Paolo

    1997-12-01

    We have developed a preliminary version of a new type of code to simulate the outcomes of impacts between solid bodies, which we plan to further refine for application to both asteroid science and space debris studies. In the current code, colliding objects are modeled as two-dimensional arrays of finite elements, which can interact with each other in both an elastic and a shock-wave regime. The finite elements are hard spheres with a given value for mass and radius. When two of them come into contact the laws of inelastic scattering are applied, thus giving rise to the propagation of shock waves. Moreover each spherical element interacts elastically with its nearest neighbours. The interaction force corresponds to that of a spring having an equilibrium length equal to the lattice spacing, and results into the propagation of elastic waves in the lattice. Dissipation effects are modeled by means of a dissipative force term proportional to the relative velocity, with a given characteristic time of decay. The possible occurrence of fractures in the material is modeled by assuming that when the distance of two neighbouring elements exceeds a threshold value, the binding force between them disappears for ever. This model requires finding a plausible correspondence between the input parameters appearing in the equations of motion, and the physical properties of real solid materials. Some of the required links are quite obvious (e.g., the relationship between mass of the elements and elastic constant on one side, and material density and sound velocity on the other side), some others a priori are unclear, and additional hypotheses on them must be made (e.g., on the restitution coefficient of inelastic scattering). Despite the preliminary character of the model, we have obtained some interesting results, which appear to mimic in a realistic way the outcomes of actual impacts. For instance, we have observed the formation of craters and fractures, and (for high impact

  11. Reviving a Legacy Citizen Science Project to Illuminate Shifts in Bird Phenology

    Directory of Open Access Journals (Sweden)

    Jessica Zelt

    2012-01-01

    Full Text Available Climate change has been of high interest to both the scientific community and the public at large since the phenomenon was first suggested. Subsequently, and with growing evidence of its impending ramifications, numerous studies have attempted to illuminate climate change impacts on bird migration. Migration is a key event in the annual cycle in the reproductive success of birds, and changes in migration in response to climate may indicate that species populations are at risk. Previous studies report earlier arrival dates in response to climate change in many bird species, although specific mechanisms are often difficult to explain at broad spatial and temporal scales. Using a newly revived dataset of historical migration cards for over 870 species and spanning 90 years throughout North America, we are developing an historical baseline of bird arrival dates to compare with contemporary records. Here we chronicle the history and reemergence of the North American Bird Phenology Program. We present two case studies illustrating how data from this program has been used to model historical arrival dates of Ruby-Throated Hummingbird (Archilochus colubris and Purple Martin (Progne subis throughout eastern North America. Our results show the importance of considering spatial and temporal variability in understanding patterns of bird spring arrivals.

  12. Development and Validation of a Novel Bird Strike Resistant Composite Leading Edge Structure

    Science.gov (United States)

    Kermanidis, Th.; Labeas, G.; Sunaric, M.; Ubels, L.

    2005-11-01

    A novel design of a fibre-reinforced composite Leading Edge (LE) of a Horizontal Tail Plain (HTP) is proposed. The development and validation approach of the innovative composite LE structure are described. The main design goal is the satisfactory impact resistance of the novel composite LE in the case of bird strike. The design concept is based on the absorption of the major portion of the bird kinetic energy by the composite skins, in order to protect the ribs and the inner LE structure from damaging, thus preserving the tail plane functionality for safe landing. To this purpose, the LE skin is fabricated from specially designed composite panels, so called ‘tensor skin’ panels, comprising folded layers, which unfold under the impact load and increase the energy absorption capability of the LE. A numerical model simulating the bird strike process is developed and bird strike experimental testing is performed, in order to validate the proposed layout and prove the capability of the structure to successfully withstand the impact loading. The numerical modelling issues and the critical parameters of the simulation are discussed. The present work is part of the European Aeronautics Research Project, ‘Crashworthiness of aircraft for high velocity impact CRAHVI’ [1].

  13. An integrative approach to understanding bird origins.

    Science.gov (United States)

    Xu, Xing; Zhou, Zhonghe; Dudley, Robert; Mackem, Susan; Chuong, Cheng-Ming; Erickson, Gregory M; Varricchio, David J

    2014-12-12

    Recent discoveries of spectacular dinosaur fossils overwhelmingly support the hypothesis that birds are descended from maniraptoran theropod dinosaurs, and furthermore, demonstrate that distinctive bird characteristics such as feathers, flight, endothermic physiology, unique strategies for reproduction and growth, and a novel pulmonary system originated among Mesozoic terrestrial dinosaurs. The transition from ground-living to flight-capable theropod dinosaurs now probably represents one of the best-documented major evolutionary transitions in life history. Recent studies in developmental biology and other disciplines provide additional insights into how bird characteristics originated and evolved. The iconic features of extant birds for the most part evolved in a gradual and stepwise fashion throughout archosaur evolution. However, new data also highlight occasional bursts of morphological novelty at certain stages particularly close to the origin of birds and an unavoidable complex, mosaic evolutionary distribution of major bird characteristics on the theropod tree. Research into bird origins provides a premier example of how paleontological and neontological data can interact to reveal the complexity of major innovations, to answer key evolutionary questions, and to lead to new research directions. A better understanding of bird origins requires multifaceted and integrative approaches, yet fossils necessarily provide the final test of any evolutionary model.

  14. Accurate Segmentation for Infrared Flying Bird Tracking

    Institute of Scientific and Technical Information of China (English)

    ZHENG Hong; HUANG Ying; LING Haibin; ZOU Qi; YANG Hao

    2016-01-01

    Bird strikes present a huge risk for air ve-hicles, especially since traditional airport bird surveillance is mainly dependent on inefficient human observation. For improving the effectiveness and efficiency of bird monitor-ing, computer vision techniques have been proposed to detect birds, determine bird flying trajectories, and pre-dict aircraft takeoff delays. Flying bird with a huge de-formation causes a great challenge to current tracking al-gorithms. We propose a segmentation based approach to enable tracking can adapt to the varying shape of bird. The approach works by segmenting object at a region of inter-est, where is determined by the object localization method and heuristic edge information. The segmentation is per-formed by Markov random field, which is trained by fore-ground and background mixture Gaussian models. Exper-iments demonstrate that the proposed approach provides the ability to handle large deformations and outperforms the m ost state-of-the-art tracker in the infrared flying bird tracking problem.

  15. Light dulls and darkens bird eggs.

    Directory of Open Access Journals (Sweden)

    Johanna Y Navarro

    Full Text Available Although egg color is generally consistent within individual birds and robust to environmental variation, recent evidence suggests a degree of susceptibility to environmental perturbation or modulation of egg color. Most of this variation manifests via the physiology of the laying female, but some direct impacts of the environment on laid eggs have also been discovered. Here we test whether light changes bird egg color and we quantify its effect, by subjecting variable blue-green eggs of Rüppell's weaver (Ploceus galbula to a broad-spectrum light source under laboratory conditions, and measuring egg reflectance every few hours. Eggshells gradually decreased in reflectance across the entire measured wavelength spectrum of 250-800 nm. Reflectance peaks were disproportionately affected, such that the height decreased of both the blue-green peak and the smaller UV peak typical of blue-green eggs. The reflectance of lighter eggs was affected slightly more than that of darker eggs. These changes are similar to previous results for changes over long periods of time in darkness, suggesting that light might hasten the same process of pigment degradation that proceeds even without light. Comparison between the experimental light source and both sunlight and typical artificial lighting situations raises the possibility that significant color change might occur during incubation in some birds, but indicates that eggshell illumination in museums for short periods of study is unlikely to affect their color to a detectable extent. Additional research should be performed on eggs of other species and in other light environments, with an eye to an eventual generalized model of the effect of light on eggshell color.

  16. Dosage compensation in birds

    OpenAIRE

    McQueen, H A; McBride, D; Miele, G; Bird, A.P.; Clinton, M

    2001-01-01

    The Z and W sex chromosomes of birds have evolved independently from the mammalian X and Y chromosomes [1]. Unlike mammals, female birds are heterogametic (ZW), while males are homogametic (ZZ). Therefore male birds, like female mammals, carry a double dose of sex-linked genes relative to the other sex. Other animals with nonhomologous sex chromosomes possess "dosage compensation" systems to equalize the expression of sex-linked genes. Dosage compensation occurs in animals as diverse as mamma...

  17. Interspecific hybrids of dwarf hamsters and Phasianidae birds as animal models for studying the genetic and developmental basis of hybrid incompatibility.

    Science.gov (United States)

    Ishishita, Satoshi; Matsuda, Yoichi

    2016-10-13

    Hybrid incompatibility is important in speciation as it prevents gene flow between closely related populations. Reduced fitness from hybrid incompatibility may also reinforce prezygotic reproductive isolation between sympatric populations. However, the genetic and developmental basis of hybrid incompatibility in higher vertebrates remains poorly understood. Mammals and birds, both amniotes, have similar developmental processes, but marked differences in development such as the XY/ZW sex determination systems and the presence or absence of genomic imprinting. Here, we review the sterile phenotype of hybrids between the Phodopus dwarf hamsters P. campbelli and P. sungorus, and the inviable phenotype of hybrids between two birds of the family Phasianidae, chicken (Gallus gallus domesticus) and Japanese quail (Coturnix japonica). We propose hypotheses for developmental defects that are associated with these hybrid incompatibilities. In addition, we discuss the genetic and developmental basis for these defects in conjunction with recent findings from mouse and avian models of genetics, reproductive biology and genomics. We suggest that these hybrids are ideal animal models for studying the genetic and developmental basis of hybrid incompatibility in amniotes.

  18. Design of Dynamic Strain Measurement System of Rotor Blades Impacted by Bird%旋转叶片鸟撞动态应变测量系统设计

    Institute of Scientific and Technical Information of China (English)

    马坚刚; 张天宏; 孙健国

    2013-01-01

    In order to solve the difficulties of dynamic strain measurement of rotor blades impacted by bird,a method based on on-line detection and high-speed temporary storage is put forward.Through the real-time online detection,the strain data of bird impact in the whole process is collected and stored in a non-volatile SRAM.A multi-channel dynamic strain measurement system is designed mainly,including the detection and storage unit and the ground auxiliary device,which can meet the requirements of accuracy and speed,and realize the functions of on-line detection,high-speed storage and wireless data transmission.The tests indicate that the system has high accuracy and can detect the bird impact in real-time,and the speed of collection and storage is 200 kHz with 6 channels,and the test is convenient by using radio communication,which satisfies the dynamic strain measurement of rotor blades impacted by bird.%为了解决旋转叶片鸟撞时动态应变测量困难的问题,提出一种基于在线检测和高速暂存的测量方法.通过实时在线检测,将鸟撞发生时全过程的应变量采集并高速存储在非易失性存储器中.重点设计多通道动态应变测量系统,包括检测存储单元和地面辅助装置,满足精度、速率要求,实现在线检测、高速存储和无线数据传输等功能.试验表明,系统具有较高的测量精度,能实时检测到鸟撞发生,最快以6通道200 kHz的速率采集和存储,并利用无线数据传输,满足旋转叶片鸟撞动态应变测量要求.

  19. 鸟撞飞机前风挡动态响应的数值模拟%Numerical Simulation of the Dynamic Behavior on Windshield Subjected to Bird Impact

    Institute of Scientific and Technical Information of China (English)

    何俊; 王猛

    2012-01-01

    The nonlinear dynamic analysis program ANSYS/LS-DYNA is employed to the numerical simulation of dynamic response for the windshield under bird impact. Based on the simulation, the dynamic process of bird impact only persisting several milliseconds, and failure may occur at the back frame for the reflecting and superposition of the waves. For another proposed windshield with nick feature in the front part, the critical velocity was only reduced little although the principal stress being quite high in the nick position during impacting. Such a result shows that the windshield with nick feature is feasible on the structure designing based on the simulation, which may be available for new windshield design.%利用Ansys/Ls-Dyna非线性三维有限元程序,模拟计算鸟撞飞机前风挡的动态响应.模拟结果表明,鸟撞是毫秒级的冲击过程,由于应力波的反射、叠加,后弧框中间位置可能首先发生破坏;对于另外一种不时称风挡结构,尽管撞击过程中缺口处首先产生较大的应力值,但并不会给临界速度带来明显的降低,可为新型风挡结构设计提供参考.

  20. Guam and the Northern Mariana Islands ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for pelagic birds, shorebirds, wading birds, waterfowl, gulls, terns, and passerine birds in Guam and the...

  1. Coastal Resources Atlas: Long Island: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, seabirds, passerine birds, and gulls and...

  2. Weather, not climate, defines distributions of vagile bird species.

    Directory of Open Access Journals (Sweden)

    April E Reside

    Full Text Available BACKGROUND: Accurate predictions of species distributions are essential for climate change impact assessments. However the standard practice of using long-term climate averages to train species distribution models might mute important temporal patterns of species distribution. The benefit of using temporally explicit weather and distribution data has not been assessed. We hypothesized that short-term weather associated with the time a species was recorded should be superior to long-term climate measures for predicting distributions of mobile species. METHODOLOGY: We tested our hypothesis by generating distribution models for 157 bird species found in Australian tropical savannas (ATS using modelling algorithm Maxent. The variable weather of the ATS supports a bird assemblage with variable movement patterns and a high incidence of nomadism. We developed "weather" models by relating climatic variables (mean temperature, rainfall, rainfall seasonality and temperature seasonality from the three month, six month and one year period preceding each bird record over a 58 year period (1950-2008. These weather models were compared against models built using long-term (30 year averages of the same climatic variables. CONCLUSIONS: Weather models consistently achieved higher model scores than climate models, particularly for wide-ranging, nomadic and desert species. Climate models predicted larger range areas for species, whereas weather models quantified fluctuations in habitat suitability across months, seasons and years. Models based on long-term climate averages over-estimate availability of suitable habitat and species' climatic tolerances, masking species potential vulnerability to climate change. Our results demonstrate that dynamic approaches to distribution modelling, such as incorporating organism-appropriate temporal scales, improves understanding of species distributions.

  3. Platypus globin genes and flanking loci suggest a new insertional model for beta-globin evolution in birds and mammals.

    Science.gov (United States)

    Patel, Vidushi S; Cooper, Steven J B; Deakin, Janine E; Fulton, Bob; Graves, Tina; Warren, Wesley C; Wilson, Richard K; Graves, Jennifer A M

    2008-07-25

    Vertebrate alpha (alpha)- and beta (beta)-globin gene families exemplify the way in which genomes evolve to produce functional complexity. From tandem duplication of a single globin locus, the alpha- and beta-globin clusters expanded, and then were separated onto different chromosomes. The previous finding of a fossil beta-globin gene (omega) in the marsupial alpha-cluster, however, suggested that duplication of the alpha-beta cluster onto two chromosomes, followed by lineage-specific gene loss and duplication, produced paralogous alpha- and beta-globin clusters in birds and mammals. Here we analyse genomic data from an egg-laying monotreme mammal, the platypus (Ornithorhynchus anatinus), to explore haemoglobin evolution at the stem of the mammalian radiation. The platypus alpha-globin cluster (chromosome 21) contains embryonic and adult alpha- globin genes, a beta-like omega-globin gene, and the GBY globin gene with homology to cytoglobin, arranged as 5'-zeta-zeta'-alphaD-alpha3-alpha2-alpha1-omega-GBY-3'. The platypus beta-globin cluster (chromosome 2) contains single embryonic and adult globin genes arranged as 5'-epsilon-beta-3'. Surprisingly, all of these globin genes were expressed in some adult tissues. Comparison of flanking sequences revealed that all jawed vertebrate alpha-globin clusters are flanked by MPG-C16orf35 and LUC7L, whereas all bird and mammal beta-globin clusters are embedded in olfactory genes. Thus, the mammalian alpha- and beta-globin clusters are orthologous to the bird alpha- and beta-globin clusters respectively. We propose that alpha- and beta-globin clusters evolved from an ancient MPG-C16orf35-alpha-beta-GBY-LUC7L arrangement 410 million years ago. A copy of the original beta (represented by omega in marsupials and monotremes) was inserted into an array of olfactory genes before the amniote radiation (>315 million years ago), then duplicated and diverged to form orthologous clusters of beta-globin genes with different expression

  4. Platypus globin genes and flanking loci suggest a new insertional model for beta-globin evolution in birds and mammals

    Directory of Open Access Journals (Sweden)

    Warren Wesley C

    2008-07-01

    Full Text Available Abstract Background Vertebrate alpha (α- and beta (β-globin gene families exemplify the way in which genomes evolve to produce functional complexity. From tandem duplication of a single globin locus, the α- and β-globin clusters expanded, and then were separated onto different chromosomes. The previous finding of a fossil β-globin gene (ω in the marsupial α-cluster, however, suggested that duplication of the α-β cluster onto two chromosomes, followed by lineage-specific gene loss and duplication, produced paralogous α- and β-globin clusters in birds and mammals. Here we analyse genomic data from an egg-laying monotreme mammal, the platypus (Ornithorhynchus anatinus, to explore haemoglobin evolution at the stem of the mammalian radiation. Results The platypus α-globin cluster (chromosome 21 contains embryonic and adult α- globin genes, a β-like ω-globin gene, and the GBY globin gene with homology to cytoglobin, arranged as 5'-ζ-ζ'-αD-α3-α2-α1-ω-GBY-3'. The platypus β-globin cluster (chromosome 2 contains single embryonic and adult globin genes arranged as 5'-ε-β-3'. Surprisingly, all of these globin genes were expressed in some adult tissues. Comparison of flanking sequences revealed that all jawed vertebrate α-globin clusters are flanked by MPG-C16orf35 and LUC7L, whereas all bird and mammal β-globin clusters are embedded in olfactory genes. Thus, the mammalian α- and β-globin clusters are orthologous to the bird α- and β-globin clusters respectively. Conclusion We propose that α- and β-globin clusters evolved from an ancient MPG-C16orf35-α-β-GBY-LUC7L arrangement 410 million years ago. A copy of the original β (represented by ω in marsupials and monotremes was inserted into an array of olfactory genes before the amniote radiation (>315 million years ago, then duplicated and diverged to form orthologous clusters of β-globin genes with different expression profiles in different lineages.

  5. Urban bird conservation

    NARCIS (Netherlands)

    Snep, Robbert P.H.; Kooijmans, Jip Louwe; Kwak, Robert G.M.; Foppen, Ruud P.B.; Parsons, Holly; Awasthy, Monica; Sierdsema, Henk L.K.; Marzluff, John M.; Fernandez-Juricic, Esteban; Laet, de Jenny

    2016-01-01

    Following the call from the United Nations Convention on Biological Diversity “Cities & Biodiversity Outlook” project to better preserve urban biodiversity, this paper presents stakeholder-specific statements for bird conservation in city environments. Based upon the current urban bird

  6. What Is Bird Flu?

    Institute of Scientific and Technical Information of China (English)

    邢连香

    2004-01-01

    What is bird flu? It's a form of influenza believed to strike all birds. Though poultry (家禽)are believed to be especially prone to (倾向于)humans, no human-to-human transmission(传播) has been reported.

  7. Nanoscale magnetoreceptors in birds

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Greiner, Walter

    2012-01-01

    The Earth's magnetic field provides an important source of directional information for many living organisms, especially birds, but the sensory receptor responsible for magnetic field detection still has to be identified. Recently, magnetic iron oxide particles were detected in dendritic endings...... field, by a bird....

  8. Mathematical modeling of steel fiber concrete under dynamic impact

    Science.gov (United States)

    Belov, N. N.; Yugov, N. T.; Kopanitsa, D. G.; Kopanitsa, G. D.; Yugov, A. A.; Shashkov, V. V.

    2015-01-01

    This paper introduces a continuum mechanics mathematical model that describes the processes of deformation and destruction of steel-fiber-concrete under a shock wave impact. A computer modeling method was applied to study the processes of shock wave impact of a steel cylindrical rod and concrete and steel fiber concrete plates. The impact speeds were within 100-500 m/s.

  9. Birds as biodiversity surrogates

    DEFF Research Database (Denmark)

    Larsen, Frank Wugt; Bladt, Jesper Stentoft; Balmford, Andrew

    2012-01-01

    1. Most biodiversity is still unknown, and therefore, priority areas for conservation typically are identified based on the presence of surrogates, or indicator groups. Birds are commonly used as surrogates of biodiversity owing to the wide availability of relevant data and their broad popular...... appeal. However, some studies have found birds to perform relatively poorly as indicators. We therefore ask how the effectiveness of this approach can be improved by supplementing data on birds with information on other taxa. 2. Here, we explore two strategies using (i) species data for other taxa...... areas identified on the basis of birds alone performed well in representing overall species diversity where birds were relatively speciose compared to the other taxa in the data sets. Adding species data for one taxon increased surrogate effectiveness better than adding genus- and family-level data...

  10. Modeling climate change impacts on water trading.

    Science.gov (United States)

    Luo, Bin; Maqsood, Imran; Gong, Yazhen

    2010-04-01

    This paper presents a new method of evaluating the impacts of climate change on the long-term performance of water trading programs, through designing an indicator to measure the mean of periodic water volume that can be released by trading through a water-use system. The indicator is computed with a stochastic optimization model which can reflect the random uncertainty of water availability. The developed method was demonstrated in the Swift Current Creek watershed of Prairie Canada under two future scenarios simulated by a Canadian Regional Climate Model, in which total water availabilities under future scenarios were estimated using a monthly water balance model. Frequency analysis was performed to obtain the best probability distributions for both observed and simulated water quantity data. Results from the case study indicate that the performance of a trading system is highly scenario-dependent in future climate, with trading effectiveness highly optimistic or undesirable under different future scenarios. Trading effectiveness also largely depends on trading costs, with high costs resulting in failure of the trading program.

  11. Adaptation of bird communities to farmland abandonment in a mountain landscape.

    Directory of Open Access Journals (Sweden)

    João Lopes Guilherme

    Full Text Available Widespread farmland abandonment has led to significant landscape transformations of many European mountain areas. These semi-natural multi-habitat landscapes are important reservoirs of biodiversity and their abandonment has important conservation implications. In multi-habitat landscapes the adaptation of communities depends on the differential affinity of the species to the available habitats. We use nested species-area relationships (SAR to model species richness patterns of bird communities across scales in a mountain landscape, in NW Portugal. We compare the performance of the classic-SAR and the countryside-SAR (i.e. multi-habitat models at the landscape scale, and compare species similarity decay (SSD at the regional scale. We find a considerable overlap of bird communities in the different land-uses (farmland, shrubland and oak forest at the landscape scale. Analysis of the classic and countryside SAR show that specialist species are strongly related to their favourite habitat. Farmland and shrubland have higher regional SSD compared to oak forests. However, this is due to the opportunistic use of farmlands by generalist birds. Forest specialists display significant regional turnover in oak forest. Overall, the countryside-SAR model had a better fit to the data showing that habitat composition determines species richness across scales. Finally, we use the countryside-SAR model to forecast bird diversity under four scenarios of land-use change. Farmland abandonment scenarios show little impact on bird diversity as the model predicts that the complete loss of farmland is less dramatic, in terms of species diversity loss, than the disappearance of native Galicio-Portuguese oak forest. The affinities of species to non-preferred habitats suggest that bird communities can adapt to land-use changes derived from farmland abandonment. Based on model predictions we argue that rewilding may be a suitable management option for many European mountain

  12. Adaptation of bird communities to farmland abandonment in a mountain landscape.

    Science.gov (United States)

    Guilherme, João Lopes; Miguel Pereira, Henrique

    2013-01-01

    Widespread farmland abandonment has led to significant landscape transformations of many European mountain areas. These semi-natural multi-habitat landscapes are important reservoirs of biodiversity and their abandonment has important conservation implications. In multi-habitat landscapes the adaptation of communities depends on the differential affinity of the species to the available habitats. We use nested species-area relationships (SAR) to model species richness patterns of bird communities across scales in a mountain landscape, in NW Portugal. We compare the performance of the classic-SAR and the countryside-SAR (i.e. multi-habitat) models at the landscape scale, and compare species similarity decay (SSD) at the regional scale. We find a considerable overlap of bird communities in the different land-uses (farmland, shrubland and oak forest) at the landscape scale. Analysis of the classic and countryside SAR show that specialist species are strongly related to their favourite habitat. Farmland and shrubland have higher regional SSD compared to oak forests. However, this is due to the opportunistic use of farmlands by generalist birds. Forest specialists display significant regional turnover in oak forest. Overall, the countryside-SAR model had a better fit to the data showing that habitat composition determines species richness across scales. Finally, we use the countryside-SAR model to forecast bird diversity under four scenarios of land-use change. Farmland abandonment scenarios show little impact on bird diversity as the model predicts that the complete loss of farmland is less dramatic, in terms of species diversity loss, than the disappearance of native Galicio-Portuguese oak forest. The affinities of species to non-preferred habitats suggest that bird communities can adapt to land-use changes derived from farmland abandonment. Based on model predictions we argue that rewilding may be a suitable management option for many European mountain areas.

  13. Evaluating the feeding preferences of West Nile virus mosquito vectors using bird-baited traps.

    Science.gov (United States)

    Victoriano Llopis, Isis; Tomassone, Laura; Grego, Elena; Serrano, Emmanuel; Mosca, Andrea; Vaschetti, Gabriella; Andrade, Daniela; Rossi, Luca

    2016-08-31

    The total contact rates (TCRs) between mosquito vectors and their potential hosts have a serious impact on disease transmission dynamics. Culex pipiens (sensu stricto) (s.s.) is considered the main vector of the West Nile Virus (WNV) in Europe and birds are the reservoir hosts. The results of our previous study showed that WNV seroreactors are significantly more prevalent among raptors compared to a range of other wild avian groups. The current study aims to assess the role of bird type (raptor vs others) and bird size on mosquito feeding preferences in a free-choice experiment using bird-baited traps. From July to September 2014, a battery of six bird-baited traps was operated in twelve mosquito capture sessions. Eight bird species, belonging to five different orders, including raptors, were used. After each session, the trapped mosquitoes were collected and identified using standard keys. Two sets of independent generalized linear mixed models (GLMM) were used to assess mosquito vector feeding preferences (MFp) among different bird species and types. A total of 304 mosquitoes belonging to seven taxa were collected, C. pipiens being by far the most abundant (84.2 % of the total mosquito catch). Most C. pipiens were engorged (83.59 %). The selected model showed that 25.6 % of the observed variability of MFp is explained by the interaction between bird size and bird type, with C. pipiens preferring to feed on large birds, especially raptors. The proportion of engorged mosquitoes was 1.9-fold higher in large (22.88 %; range 0-42 %) than in medium-sized raptors (11.71 %; range 0-33 %), and was nearly the same in medium-sized (9.08 %; range 0-26 %) and large (8.5 %; 6-24 %) non-raptor species. Culex pipiens showed an obvious preference for large raptors, which concurs with the higher seroprevalence to WNV in our previous study. The appreciable feeding by C. pipiens on large raptors makes them useful alternative sentinels to poultry for WNV surveillance. Thus

  14. Inferential monitoring of global change impact on biodiversity through remote sensing and species distribution modeling

    Science.gov (United States)

    Sangermano, Florencia

    2009-12-01

    The world is suffering from rapid changes in both climate and land cover which are the main factors affecting global biodiversity. These changes may affect ecosystems by altering species distributions, population sizes, and community compositions, which emphasizes the need for a rapid assessment of biodiversity status for conservation and management purposes. Current approaches on monitoring biodiversity rely mainly on long term observations of predetermined sites, which require large amounts of time, money and personnel to be executed. In order to overcome problems associated with current field monitoring methods, the main objective of this dissertation is the development of framework for inferential monitoring of the impact of global change on biodiversity based on remotely sensed data coupled with species distribution modeling techniques. Several research pieces were performed independently in order to fulfill this goal. First, species distribution modeling was used to identify the ranges of 6362 birds, mammals and amphibians in South America. Chapter 1 compares the power of different presence-only species distribution methods for modeling distributions of species with different response curves to environmental gradients and sample sizes. It was found that there is large variability in the power of the methods for modeling habitat suitability and species ranges, showing the importance of performing, when possible, a preliminary gradient analysis of the species distribution before selecting the method to be used. Chapter 2 presents a new methodology for the redefinition of species range polygons. Using a method capable of establishing the uncertainty in the definition of existing range polygons, the automated procedure identifies the relative importance of bioclimatic variables for the species, predicts their ranges and generates a quality assessment report to explore prediction errors. Analysis using independent validation data shows the power of this

  15. Pesticide acute toxicity is a better correlate of U.S. grassland bird declines than agricultural intensification.

    Directory of Open Access Journals (Sweden)

    Pierre Mineau

    Full Text Available Common agricultural birds are in decline, both in Europe and in North America. Evidence from Europe suggests that agricultural intensification and, for some species, the indirect effects of pesticides mediated through a loss of insect food resource is in part responsible. On a state-by-state basis for the conterminous Unites States (U.S., we looked at several agronomic variables to predict the number of grassland species increasing or declining according to breeding bird surveys conducted between 1980 and 2003. Best predictors of species declines were the lethal risk from insecticide use modeled from pesticide impact studies, followed by the loss of cropped pasture. Loss of permanent pasture or simple measures of agricultural intensification such as the proportion of land under crop or the proportion of farmland treated with herbicides did not explain bird declines as well. Because the proportion of farmland treated with insecticides, and more particularly the lethal risk to birds from the use of current insecticides feature so prominently in the best models, this suggests that, in the U.S. at least, pesticide toxicity to birds should be considered as an important factor in grassland bird declines.

  16. Traffic effects on bird counts on North American Breeding Bird Survey routes

    Science.gov (United States)

    Griffith, Emily H.; Sauer, John R.; Royle, J. Andrew

    2010-01-01

    The North American Breeding Bird Survey (BBS) is an annual roadside survey used to estimate population change in >420 species of birds that breed in North America. Roadside sampling has been criticized, in part because traffic noise can interfere with bird counts. Since 1997, data have been collected on the numbers of vehicles that pass during counts at each stop. We assessed the effect of traffic by modeling total vehicles as a covariate of counts in hierarchical Poisson regression models used to estimate population change. We selected species for analysis that represent birds detected at low and high abundance and birds with songs of low and high frequencies. Increases in vehicle counts were associated with decreases in bird counts in most of the species examined. The size and direction of these effects remained relatively constant between two alternative models that we analyzed. Although this analysis indicated only a small effect of incorporating traffic effects when modeling roadside counts of birds, we suggest that continued evaluation of changes in traffic at BBS stops should be a component of future BBS analyses.

  17. Oxyspiruriasis in zoo birds.

    Science.gov (United States)

    Vellayan, S; Jeffery, J; Oothuman, P; Zahedi, M; Krishnasamy, M; Paramaswaran, S; Rohela, M; Abdul-Aziz, N M

    2012-06-01

    Oxyspiruriasis caused by the bird eyeworm, Oxyspirura mansoni, a thelaziid nematode, in three species of pheasants, 3 Chrysolophus pictus (golden pheasant), 7 Lophura nycthemera (silver pheasant) and 9 Phasianus colchicus (common pheasant) in Zoo Negara Malaysia are reported. Birds with the disease were treated with a solution of 0.5% iodine or 0.5% lysol. Antistress powder for 4 days in water and non-strep vitamin powder in water was also provided. Control measures included removal of the cockroach intermediate host, Pycnoscelus surinamensis (Surinam cockroach) from the vicinity of the birds. The golden pheasant is a new host for O. mansoni in peninsular Malaysia.

  18. [Birds' sense of direction].

    Science.gov (United States)

    Hohtola, Esa

    2016-01-01

    Birds utilize several distinct sensory systems in a flexible manner in their navigation. When navigating with the help of landmarks, location of the sun and stars, or polarization image of the dome of the sky, they resort to vision. The significance of olfaction in long-range navigation has been under debate, even though its significance in local orientation is well documented. The hearing in birds extends to the infrasound region. It has been assumed that they are able to hear the infrasounds generated in the mountains and seaside and navigate by using them. Of the senses of birds, the most exotic one is the ability to sense magnetic fields of the earth.

  19. EcoMark: Evaluating Models of Vehicular Environmental Impact

    DEFF Research Database (Denmark)

    Guo, Chenjuan; Ma, Mike; Yang, Bin

    2012-01-01

    the vehicle travels in. We develop an evaluation framework, called EcoMark, for such environmental impact models. In addition, we survey all eleven state-of-the-art impact models known to us. To gain insight into the capabilities of the models and to understand the effectiveness of the EcoMark, we apply...

  20. A dimensionless model of impact piezoelectric energy harvesting with dissipation

    Science.gov (United States)

    Fu, Xinlei; Liao, Wei-Hsin

    2016-04-01

    Impact excitation is common in the environment. Impact piezoelectric energy harvesting could realize frequency up-conversion. However, the dissipation mechanism in impact piezoelectric energy harvesting has not been investigated so far. There is no comprehensive model to be able to analyze the impact piezoelectric energy harvesting thoroughly. This paper is aimed to develop a generalized model that considers dissipation mechanism of impact piezoelectric energy harvesting. In this electromechanical model, Hertzian contact theory and impact dissipation mechanism are identified as constitutive mechanisms. The impact force is compared and the energy distribution is analyzed so that input energy corresponds to impact dissipated energy, structural damping dissipated energy and harvested electrical energy. We then nondimensionalize the developed model and define five dimensionless parameters with attributed physical meanings, including dimensionless parameters of impact dissipation, mass ratio, structural damping, electromechanical coupling, and electrical load. We conclude it is more accurate to consider impact dissipation mechanism to predict impact force and harvested energy. The guideline for improving harvested energy based on parametric studies of dimensionless model is to increase mass ratio, to minimize structural damping, to maximize electromechanical coupling, to use optimal load resistance for impedance matching, and to choose proper impact velocity .

  1. Experimental evolution of an RNA virus in wild birds: evidence for host-dependent impacts on population structure and competitive fitness.

    Directory of Open Access Journals (Sweden)

    Nathan D Grubaugh

    2015-05-01

    Full Text Available Within hosts, RNA viruses form populations that are genetically and phenotypically complex. Heterogeneity in RNA virus genomes arises due to error-prone replication and is reduced by stochastic and selective mechanisms that are incompletely understood. Defining how natural selection shapes RNA virus populations is critical because it can inform treatment paradigms and enhance control efforts. We allowed West Nile virus (WNV to replicate in wild-caught American crows, house sparrows and American robins to assess how natural selection shapes RNA virus populations in ecologically relevant hosts that differ in susceptibility to virus-induced mortality. After five sequential passages in each bird species, we examined the phenotype and population diversity of WNV through fitness competition assays and next generation sequencing. We demonstrate that fitness gains occur in a species-specific manner, with the greatest replicative fitness gains in robin-passaged WNV and the least in WNV passaged in crows. Sequencing data revealed that intrahost WNV populations were strongly influenced by purifying selection and the overall complexity of the viral populations was similar among passaged hosts. However, the selective pressures that control WNV populations seem to be bird species-dependent. Specifically, crow-passaged WNV populations contained the most unique mutations (~1.7× more than sparrows, ~3.4× more than robins and defective genomes (~1.4× greater than sparrows, ~2.7× greater than robins, but the lowest average mutation frequency (about equal to sparrows, ~2.6× lower than robins. Therefore, our data suggest that WNV replication in the most disease-susceptible bird species is positively associated with virus mutational tolerance, likely via complementation, and negatively associated with the strength of selection. These differences in genetic composition most likely have distinct phenotypic consequences for the virus populations. Taken together

  2. Unzipping bird feathers

    Science.gov (United States)

    Kovalev, Alexander; Filippov, Alexander E.; Gorb, Stanislav N.

    2014-01-01

    The bird feather vane can be separated into two parts by pulling the barbs apart. The original state can be re-established easily by lightly stroking through the feather. Hooklets responsible for holding vane barbs together are not damaged by multiple zipping and unzipping cycles. Because numerous microhooks keep the integrity of the feather, their properties are of great interest for understanding mechanics of the entire feather structure. This study was undertaken to estimate the separation force of single hooklets and their arrays using force measurement of an unzipping feather vane. The hooklets usually separate in some number synchronously (20 on average) with the highest observed separation force of 1.74 mN (average force 0.27 mN), whereas the single hooklet separation force was 14 μN. A simple numerical model was suggested for a better understanding of zipping and unzipping behaviour in feathers. The model demonstrates features similar to those observed in experiments. PMID:24352674

  3. A brief report on the illegal cage-bird trade in southern Florida: a potentially serious negative impact on the eastern population of Painted Bunting (Passerina ciris)

    Science.gov (United States)

    Sykes, P.W.; Manfredi, L.; Padura, M.

    2006-01-01

    Populations of Painted Bunting (Passerina ciris) have been declining annually over the past 35 years. A cursory survey indicates that illegal trapping of Painted Buntings for a black market cage-bird trade is widespread in southeastern Florida. Coupled with other negative factors confronting the eastern population, the trapping of buntings for the cagebird trade may, in time, produce dire results for this native songbird. Law enforcement personnel need to continue to monitor the illegal activity of trapping native passerines for the local songbird market and to continue to arrest those who support it.

  4. New Discrete Element Models for Three-Dimensional Impact Problems

    Institute of Scientific and Technical Information of China (English)

    SHAN Li; CHENG Ming; LIU Kai-xin; LIU Wei-Fu; CHEN Shi-Yang

    2009-01-01

    Two 3-D numerical models of the discrete element method(DEM)for impact problems are proposed.The models can calculate not only the impact problems of continuum and non-continuum,but also the transient process from continuum to non-continuum.The stress wave propagation in a concrete block and a dynamic splitting process of a marble disc under impact loading are numerically simulated with the proposed models.By comparing the numerical results with the corresponding results obtained by the finite element method(FEM)and the experiments,it is proved that the models are reliable for three-dimensional impact problems.

  5. Bayesian hierarchical modelling of continuous non-negative longitudinal data with a spike at zero: An application to a study of birds visiting gardens in winter.

    Science.gov (United States)

    Swallow, Ben; Buckland, Stephen T; King, Ruth; Toms, Mike P

    2016-03-01

    The development of methods for dealing with continuous data with a spike at zero has lagged behind those for overdispersed or zero-inflated count data. We consider longitudinal ecological data corresponding to an annual average of 26 weekly maximum counts of birds, and are hence effectively continuous, bounded below by zero but also with a discrete mass at zero. We develop a Bayesian hierarchical Tweedie regression model that can directly accommodate the excess number of zeros common to this type of data, whilst accounting for both spatial and temporal correlation. Implementation of the model is conducted in a Markov chain Monte Carlo (MCMC) framework, using reversible jump MCMC to explore uncertainty across both parameter and model spaces. This regression modelling framework is very flexible and removes the need to make strong assumptions about mean-variance relationships a priori. It can also directly account for the spike at zero, whilst being easily applicable to other types of data and other model formulations. Whilst a correlative study such as this cannot prove causation, our results suggest that an increase in an avian predator may have led to an overall decrease in the number of one of its prey species visiting garden feeding stations in the United Kingdom. This may reflect a change in behaviour of house sparrows to avoid feeding stations frequented by sparrowhawks, or a reduction in house sparrow population size as a result of sparrowhawk increase.

  6. Cranial kinesis in palaeognathous birds.

    Science.gov (United States)

    Gussekloo, Sander W S; Bout, Ron G

    2005-09-01

    Cranial kinesis in birds is induced by muscles located caudal on the cranium. These forces are transferred onto the moveable parts of the skull via the Pterygoid-Palatinum Complex (PPC). This bony structure therefore plays an essential role in cranial kinesis. In palaeognathous birds the morphology of the PPC is remarkably different from that of neognathous birds and is thought to be related to the specific type of cranial kinesis in palaeognaths known as central rhynchokinesis. We determined whether clear bending zones as found in neognaths are present in the upper bill of paleognaths, and measured bending forces opposing elevation of the upper bill. A static force model was used to calculate the opening forces that can be produced by some of the palaeognathous species. We found that no clear bending zones are present in the upper bill, and bending is expected to occur over the whole length of the upper bill. Muscle forces are more than sufficient to overcome bending forces and to elevate the upper bill. The resistance against bending by the bony elements alone is very low, which might indicate that bending of bony elements can occur during food handling when muscles are not used to stabilise the upper bill. Model calculations suggest that the large processi basipterygoidei play a role in stabilizing the skull elements, when birds have to resist external opening forces on the upper bill as might occur during tearing leafs from plants. We conclude that the specific morphology of the palaeognathous upper bill and PPC are not designed for active cranial kinesis, but are adapted to resist external forces that might cause unwanted elevation of the upper bill during feeding.

  7. Breeding bird survey data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The data are maintained by the USGS (https://www.pwrc.usgs.gov/bbs/RawData/) and provides information on the trends and status of North American bird populations...

  8. Awesome Audubon Birds

    Science.gov (United States)

    Kahler, Laura

    2010-01-01

    In this article, the author describes a watercolor art lesson on Audubon birds. She also discusses how science, technology, writing skills, and the elements and principles of art can be incorporated into the lesson.

  9. Birds - Breeding [ds60

    Data.gov (United States)

    California Department of Resources — This data set provides access to information gathered on annual breeding bird surveys in California using a map layer developed by the Department. This data layer...

  10. Implications of climate change for wetland-dependent birds in the Prairie Pothole Region

    Science.gov (United States)

    Steen, Valerie; Skagen, Susan; Melcher, Cynthia P.

    2016-01-01

    The habitats and food resources required to support breeding and migrant birds dependent on North American prairie wetlands are threatened by impending climate change. The North American Prairie Pothole Region (PPR) hosts nearly 120 species of wetland-dependent birds representing 21 families. Strategic management requires knowledge of avian habitat requirements and assessment of species most vulnerable to future threats. We applied bioclimatic species distribution models (SDMs) to project range changes of 29 wetland-dependent bird species using ensemble modeling techniques, a large number of General Circulation Models (GCMs), and hydrological climate covariates. For the U.S. PPR, mean projected range change, expressed as a proportion of currently occupied range, was −0.31 (± 0.22 SD; range − 0.75 to 0.16), and all but two species were projected to lose habitat. Species associated with deeper water were expected to experience smaller negative impacts of climate change. The magnitude of climate change impacts was somewhat lower in this study than earlier efforts most likely due to use of different focal species, varying methodologies, different modeling decisions, or alternative GCMs. Quantification of the projected species-specific impacts of climate change using species distribution modeling offers valuable information for vulnerability assessments within the conservation planning process.

  11. Bird Vision System

    Science.gov (United States)

    2008-01-01

    The Bird Vision system is a multicamera photogrammerty software application that runs on a Microsoft Windows XP platform and was developed at Kennedy Space Center by ASRC Aerospace. This software system collects data about the locations of birds within a volume centered on the Space Shuttle and transmits it in real time to the laptop computer of a test director in the Launch Control Center (LCC) Firing Room.

  12. A Clever Bird

    Institute of Scientific and Technical Information of China (English)

    徐芳; 孙菊

    2008-01-01

    @@ 一、故事内容 It is getting hotter and hotter day by day.So the birds don't often fly in the sky in daytime.They usually fly in the evening to look for food.But a bird named Polly is very naughty.He just knows how to fly,so he wants to fly every day.One day,when he is flying in the forest,he feels very thirsty.

  13. Dynamic Response Analysis of Bird Strike on Aircraft Windshield Based on Damage-modified Nonlinear Viscoelastic Constitutive Relation

    Institute of Scientific and Technical Information of China (English)

    Wang Xinjun; Feng Zhenzhou; Wang Fusheng; Yue Zhufeng

    2007-01-01

    Damage-modified nonlinear viscoelastic constitutive equation and failure criterion are introduced and the three-dimensional incremental forms are deduced based on the updated Lagrangian approach. A simple tensile test model and a split Hopkinson pressure bar model are built to verify the accuracy of the subroutine implemented within the non-linear finite element program LS-DYNA. A numerical model of bird strike on windshield is established to study the responses of windshield under three different bird velocities at three sites. The bird is represented by a cylinder with a hemisphere at each end and the contact-impact coupling algorithm is used in this study. It is found that the implemented subroutine can properly describe the mechanical behavior of polymethyl methacrylate under low and high strain rates and large deformation, and can be used validly.

  14. Bird Activity Analysis Using Avian Radar Information in Naval Air Station airport, WA

    Science.gov (United States)

    Wang, J.; Herricks, E.

    2010-12-01

    The number of bird strikes on aircraft has increased sharply over recent years and airport bird hazard management has gained increasing attention in wildlife management and control. Evaluation of bird activity near airport is very critical to analyze the hazard of bird strikes. Traditional methods for bird activity analysis using visual counting provide a direct approach to bird hazard assessment. However this approach is limited to daylight and good visual conditions. Radar has been proven to be a useful and effective tool for bird detection and movement analysis. Radar eliminates observation bias and supports consistent data collection for bird activity analysis and hazard management. In this study bird activity data from the Naval Air Station Whidbey Island was collected by Accipiter Avian Radar System. Radar data was pre-processed by filtering out non-bird noises, including traffic vehicle, aircraft, insects, wind, rainfall, ocean waves and so on. Filtered data is then statistically analyzed using MATLAB programs. The results indicated bird movement dynamics in target areas near the airport, which includes (1) the daily activity varied at dawn and dusk; (2) bird activity varied by target area due to the habitat difference; and (3) both temporal and spatial movement patterns varied by bird species. This bird activity analysis supports bird hazard evaluation and related analysis and modeling to provide very useful information in airport bird hazard management planning.

  15. Tracking Invasive Birds: A Programme for Implementing Dynamic Open Inquiry Learning and Conservation Education

    Science.gov (United States)

    Zion, Michal; Spektor-Levy, Ornit; Orchan, Yotam; Shwartz, Assaf; Sadeh, Irit; Kark, Salit

    2011-01-01

    Among potential topics in the new science of biodiversity, understanding the characteristics and impact of invasive birds is an attractive subject to include as part of junior high school biology studies. Birds are aesthetic and raise curiosity. Curiosity about birds, combined with field observations, can stimulate students to ask authentic…

  16. Modelling climate change impacts on mycotoxin contamination

    NARCIS (Netherlands)

    Fels, van der Ine; Liu, C.; Battilani, P.

    2016-01-01

    Projected climate change effects will influence primary agricultural systems and thus food security, directly via impacts on yields, and indirectly via impacts on its safety, with mycotoxins considered as crucial hazards. Mycotoxins are produced by a wide variety of fungal species, each having their

  17. Modelling climate change impacts on mycotoxin contamination

    NARCIS (Netherlands)

    Fels, van der Ine; Liu, C.; Battilani, P.

    2016-01-01

    Projected climate change effects will influence primary agricultural systems and thus food security, directly via impacts on yields, and indirectly via impacts on its safety, with mycotoxins considered as crucial hazards. Mycotoxins are produced by a wide variety of fungal species, each having their

  18. Coordinated bird monitoring: Technical recommendations for military lands

    Science.gov (United States)

    Bart, Jonathan; Manning, Ann; Fischer, Richard; Eberly, Chris

    2012-01-01

    The Department of Defense (DoD) is subject to several rules and regulations establishing responsibilities for monitoring migratory birds. The Sikes Act requires all military installations with significant natural resources to prepare and implement Integrated Natural Resources Management Plans (INRMPs). These plans guide the conservation and long-term management of natural resources on military lands in a manner that is compatible with and sustains the military mission. An INRMP also supports compliance with all legal requirements and guides the military in fulfilling its obligation to be a good steward of public land.The management and conservation of migratory birds is addressed in installation INRMPs. The National Environmental Policy Act (NEPA) requires federal agencies to evaluate and disclose the potential environmental impacts of their proposed actions. More recently, DoD signed an MOU (http://www.dodpif.org/downloads/EO13186_MOU-DoD.pdf) for migratory birds, under Executive Order 13186, with the US Fish and Wildlife Service (USFWS) in July 2006 and a Migratory Bird Rule (http://www.dodpif.org/downloads/MigBirdFINALRule_FRFeb2007.pdf) was passed by Congress in February 2007. The Migratory Bird Rule addresses the potential impacts of military readiness activities on populations of migratory birds and establishes a process to implement conservation measures if and when a military readiness activity is expected to have a significant adverse impact on a population of migratory bird species (as determined through the NEPA process). The MOU states that for nonmilitary readiness activities, prior to initiating any activity likely to affect populations of migratory birds DoD shall (1) identify the migratory bird species likely to occur in the area of the proposed action and determine if any species of concern could be affected by the activity, and (2) assess and document, using NEPA when applicable, the effect of the proposed action on species of concern. By

  19. Marine bird populations in Prince William Sound, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Marine bird populations in Prince William Sound, Alaska, were censused in the winter and summer of 1972 and 1973 to assess the potential impact of oil transport...

  20. The Impact of Modeling Assumptions in Galactic Chemical Evolution Models

    CERN Document Server

    Côté, Benoit; Ritter, Christian; Herwig, Falk; Venn, Kim A

    2016-01-01

    We use the OMEGA galactic chemical evolution code to investigate how the assumptions used for the treatment of galactic inflows and outflows impact numerical predictions. The goal is to determine how our capacity to reproduce the chemical evolution trends of a galaxy is affected by the choice of implementation used to include those physical processes. In pursuit of this goal, we experiment with three different prescriptions for galactic inflows and outflows and use OMEGA within a Markov Chain Monte Carlo code to recover the set of input parameters that best reproduces the chemical evolution of nine elements in the dwarf spheroidal galaxy Sculptor. Despite their different degrees of intended physical realism, we found that all three prescriptions can reproduce in an almost identical way the stellar abundance trends observed in Sculptor. While the three models have the same capacity to fit the data, the best values recovered for the parameters controlling the number of Type Ia supernovae and the strength of gal...

  1. International Jobs and Economic Development Impacts (I-JEDI) Model

    Energy Technology Data Exchange (ETDEWEB)

    2016-09-01

    International Jobs and Economic Development Impacts (I-JEDI) is a freely available economic model that estimates gross economic impacts from wind, solar, biomass, and geothermal energy projects. Building on a similar model for the United States, I-JEDI was developed by the National Renewable Energy Laboratory under the U.S. government's Enhancing Capacity for Low Emission Development Strategies (EC-LEDS) program to support partner countries in assessing economic impacts of LEDS actions in the energy sector.

  2. Numerical Modeling of Shatter Cones Development in Impact Craters

    Science.gov (United States)

    Baratoux, D.; Melosh, H. J.

    2003-03-01

    We present a new model for the formation of shatter cones in impact craters. Our model has been tested by means of numerical simulations. Our results are consistent with the observations of shatter cones in natural impact craters and explosions experiments.

  3. Modeling and Analysis of Sea-level Rise Impacts on Salinity in the Lower St. Johns River

    Science.gov (United States)

    Bacopoulos, P.

    2015-12-01

    There is deliberate attention being paid to studying sea-level rise impacts on the lower St. Johns River, a drowned coastal plain-type estuary with low topographic drive, located in northeastern Florida. One area of attention is salinity in the river, which influences the entire food web, including sea and marsh grasses, juvenile crustaceans and fishes, wading birds and migratory waterfowl, marine mammals and other predator animals. It is expected that elevated ocean levels will increase the salinity of the estuarine waters, leading to deleterious effects on dependent species of the river biology. The objective of the modeling and analysis was: 1) to establish baseline conditions of salinity for the lower St. Johns River; and 2) to examine future conditions of salinity, as impacted by sea-level rise. Establishing baseline conditions entailed validation of the model for present-day salinity in the lower St. Johns River via comparison to available data. Examining future conditions entailed application of the model for sea-level rise scenarios, with comparison to the baseline conditions, for evaluation of sea-level rise impacts on salinity. While the central focus was on the physics of sea-level rise impacts on salinity, some level of salinity-biological assessment was conducted to identify sea-level rise/salinity thresholds, as related to negatively impacting different species of the river biology.

  4. Spatial modeling of wild bird risk factors to investigate highly pathogenic A(H5N1) avian influenza virus transmission

    Science.gov (United States)

    Prosser, Diann J.; Hungerford, Laura L.; Erwin, R. Michael; Ottinger, Mary Ann; Takekawa, John Y.; Newman, Scott H.; Xiao, Xianming; Ellis, Erie C.

    2016-01-01

    One of the longest-persisting avian influenza viruses in history, highly pathogenic avian influenza virus (HPAIV) A(H5N1), continues to evolve after 18 years, advancing the threat of a global pandemic. Wild waterfowl (family Anatidae), are reported as secondary transmitters of HPAIV, and primary reservoirs for low-pathogenic avian influenza viruses, yet spatial inputs for disease risk modeling for this group have been lacking. Using GIS and Monte Carlo simulations, we developed geospatial indices of waterfowl abundance at 1 and 30 km resolutions and for the breeding and wintering seasons for China, the epicenter of H5N1. Two spatial layers were developed: cumulative waterfowl abundance (WAB), a measure of predicted abundance across species, and cumulative abundance weighted by H5N1 prevalence (WPR), whereby abundance for each species was adjusted based on prevalence values then totaled across species. Spatial patterns of the model output differed between seasons, with higher WAB and WPR in the northern and western regions of China for the breeding season and in the southeast for the wintering season. Uncertainty measures indicated highest error in southeastern China for both WAB and WPR. We also explored the effect of resampling waterfowl layers from 1 km to 30 km resolution for multi-scale risk modeling. Results indicated low average difference (less than 0.16 and 0.01 standard deviations for WAB and WPR, respectively), with greatest differences in the north for the breeding season and southeast for the wintering season. This work provides the first geospatial models of waterfowl abundance available for China. The indices provide important inputs for modeling disease transmission risk at the interface of poultry and wild birds. These models are easily adaptable, have broad utility to both disease and conservation needs, and will be available to the scientific community for advanced modeling applications.

  5. The Impact of Modeling Assumptions in Galactic Chemical Evolution Models

    Science.gov (United States)

    Côté, Benoit; O'Shea, Brian W.; Ritter, Christian; Herwig, Falk; Venn, Kim A.

    2017-02-01

    We use the OMEGA galactic chemical evolution code to investigate how the assumptions used for the treatment of galactic inflows and outflows impact numerical predictions. The goal is to determine how our capacity to reproduce the chemical evolution trends of a galaxy is affected by the choice of implementation used to include those physical processes. In pursuit of this goal, we experiment with three different prescriptions for galactic inflows and outflows and use OMEGA within a Markov Chain Monte Carlo code to recover the set of input parameters that best reproduces the chemical evolution of nine elements in the dwarf spheroidal galaxy Sculptor. This provides a consistent framework for comparing the best-fit solutions generated by our different models. Despite their different degrees of intended physical realism, we found that all three prescriptions can reproduce in an almost identical way the stellar abundance trends observed in Sculptor. This result supports the similar conclusions originally claimed by Romano & Starkenburg for Sculptor. While the three models have the same capacity to fit the data, the best values recovered for the parameters controlling the number of SNe Ia and the strength of galactic outflows, are substantially different and in fact mutually exclusive from one model to another. For the purpose of understanding how a galaxy evolves, we conclude that only reproducing the evolution of a limited number of elements is insufficient and can lead to misleading conclusions. More elements or additional constraints such as the Galaxy’s star-formation efficiency and the gas fraction are needed in order to break the degeneracy between the different modeling assumptions. Our results show that the successes and failures of chemical evolution models are predominantly driven by the input stellar yields, rather than by the complexity of the Galaxy model itself. Simple models such as OMEGA are therefore sufficient to test and validate stellar yields. OMEGA

  6. Impacts of forest fragmentation on species richness: a hierarchical approach to community modelling

    Science.gov (United States)

    Zipkin, Elise F.; DeWan, Amielle; Royle, J. Andrew

    2009-01-01

    1. Species richness is often used as a tool for prioritizing conservation action. One method for predicting richness and other summaries of community structure is to develop species-specific models of occurrence probability based on habitat or landscape characteristics. However, this approach can be challenging for rare or elusive species for which survey data are often sparse. 2. Recent developments have allowed for improved inference about community structure based on species-specific models of occurrence probability, integrated within a hierarchical modelling framework. This framework offers advantages to inference about species richness over typical approaches by accounting for both species-level effects and the aggregated effects of landscape composition on a community as a whole, thus leading to increased precision in estimates of species richness by improving occupancy estimates for all species, including those that were observed infrequently. 3. We developed a hierarchical model to assess the community response of breeding birds in the Hudson River Valley, New York, to habitat fragmentation and analysed the model using a Bayesian approach. 4. The model was designed to estimate species-specific occurrence and the effects of fragment area and edge (as measured through the perimeter and the perimeter/area ratio, P/A), while accounting for imperfect detection of species. 5. We used the fitted model to make predictions of species richness within forest fragments of variable morphology. The model revealed that species richness of the observed bird community was maximized in small forest fragments with a high P/A. However, the number of forest interior species, a subset of the community with high conservation value, was maximized in large fragments with low P/A. 6. Synthesis and applications. Our results demonstrate the importance of understanding the responses of both individual, and groups of species, to environmental heterogeneity while illustrating the utility

  7. Comparing the effects of climate and impact model uncertainty on climate impacts estimates for grain maize

    Science.gov (United States)

    Holzkämper, Annelie; Honti, Mark; Fuhrer, Jürg

    2015-04-01

    Crop models are commonly applied to estimate impacts of projected climate change and to anticipate suitable adaptation measures. Thereby, uncertainties from global climate models, regional climate models, and impacts models cascade down to impact estimates. It is essential to quantify and understand uncertainties in impact assessments in order to provide informed guidance for decision making in adaptation planning. A question that has hardly been investigated in this context is how sensitive climate impact estimates are to the choice of the impact model approach. In a case study for Switzerland we compare results of three different crop modelling approaches to assess the relevance of impact model choice in relation to other uncertainty sources. The three approaches include an expert-based, a statistical and a process-based model. With each approach impact model parameter uncertainty and climate model uncertainty (originating from climate model chain and downscaling approach) are accounted for. ANOVA-based uncertainty partitioning is performed to quantify the relative importance of different uncertainty sources. Results suggest that uncertainty in estimated yield changes originating from the choice of the crop modelling approach can be greater than uncertainty from climate model chains. The uncertainty originating from crop model parameterization is small in comparison. While estimates of yield changes are highly uncertain, the directions of estimated changes in climatic limitations are largely consistent. This leads us to the conclusion that by focusing on estimated changes in climate limitations, more meaningful information can be provided to support decision making in adaptation planning - especially in cases where yield changes are highly uncertain.

  8. Evaluation of a laboratory model of human head impact biomechanics.

    Science.gov (United States)

    Hernandez, Fidel; Shull, Peter B; Camarillo, David B

    2015-09-18

    This work describes methodology for evaluating laboratory models of head impact biomechanics. Using this methodology, we investigated: how closely does twin-wire drop testing model head rotation in American football impacts? Head rotation is believed to cause mild traumatic brain injury (mTBI) but helmet safety standards only model head translations believed to cause severe TBI. It is unknown whether laboratory head impact models in safety standards, like twin-wire drop testing, reproduce six degree-of-freedom (6DOF) head impact biomechanics that may cause mTBI. We compared 6DOF measurements of 421 American football head impacts to twin-wire drop tests at impact sites and velocities weighted to represent typical field exposure. The highest rotational velocities produced by drop testing were the 74th percentile of non-injury field impacts. For a given translational acceleration level, drop testing underestimated field rotational acceleration by 46% and rotational velocity by 72%. Primary rotational acceleration frequencies were much larger in drop tests (~100 Hz) than field impacts (~10 Hz). Drop testing was physically unable to produce acceleration directions common in field impacts. Initial conditions of a single field impact were highly resolved in stereo high-speed video and reconstructed in a drop test. Reconstruction results reflected aggregate trends of lower amplitude rotational velocity and higher frequency rotational acceleration in drop testing, apparently due to twin-wire constraints and the absence of a neck. These results suggest twin-wire drop testing is limited in modeling head rotation during impact, and motivate continued evaluation of head impact models to ensure helmets are tested under conditions that may cause mTBI. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Genetic differentiation in two widespread, open-forest bird species of Southeast Asia (Copsychus saularis andMegalaima haemacephala):Insights from ecological niche modeling

    Institute of Scientific and Technical Information of China (English)

    Haw Chuan LIM; Fasheng ZOU; Frederick H SHELDON

    2015-01-01

    Ecological niche modeling has emerged as an useful tool in the investigation of the phylogeographic histories of spe-cies or communities in a region. The high biodiversity (oftentimes cryptic), and complex geography and geological history of Southeast Asia particularly call for multipronged approaches in phylogeographic investigations. Past studies have focused on taxa that are associated with lowland rainforests, which is the dominant natural vegetation type. Here, we combine published phylo-genetic data, ecological niche modeling and paleo-climate models to reveal potential drivers of divergence in two open-forest bird species, the oriental magpie-robinCopsychus saularis and Coppersmith barbetMegalaima haemacephala. In spite of broad overlap in current distributions, there are subtle differences in their climatic niches, which result in different responses to past climatic changes. ForC. saularis, both Last Glacial Maximum climate models indicated that the entire Sundaland was climati-cally suitable, while phylogenetic analyses found divergent eastern and western Sundaland lineages. We thus postulate that this genetic divergence was a result of past separations of coastal habitats into eastern and western portions due to the emergence of Sunda shelf as sea-level fell. The current separation of morphological subspecies in Borneo is maintained by low climatic suita-bility (high annual rainfall) in certain regions. The extirpation ofM. haemacephala from Borneo and southern Malay Peninsula might have been driven by unsuitable conditions (high temperature seasonality) in central Sundaland and/or the lack of open woodlands. Our study shows that ecological niche modeling adds a powerful dimension to our attempt to understand lineage evolution in space [Current Zoology 61 (5): 922–934, 2015].

  10. Cook Inlet and Kenai Peninsula, Alaska ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for alcids, shorebirds, waterfowl, diving birds, pelagic birds, gulls and terns in Cook Inlet and Kenai Peninsula,...

  11. Music for the birds: effects of auditory enrichment on captive bird species.

    Science.gov (United States)

    Robbins, Lindsey; Margulis, Susan W

    2016-01-01

    With the increase of mixed species exhibits in zoos, targeting enrichment for individual species may be problematic. Often, mammals may be the primary targets of enrichment, yet other species that share their environment (such as birds) will unavoidably be exposed to the enrichment as well. The purpose of this study was to determine if (1) auditory stimuli designed for enrichment of primates influenced the behavior of captive birds in the zoo setting, and (2) if the specific type of auditory enrichment impacted bird behavior. Three different African bird species were observed at the Buffalo Zoo during exposure to natural sounds, classical music and rock music. The results revealed that the average frequency of flying in all three bird species increased with naturalistic sounds and decreased with rock music (F = 7.63, df = 3,6, P = 0.018); vocalizations for two of the three species (Superb Starlings and Mousebirds) increased (F = 18.61, df = 2,6, P = 0.0027) in response to all auditory stimuli, however one species (Lady Ross's Turacos) increased frequency of duetting only in response to rock music (X(2) = 18.5, df = 2, P behavior in non-target species as well, in this case leading to increased activity by birds.

  12. Ecological impacts of flood control project on birds%防洪改善计划对鸟类的生态影响

    Institute of Scientific and Technical Information of China (English)

    郭汉佳; 戴名扬

    2006-01-01

    A total of 23 hm2 of fishponds and 22 hm2 of cultivated lands in the New Territories of Hong Kong Special Administrative Region (HKSAR) were converted to two flood control channels(Channels 60 and 43) by the Main Drainage Channels Project for Ngau Tam Mei, Yuen Long, and Kam Tin (MDC Projects). Post construction ecological monitoring surveys showed that bird abundance of the two flood control channels were lower than those of the habitats they replaced. Conversion of cu ltivated lands to Channel 43 resulted in decline of mean bird density from 33.9individuals/hm 2 to 2.2 individuals/hm2. Conversion of fishponds to Channel 60 resulted in decline of mean bird density from 5.2 individuals/hm 2 to 0.4 individual/hm 2.This was probably due to declines in food abundance, vegetati on cover and habitat complexity. Losses of ecological habitats were observed. The inner embankment of Channel 43 was lined with grasscrete to provide wildlife habitats to mitigate the loss of cultivated lands. This mitigation measure, however, proved ineffective.%香港特别行政区新界内有23 hm2的鱼塘和22 hm2的耕地,在"元朗-锦田-牛潭尾主要防洪改善计划"中被改变成两条防洪渠(防洪渠60号和43号).于该防洪改善计划中的生态监察调查中发现这两条防洪渠的鸟类数量均较原先的生境大大减少.在耕地改变成防洪渠43号的过程中,鸟类密度由33.9 只/hm2减少至2.2只/hm2.在鱼塘改变成防洪渠60号的过程中,鸟类密度由5.2 只/hm2 减少至0.4只/hm2.研究亦发现一些原本在鱼塘和耕地很常见的鸟类物种因为生境被改变而消失.这些转变可能和食物,植被及生境复杂程度的减少有关.另一方面,为纾缓因这防洪改善计划中损失的耕地生境,渠务署在防洪渠43号的河岸铺上混凝土草格,促进植物繁衍,为鸟类提供生境.但研究发现以混凝土草格建造的草坡并未能提供有效的纾缓措施,取代耕地生境以减少生态影响.

  13. National Built Environment Health Impact Assessment Model ...

    Science.gov (United States)

    Behavioral (activity, diet, social interaction) and exposure (air pollution, traffic injury, and noise) related health impacts of land use and transportation investment decisions are becoming better understood and quantified. Research has shown relationships between density, mix, street connectivity, access to parks, shops, transit, presence of sidewalks and bikeways, and healthy food with physical activity, obesity, cardiovascular disease, type II diabetes, and some mental health outcomes. This session demonstrates successful integration of health impact assessment into multiple scenario planning tool platforms. Detailed evidence on chronic disease and related costs associated with contrasting land use and transportation investments are built into a general-purpose module that can be accessed by multiple platforms. Funders, researchers, and end users of the tool will present a detailed description of the key elements of the approach, how it has been applied, and how will evolve. A critical focus will be placed on equity and social justice inherent within the assessment of health disparities that will be featured in the session. Health impacts of community design have significant cost benefit implications. Recent research is now extending relationships between community design features and chronic disease to health care costs. This session will demonstrate the recent application of this evidence on health impacts to the newly adopted Los Angeles Regional Transpo

  14. Chinese and Foreign Bird Lovers Watch Birds in Deyang

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>Invited by the Sichuan Provincial People’s Association for Friendship with Foreign Countries (SIFA) and the Chengdu Bird Watching Society, 60 Chinese and foreign bird lovers went to Deyang, a city in Sichuan Province that had suffered grave damages in the Wenchuan earthquake, to watch birds,

  15. Mass and performance optimization of an airplane wing leading edge structure against bird strike using Taguchi-based grey relational analysis

    Institute of Scientific and Technical Information of China (English)

    Hassan Pahange; Mohammad Hossein Abolbashari

    2016-01-01

    Collisions between birds and aircraft are one of the most dangerous threats to flight safety. In this study, smoothed particles hydrodynamics (SPH) method is used for simulating the bird strike to an airplane wing leading edge structure. In order to verify the model, first, experiment of bird strike to a flat aluminum plate is simulated, and then bird impact on an airplane wing lead-ing edge structure is investigated. After that, considering dimensions of wing internal structural components like ribs, skin and spar as design variables, we try to minimize structural mass and wing skin deformation simultaneously. To do this, bird strike simulations to 18 different wing structures are made based on Taguchi’s L18 factorial design of experiment. Then grey relational analysis is used to minimize structural mass and wing skin deformation due to the bird strike. The analysis of variance (ANOVA) is also applied and it is concluded that the most significant parameter for the performance of wing structure against impact is the skin thickness. Finally, a validation simu-lation is conducted under the optimal condition to show the improvement of performance of the wing structure.

  16. Mass and performance optimization of an airplane wing leading edge structure against bird strike using Taguchi-based grey relational analysis

    Directory of Open Access Journals (Sweden)

    Hassan Pahange

    2016-08-01

    Full Text Available Collisions between birds and aircraft are one of the most dangerous threats to flight safety. In this study, smoothed particles hydrodynamics (SPH method is used for simulating the bird strike to an airplane wing leading edge structure. In order to verify the model, first, experiment of bird strike to a flat aluminum plate is simulated, and then bird impact on an airplane wing leading edge structure is investigated. After that, considering dimensions of wing internal structural components like ribs, skin and spar as design variables, we try to minimize structural mass and wing skin deformation simultaneously. To do this, bird strike simulations to 18 different wing structures are made based on Taguchi’s L18 factorial design of experiment. Then grey relational analysis is used to minimize structural mass and wing skin deformation due to the bird strike. The analysis of variance (ANOVA is also applied and it is concluded that the most significant parameter for the performance of wing structure against impact is the skin thickness. Finally, a validation simulation is conducted under the optimal condition to show the improvement of performance of the wing structure.

  17. Impact Flash Physics: Modeling and Comparisons With Experimental Results

    Science.gov (United States)

    Rainey, E.; Stickle, A. M.; Ernst, C. M.; Schultz, P. H.; Mehta, N. L.; Brown, R. C.; Swaminathan, P. K.; Michaelis, C. H.; Erlandson, R. E.

    2015-12-01

    Hypervelocity impacts frequently generate an observable "flash" of light with two components: a short-duration spike due to emissions from vaporized material, and a long-duration peak due to thermal emissions from expanding hot debris. The intensity and duration of these peaks depend on the impact velocity, angle, and the target and projectile mass and composition. Thus remote sensing measurements of planetary impact flashes have the potential to constrain the properties of impacting meteors and improve our understanding of impact flux and cratering processes. Interpreting impact flash measurements requires a thorough understanding of how flash characteristics correlate with impact conditions. Because planetary-scale impacts cannot be replicated in the laboratory, numerical simulations are needed to provide this insight for the solar system. Computational hydrocodes can produce detailed simulations of the impact process, but they lack the radiation physics required to model the optical flash. The Johns Hopkins University Applied Physics Laboratory (APL) developed a model to calculate the optical signature from the hot debris cloud produced by an impact. While the phenomenology of the optical signature is understood, the details required to accurately model it are complicated by uncertainties in material and optical properties and the simplifications required to numerically model radiation from large-scale impacts. Comparisons with laboratory impact experiments allow us to validate our approach and to draw insight regarding processes that occur at all scales in impact events, such as melt generation. We used Sandia National Lab's CTH shock physics hydrocode along with the optical signature model developed at APL to compare with a series of laboratory experiments conducted at the NASA Ames Vertical Gun Range. The experiments used Pyrex projectiles to impact pumice powder targets with velocities ranging from 1 to 6 km/s at angles of 30 and 90 degrees with respect to

  18. Local equilibrium in bird flocks

    Science.gov (United States)

    Mora, Thierry; Walczak, Aleksandra M.; Del Castello, Lorenzo; Ginelli, Francesco; Melillo, Stefania; Parisi, Leonardo; Viale, Massimiliano; Cavagna, Andrea; Giardina, Irene

    2016-12-01

    The correlated motion of flocks is an example of global order emerging from local interactions. An essential difference with respect to analogous ferromagnetic systems is that flocks are active: animals move relative to each other, dynamically rearranging their interaction network. This non-equilibrium characteristic has been studied theoretically, but its impact on actual animal groups remains to be fully explored experimentally. Here, we introduce a novel dynamical inference technique, based on the principle of maximum entropy, which accommodates network rearrangements and overcomes the problem of slow experimental sampling rates. We use this method to infer the strength and range of alignment forces from data of starling flocks. We find that local bird alignment occurs on a much faster timescale than neighbour rearrangement. Accordingly, equilibrium inference, which assumes a fixed interaction network, gives results consistent with dynamical inference. We conclude that bird orientations are in a state of local quasi-equilibrium over the interaction length scale, providing firm ground for the applicability of statistical physics in certain active systems.

  19. Thyroid hormone deiodination in birds.

    Science.gov (United States)

    Darras, Veerle M; Verhoelst, Carla H J; Reyns, Geert E; Kühn, Eduard R; Van der Geyten, Serge

    2006-01-01

    Because the avian thyroid gland secretes almost exclusively thyroxine (T4), the availability of receptor-active 3,3',5-triiodothyronine (T3) has to be regulated in the extrathyroidal tissues, essentially by deiodination. Like mammals and most other vertebrates, birds possess three types of iodothyronine deiodinases (D1, D2, and D3) that closely resemble their mammalian counterparts, as shown by biochemical characterization studies in several avian species and by cDNA cloning of the three enzymes in chicken. The tissue distribution of these deiodinases has been studied in detail in chicken at the level of activity and mRNA expression. More recently specific antibodies were used to study cellular localization at the protein level. The abundance and distribution of the different deiodinases shows substantial variation during embryonic development and postnatal life. Deiodination in birds is subject to regulation by hormones from several endocrine axes, including thyroid hormones, growth hormone and glucocorticoids. In addition, deiodination is also influenced by external parameters, such as nutrition, temperature, light and also a number of environmental pollutants. The balance between the outer and inner ring deiodination resulting from the impact of all these factors ultimately controls T3 availability.

  20. Modeling and Evaluating Emotions Impact on Cognition

    Science.gov (United States)

    2013-07-01

    International Conference on Automatic Face and Gesture Recognition . Shanghai, China, April 2013 • Wenji Mao and Jonathan Gratch. Modeling Social...Modeling, Lorentz Center, Leiden. August 2011 • Keynote speaker, IEEE International Conference on Automatic Face and Gesture Recognition , Santa

  1. Food preferences of winter bird communities in different forest types.

    Directory of Open Access Journals (Sweden)

    Swen C Renner

    Full Text Available Food availability for forest birds is a function of habitat type, forest management regime, and season. In winter, it is also impacted by variations in the weather. In the current study we assessed the food preferences of wild bird populations in two types of forest (spruce and beech during the months of November 2010 to April 2011 in the Schwäbische Alb Biodiversity Exploratory, south-western Germany. Our aim was to investigate whether local bird communities preferred fat-rich, carbohydrate-rich or wild fruits and to determine how forest structure, seasonality and local weather conditions affected food preferences. We found higher bird activity in beech forests for the eleven resident species. We observed a clear preference for fat-rich food for all birds in both forest types. Snow cover affected activity at food stations but did not affect food preferences. Periods of extreme low temperatures increased activity.

  2. Modelling land use change and environmental impact

    NARCIS (Netherlands)

    Veldkamp, A.; Verburg, P.H.

    2004-01-01

    Land use change models are tools for understanding and explaining the causes and consequences of land use dynamics. Recently, new models, combining knowledge and tools from biophysical and socio-economic sciences, have become available. This has resulted in spatially explicit models focussed on patt

  3. Temporal Beta Diversity of Bird Assemblages in Agricultural Landscapes: Land Cover Change vs. Stochastic Processes.

    Science.gov (United States)

    Baselga, Andrés; Bonthoux, Sébastien; Balent, Gérard

    2015-01-01

    Temporal variation in the composition of species assemblages could be the result of deterministic processes driven by environmental change and/or stochastic processes of colonization and local extinction. Here, we analyzed the relative roles of deterministic and stochastic processes on bird assemblages in an agricultural landscape of southwestern France. We first assessed the impact of land cover change that occurred between 1982 and 2007 on (i) the species composition (presence/absence) of bird assemblages and (ii) the spatial pattern of taxonomic beta diversity. We also compared the observed temporal change of bird assemblages with a null model accounting for the effect of stochastic dynamics on temporal beta diversity. Temporal assemblage dissimilarity was partitioned into two separate components, accounting for the replacement of species (i.e. turnover) and for the nested species losses (or gains) from one time to the other (i.e. nestedness-resultant dissimilarity), respectively. Neither the turnover nor the nestedness-resultant components of temporal variation were accurately explained by any of the measured variables accounting for land cover change (r(2)turnover and 13% of sites for nestedness-resultant dissimilarity. Taken together, our results suggest that land cover change in this agricultural landscape had little impact on temporal beta diversity of bird assemblages. Although other unmeasured deterministic process could be driving the observed patterns, it is also possible that the observed changes in presence/absence species composition of local bird assemblages might be the consequence of stochastic processes in which species populations appeared and disappeared from specific localities in a random-like way. Our results might be case-specific, but if stochastic dynamics are generally dominant, the ability of correlative and mechanistic models to predict land cover change effects on species composition would be compromised.

  4. Equivalent Kelvin Impact Model for Seismic Pounding Analysis of Bridges

    Institute of Scientific and Technical Information of China (English)

    DING Yang; YUE Fuqing; LI Zhongxian

    2006-01-01

    Based on Hertz contact theory,a method to determine the parameters of Kelvin impact model for seismic pounding analysis of bridges is proposed.The impact stiffness of Kelvin model is determined by the ratio of maximum impact force to maximum contact deformation,which is calculated based on Hertz contact theory with considering the vibration effect.The restitution coefficient which has great influence on the damping coefficient of Kelvin impact model is investigated by numerical analysis.Numerical results indicate that the impact stiffness of Kelvin impact model increases with the increment of the Hertz contact stiffness,approaching velocity or the length ratio of short to long girders.Vibration effect has remarkable influence on the impact stiffness and cannot be neglected.The restitution coefficient decreases when approaching velocity increases or the length ratio of short girder to long girder decreasing.The practical ranges of impact stiffness and restitution coefficient are obtained as 3 × 108-6 × 108 N/m and 0.6-0.95 respectively.

  5. Projected Statewide Impact of "Opportunity Culture" School Models

    Science.gov (United States)

    Holly, Christen; Dean, Stephanie; Hassel, Emily Ayscue; Hassel, Bryan C.

    2014-01-01

    This brief estimates the impact of a statewide implementation of Opportunity Culture models, using North Carolina as an example. Impacts estimated include student learning outcomes, gross state product, teacher pay, and other career characteristics, and state income tax revenue. Estimates indicate the potential for a statewide transition to…

  6. Bird pollination of Canary Island endemic plants

    Science.gov (United States)

    Ollerton, Jeff; Cranmer, Louise; Stelzer, Ralph J.; Sullivan, Steve; Chittka, Lars

    2009-02-01

    The Canary Islands are home to a guild of endemic, threatened bird-pollinated plants. Previous work has suggested that these plants evolved floral traits as adaptations to pollination by flower specialist sunbirds, but subsequently, they appear to have co-opted generalist passerine birds as sub-optimal pollinators. To test this idea, we carried out a quantitative study of the pollination biology of three of the bird-pollinated plants, Canarina canariensis (Campanulaceae), Isoplexis canariensis (Veronicaceae) and Lotus berthelotii (Fabaceae), on the island of Tenerife. Using colour vision models, we predicted the detectability of flowers to bird and bee pollinators. We measured pollinator visitation rates, nectar standing crops as well as seed-set and pollen removal and deposition. These data showed that the plants are effectively pollinated by non-flower specialist passerine birds that only occasionally visit flowers. The large nectar standing crops and extended flower longevities (>10 days) of Canarina and Isoplexis suggests that they have evolved a bird pollination system that effectively exploits these low frequency non-specialist pollen vectors and is in no way sub-optimal. Seed set in two of the three species was high and was significantly reduced or zero in flowers where pollinator access was restricted. In L. berthelotii, however, no fruit set was observed, probably because the plants were self-incompatible horticultural clones of a single genet. We also show that, while all three species are easily detectable for birds, the orange Canarina and the red Lotus (but less so the yellow-orange Isoplexis) should be difficult to detect for insect pollinators without specialised red receptors, such as bumblebees. Contrary to expectations if we accept that the flowers are primarily adapted to sunbird pollination, the chiffchaff ( Phylloscopus canariensis) was an effective pollinator of these species.

  7. [Anesthesia in birds].

    Science.gov (United States)

    Grimm, F

    1987-01-01

    Anaesthesia in birds is ordered by law and is also necessary for various operations and manipulations. Anaesthesia by injection of Ketamin, which in special cases may be combined with Diazepam, has been found useful. Anaesthesia by inhalation with Halothan, Methoxyfluran or Isofluran is the most careful method. Local anaesthesia has few indications.

  8. Synanthropic birds and parasites.

    Science.gov (United States)

    Dipineto, Ludovico; Borrelli, Luca; Pepe, Paola; Fioretti, Alessandro; Caputo, Vincenzo; Cringoli, Giuseppe; Rinaldi, Laura

    2013-12-01

    This paper describes the parasitologic findings for 60 synanthropic bird carcasses recovered in the Campania region of southern Italy. Birds consisted of 20 yellow-legged gulls (Larus michahellis), 15 rock pigeons (Columba livia), 15 common kestrels (Falco tinnunculus), and 10 carrion crows (Corvus corone). Each carcass was examined to detect the presence of ectoparasites and then necropsied to detect helminths. Ectoparasites occurred in 100% of the birds examined. In particular, chewing lice were recovered with a prevalence of 100%, whereas Pseudolynchia canariensis (Hippoboscidae) were found only in pigeons with a prevalence of 80%. Regarding endoparasites, a total of seven helminth species were identified: three nematodes (Ascaridia columbae, Capillaria columbae, Physaloptera alata), one cestoda (Raillietina tetragona), one trematoda (Cardiocephalus longicollis), and two acanthocephalans (Centrorhynchus globocaudatus and Centrorhynchus buteonis). The findings of the present study add data to the parasitologic scenario of synanthropic birds. This is important because parasitic infection can lead to serious health problems when combined with other factors and may affect flying performance and predatory effectiveness.

  9. The Umbrella Bird

    NARCIS (Netherlands)

    Crandall, Lee S.

    1949-01-01

    When CHARLES CORDIER arrived from Costa Rica on October 9, 1942, bringing with him, among other great rarities, three Bare-necked Umbrella Birds (Cephalopterus ornatus glabricollis), it seemed to us that the mere possession of such fabulous creatures was satisfaction enough. True, they were not

  10. Attracting Birds to Your Backyard.

    Science.gov (United States)

    Joyce, Brian

    1994-01-01

    Discusses methods for drawing birds to outdoor education areas, including the use of wild and native vegetation. Lists specific garden plants suitable for attracting birds in each season. Includes a guide to commercial bird seed and instructions for building homemade birdfeeders and nestboxes. (LZ)

  11. Birds of Prey of Wisconsin.

    Science.gov (United States)

    Hamerstrom, Frances

    This copiously illustrated document is designed to be a field quide to birds of prey that are common to Wisconsin, as well as to some that enter the state occasionally. An introduction discusses birds of prey with regard to migration patterns, the relationship between common names and the attitudes of people toward certain birds, and natural signs…

  12. Impact analytical models for earthquake-induced pounding simulation

    Institute of Scientific and Technical Information of China (English)

    Kun YE; Li LI

    2009-01-01

    Structural pounding under earthquake has been recently extensively investigated using various impact analytical models. In this paper, a brief review on the commonly used impact analytical models is conducted.Based on this review, the formula used to determine the damping constant related to the impact spring stiffness,coefficient of restitution, and relative approaching velocity in the Hertz model with nonlinear damping is found to be incorrect. To correct this error, a more accurate approximating formula for the damping constant is theoretically derived 5~nd numerically verified. At the same time, a modified Kelvin impact model, which can reasonably account for the physical nature of pounding and conveniently implemented in the earthquake-induced pounding simulation of structural engineering is proposed.

  13. Measuring Phenological Changes due to Defoliation of the Non-Native Species, Saltcedar (Tamarisk) Following Episodic Foliage Removal by the Beetle Diorhabda elongate and Phenological Impacts on Forage Quality for Insectivorous Birds on the Dolores River

    Science.gov (United States)

    Nagler, P. L.; Dennison, P. E.; Hultine, K. R.; van Riper, C.; Glenn, E. P.

    2008-12-01

    Since its introduction to the western U.S. more than a century ago, tamarisk (Tamarix spp.) has become dominant or sub-dominant over many major arid, and semi-arid river systems and their tributaries. The presence of tamarisk has been cited for reducing water availability for human enterprise and biodiversity, displacing native vegetation and for reducing habitat quality for wildlife. With increasing emphasis by public and private sectors on controlling saltcedar (Tamarix chinensis) in the western US, there will likely be a dramatic change in riparian vegetation composition over the course of the next several decades. The rates at which these changes will occur, and the resultant effects on riparian insects and birds that utilize insects for food, are presently unknown. Effects on riparian vegetation communities, resulting from changes in host plant species composition, will likely include changes in plant biomass, microclimate changes, and plant species diversity. These changes could potentially have a profound impact on migratory and breeding birds within riparian corridors throughout the southwest. Recently, the saltcedar leaf beetle (Diorhabda elongata) was released as a tamarisk biocontrol agent. This beetle has successfully defoliated tamarisk where it has been introduced, but there are currently no comprehensive programs in place for monitoring the rapid spread of Diorhabda, the impact of defoliation on habitat and water resources, or the long-term impact of defoliation on tamarisk. We used higher spatial resolution ASTER data and coarser MODIS data for monitoring defoliation caused by Diorhabda elongata and subsequent changes in evapotranspiration (ET). Widespread tamarisk defoliation was observed in an eastern Utah study area during summers 2007, 2008. We measured stem sap flux, leaf carbon isotope ratios, leaf area, LAI, and vegetation indices from mounted visible and infrared cameras and satellite imagery. The cameras were paired on towers installed 30

  14. Seasonal bird use of canopy gaps in a bottomland forest.

    Energy Technology Data Exchange (ETDEWEB)

    Bowen, Liessa, T,; Moorman, Christopher, E.; Kilgo, John, C.

    2007-04-01

    ABSTRACT.—Bird use of small canopy gaps within mature forests has not been well studied, particularly across multiple seasons. We investigated seasonal differences in bird use of gap and forest habitat within a bottomland hardwood forest in the Upper Coastal Plain of South Carolina. Gaps were 0.13- to 0.5-ha, 7- to 8-year-old group-selection timber harvest openings. Our study occurred during four bird-use periods (spring migration, breeding, postbreeding, and fall migration) in 2001 and 2002. We used plot counts and mist netting to estimate bird abundance in canopy gaps and surrounding mature forest habitats. Using both survey methods, we observed more birds, including forest-interior species, forest-edge species, field-edge species, and several individual species in canopy gap and gap-edge habitats than in surrounding mature forest during all periods. Interactions between period and habitat type often were significant in models, suggesting a seasonal shift in habitat use. Bird activity generally shifted between the interior of canopy gaps and the immediate gap edge, but many species increased their use of forested habitat during the breeding period. This suggests that many species of birds selectively choose gap and gap-edge habitat over surrounding mature forest during the non-breeding period. Creation of small canopy gaps within a mature forest may increase local bird species richness. The reasons for increased bird activity in gaps remain unclear.

  15. Selection of climate change scenario data for impact modelling

    DEFF Research Database (Denmark)

    Sloth Madsen, M; Fox Maule, C; MacKellar, N

    2012-01-01

    Impact models investigating climate change effects on food safety often need detailed climate data. The aim of this study was to select climate change projection data for selected crop phenology and mycotoxin impact models. Using the ENSEMBLES database of climate model output, this study...... illustrates how the projected climate change signal of important variables as temperature, precipitation and relative humidity depends on the choice of the climate model. Using climate change projections from at least two different climate models is recommended to account for model uncertainty. To make...... the climate projections suitable for impact analysis at the local scale a weather generator approach was adopted. As the weather generator did not treat all the necessary variables, an ad-hoc statistical method was developed to synthesise realistic values of missing variables. The method is presented...

  16. Modeling the Environmental Impact of Air Traffic Operations

    Science.gov (United States)

    Chen, Neil

    2011-01-01

    There is increased interest to understand and mitigate the impacts of air traffic on the climate, since greenhouse gases, nitrogen oxides, and contrails generated by air traffic can have adverse impacts on the climate. The models described in this presentation are useful for quantifying these impacts and for studying alternative environmentally aware operational concepts. These models have been developed by leveraging and building upon existing simulation and optimization techniques developed for the design of efficient traffic flow management strategies. Specific enhancements to the existing simulation and optimization techniques include new models that simulate aircraft fuel flow, emissions and contrails. To ensure that these new models are beneficial to the larger climate research community, the outputs of these new models are compatible with existing global climate modeling tools like the FAA's Aviation Environmental Design Tool.

  17. Large meteorite impacts: The K/T model

    Science.gov (United States)

    Bohor, B. F.

    1992-01-01

    The Cretaceous/Tertiary (K/T) boundary event represents probably the largest meteorite impact known on Earth. It is the only impact event conclusively linked to a worldwide mass extinction, a reflection of its gigantic scale and global influence. Until recently, the impact crater was not definitively located and only the distal ejecta of this impact was available for study. However, detailed investigations of this ejecta's mineralogy, geochemistry, microstratigraphy, and textures have allowed its modes of ejection and dispersal to be modeled without benefit of a source crater of known size and location.

  18. Modeling Terrain Impact on Mobile Ad Hoc Networks (MANET) Connectivity

    Science.gov (United States)

    2014-05-01

    Modeling Terrain Impact on Mobile Ad Hoc Networks ( MANET ) Connectivity Lance Joneckis Corinne Kramer David Sparrow David Tate I N S T I T U T E F...SUBTITLE Modeling Terrain Impact on Mobile Ad Hoc Networks ( MANET ) Connectivity 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...1882 ljonecki@ida.org Abstract—Terrain affects connectivity in mobile ad hoc net- works ( MANET ). Both average pairwise link closure and the rate

  19. Mathematical human modelling for impact loading

    NARCIS (Netherlands)

    Happee, R.; Hoof, J.F.A.M. van; Lange, R. de

    2001-01-01

    Mathematical modeling of the human body is widely used for automotive crash-safety research and design. Simulations have contributed to a reduction of injury numbers by optimization of vehicle structures and restraint systems. Currently, such simulations are largely performed using occupant models b

  20. Mathematical human modelling for impact loading

    NARCIS (Netherlands)

    Happee, R.; Hoof, J.F.A.M. van; Lange, R. de

    2001-01-01

    Mathematical modeling of the human body is widely used for automotive crash-safety research and design. Simulations have contributed to a reduction of injury numbers by optimization of vehicle structures and restraint systems. Currently, such simulations are largely performed using occupant models

  1. Mathematical human body modelling for impact loading

    NARCIS (Netherlands)

    Happee, R.; Morsink, P.L.J.; Wismans, J.S.H.M.

    1999-01-01

    Mathematical modelling of the human body is widely used for automotive crash safety research and design. Simulations have contributed to a reduction of injury numbers by optimisation of vehicle structures and restraint systems. Currently such simulations are largely performed using occupant models

  2. Mathematical human body modelling for impact loading

    NARCIS (Netherlands)

    Happee, R.; Morsink, P.L.J.; Wismans, J.S.H.M.

    1999-01-01

    Mathematical modelling of the human body is widely used for automotive crash safety research and design. Simulations have contributed to a reduction of injury numbers by optimisation of vehicle structures and restraint systems. Currently such simulations are largely performed using occupant models b

  3. Translating Climate-Change Probabilities into Impact Risks - Overcoming the Impact- Model Bottleneck

    Science.gov (United States)

    Dettinger, M.

    2008-12-01

    Projections of climate change in response to increasing greenhouse-gas concentrations are uncertain and likely to remain so for the foreseeable future. As more projections become available for analysts, we are increasingly able to characterize the probabilities of obtaining various levels of climate change in current projections. However, the probabilities of most interest in impact assessments are not the probabilities of climate changes, but rather the probabilities (or risks) of various levels and kinds of climate-change impact. These risks can be difficult to estimate even if the climate-change probabilities are well known. The difficulty arises because, frequently, impact models and assessments are computationally demanding or time consuming of hands-on, human expert analyses, so that severe limits are placed on the numbers of climate- change scenarios from which detailed impacts can be assessed. Estimation of risks of various impacts is generally difficult with the few resulting examples. However, real-world examples from the water-resources sector will be used to show that, by applying several different "derived distributions" approaches for estimating the risks of various impacts from known climate-change probabilities to just a few impact-model simulations, risks can be estimated along with indications of how accurate are the impact-risk estimates. The prospects for a priori selection of a few climate-change scenarios (from a larger ensemble of available projections) that will allow the best, most economical estimates of impact risks will be explored with a simple but real-world example.

  4. Hydrological characteristics and flood plain vegetation of human impacted wetlands: A case study from Okhla Bird Sanctuary, National Capital Region, India

    Directory of Open Access Journals (Sweden)

    Upma Manral

    2012-12-01

    Full Text Available Yamuna River has been subjected to severe anthropogenic pressures such as water abstraction, discharge of wastewater, development activities on river floodplains, deforestation in the river basin resulting in reduced flow, loss of habitat, deterioration of water quality and loss of biological diversity. We studied hydrological characteristics such as river flow, water depth and quality and floodplain vegetation characteristics of Okhla Bird Sanctuary (OBS, a human modified floodplain wetland formed due to the construction of Okhla barrage across the Yamuna River in National Capital Region (NCR, on the Delhi-Uttar Pradesh border. The flow data for Yamuna was collected from Delhi Jal board and irrigation department of Uttar Pradesh. Study indicates reduced flow in the river downstream Wazirabad with no release of water in the summers of 2006 and 2010. For bathymetry, GARMIN 160 C Fish Finder was used after dividing study area into 50 m x 50 m grids. About 65% area had depth less than 2 m indicating more of shallower areas. Results for water quality analysis show a dissolved oxygen level at 1.6 ± 0.84 mgl-1, Biological and Chemical Oxygen demand at 16.72 ± 4.28 mgl-1 and 39.8 ± 7.71 mgl-1 respectively, indicating a high organic load in the river. The Sanctuary is facing serious threats from the rapid proliferation of Typha angustifolia and Eichhornia crassipes which were dominant species in shallow water and open water habitats, respectively. Thus, the remaining Yamuna river flood plain in the NCR, Delhi should be declared as ecologically sensitive area and appropriate measures should be taken to maintain its integrity.

  5. IMPACT MODEL RESOLUTION ON PAINLEV(E)'S PARADOX

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zhen; CHEN Bin; LIU Caishan; JIN Hai

    2004-01-01

    Painlevé's paradox is one of the basic difficulties for solving LCP of dynamic systems subjected to unilateral constraints. A bi-nonlinear parameterized impact model, consistent with dynamic principles and experimental results, is established on the localized and quasi-static impact model theory. Numerical simulations are carried out on the dynamic motion of Painleve's example. The results confirm "impact without collision" in the inconsistent states of the system. A "critical normal force" which brings an important effect on the future movement of the system in the indeterminate states is found. After the motion pattern for the impact process is obtained from numerical results,a rule of the velocity's jump that incorporates the tangential impact process is deduced by using an approximate impulse theory and the coefficient of restitution defined by Stronge. The results of the jump rule are quite precise if the system rigidity is big enough.

  6. Electron impact ionization of tungsten ions in a statistical model

    Science.gov (United States)

    Demura, A. V.; Kadomtsev, M. B.; Lisitsa, V. S.; Shurygin, V. A.

    2015-01-01

    The statistical model for calculations of the electron impact ionization cross sections of multielectron ions is developed for the first time. The model is based on the idea of collective excitations of atomic electrons with the local plasma frequency, while the Thomas-Fermi model is used for atomic electrons density distribution. The electron impact ionization cross sections and related ionization rates of tungsten ions from W+ up to W63+ are calculated and then compared with the vast collection of modern experimental and modeling results. The reasonable correspondence between experimental and theoretical data demonstrates the universal nature of statistical approach to the description of atomic processes in multielectron systems.

  7. Price manipulation in a market impact model with dark pool

    OpenAIRE

    Florian Kl\\"ock; Alexander Schied; Yuemeng Sun

    2012-01-01

    For a market impact model, price manipulation and related notions play a role that is similar to the role of arbitrage in a derivatives pricing model. Here, we give a systematic investigation into such regularity issues when orders can be executed both at a traditional exchange and in a dark pool. To this end, we focus on a class of dark-pool models whose market impact at the exchange is described by an Almgren--Chriss model. Conditions for the absence of price manipulation for all Almgren--C...

  8. Fuel dispersal modeling for aircraft-runway impact scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Tieszen, S.R.

    1995-11-01

    A fuel dispersal model for C-141 transport accidents was developed for the Defense Nuclear Agency`s Fuel Fire Technology Base Program to support Weapon System Safety Assessments. The spectrum of accidents resulting from aircraft impact on a runway was divided into three fuel dispersal regimes: low, intermediate, and high-velocity impact. Sufficient data existed in the accident, crash test, and fuel-filled bomb literature to support development of a qualitative framework for dispersal models, but not quantitative models for all regimes. Therefore, a test series at intermediate scale was conducted to generate data on which to base the model for the high-velocity regime. Tests were conducted over an impact velocity range from 12 m/s to 91 m/s and angles of impact from 22.5{degrees} to 67.5{degrees}. Dependent variables were area covered by dispersed fuel, amount of mass in that area, and location of the area relative to the impact line. Test results showed that no liquid pooling occurred for impact velocities greater than 61 m/s, independent of the angle of impact. Some pooling did occur at lower velocities, but in no test was the liquid-layer thickness greater than 5.25 mm.

  9. Towards understanding of birds magnetoreceptor mechanism

    CERN Document Server

    Solovyov, Ilia A

    2007-01-01

    In the present letter we suggest a new theoretical model for a quantitative description of the magnetoreception mechanism in birds. The considered mechanism involves two types of iron minerals (magnetite and maghemite) which were found in subcellular compartments within sensory dendrites of the upper beak of several bird species. The analysis of forces acting between the iron particles shows that the orientation of the external geomagnetic field can significantly change the probability of the mechanosensitive ion channels opening and closing. The performed theoretical analysis shows that the suggested magnetoreceptor system might be a sensitive biological magnetometer providing an essential part of the magnetic map for navigation.

  10. Quantifying the impact of model inaccuracy in climate change impact assessment studies using an agro-hydrological model

    Directory of Open Access Journals (Sweden)

    P. Droogers

    2008-04-01

    Full Text Available Numerical simulation models are frequently applied to assess the impact of climate change on hydrology and agriculture. A common hypothesis is that unavoidable model errors are reflected in the reference situation as well as in the climate change situation so that by comparing reference to scenario model errors will level out. For a polder in The Netherlands an innovative procedure has been introduced, referred to as the Model-Scenario-Ratio (MSR, to express model inaccuracy on climate change impact assessment studies based on simulation models comparing a reference situation to a climate change situation. The SWAP (Soil Water Atmosphere Plant model was used for the case study and the reference situation was compared to two climate change scenarios. MSR values close to 1, indicating that impact assessment is mainly a function of the scenario itself rather than of the quality of the model, were found for most indicators evaluated. A climate change scenario with enhanced drought conditions and indicators based on threshold values showed lower MSR values, indicating that model accuracy is an important component of the climate change impact assessment. It was concluded that the MSR approach can be applied easily and will lead to more robust impact assessment analyses.

  11. Modeling Forest Structural Parameters in the Mediterranean Pines of Central Spain using QuickBird-2 Imagery and Classification and Regression Tree Analysis (CART

    Directory of Open Access Journals (Sweden)

    José A. Delgado

    2012-01-01

    Full Text Available Forest structural parameters such as quadratic mean diameter, basal area, and number of trees per unit area are important for the assessment of wood volume and biomass and represent key forest inventory attributes. Forest inventory information is required to support sustainable management, carbon accounting, and policy development activities. Digital image processing of remotely sensed imagery is increasingly utilized to assist traditional, more manual, methods in the estimation of forest structural attributes over extensive areas, also enabling evaluation of change over time. Empirical attribute estimation with remotely sensed data is frequently employed, yet with known limitations, especially over complex environments such as Mediterranean forests. In this study, the capacity of high spatial resolution (HSR imagery and related techniques to model structural parameters at the stand level (n = 490 in Mediterranean pines in Central Spain is tested using data from the commercial satellite QuickBird-2. Spectral and spatial information derived from multispectral and panchromatic imagery (2.4 m and 0.68 m sided pixels, respectively served to model structural parameters. Classification and Regression Tree Analysis (CART was selected for the modeling of attributes. Accurate models were produced of quadratic mean diameter (QMD (R2 = 0.8; RMSE = 0.13 m with an average error of 17% while basal area (BA models produced an average error of 22% (RMSE = 5.79 m2/ha. When the measured number of trees per unit area (N was categorized, as per frequent forest management practices, CART models correctly classified 70% of the stands, with all other stands classified in an adjacent class. The accuracy of the attributes estimated here is expected to be better when canopy cover is more open and attribute values are at the lower end of the range present, as related in the pattern of the residuals found in this study. Our findings indicate that attributes derived from

  12. Ratios among atmospheric trace gases together with winds imply exploitable information for bird navigation: a model elucidating experimental results

    Science.gov (United States)

    Wallraff, H. G.

    2013-11-01

    A model of avian goal-oriented navigation is described that is based on two empirical findings building a bridge from ornithology to atmospheric chemistry. (1) To orient their courses homeward from distant unfamiliar areas, homing pigeons require long-term exposure to undisturbed winds at the home site and olfactory access to the environmental air at home and abroad. (2) Above Germany, ratios among some atmospheric trace gases vary along differently oriented spatial gradients as well as depending on wind direction. The model emulates finding (1) by utilising the analysed air samples on which finding (2) is based. Starting with an available set of 46 omnipresent compounds, virtual pigeons determine the profile of relative weights among them at each of 96 sites regularly distributed around a central home site within a radius of 200 km and compare this profile with corresponding profiles determined at home under varying wind conditions. Referring to particular similarities and dissimilarities depending on home-wind direction, they try to estimate, at each site, the compass direction they should fly in order to approach home. To make the model work, an iterative algorithm imitates evolution by modifying sensitivity to the individual compounds stepwise at random. In the course of thousands of trial-and-error steps it gradually improves homeward orientation by selecting smaller sets of most useful and optimally weighted substances from whose proportional configurations at home and abroad it finally derives navigational performances similar to those accomplished by real pigeons. It is concluded that the dynamic chemical atmosphere most likely contains sufficient spatial information for home-finding over hundreds of kilometres of unfamiliar terrain. The underlying chemo-atmospheric processes remain to be clarified.

  13. An overview of bird related issues in electrical power systems

    Science.gov (United States)

    Polat, Ö.; Yumak, K.; Atilla, N. E.; Bağriyanik, M.

    2016-11-01

    Power system equipments, especially overhead lines and utility poles are posing great risk to avian species. Main purpose of this paper is to draw attention of distribution companies and community on conserving bird species and their habitats. The paper also provides regulatory framework about protecting bird species, impacts of birds on utility equipments and remedial actions that can be taken for problem specific cases. Furthermore, a sector review of industrial applications and effectiveness of mitigation measures are given. Distribution companies may apply a systematic approach for reducing electrocutions and collisions by developing and implementing Avian Protection Plans (APPs).

  14. Modelling Options for Policy Impact Analysis on African Dairy Farms

    Directory of Open Access Journals (Sweden)

    Oghaiki Asaah NDAMBI

    2008-01-01

    Full Text Available Studies on the priorities for agricultural research in Eastern and CentralAfrica concluded that milk is the most important commodity for research anddevelopment in the region, based on its potential contribution to the agriculturalGDP. It has been presumed that, the right policies, marketing systems and technicalsupport must be sought for dairy development in Africa. In order to determine theright development pattern, appropriate analytical tools must be applied. The TIPICAL(Technology Impact Policy Impact model was used to analyse the impact ofdifferent policies on two typical dairy farming systems in Uganda, which accountfor more than 70% of milk produced in the country. Seven influential policy areaswere also identified: provision of veterinary services, consumption promotion,marketing promotion, input provision, credit access improvement, milk qualityimprovement and genetic improvement. In general, the policy impacts are very littleon farms with local cows but can be magnified up to threefold, if the farms havegraded cows. Policies which improve farmers’ accessibility to markets have thegreatest impacts. The results obtained from this model were compared to thoseusing the EXTRAPOLATE model. This comparison shows that both models couldcomplement each other in analysing policy impacts on African dairy farms.However, differences in results from the models indicate that more focus should bemade on farmers’ willingness to adopt new technology.

  15. Blood protozoa of free-living birds

    Science.gov (United States)

    Herman, C.M.; McDiarmid, Archibald

    1969-01-01

    Blood protozoa were first reported from wild birds in 1884. Since then numerous surveys throughout the world have demonstrated their presence in a wide variety of hosts and localities with continuing designations of new species. Taxonomic determinations include parasites in the genera Plasmodium, Haemoproteus, Leucocytozoon, Babesia, Lankesterella and Trypanosoma. Transmission of Plasmodium by mosquitoes was demonstrated with a bird parasite before these insects were proven as vectors of human malaria. All the genera under consideration require an insect vector to complete their life-cycles and susceptible vectors have been demonstrated. Most experimental work on the blood protozoa of birds has been carried on with captive birds. An extensive volume of research has been conducted on Plasmodium because of its close similarity to malaria in man. Field studies that would provide information on the epizootiology of occurrence of these parasites in wild populations have been very limited, mainly confined to single blood film surveys. Such data are inadequate to provide an understanding of true prevalence or incidence or of factual knowledge of their impact on the wild population. Mechanisms for procuring such information are available in some cases and can be developed to fit other situations. Isodiagnosis, inoculation of blood from wild birds into susceptible captive hosts, has revealed a prevalence of over 60 % for Plasmodium in situations where microscope examination of single peripheral blood preparations yielded less than 1 %. Culture of bone marrow collected by biopsy demonstrates high prevalence of trypanosomes even when none are evident from microscopic examination of blood. Often preparations of tissues collected at necropsy reveal Leucocytozoon and Lankesterella when examination of peripheral blood gave no indication of infection. Methods developed by bird ringers provide techniques for obtaining repeat examinations of free-living birds that can yield further

  16. Cuckoo forgeries - a bird's-eye view

    Science.gov (United States)

    Kalaugher, Liz

    2017-01-01

    It's hard to get inside another human's head - let alone a member of a different species - but that's where physics and computer models help. Liz Kalaugher reports how researchers are visualizing what birds see in order to help work out why they don't reject intruder cuckoo eggs

  17. Effects of seismic lines on the abundance of breeding birds in the Kendall Island Bird Sanctuary, Northwest Territories, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Ashenhurst, A.R.; Hannon, S.J. [Alberta Univ., Edmonton, AB (Canada). Dept. of Biological Sciences

    2008-06-15

    The effects of oil and gas exploration activities on bird abundance in the Arctic were investigated. The study examined the impacts of new and oil visible seismic lines within the Kendall Island Bird Sanctuary on the abundance of breeding passerines, Lapland longspur, common redpoll, American tree sparrow, and red-necked phalarope in upland tundra region and sedge-willow habitats. Results of the study showed that the effects on abundance with newer seismic lines were not statistically significant for most groups of birds. However, more birds were seen on reference transects than on seismic lines. The seismic lines had a significant impact on passerines grouped in upland tundra, as well as for sparrows in sedge and willows. Along older seismic lines, passerine abundance was lower than on reference transects in upland tundra. The study demonstrated that seismic lines created between 10 and 30 years ago had persistent vegetative changes that have reduced bird abundance. It was concluded that although the birds were not avoiding lines, some birds appeared to have increased the size of their territories in order to compensate for vegetative changes. 34 refs., 4 tabs.

  18. Computational modelling of the impact of AIDS on business.

    Science.gov (United States)

    Matthews, Alan P

    2007-07-01

    An overview of computational modelling of the impact of AIDS on business in South Africa, with a detailed description of the AIDS Projection Model (APM) for companies, developed by the author, and suggestions for further work. Computational modelling of the impact of AIDS on business in South Africa requires modelling of the epidemic as a whole, and of its impact on a company. This paper gives an overview of epidemiological modelling, with an introduction to the Actuarial Society of South Africa (ASSA) model, the most widely used such model for South Africa. The APM produces projections of HIV prevalence, new infections, and AIDS mortality on a company, based on the anonymous HIV testing of company employees, and projections from the ASSA model. A smoothed statistical model of the prevalence test data is computed, and then the ASSA model projection for each category of employees is adjusted so that it matches the measured prevalence in the year of testing. FURTHER WORK: Further techniques that could be developed are microsimulation (representing individuals in the computer), scenario planning for testing strategies, and models for the business environment, such as models of entire sectors, and mapping of HIV prevalence in time and space, based on workplace and community data.

  19. Research on an Infectious Disease Transmission by Flocking Birds

    Directory of Open Access Journals (Sweden)

    Mingsheng Tang

    2013-01-01

    Full Text Available The swarm intelligence is becoming a hot topic. The flocking of birds is a natural phenomenon, which is formed and organized without central or external controls for some benefits (e.g., reduction of energy consummation. However, the flocking also has some negative effects on the human, as the infectious disease H7N9 will easily be transmited from the denser flocking birds to the human. Zombie-city model has been proposed to help analyzing and modeling the flocking birds and the artificial society. This paper focuses on the H7N9 virus transmission in the flocking birds and from the flocking birds to the human. And some interesting results have been shown: (1 only some simple rules could result in an emergence such as the flocking; (2 the minimum distance between birds could affect H7N9 virus transmission in the flocking birds and even affect the virus transmissions from the flocking birds to the human.

  20. Climate impact of transportation A model comparison

    NARCIS (Netherlands)

    Girod, B.; Vuuren, D.P. van; Grahn, M.; Kitous, A.; Kim, S.H.; Kyle, P.

    2013-01-01

    Transportation contributes to a significant and rising share of global energy use and GHG emissions. Therefore modeling future travel demand, its fuel use, and resulting CO2 emission is highly relevant for climate change mitigation. In this study we compare the baseline projections for global

  1. Climate impact of transportation A model comparison

    NARCIS (Netherlands)

    Girod, B.; Vuuren, D.P. van; Grahn, M.; Kitous, A.; Kim, S.H.; Kyle, P.

    2013-01-01

    Transportation contributes to a significant and rising share of global energy use and GHG emissions. Therefore modeling future travel demand, its fuel use, and resulting CO2 emission is highly relevant for climate change mitigation. In this study we compare the baseline projections for global servic

  2. Zoonoses in pet birds: review and perspectives.

    Science.gov (United States)

    Boseret, Geraldine; Losson, Bertrand; Mainil, Jacques G; Thiry, Etienne; Saegerman, Claude

    2013-05-20

    Pet birds are a not-so-well known veterinarian's clientship fraction. Bought individually or in couples, as families often do (which is a lucrative business for pet shops or local breeders) or traded (sometimes illegally) for their very high genetic or exotic value, these birds, commonly canaries, parakeets or parrots, are regularly sold at high prices. These animals, however, are potential carriers and/or transmitters of zoonotic diseases. Some of them could have an important impact on human health, like chlamydophilosis, salmonellosis or even highly pathogenic avian influenza A H5N1. This review paper, although non exhaustive, aims at enlightening, by the description of several cases of bird-human transmission, the risks encountered by bird owners, including children. Public health consequences will be discussed and emphasis will be made on some vector-borne diseases, known to be emergent or which are underestimated, like those transmitted by the red mite Dermanyssus gallinae. Finally, biosecurity and hygiene, as well as prevention guidelines will be developed and perspectives proposed.

  3. Zoonoses in pet birds: review and perspectives

    Science.gov (United States)

    2013-01-01

    Pet birds are a not-so-well known veterinarian’s clientship fraction. Bought individually or in couples, as families often do (which is a lucrative business for pet shops or local breeders) or traded (sometimes illegally) for their very high genetic or exotic value, these birds, commonly canaries, parakeets or parrots, are regularly sold at high prices. These animals, however, are potential carriers and/or transmitters of zoonotic diseases. Some of them could have an important impact on human health, like chlamydophilosis, salmonellosis or even highly pathogenic avian influenza A H5N1. This review paper, although non exhaustive, aims at enlightening, by the description of several cases of bird-human transmission, the risks encountered by bird owners, including children. Public health consequences will be discussed and emphasis will be made on some vector-borne diseases, known to be emergent or which are underestimated, like those transmitted by the red mite Dermanyssus gallinae. Finally, biosecurity and hygiene, as well as prevention guidelines will be developed and perspectives proposed. PMID:23687940

  4. Session: What do we know about cumulative or population impacts

    Energy Technology Data Exchange (ETDEWEB)

    Kerlinger, Paul; Manville, Al; Kendall, Bill

    2004-09-01

    This session at the Wind Energy and Birds/Bats workshop consisted of a panel discussion followed by a discussion/question and answer period. The panelists were Paul Kerlinger, Curry and Kerlinger, LLC, Al Manville, U.S. Fish and Wildlife Service, and Bill Kendall, US Geological Service. The panel addressed the potential cumulative impacts of wind turbines on bird and bat populations over time. Panel members gave brief presentations that touched on what is currently known, what laws apply, and the usefulness of population modeling. Topics addressed included which sources of modeling should be included in cumulative impacts, comparison of impacts from different modes of energy generation, as well as what research is still needed regarding cumulative impacts of wind energy development on bird and bat populations.

  5. Predicting Market Impact Costs Using Nonparametric Machine Learning Models.

    Directory of Open Access Journals (Sweden)

    Saerom Park

    Full Text Available Market impact cost is the most significant portion of implicit transaction costs that can reduce the overall transaction cost, although it cannot be measured directly. In this paper, we employed the state-of-the-art nonparametric machine learning models: neural networks, Bayesian neural network, Gaussian process, and support vector regression, to predict market impact cost accurately and to provide the predictive model that is versatile in the number of variables. We collected a large amount of real single transaction data of US stock market from Bloomberg Terminal and generated three independent input variables. As a result, most nonparametric machine learning models outperformed a-state-of-the-art benchmark parametric model such as I-star model in four error measures. Although these models encounter certain difficulties in separating the permanent and temporary cost directly, nonparametric machine learning models can be good alternatives in reducing transaction costs by considerably improving in prediction performance.

  6. Predicting Market Impact Costs Using Nonparametric Machine Learning Models.

    Science.gov (United States)

    Park, Saerom; Lee, Jaewook; Son, Youngdoo

    2016-01-01

    Market impact cost is the most significant portion of implicit transaction costs that can reduce the overall transaction cost, although it cannot be measured directly. In this paper, we employed the state-of-the-art nonparametric machine learning models: neural networks, Bayesian neural network, Gaussian process, and support vector regression, to predict market impact cost accurately and to provide the predictive model that is versatile in the number of variables. We collected a large amount of real single transaction data of US stock market from Bloomberg Terminal and generated three independent input variables. As a result, most nonparametric machine learning models outperformed a-state-of-the-art benchmark parametric model such as I-star model in four error measures. Although these models encounter certain difficulties in separating the permanent and temporary cost directly, nonparametric machine learning models can be good alternatives in reducing transaction costs by considerably improving in prediction performance.

  7. Phenological and geographical shifts have interactive effects on migratory bird populations.

    Science.gov (United States)

    James, Aubrie R M; Abbott, Karen C

    2014-01-01

    For many taxa, ranges are shifting toward the poles and the timing of seasonal reproduction is advancing in response to climate change. For migratory birds, changes such as these could produce particularly strong impacts because of their potential to affect migratory timing and distance. Due to the relatively complex life histories of migratory species, however, it is difficult to intuit exactly what these impacts will be. Here, we develop a general population model for a long-distance migrant, introducing a framework for understanding the potential implications of changes in both phenology and migratory distance for bird abundances. We find that population sizes may increase with either shorter or longer migratory distances, depending on the nature of any concurrent phenological changes. This interaction between timing and distance suggests a need to consider multiple potential responses to climate change simultaneously in order to understand the overall impact of climate change on migratory populations. Our results reveal a degree of variability in the qualitative nature of this phenology-distance interaction, suggesting a possible explanation for observed variation in how migratory birds have already responded to climate change.

  8. Large-scale range collapse of Hawaiian forest birds under climate change and the need 21st century conservation options

    Science.gov (United States)

    Fortini, Lucas; Vorsino, Adam E.; Amidon, Fred A.; Paxton, Eben; Jacobi, James D.

    2015-01-01

    Hawaiian forest birds serve as an ideal group to explore the extent of climate change impacts on at-risk species. Avian malaria constrains many remaining Hawaiian forest bird species to high elevations where temperatures are too cool for malaria's life cycle and its principal mosquito vector. The impact of climate change on Hawaiian forest birds has been a recent focus of Hawaiian conservation biology, and has centered on the links between climate and avian malaria. To elucidate the differential impacts of projected climate shifts on species with known varying niches, disease resistance and tolerance, we use a comprehensive database of species sightings, regional climate projections and ensemble distribution models to project distribution shifts for all Hawaiian forest bird species. We illustrate that, under a likely scenario of continued disease-driven distribution limitation, all 10 species with highly reliable models (mostly narrow-ranged, single-island endemics) are expected to lose >50% of their range by 2100. Of those, three are expected to lose all range and three others are expected to lose >90% of their range. Projected range loss was smaller for several of the more widespread species; however improved data and models are necessary to refine future projections. Like other at-risk species, Hawaiian forest birds have specific habitat requirements that limit the possibility of range expansion for most species, as projected expansion is frequently in areas where forest habitat is presently not available (such as recent lava flows). Given the large projected range losses for all species, protecting high elevation forest alone is not an adequate long-term strategy for many species under climate change. We describe the types of additional conservation actions practitioners will likely need to consider, while providing results to help with such considerations.

  9. 3. Bird conservation

    OpenAIRE

    2016-01-01

    Expert assessors Tatsuya Amano, Cambridge University, UK Andy Brown, Natural England, UK Fiona Burns, Royal Society for the Protection of Birds, UK Yohay Carmel, Israel Institute of Technology, Israel Mick Clout, University of Auckland, New Zealand Geoff Hilton, Wildfowl & Wetlands Trust, UK Nancy Ockendon, Cambridge University, UK James Pearce-Higgins, British Trust for Ornithology, UK Sugoto Roy, Food and Environment Research Agency, DEFRA, UK Rebecca Smith, Cambridge University, UK William...

  10. Bird Watching in China

    Institute of Scientific and Technical Information of China (English)

    CHRIS; DEVONSHIRE-ELLIS

    2006-01-01

    Being based in, and conducting business in, some of China's largest cities is an exciting, yet stressful occupation and 1 like to relax by taking a pair of binoculars, getting out into the open air of China's huge countryside, and spending time seeing what birds I can identify. I'm not really a twitcher (one who relentlessly pursues sightings of as many different species as possible)-just happy to get into nature. In my travels around the country, I listed

  11. Impact Cratering Theory and Modeling for the Deep Impact Mission: From Mission Planning to Data Analysis

    Science.gov (United States)

    Richardson, James E.; Melosh, H. Jay; Artemeiva, Natasha A.; Pierazzo, Elisabetta

    2005-03-01

    The cratering event produced by the Deep Impact mission is a unique experimental opportunity, beyond the capability of Earth-based laboratories with regard to the impacting energy, target material, space environment, and extremely low-gravity field. Consequently, impact cratering theory and modeling play an important role in this mission, from initial inception to final data analysis. Experimentally derived impact cratering scaling laws provide us with our best estimates for the crater diameter, depth, and formation time: critical in the mission planning stage for producing the flight plan and instrument specifications. Cratering theory has strongly influenced the impactor design, producing a probe that should produce the largest possible crater on the surface of Tempel 1 under a wide range of scenarios. Numerical hydrocode modeling allows us to estimate the volume and thermodynamic characteristics of the material vaporized in the early stages of the impact. Hydrocode modeling will also aid us in understanding the observed crater excavation process, especially in the area of impacts into porous materials. Finally, experimentally derived ejecta scaling laws and modeling provide us with a means to predict and analyze the observed behavior of the material launched from the comet during crater excavation, and may provide us with a unique means of estimating the magnitude of the comet’s gravity field and by extension the mass and density of comet Tempel 1.

  12. Energy technology impacts on agriculture with a bibliography of models for impact assessment on crop ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Rupp, E.M.; Luxmoore, R.J.; Parzyck, D.C.

    1979-09-01

    Possible impacts of energy technologies on agriculture are evaluated, and some of the available simulation models that can be used for predictive purposes are identified. An overview of energy technologies and impacts on the environment is presented to provide a framework for the commentary on the models. Coal combustion is shown to have major impacts on the environment and these will continue into the next century according to current Department of Energy projections. Air pollution effects will thus remain as the major impacts on crop ecosystems. Two hundred reports were evaluated, representing a wide range of models increasing in complexity from mathematical functions (fitted to data) through parametric models (which represent phenomena without describing the mechanisms) to mechanistic models (based on physical, chemical, and physiological principles). Many models were viewed as suitable for adaptation to technology assessment through the incorporation of representative dose-response relationships. It is clear that in many cases available models cannot be taken and directly applied in technology assessment. Very few models of air pollutant-crop interactions were identified, even though there is a considerable data base of pollutant effects on crops.

  13. A conceptual model for assessing the impact of electronic procurement

    NARCIS (Netherlands)

    Boer, de Luitzen; Harink, Jeroen; Heijboer, Govert

    2002-01-01

    This paper aims to contribute to the development of a conceptual model for studying the direct and indirect impact of various forms of electronic procurement (EP) on a firm's integral purchasing (-related) costs. The model builds on existing classifications of purchasing-related costs and benefits a

  14. Criteria for comparing economic impact models of tourism

    NARCIS (Netherlands)

    Klijs, J.; Heijman, W.J.M.; Korteweg Maris, D.; Bryon, J.

    2012-01-01

    There are substantial differences between models of the economic impacts of tourism. Not only do the nature and precision of results vary, but data demands, complexity and underlying assumptions also differ. Often, it is not clear whether the models chosen are appropriate for the specific situation

  15. Criteria for comparing economic impact models of tourism

    NARCIS (Netherlands)

    Klijs, J.; Heijman, W.J.M.; Korteweg Maris, D.; Bryon, J.

    2012-01-01

    There are substantial differences between models of the economic impacts of tourism. Not only do the nature and precision of results vary, but data demands, complexity and underlying assumptions also differ. Often, it is not clear whether the models chosen are appropriate for the specific situation

  16. Prevalence of haemosporidians in a Neotropical endemic bird area

    Directory of Open Access Journals (Sweden)

    Catalina Gonzalez-Quevedo

    2016-06-01

    Full Text Available Haemosporidians are vector-transmitted intracellular parasites that occur in many bird species worldwide and may have important implications for wild bird populations. Surveys of haemosporidians have traditionally focused on Europe and North America, and only recently have they been carried out in the Neotropics, where the prevalence and impacts of the disease have been less studied and are not well understood. In this study we carried out a survey in the endemic bird area of the Sierra Nevada de Santa Marta (SNSM, an isolated coastal massif in northern Colombia that contains a large number of biomes and that is experiencing high rates of habitat loss. We sampled birds from 25 species at 2 different altitudes (1640 and 2100 m asl and determined avian haemosporidian infection by polymerase chain reaction and sequencing a portion of the cytochrome b (cyt b gene of the parasite. From the sampled birds, 32.1% were infected by at least 1 of 12 unique cyt b lineages of haemosporidian genera: Plasmodium, Leucocytozoon, Haemoproteus, and subgenus Parahaemoproteus. We found a higher prevalence of avian haemosporidians at low altitudes (1640 m asl. All endemic bird species we sampled had at least one individual infected with avian haemosporidians. We also found evidence of higher overall prevalence among endemic rather than nonendemic birds, suggesting higher susceptibility in endemic birds. Overall, our findings suggest a high haemosporidian species richness in the bird community of the SNSM. Considering the rate of habitat loss that this area is experiencing, it is important to understand how avian haemosporidians affect bird populations; furthermore, more exhaustive sampling is required to fully comprehend the extent of avian haemosporidian infection in the area.

  17. Modeling violent reaction following low speed impact on confined explosives

    Science.gov (United States)

    Curtis, John Philip; Jones, Andrew; Hughes, Christopher; Reaugh, John

    2012-03-01

    To ensure the safe storage and deployment of explosives it is important to understand the mechanisms that give rise to ignition and reaction growth in low speed impacts. The High Explosive Response to Mechanical Stimulus (HERMES) material model, integrated in the Lagrangian code LSDYNA, has been developed to model the progress of the reaction after such an impact. The low speed impact characteristics of an HMX based formulation have been examined using the AWE Steven Test. Axisymmetric simulations of an HMX explosive in the AWE Steven Test have been performed. A sensitivity study included the influence of friction, mesh resolution, and confinement. By comparing the experimental and calculated results, key model parameters which determine the explosive's response in this configuration have been identified. The model qualitatively predicts the point of ignition within the vehicle. Future refinements are discussed.

  18. On the influence of impact effect modelling for global asteroid impact risk distribution

    Science.gov (United States)

    Rumpf, Clemens; Lewis, Hugh G.; Atkinson, Peter M.

    2016-06-01

    The collision of an asteroid with Earth can potentially have significant consequences for the human population. The European and United States space agencies (ESA and NASA) maintain asteroid hazard lists that contain all known asteroids with a non-zero chance of colliding with the Earth in the future. Some software tools exist that are, either, capable of calculating the impact points of those asteroids, or that can estimate the impact effects of a given impact incident. However, no single tool is available that combines both aspects and enables a comprehensive risk analysis. The question is, thus, whether tools that can calculate impact location may be used to obtain a qualitative understanding of the asteroid impact risk distribution. To answer this question, two impact risk distributions that control for impact effect modelling were generated and compared. The Asteroid Risk Mitigation Optimisation and Research (ARMOR) tool, in conjunction with the freely available software OrbFit, was used to project the impact probabilities of listed asteroids with a minimum diameter of 30 m onto the surface of the Earth representing a random sample (15% of all objects) of the hazard list. The resulting 261 impact corridors were visualised on a global map. Furthermore, the impact corridors were combined with Earth population data to estimate the "simplified" risk (without impact effects) and "advanced" risk (with impact effects) associated with the direct asteroid impacts that each nation faces from present to 2100 based on this sample. The relationship between risk and population size was examined for the 40 most populous countries and it was apparent that population size is a good proxy for relative risk. The advanced and simplified risk distributions were compared and the alteration of the results based on the introduction of physical impact effects was discussed. Population remained a valid proxy for relative impact risk, but the inclusion of impact effects resulted in

  19. Threatened bird valuation in Australia.

    Science.gov (United States)

    Zander, Kerstin K; Ainsworth, Gillian B; Meyerhoff, Jürgen; Garnett, Stephen T

    2014-01-01

    Threatened species programs need a social license to justify public funding. A contingent valuation survey of a broadly representative sample of the Australian public found that almost two thirds (63%) supported funding of threatened bird conservation. These included 45% of a sample of 645 respondents willing to pay into a fund for threatened bird conservation, 3% who already supported bird conservation in another form, and 15% who could not afford to pay into a conservation fund but who nevertheless thought that humans have a moral obligation to protect threatened birds. Only 6% explicitly opposed such payments. Respondents were willing to pay about AUD 11 annually into a conservation fund (median value), including those who would pay nothing. Highest values were offered by young or middle aged men, and those with knowledge of birds and those with an emotional response to encountering an endangered bird. However, the prospect of a bird going extinct alarmed almost everybody, even most of those inclined to put the interests of people ahead of birds and those who resent the way threatened species sometimes hold up development. The results suggest that funding for threatened birds has widespread popular support among the Australian population. Conservatively they would be willing to pay about AUD 14 million per year, and realistically about AUD 70 million, which is substantially more than the AUD 10 million currently thought to be required to prevent Australian bird extinctions.

  20. Modeling Mosquito Distribution. Impact of the Landscape

    Science.gov (United States)

    Dumont, Y.

    2011-09-01

    In order to use efficiently vector control tools, like insecticides, and mechanical control, it is necessary to provide mosquito density estimate and mosquito distribution, taking into account the environment and entomological knowledges. Mosquito dispersal modeling, together with a compartmental approach, leads to a quasilinear parabolic system. Using the time splitting approach and appropriate numerical methods for each operator, we construct a reliable numerical scheme. Considering various landscapes, we show that the environment can have a strong influence on mosquito distribution and, thus, in the efficiency or not of vector control.

  1. Assessing vulnerability of marine bird populations to offshore wind farms.

    Science.gov (United States)

    Furness, Robert W; Wade, Helen M; Masden, Elizabeth A

    2013-04-15

    Offshore wind farms may affect bird populations through collision mortality and displacement. Given the pressures to develop offshore wind farms, there is an urgent need to assess population-level impacts on protected marine birds. Here we refine an approach to assess aspects of their ecology that influence population vulnerability to wind farm impacts, also taking into account the conservation importance of each species. Flight height appears to be a key factor influencing collision mortality risk but improved data on flight heights of marine birds are needed. Collision index calculations identify populations of gulls, white-tailed eagles, northern gannets and skuas as of particularly high concern in Scottish waters. Displacement index calculations identify populations of divers and common scoters as most vulnerable to population-level impacts of displacement, but these are likely to be less evident than impacts of collision mortality. The collision and displacement indices developed here for Scottish marine bird populations could be applied to populations elsewhere, and this approach will help in identifying likely impacts of future offshore wind farms on marine birds and prioritising monitoring programmes, at least until data on macro-avoidance rates become available.

  2. Modeling drop impacts on inclined flowing soap films

    Science.gov (United States)

    Basu, Saikat; Yawar, Ali; Concha, Andres; Bandi, Mahesh

    2015-11-01

    Small drops impinging on soap films flowing at an angle primarily exhibit three fundamental regimes of post-impact dynamics: (a) the drop bounces off the film surface, (b) it coalesces with the downstream flow, and (c) it pierces through the film. During impact, the drop deforms along with a simultaneous, almost elastic deformation of the film transverse to the stream direction. Hence, the governing dynamics for this interaction present the rare opportunity to explore the in-tandem effects of elasticity and hydrodynamics alike. In this talk, we outline the analytical framework to study the drop impact dynamics. The model assumes a deformable drop and a deformable three-dimensional soap film and invokes a parametric study to qualify the three mentioned impact types. The physical parameters include the impact angle, drop impact speed, and the diameters of the drop prior to and during impact when it deforms and spreads out. Our model system offers a path towards optimization of interactions between a spray and a flowing liquid.

  3. Herding of reindeer in relation to birds and mammals on the northern Seward Peninsula

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Impacts of herding reindeer on foot, air, ATV. Also discusses impacts of egg gathering, bird hunting, and predator management completed by subsistent and reindeer...

  4. An Airborne Observing Campaign of an Announced Small Asteroid Impact for High Fidelity Impact Modeling Validation

    Science.gov (United States)

    Jenniskens, P. M. M.; Grinstead, J. H.

    2015-12-01

    High fidelity modeling of an asteroid impact requires a known size, mass, shape, entry orientation, entry speed, entry angle, time and location of entry, and material properties of the impacting asteroid. Much of that information can be gathered from small asteroids on an impact trajectory with Earth while they are on approach, given sufficient warning time. That makes small asteroid impacts uniquely suited for collecting data to validate such models. One-meter sized asteroids impact Earth about once a week, 4-meter sized asteroids impact once a year. So far, only asteroid 2008 TC3 was observed in space, characterized prior to impact, and then recovered in part as meteorites on the ground. The next TC3-like impact could provide more warming time to study the impact in detail. Close to 70 percent of all asteroid impacts on Earth occur over the ocean. Hence, small asteroid impact observations require an instrumented airborne platform to take a multi-disciplined research team to the right location at the right time. From a safe 100-km distance, the impact would be observed low enough in the sky to study the process of fragmentation that dictates at which altitude the kinetic energy is deposited that can cause an airburst. Constraints on radiative heating, ablation rate, and fragmentation processes can be obtained from measuring the air plasma emission escaping the shock, elemental atom line emissions and excitation conditions, pressure broadening, and deceleration in the plane of the known trajectory. It is also possible to measure wake, lightcurve and air plasma emission line intensities early in flight that can be used to evaluate the presence of regolith and the internal cohesion of asteroids. The main element abundance (asteroid composition) can be measured for individual fragments, while CN-band emission can point to the presence of organic matter. Such information will help constrain the meteorite type if no meteorites can be recovered in an over

  5. Storm-impact scenario XBeach model inputs and tesults

    Science.gov (United States)

    Mickey, Rangley; Long, Joseph W.; Thompson, David M.; Plant, Nathaniel G.; Dalyander, P. Soupy

    2017-01-01

    The XBeach model input and output of topography and bathymetry resulting from simulation of storm-impact scenarios at the Chandeleur Islands, LA, as described in USGS Open-File Report 2017–1009 (https://doi.org/10.3133/ofr20171009), are provided here. For further information regarding model input generation and visualization of model output topography and bathymetry refer to USGS Open-File Report 2017–1009 (https://doi.org/10.3133/ofr20171009).

  6. Conceptual Model of Climate Change Impacts at LANL

    Energy Technology Data Exchange (ETDEWEB)

    Dewart, Jean Marie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-17

    Goal 9 of the LANL FY15 Site Sustainability Plan (LANL 2014a) addresses Climate Change Adaptation. As part of Goal 9, the plan reviews many of the individual programs the Laboratory has initiated over the past 20 years to address climate change impacts to LANL (e.g. Wildland Fire Management Plan, Forest Management Plan, etc.). However, at that time, LANL did not yet have a comprehensive approach to climate change adaptation. To fill this gap, the FY15 Work Plan for the LANL Long Term Strategy for Environmental Stewardship and Sustainability (LANL 2015) included a goal of (1) establishing a comprehensive conceptual model of climate change impacts at LANL and (2) establishing specific climate change indices to measure climate change and impacts at Los Alamos. Establishing a conceptual model of climate change impacts will demonstrate that the Laboratory is addressing climate change impacts in a comprehensive manner. This paper fulfills the requirement of goal 1. The establishment of specific indices of climate change at Los Alamos (goal 2), will improve our ability to determine climate change vulnerabilities and assess risk. Future work will include prioritizing risks, evaluating options/technologies/costs, and where appropriate, taking actions. To develop a comprehensive conceptual model of climate change impacts, we selected the framework provided in the National Oceanic and Atmospheric Administration (NOAA) Climate Resilience Toolkit (http://toolkit.climate.gov/).

  7. On the influence of impact effect modelling for global asteroid impact risk distribution

    CERN Document Server

    Rumpf, Clemens M; Atkinson, Peter M

    2016-01-01

    ESA and NASA maintain asteroid hazard lists that contain all known asteroids with a non zero chance of colliding with the Earth in the future. Some software tools exist that are, either, capable of calculating the impact points of those asteroids, or that can estimate the impact effects of a given impact incident. However, no single tool is available that combines both aspects and enables a comprehensive risk analysis. The question is, thus, whether tools that can calculate impact location may be used to obtain a qualitative understanding of the asteroid impact risk distribution. To answer this question, two impact risk distributions that control for impact effect modelling were generated and compared. The Asteroid Risk Mitigation Optimization and Research (ARMOR) tool, in conjunction with the freely available software OrbFit, was used to project the impact probabilities of listed asteroids with a minimum diameter of 30 m onto the surface of the Earth representing a random sample (15% of all objects) of the h...

  8. Soaring migratory birds avoid wind farm in the Isthmus of Tehuantepec, southern Mexico.

    Directory of Open Access Journals (Sweden)

    Rafael Villegas-Patraca

    Full Text Available The number of wind farms operating in the Isthmus of Tehuantepec, southern Mexico, has rapidly increased in recent years; yet, this region serves as a major migration route for various soaring birds, including Turkey Vultures (Cathartes aura and Swainson's Hawks (Buteo swainsoni. We analyzed the flight trajectories of soaring migrant birds passing the La Venta II wind farm during the two migratory seasons of 2011, to determine whether an avoidance pattern existed or not. We recorded three polar coordinates for the flight path of migrating soaring birds that were detected using marine radar, plotted the flight trajectories and estimated the number of trajectories that intersected the polygon defined by the wind turbines of La Venta II. Finally, we estimated the actual number of intersections per kilometer and compared this value with the null distributions obtained by running 10,000 simulations of our datasets. The observed number of intersections per kilometer fell within or beyond the lower end of the null distributions in the five models proposed for the fall season and in three of the four models proposed for the spring season. Flight trajectories had a non-random distribution around La Venta II, suggesting a strong avoidance pattern during fall and a possible avoidance pattern during spring. We suggest that a nearby ridgeline plays an important role in this pattern, an issue that may be incorporated into strategies to minimize the potential negative impacts of future wind farms on soaring birds. Studies evaluating these issues in the Isthmus of Tehuantepec have not been previously published; hence this work contributes important baseline information about the movement patterns of soaring birds and its relationship to wind farms in the region.

  9. Soaring Migratory Birds Avoid Wind Farm in the Isthmus of Tehuantepec, Southern Mexico

    Science.gov (United States)

    Villegas-Patraca, Rafael; Cabrera-Cruz, Sergio A.; Herrera-Alsina, Leonel

    2014-01-01

    The number of wind farms operating in the Isthmus of Tehuantepec, southern Mexico, has rapidly increased in recent years; yet, this region serves as a major migration route for various soaring birds, including Turkey Vultures (Cathartes aura) and Swainson's Hawks (Buteo swainsoni). We analyzed the flight trajectories of soaring migrant birds passing the La Venta II wind farm during the two migratory seasons of 2011, to determine whether an avoidance pattern existed or not. We recorded three polar coordinates for the flight path of migrating soaring birds that were detected using marine radar, plotted the flight trajectories and estimated the number of trajectories that intersected the polygon defined by the wind turbines of La Venta II. Finally, we estimated the actual number of intersections per kilometer and compared this value with the null distributions obtained by running 10,000 simulations of our datasets. The observed number of intersections per kilometer fell within or beyond the lower end of the null distributions in the five models proposed for the fall season and in three of the four models proposed for the spring season. Flight trajectories had a non-random distribution around La Venta II, suggesting a strong avoidance pattern during fall and a possible avoidance pattern during spring. We suggest that a nearby ridgeline plays an important role in this pattern, an issue that may be incorporated into strategies to minimize the potential negative impacts of future wind farms on soaring birds. Studies evaluating these issues in the Isthmus of Tehuantepec have not been previously published; hence this work contributes important baseline information about the movement patterns of soaring birds and its relationship to wind farms in the region. PMID:24647442

  10. Soaring migratory birds avoid wind farm in the Isthmus of Tehuantepec, southern Mexico.

    Science.gov (United States)

    Villegas-Patraca, Rafael; Cabrera-Cruz, Sergio A; Herrera-Alsina, Leonel

    2014-01-01

    The number of wind farms operating in the Isthmus of Tehuantepec, southern Mexico, has rapidly increased in recent years; yet, this region serves as a major migration route for various soaring birds, including Turkey Vultures (Cathartes aura) and Swainson's Hawks (Buteo swainsoni). We analyzed the flight trajectories of soaring migrant birds passing the La Venta II wind farm during the two migratory seasons of 2011, to determine whether an avoidance pattern existed or not. We recorded three polar coordinates for the flight path of migrating soaring birds that were detected using marine radar, plotted the flight trajectories and estimated the number of trajectories that intersected the polygon defined by the wind turbines of La Venta II. Finally, we estimated the actual number of intersections per kilometer and compared this value with the null distributions obtained by running 10,000 simulations of our datasets. The observed number of intersections per kilometer fell within or beyond the lower end of the null distributions in the five models proposed for the fall season and in three of the four models proposed for the spring season. Flight trajectories had a non-random distribution around La Venta II, suggesting a strong avoidance pattern during fall and a possible avoidance pattern during spring. We suggest that a nearby ridgeline plays an important role in this pattern, an issue that may be incorporated into strategies to minimize the potential negative impacts of future wind farms on soaring birds. Studies evaluating these issues in the Isthmus of Tehuantepec have not been previously published; hence this work contributes important baseline information about the movement patterns of soaring birds and its relationship to wind farms in the region.

  11. Quantifying the impact of model inaccuracy in climate change impact assessment studies using an agro-hydrological model

    NARCIS (Netherlands)

    Droogers, P.; Loon, van A.F.; Immerzeel, W.W.

    2008-01-01

    Numerical simulation models are frequently applied to assess the impact of climate change on hydrology and agriculture. A common hypothesis is that unavoidable model errors are reflected in the reference situation as well as in the climate change situation so that by comparing reference to scenario

  12. Agricultural climate impacts assessment for economic modeling and decision support

    Science.gov (United States)

    Thomson, A. M.; Izaurralde, R. C.; Beach, R.; Zhang, X.; Zhao, K.; Monier, E.

    2013-12-01

    A range of approaches can be used in the application of climate change projections to agricultural impacts assessment. Climate projections can be used directly to drive crop models, which in turn can be used to provide inputs for agricultural economic or integrated assessment models. These model applications, and the transfer of information between models, must be guided by the state of the science. But the methodology must also account for the specific needs of stakeholders and the intended use of model results beyond pure scientific inquiry, including meeting the requirements of agencies responsible for designing and assessing policies, programs, and regulations. Here we present methodology and results of two climate impacts studies that applied climate model projections from CMIP3 and from the EPA Climate Impacts and Risk Analysis (CIRA) project in a crop model (EPIC - Environmental Policy Indicator Climate) in order to generate estimates of changes in crop productivity for use in an agricultural economic model for the United States (FASOM - Forest and Agricultural Sector Optimization Model). The FASOM model is a forward-looking dynamic model of the US forest and agricultural sector used to assess market responses to changing productivity of alternative land uses. The first study, focused on climate change impacts on the UDSA crop insurance program, was designed to use available daily climate projections from the CMIP3 archive. The decision to focus on daily data for this application limited the climate model and time period selection significantly; however for the intended purpose of assessing impacts on crop insurance payments, consideration of extreme event frequency was critical for assessing periodic crop failures. In a second, coordinated impacts study designed to assess the relative difference in climate impacts under a no-mitigation policy and different future climate mitigation scenarios, the stakeholder specifically requested an assessment of a

  13. Post-insemination sexual selection in birds.

    Science.gov (United States)

    Pizzari, Tommaso

    2007-01-01

    In many avian species females obtain sperm from multiple males during a single reproductive event, setting the scene for post-insemination sexual selection through the competition of the ejaculates of different males over fertilisation (sperm competition) and female biased utilisation of sperm (cryptic female choice). The use of poultry techniques in combination with molecular tools is catalysing an interest in birds as vertebrate model systems to study the mechanisms of post-insemination sexual selection. This chapter: (i) outlines the main mechanisms of avian sperm competition, (ii) introduces methodological approaches to study post-insemination sexual selection in birds, (iii) reviews recent evidence of multiple mechanisms of strategic sperm allocation by males, and (iv) discusses mechanisms of cryptic female choice. Post-insemination variance in paternity in birds, appears to be determined by the interactions between complex male and female strategies of differential sperm utilisation. It is argued that a better understanding of the operation of post-insemination sexual selection in birds may be achieved through a two-pronged approach which, on the one hand, investigates behavioural and physiological mechanisms applying poultry techniques and molecular tools to domestic model species, and on the other, verifies these mechanisms and tests their adaptive significance in more natural populations.

  14. Avian schistosomes in French aquatic birds: a molecular approach.

    Science.gov (United States)

    Jouet, D; Ferté, H; Hologne, C; Kaltenbach, M L; Depaquit, J

    2009-06-01

    The prevalence of human cercarial dermatitis (HCD) caused by bird schistosomes appears to be increasing in France, in light of the impact of tourism combined with high densities of wild aquatic hosts in freshwater areas. The present work expands our knowledge of schistosome systematics by including samples of bird schistosomes collected from their natural hosts in France. Heads (318) and viscera (81) of aquatic birds belonging to 16 species from five orders, collecting during the hunting seasons or found dead, were autopsied for nasal and visceral schistosomes. Eggs and/or adults were analysed by molecular methods using the D2 domain and the second internal transcribed spacer (ITS-2) region of rDNA to determine species. Even if nasal eggs were polymorphic according to the host, all haplotypes were similar to that of Trichobilharzia regenti. Marked diversity of visceral species was observed. Final hosts under natural conditions were reported. For the first time, Trichobilharzia franki is reported in its natural bird hosts, Anas platyrhynchos, Anas crecca, Aythya fuligula and Cygnus olor. We also identified T. szidati in A. crecca and Anas clypeata. Bilharziella polonica was found in six species of aquatic birds, including Grus grus. This finding is the first record of bird schistosomes in this aquatic bird. Three new taxa of visceral schistosomes in Anser anser are strongly suspected according to their haplotypes. Futhermore, a new haplotype of visceral schistosomes isolated in Cygnus olor and similar to Allobilharzia visceralis was identified.

  15. Occupancy dynamics in a tropical bird community: unexpectedly high forest use by birds classified as non-forest species

    Science.gov (United States)

    Ruiz-Gutierrez, Viviana; Zipkin, Elise F.; Dhondt, Andre A.

    2010-01-01

    1. Worldwide loss of biodiversity necessitates a clear understanding of the factors driving population declines as well as informed predictions about which species and populations are at greatest risk. The biggest threat to the long-term persistence of populations is the reduction and changes in configuration of their natural habitat. 2. Inconsistencies have been noted in the responses of populations to the combined effects of habitat loss and fragmentation. These have been widely attributed to the effects of the matrix habitats in which remnant focal habitats are typically embedded. 3. We quantified the potential effects of the inter-patch matrix by estimating occupancy and colonization of forest and surrounding non-forest matrix (NF). We estimated species-specific parameters using a dynamic, multi-species hierarchical model on a bird community in southwestern Costa Rica. 4. Overall, we found higher probabilities of occupancy and colonization of forest relative to the NF across bird species, including those previously categorized as open habitat generalists not needing forest to persist. Forest dependency was a poor predictor of occupancy dynamics in our study region, largely predicting occupancy and colonization of only non-forest habitats. 5. Our results indicate that the protection of remnant forest habitats is key for the long-term persistence of all members of the bird community in this fragmented landscape, including species typically associated with open, non-forest habitats. 6.Synthesis and applications. We identified 39 bird species of conservation concern defined by having high estimates of forest occupancy, and low estimates of occupancy and colonization of non-forest. These species survive in forest but are unlikely to venture out into open, non-forested habitats, therefore, they are vulnerable to the effects of habitat loss and fragmentation. Our hierarchical community-level model can be used to estimate species-specific occupancy dynamics for focal

  16. High Resolution Beam Modeling and Optimization with IMPACT

    Science.gov (United States)

    Qiang, Ji

    2017-01-01

    The LCLS-II, a new BES x-ray FEL facility at SLAC, is being designed using the IMPACT simulation code which includes a full model for the electron beam transport with 3-D space charge effects as well as IntraBeam Scattering and Coherent Synchrotron Radiation. A 22 parameter optimization is being used to find injector and linac configurations that achieve the design specifications. The detailed physics models in IMPACT are being benchmarked against experiments at LCLS. This work was done in collaboration with SLAC LCLS-II design team and supported by the DOE under contract No. DE-AC02-05CH11231.

  17. Risk of Agricultural Practices and Habitat Change to Farmland Birds

    Directory of Open Access Journals (Sweden)

    David Anthony. Kirk

    2011-06-01

    Full Text Available Many common bird species have declined as a result of agricultural intensification and this could be mitigated by organic farming. We paired sites for habitat and geographical location on organic and nonorganic farms in Ontario, Canada to test a priori predictions of effects on birds overall, 9 guilds and 22 species in relation to candidate models for farming practices (13 variables, local habitat features (12 variables, or habitat features that influence susceptibility to predation. We found that: (1 Overall bird abundance, but not richness, was significantly (p < 0.05 higher on organic sites (mean 43.1 individuals per site than nonorganic sites (35.8 individuals per site. Significantly more species of birds were observed for five guilds, including primary grassland birds, on organic vs. nonorganic sites. No guild had higher richness or abundance on nonorganic farms; (2 Farming practice models were the best (Î"AIC < 4 for abundance of birds overall, primary grassland bird richness, sallier aerial insectivore richness and abundance, and abundance of ground nesters; (3 Habitat models were the best for overall richness, Neotropical migrant abundance, richness and abundance of Ontario-USA-Mexico (short-distance migrants and resident richness; (4 Predation models were the best for richness of secondary grassland birds and ground feeders; (5 A combination of variables from the model types were best for richness or abundance overall, 13 of 18 guilds (richness and abundance and 16 of 22 species analyzed. Five of 10 farming practice variables (including herbicide use, organic farm type and 9 of 13 habitat variables (including hedgerow length, proportion of hay were significant in best models. Risk modeling indicated that herbicide use could decrease primary grassland birds by one species (35% decline from 3.4 to 2.3 species per site. Organic farming could benefit species of conservation concern by 49% (an increase from 7.6 to 11.4 grassland birds. An

  18. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Central California: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for alcids, diving birds, gulls, terns, passerine birds, pelagic birds, raptors, shorebirds, wading birds,...

  19. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: South Florida: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for diving birds, gulls, terns, passerine birds, pelagic birds, raptors, shorebirds, wading birds, and...

  20. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Upper Coast of Texas: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for diving birds, gulls, terns, passerine birds, pelagic birds, raptors, shorebirds, wading birds,...

  1. Rhode Island, Connecticut, New York, and New Jersey ESI: BIRDS (Bird Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, pelagic birds, passerine birds, gulls and...

  2. Pretty Bird by Bob Sinclair

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Recently I was reminded of a story which my mother swears is trus (though she doesn t call me Bobby muchanymore):Back in 1958,when I was just past four years old,my parents gave me a young parakeet.My mother determinedthat our parakeet would learn to talk,and to this end sat at the microphone of a borrowed tape recorder for a full 1/2hour,saying over and over again:“Pretty bird!Pretty bird!Pretty bird!Pretty bird!...”and so on.The resultingtaped message was played for our parakeet at least once pe...

  3. Mechanical Model for Dynamic Behavior of Concrete Under Impact Loading

    Science.gov (United States)

    Sun, Yuanxiang

    Concrete is a geo-material which is used substantively in the civil building and military safeguard. One coupled model of damage and plasticity to describe the complex behavior of concrete subjected to impact loading is proposed in this research work. The concrete is assumed as homogeneous continuum with pre-existing micro-cracks and micro-voids. Damage to concrete is caused due to micro-crack nucleation, growth and coalescence, and defined as the probability of fracture at a given crack density. It induces a decrease of strength and stiffness of concrete. Compaction of concrete is physically a collapse of the material voids. It produces the plastic strain in the concrete and, at the same time, an increase of the bulk modulus. In terms of crack growth model, micro-cracks are activated, and begin to propagate gradually. When crack density reaches a critical value, concrete takes place the smashing destroy. The model parameters for mortar are determined using plate impact experiment with uni-axial strain state. Comparison with the test results shows that the proposed model can give consistent prediction of the impact behavior of concrete. The proposed model may be used to design and analysis of concrete structures under impact and shock loading. This work is supported by State Key Laboratory of Explosion science and Technology, Beijing Institute of Technology (YBKT14-02).

  4. Numerical Modeling of Shatter Cones Development in Impact Craters

    Science.gov (United States)

    Baratoux, D.; Melosh, H. J.

    2003-01-01

    Shatter cones are the characteristic forms of rock fractures in impact structures. They have been used for decades as unequivocal fingerprints of meteoritic impacts on Earth. The abundant data about shapes, apical angles, sizes and distributions of shatter cones for many terrestrial impact structures should provide insights for the determination of impact conditions and characteristics of shock waves produced by high-velocity projectiles in geologic media. However, previously proposed models for the formation of shatter cones do not agree with observations. For example, the widely accepted Johnson-Talbot mechanism requires that the longitudinal stress drops to zero between the arrival of the elastic precursor and the main plastic wave. Unfortunately, observations do not support such a drop. A model has been also proposed to explain the striated features on the surface of shatter cones but can not invoked for their conical shape. The mechanism by which shatter cones form thus remains enigmatic to date. In this paper we present a new model for the formation of shatter cones. Our model has been tested by means of numerical simulations using the hydrocodes SALE 2D enhanced with the Grady-Kipp-Melosh fragmentation model.

  5. Salmonellosis in garden birds in Scotland, 1995 to 2008: geographic region, Salmonella enterica phage type and bird species.

    Science.gov (United States)

    Pennycott, T W; Mather, H A; Bennett, G; Foster, G

    2010-04-03

    Salmonellosis was diagnosed in garden birds from 198 incidents in Scotland between September 1995 and August 2008. Salmonellosis was essentially a disease of finches in the north of Scotland, but in the south of Scotland it was also a problem in house sparrows. Almost all of the incidents were caused by Salmonella Typhimurium phage types 40 or 56/variant, but regional variation in phage types was observed. In the north of Scotland, one phage type (DT 40) predominated, but in the south of Scotland two phage types were commonly isolated (DTs 40 and 56/variant, with the latter the more common of the two phage types). This regional difference was statistically significant for salmonellosis in greenfinches, chaffinches and 'other garden birds', but not for house sparrows. Different temporal patterns for different species of bird and different phage types were also observed within regions. These findings suggest that the epidemiology of salmonellosis in garden birds varies depending on the phage type of Salmonella and the species of garden bird, with additional regional differences depending on the wild bird populations and the phage types of Salmonella in circulation. An awareness of these differences will help when formulating guidelines aimed at reducing the impact of salmonellosis in garden birds.

  6. Borrelia burgdorferi sensu lato spirochetes in wild birds in northwestern California: associations with ecological factors, bird behavior and tick infestation.

    Science.gov (United States)

    Newman, Erica A; Eisen, Lars; Eisen, Rebecca J; Fedorova, Natalia; Hasty, Jeomhee M; Vaughn, Charles; Lane, Robert S

    2015-01-01

    Although Borrelia burgdorferi sensu lato (s.l.) are found in a great diversity of vertebrates, most studies in North America have focused on the role of mammals as spirochete reservoir hosts. We investigated the roles of birds as hosts for subadult Ixodes pacificus ticks and potential reservoirs of the Lyme disease spirochete B. burgdorferi sensu stricto (s.s.) in northwestern California. Overall, 623 birds representing 53 species yielded 284 I. pacificus larvae and nymphs. We used generalized linear models and zero-inflated negative binomial models to determine associations of bird behaviors, taxonomic relationships and infestation by I. pacificus with borrelial infection in the birds. Infection status in birds was best explained by taxonomic order, number of infesting nymphs, sampling year, and log-transformed average body weight. Presence and counts of larvae and nymphs could be predicted by ground- or bark-foraging behavior and contact with dense oak woodland. Molecular analysis yielded the first reported detection of Borrelia bissettii in birds. Moreover, our data suggest that the Golden-crowned Sparrow (Zonotrichia atricapilla), a non-resident species, could be an important reservoir for B. burgdorferi s.s. Of 12 individual birds (9 species) that carried B. burgdorferi s.l.-infected larvae, no birds carried the same genospecies of B. burgdorferi s.l. in their blood as were present in the infected larvae removed from them. Possible reasons for this discrepancy are discussed. Our study is the first to explicitly incorporate both taxonomic relationships and behaviors as predictor variables to identify putative avian reservoirs of B. burgdorferi s.l. Our findings underscore the importance of bird behavior to explain local tick infestation and Borrelia infection in these animals, and suggest the potential for bird-mediated geographic spread of vector ticks and spirochetes in the far-western United States.

  7. Borrelia burgdorferi sensu lato spirochetes in wild birds in northwestern California: associations with ecological factors, bird behavior and tick infestation.

    Directory of Open Access Journals (Sweden)

    Erica A Newman

    Full Text Available Although Borrelia burgdorferi sensu lato (s.l. are found in a great diversity of vertebrates, most studies in North America have focused on the role of mammals as spirochete reservoir hosts. We investigated the roles of birds as hosts for subadult Ixodes pacificus ticks and potential reservoirs of the Lyme disease spirochete B. burgdorferi sensu stricto (s.s. in northwestern California. Overall, 623 birds representing 53 species yielded 284 I. pacificus larvae and nymphs. We used generalized linear models and zero-inflated negative binomial models to determine associations of bird behaviors, taxonomic relationships and infestation by I. pacificus with borrelial infection in the birds. Infection status in birds was best explained by taxonomic order, number of infesting nymphs, sampling year, and log-transformed average body weight. Presence and counts of larvae and nymphs could be predicted by ground- or bark-foraging behavior and contact with dense oak woodland. Molecular analysis yielded the first reported detection of Borrelia bissettii in birds. Moreover, our data suggest that the Golden-crowned Sparrow (Zonotrichia atricapilla, a non-resident species, could be an important reservoir for B. burgdorferi s.s. Of 12 individual birds (9 species that carried B. burgdorferi s.l.-infected larvae, no birds carried the same genospecies of B. burgdorferi s.l. in their blood as were present in the infected larvae removed from them. Possible reasons for this discrepancy are discussed. Our study is the first to explicitly incorporate both taxonomic relationships and behaviors as predictor variables to identify putative avian reservoirs of B. burgdorferi s.l. Our findings underscore the importance of bird behavior to explain local tick infestation and Borrelia infection in these animals, and suggest the potential for bird-mediated geographic spread of vector ticks and spirochetes in the far-western United States.

  8. Fish and Bird

    Institute of Scientific and Technical Information of China (English)

    毛秀波

    2010-01-01

    人物:B——Bird L——Little Fish M——Mother Fish N——Narracor(旁白)道具:角色头饰 N:一条生活在河里的Little Fish对天空充满了好奇,一心想飞到天空去看看。此时,Little Fish正依偎在Mother Fish身边,好奇地望着天空。

  9. Traits influencing range contraction in New Zealand's endemic forest birds.

    Science.gov (United States)

    Parlato, Elizabeth H; Armstrong, Doug P; Innes, John G

    2015-10-01

    Understanding vulnerability of endemic taxa to predation is clearly important for conservation management. In New Zealand, predation by introduced mammals such as rats and mustelids is widely recognized as the primary factor responsible for declines of indigenous fauna. The aim of our study was to evaluate the vulnerability of New Zealand's surviving endemic forest bird species to impacts of introduced mammalian predators, and identify key life history attributes underlying this vulnerability. We measured range contraction following the introduction of exotic mammalian predators for 23 endemic forest bird species using information on both pre-human and current distributions. We used Bayesian modeling techniques to analyze whether variation in range contraction was associated with life history traits potentially influencing species' predation vulnerability, while accounting for phylogenetic relatedness. Our results showed that the extent of range contraction varied greatly among species, with some species remaining in available forest habitat throughout most of their pre-human range, and others having disappeared completely from the main islands. Cavity nesting was the key trait associated with more extensive range decline, suggesting that cavity-nesting species are more vulnerable to predation than species that nest in more open sites.

  10. Assessment of Modeling Capability for Reproducing Storm Impacts on TEC

    Science.gov (United States)

    Shim, J. S.; Kuznetsova, M. M.; Rastaetter, L.; Bilitza, D.; Codrescu, M.; Coster, A. J.; Emery, B. A.; Foerster, M.; Foster, B.; Fuller-Rowell, T. J.; Huba, J. D.; Goncharenko, L. P.; Mannucci, A. J.; Namgaladze, A. A.; Pi, X.; Prokhorov, B. E.; Ridley, A. J.; Scherliess, L.; Schunk, R. W.; Sojka, J. J.; Zhu, L.

    2014-12-01

    During geomagnetic storm, the energy transfer from solar wind to magnetosphere-ionosphere system adversely affects the communication and navigation systems. Quantifying storm impacts on TEC (Total Electron Content) and assessment of modeling capability of reproducing storm impacts on TEC are of importance to specifying and forecasting space weather. In order to quantify storm impacts on TEC, we considered several parameters: TEC changes compared to quiet time (the day before storm), TEC difference between 24-hour intervals, and maximum increase/decrease during the storm. We investigated the spatial and temporal variations of the parameters during the 2006 AGU storm event (14-15 Dec. 2006) using ground-based GPS TEC measurements in the selected 5 degree eight longitude sectors. The latitudinal variations were also studied in two longitude sectors among the eight sectors where data coverage is relatively better. We obtained modeled TEC from various ionosphere/thermosphere (IT) models. The parameters from the models were compared with each other and with the observed values. We quantified performance of the models in reproducing the TEC variations during the storm using skill scores. This study has been supported by the Community Coordinated Modeling Center (CCMC) at the Goddard Space Flight Center. Model outputs and observational data used for the study will be permanently posted at the CCMC website (http://ccmc.gsfc.nasa.gov) for the space science communities to use.

  11. Bats and birds increase crop yield in tropical agroforestry landscapes.

    Science.gov (United States)

    Maas, Bea; Clough, Yann; Tscharntke, Teja

    2013-12-01

    Human welfare is significantly linked to ecosystem services such as the suppression of pest insects by birds and bats. However, effects of biocontrol services on tropical cash crop yield are still largely unknown. For the first time, we manipulated the access of birds and bats in an exclosure experiment (day, night and full exclosures compared to open controls in Indonesian cacao agroforestry) and quantified the arthropod communities, the fruit development and the final yield over a long time period (15 months). We found that bat and bird exclusion increased insect herbivore abundance, despite the concurrent release of mesopredators such as ants and spiders, and negatively affected fruit development, with final crop yield decreasing by 31% across local (shade cover) and landscape (distance to primary forest) gradients. Our results highlight the tremendous economic impact of common insectivorous birds and bats, which need to become an essential part of sustainable landscape management.

  12. Impact winter and the Cretaceous/Tertiary extinctions: Results of a Chicxulub asteroid impact model

    Science.gov (United States)

    Pope, Kevin O.; Baines, Kevin H.; Ocampo, Adriana C.; Ivanov, Boris A.

    1994-01-01

    The Chicxulub impact crater in Mexico is the site of the impact purported to have caused mass extinctions at the Cretaceous/Tertiary (K/T) boundary. 2-D hydrocode modeling of the impact, coupled with studies of the impact site geology, indiate that between 0.4 and 7.0 x 10(exp 17) g of sulfur were vaporized by the impact into anhydrite target rocks. A small portion of the sulfur was released as SO3 or SO4, which converted rapidly into H2SO4 aerosol and fell as acid rain. A radiative transfer model, coupled with a model of coagulation indicates that the aerosol prolonged the initial blackout period caused by impact dust only if the aerosol contained impurities. A larger portion of sulfur was released as SO2, which converted to aerosol slowly, due to the rate-limiting oxidation of SO2. Our radiative transfer calculations, combined with rates of acid production, coagulation, and diffusion indicate that solar transmission was reduced to 10-20% of normal for a period of 8-13 yr. This reduction produced a climate forcing (cooling) of -300 W/sq.m, which far exceeded the +8 W/sq.m greenhouse warming, caused by the CO2 released through the vaporization of carbonates, and therefore produced a decade of freezing and near-freezing temperatures. Several decades of moderate warming followed the decade of severe cooling due to the long residence time of CO2. The prolonged impact winter may have been a major cause of the K/T extinctions.

  13. Modeling Pediatric Brain Trauma: Piglet Model of Controlled Cortical Impact.

    Science.gov (United States)

    Pareja, Jennifer C Munoz; Keeley, Kristen; Duhaime, Ann-Christine; Dodge, Carter P

    2016-01-01

    The brain has different responses to traumatic injury as a function of its developmental stage. As a model of injury to the immature brain, the piglet shares numerous similarities in regards to morphology and neurodevelopmental sequence compared to humans. This chapter describes a piglet scaled focal contusion model of traumatic brain injury that accounts for the changes in mass and morphology of the brain as it matures, facilitating the study of age-dependent differences in response to a comparable mechanical trauma.

  14. WT-BIRD. Bird collision monitoring system for multi-megawatt wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Wiggelinkhuizen, E.J.; Rademakers, L.W.M.M.; Barhorst, S.A.M. [ECN Wind Energy, Petten (Netherlands); Den Boon, H.J. [E-Connection Project, Bunnik (Netherlands); Dirksen, S. [Bureau Waardenburg, Culemborg (Netherlands)

    2007-05-15

    A new method for detection and registration of bird collisions has been developed that is suitable for continuous remote operation in both onshore and offshore wind farms. The characteristic sound of a collision is detected by sensors in the blades, which triggers the storage of video registrations and sends an alert message to the operator. A prototype has been tested successfully on a Nordex N80/2.5MW turbine at ECN's Wind turbine Test park Wieringermeer. Compared to other methods employed so far this monitoring system will reduce the uncertainty in the number of birds killed by collisions with wind turbines. Further, the system enables the operator to identify species and to study the collision mechanisms. It has been found that this system can also be used for monitoring of other events in order to save costs for inspection and repair after incidents. For offshore wind farms, the WT-Bird system is currently the only alternative to count the number of bird collisions. Functional tests with tennis balls that were shot against rotating blades showed that the majority of the impacts were detected. The flight track of these dummies and the collision events were clearly visible on the video registrations. During the monitoring period of about one year two bird collisions were detected. The video recordings confirmed that a collision took place and showed that the location of both collisions was near the blade root, which resulted that in both cases the bird was not (immediately) killed. Therefore no corpses could be found beneath the turbine after these events. Also during the rest of the monitoring period no corpses were found beneath the turbine.

  15. A Tool for Sharing Empirical Models of Climate Impacts

    Science.gov (United States)

    Rising, J.; Kopp, R. E.; Hsiang, S. M.

    2013-12-01

    Scientists, policy advisors, and the public struggle to synthesize the quickly evolving empirical work on climate change impacts. The Integrated Assessment Models (IAMs) used to estimate the impacts of climate change and the effects of adaptation and mitigation policies can also benefit greatly from recent empirical results (Kopp, Hsiang & Oppenheimer, Impacts World 2013 discussion paper). This paper details a new online tool for exploring, analyzing, combining, and communicating a wide range of impact results, and supporting their integration into IAMs. The tool uses a new database of statistical results, which researchers can expand both in depth (by providing additional results that describing existing relationships) and breadth (by adding new relationships). Scientists can use the tool to quickly perform meta-analyses of related results, using Bayesian techniques to produce pooled and partially-pooled posterior distributions. Policy advisors can apply the statistical results to particular contexts, and combine different kinds of results in a cost-benefit framework. For example, models of the impact of temperature changes on agricultural yields can be first aggregated to build a best-estimate of the effect under given assumptions, then compared across countries using different temperature scenarios, and finally combined to estimate a social cost of carbon. The general public can better understand the many estimates of climate impacts and their range of uncertainty by exploring these results dynamically, with maps, bar charts, and dose-response-style plots. Front page of the climate impacts tool website. Sample "collections" of models, within which all results are estimates of the same fundamental relationship, are shown on the right. Simple pooled result for Gelman's "8 schools" example. Pooled results are calculated analytically, while partial-pooling (Bayesian hierarchical estimation) uses posterior simulations.

  16. The importance of agricultural lands for Himalayan birds in winter.

    Science.gov (United States)

    Elsen, Paul R; Kalyanaraman, Ramnarayan; Ramesh, Krishnamurthy; Wilcove, David S

    2017-04-01

    The impacts of land-use change on biodiversity in the Himalayas are poorly known, notwithstanding widespread deforestation and agricultural intensification in this highly biodiverse region. Although intact primary forests harbor many Himalayan birds during breeding, a large number of bird species use agricultural lands during winter. We assessed how Himalayan bird species richness, abundance, and composition during winter are affected by forest loss stemming from agriculture and grazing. Bird surveys along 12 elevational transects within primary forest, low-intensity agriculture, mixed subsistence agriculture, and intensively grazed pastures in winter revealed that bird species richness and abundance were greatest in low-intensity and mixed agriculture, intermediate in grazed pastures, and lowest in primary forest at both local and landscape scales; over twice as many species and individuals were recorded in low-intensity agriculture than in primary forest. Bird communities in primary forests were distinct from those in all other land-use classes, but only 4 species were unique to primary forests. Low-, medium-, and high-intensity agriculture harbored 32 unique species. Of the species observed in primary forest, 80% had equal or greater abundance in low-intensity agricultural lands, underscoring the value of these lands in retaining diverse community assemblages at high densities in winter. Among disturbed landscapes, bird species richness and abundance declined as land-use intensity increased, especially in high-intensity pastures. Our results suggest that agricultural landscapes are important for most Himalayan bird species in winter. But agricultural intensification-especially increased grazing-will likely result in biodiversity losses. Given that forest reserves alone may inadequately conserve Himalayan birds in winter, comprehensive conservation strategies in the region must go beyond protecting intact primary forests and ensure that low-intensity agricultural

  17. Mesoscale Modeling of Impact Compaction of Primitive Solar System Solids

    CERN Document Server

    Davison, Thomas M; Bland, Philip A

    2016-01-01

    We have developed a method for simulating the mesoscale compaction of early solar system solids in low velocity impact events, using the iSALE shock physics code. Chondrules are represented by nonporous disks, placed within a porous matrix. By simulating impacts into bimodal mixtures over a wide range of parameter space (including the chondrule-to-matrix ratio, the matrix porosity and composition and the impact velocity), we have shown how each of these parameters influences the shock processing of heterogeneous materials. The temperature after shock processing shows a strong dichotomy: matrix temperatures are elevated much higher than the chondrules, which remain largely cold. Chondrules can protect some matrix from shock compaction, with shadow regions in the lee side of chondrules exhibiting higher porosity that elsewhere in the matrix. Using the results from this mesoscale modelling, we show how the $\\varepsilon-\\alpha$ porous compaction model parameters depend on initial bulk porosity. We also show that ...

  18. Effects of wind-energy facilities on grassland bird distributions

    Science.gov (United States)

    Shaffer, Jill A.; Buhl, Deb

    2016-01-01

    The contribution of renewable energy to meet worldwide demand continues to grow. Wind energy is one of the fastest growing renewable sectors, but new wind facilities are often placed in prime wildlife habitat. Long-term studies that incorporate a rigorous statistical design to evaluate the effects of wind facilities on wildlife are rare. We conducted a before-after-control-impact (BACI) assessment to determine if wind facilities placed in native mixed-grass prairies displaced breeding grassland birds. During 2003–2012, we monitored changes in bird density in 3 study areas in North Dakota and South Dakota (U.S.A.). We examined whether displacement or attraction occurred 1 year after construction (immediate effect) and the average displacement or attraction 2–5 years after construction (delayed effect). We tested for these effects overall and within distance bands of 100, 200, 300, and >300 m from turbines. We observed displacement for 7 of 9 species. One species was unaffected by wind facilities and one species exhibited attraction. Displacement and attraction generally occurred within 100 m and often extended up to 300 m. In a few instances, displacement extended beyond 300 m. Displacement and attraction occurred 1 year after construction and persisted at least 5 years. Our research provides a framework for applying a BACI design to displacement studies and highlights the erroneous conclusions that can be made without the benefit of adopting such a design. More broadly, species-specific behaviors can be used to inform management decisions about turbine placement and the potential impact to individual species. Additionally, the avoidance distance metrics we estimated can facilitate future development of models evaluating impacts of wind facilities under differing land-use scenarios.

  19. Modified binary encounter Bethe model for electron-impact ionization

    CERN Document Server

    Guerra, M; Indelicato, P; Santos, J P

    2013-01-01

    Theoretical expressions for ionization cross sections by electron impact based on the binary encounter Bethe (BEB) model, valid from ionization threshold up to relativistic energies, are proposed. The new modified BEB (MBEB) and its relativistic counterpart (MRBEB) expressions are simpler than the BEB (nonrelativistic and relativistic) expressions because they require only one atomic parameter, namely the binding energy of the electrons to be ionized, and use only one scaling term for the ionization of all sub-shells. The new models are used to calculate the K-, L- and M-shell ionization cross sections by electron impact for several atoms with Z from 6 to 83. Comparisons with all, to the best of our knowledge, available experimental data show that this model is as good or better than other models, with less complexity.

  20. Understanding the impact of technology on firms’ business models

    DEFF Research Database (Denmark)

    Cavalcante, Sergio Andre

    2013-01-01

    of a new business model for the partner companies in the consortium. Practical implications – This paper is important in that it will help companies understand technological impact from a business model perspective, thereby enabling them to manage innovation better by distinguishing between the creation......Purpose – The purpose of this paper is to identify the impact of a new global positioning technology on firms’ business models. Design/methodology/approach – The empirical setting was a consortium of Danish organizations, established to develop a positioning-based technology platform as a basis...... for innovative commercial products and/or services. Three of the consortium companies were selected for case-study research. Findings – The main findings were that companies will use the new technology to extend their existing business models, and that the technology platform potentially represents the creation...

  1. Impact of surface waves in a Regional Climate Model

    DEFF Research Database (Denmark)

    Rutgersson, Anna; Sætra, Oyvind; Semedo, Alvaro

    2010-01-01

    A coupled regional atmosphere-wave model system is developed with the purpose of investigating the impact of climate changes on the wave field, as well as feed-back effects of the wave field on the atmospheric parameters. This study focuses on the effects of introducing a two-way atmosphere-wave...... coupling on the atmosphere as well as on wave parameters. The model components are the regional climate model RCA, and the third generation wave model WAM. Two different methods are used for the coupling, using the roughness length and only including the effect of growing sea, and using the wave age...... and introducing the reduction of roughness due to decaying sea (swell). Introducing a two-way coupling results in an altered frequency distribution of wind speed and wave heights. When only including growing sea the impact of waves on the long term mean atmospheric parameters is limited, inducing a reduction...

  2. Impact of transport model errors on the global and regional methane emissions estimated by inverse modelling

    NARCIS (Netherlands)

    Locatelli, R.; Bousquet, P.; Chevallier, F.; Fortems-Cheney, A.; Szopa, S.; Saunois, M.; Agusti-Panareda, A.; Bergmann, D.; Bian, H.; Cameron-Smith, P.; Chipperfield, M.P.; Gloor, E.; Houweling, S.; Kawa, S.R.; Krol, M.C.; Patra, P.K.; Prinn, R.G.; Rigby, M.; Saito, R.; Wilson, C.

    2013-01-01

    A modelling experiment has been conceived to assess the impact of transport model errors on methane emissions estimated in an atmospheric inversion system. Synthetic methane observations, obtained from 10 different model outputs from the international TransCom-CH4 model inter-comparison exercise, ar

  3. Uncertainties in modelling the climate impact of irrigation

    Science.gov (United States)

    de Vrese, Philipp; Hagemann, Stefan

    2017-04-01

    Many issues related to the climate impact of irrigation are addressed in studies that apply a wide range of models. These involve uncertainties related to differences in the model's general structure and parametrizations on the one hand and the need for simplifying assumptions with respect to the representation of irrigation on the other hand. To address these uncertainties, we used the Max Planck Institute for Meteorology's Earth System model into which a simple irrigation scheme was implemented. In several simulations, we varied certain irrigation characteristics to estimate the resulting variations in irrigation's climate impact and found a large sensitivity with respect to the irrigation effectiveness. Here, the assumed effectiveness of the scheme is a combination of the target soil moisture and the degree to which water losses are accounted for. In general, the simulated impact of irrigation on the state of the land surface and the atmosphere is more than three times larger when assuming a low irrigation effectiveness compared to a high effectiveness. In an additional set of simulations, we varied certain aspects of the model's general structure, namely the land-surface-atmosphere coupling, to estimate the related uncertainties. Here we compared the impact of irrigation between simulations using a parameter aggregation, a simple flux aggregation scheme and a coupling scheme that also accounts for spatial heterogeneity within the lowest layers of the atmosphere. It was found that changes in the land-surface-atmosphere coupling do not only affect the magnitude of climate impacts but they can even affect the direction of the impacts.

  4. BIRD FLU MASKS

    Directory of Open Access Journals (Sweden)

    YASAR KESKIN

    2006-08-01

    Full Text Available Avian influenza (bird flu is a disease of birds caused by influenza viruses closely related to human influenza viruses. The potential for transformation of avian influenza into a form that both causes severe disease in humans and spreads easily from person to person is a great concern for world health. The main purpose of a mask is to help prevent particles (droplets being expelled into the environment by the wearer. Masks are also resistant to fluids, and help protect the wearer from splashes of blood or other potentially infectious substances. They are not necessarily designed for filtration efficiency, or to seal tightly to the face. Masks and respirators are components of a number of infection control measures intended to protect healthcare workers, and prevent the spread of diseases. All healthcare workers who come into contact with a possible or probable case of any respiratory track infections should wear a respirator conforming to at least EN149:2001 FFP3. [TAF Prev Med Bull 2006; 5(4.000: 296-306

  5. Burrowing Owl and Other Migratory Bird Mitigation for a Runway Construction Project at Edwards AFB

    OpenAIRE

    Hoehn, Amber L.; Hagan, Mark; Bratton, Mark

    2009-01-01

    Edwards Air Force Base (AFB) scheduled the construction of a runway in the spring of 2007. The runway would be in an area that contained migratory birds and their habitat. The construction project would be near Edwards AFB main runway and had the potential not only to impact species protected under the Migratory Bird Treaty Act (MBTA), including the burrowing owl (Athene cunicularia), but also to increase bird and wildlife–aircraft strike hazards in the active flightline areas. To discourage ...

  6. Impact of improved snowmelt modelling in a monthly hydrological model.

    Science.gov (United States)

    Folton, Nathalie; Garcia, Florine

    2016-04-01

    The quantification and the management of water resources at the regional scale require hydrological models that are both easy to implement and efficient. To be reliable and robust, these models must be calibrated and validated on a large number of catchments that are representative of various hydro-meteorological conditions, physiographic contexts, and specific hydrological behavior (e.g. mountainous catchments). The GRLoiEau monthly model, with its simple structure and its two free parameters, answer our need of such a simple model. It required the development of a snow routine to model catchments with temporarily snow-covered areas. The snow routine developed here does not claim to represent physical snowmelt processes but rather to simulate them globally on the catchment. The snowmelt equation is based on the degree-day method which is widely used by the hydrological community, in particular in engineering studies (Etchevers 2000). A potential snowmelt (Schaefli et al. 2005) was computed, and the parameters of the snow routine were regionalized for each mountain area. The GRLoiEau parsimonious structure requires meteorological data. They come from the distributed mesoscale atmospheric analysis system SAFRAN, which provides estimations of daily solid and liquid precipitations and temperatures on a regular square grid at the spatial resolution of 8*8 km², throughout France. Potential evapotranspiration was estimated using the formula by Oudin et al. (2005). The aim of this study is to improve the quality of monthly simulations for ungauged basins, in particular for all types of mountain catchments, without increasing the number of free parameters of the model. By using daily SAFRAN data, the production store and snowmelt can be run at a daily time scale. The question then arises whether simulating the monthly flows using a production function at a finer time step would improve the results. And by using the SAFRAN distributed climate series, a distributed approach

  7. The impact of advertising in a duopoly model

    NARCIS (Netherlands)

    Schoonbeek, Lambert; Kooreman, Peter

    1999-01-01

    We investigate the impact of advertising in a simple static differentiated duopoly model. First, we consider the Nash equilibrium of the situation in which the duopolistic firms compete simultaneously with two instruments, i.e. the prices and the advertising expenditures. Second, we examine the Nash

  8. A Bayesian network approach to coastal storm impact modeling

    NARCIS (Netherlands)

    Jäger, W.S.; Den Heijer, C.; Bolle, A.; Hanea, A.M.

    2015-01-01

    In this paper we develop a Bayesian network (BN) that relates offshore storm conditions to their accompagnying flood characteristics and damages to residential buildings, following on the trend of integrated flood impact modeling. It is based on data from hydrodynamic storm simulations, information

  9. A new approach to modelling the impact of disruptive events

    NARCIS (Netherlands)

    Oosterhaven, Jan; Bouwmeester, Maaike

    This paper develops a new methodology to predict the interregional and interindustry impacts of disruptive events. We model the reactions of economic agents by minimizing the information gain between the pre- and postevent pattern of economic transactions. The resulting nonlinear program reproduces,

  10. A Chemical Model of Micrometeorite Impact into Olivine

    Science.gov (United States)

    Sheffer, A. A.; Melosh, H. J.

    2005-01-01

    Laboratory simulations of space weathering using laser irradiation have been successful in reproducing space weathering characteristics such as the reduction of olivine to form nanophase iron particles. However, the chemistry of the reduction of Fe2+ in olivine to Fe metal has not been fully explored. We present a thermodynamic model of olivine undergoing post-impact cooling and decompression.

  11. Modelling climate change impacts on stream habitat conditions

    DEFF Research Database (Denmark)

    Boegh, Eva; Conallin, John; Karthikeyan, Matheswaran;

    , climate impacts on stream ecological conditions were quantified by combining a heat and mass stream flow with a habitat suitability modelling approach. Habitat suitability indices were developed for stream velocity, water depth, water temperature and substrate. Generally, water depth was found...

  12. Modeling tools to Account for Ethanol Impacts on BTEX Plumes

    Science.gov (United States)

    Widespread usage of ethanol in gasoline leads to impacts at leak sites which differ from those of non-ethanol gasolines. The presentation reviews current research results on the distribution of gasoline and ethanol, biodegradation, phase separation and cosolvancy. Model results f...

  13. Evaluation of occupant models for rear impact injury analysis

    NARCIS (Netherlands)

    Wu, W.P.; Griffioen, J.; Marshall, R.

    1999-01-01

    Occupant injury in automobile rear-end collisions is becoming one of the most costly and aggravating traffic safety problems. Designing seat and head restraints to help limit injury associated with rear-end impact can become more efficient by using new mathematical modeling techniques. Using the

  14. Do bird assemblages predict susceptibility by e-waste pollution? A comparative study based on species- and guild-dependent responses in China agroecosystems.

    Science.gov (United States)

    Zhang, Qiang; Wu, Jiangping; Sun, Yuxin; Zhang, Min; Mai, Bixian; Mo, Ling; Lee, Tien Ming; Zou, Fasheng

    2015-01-01

    Indirect effects of electronic waste (e-waste) have been proposed as a causal factor in the decline of bird populations, but analyses of the severity impacts on community assembly are currently lacking. To explore how population abundance/species diversity are influenced, and which functional traits are important in determining e-waste susceptibility, here we surveyed breeding and overwintering birds with a hierarchically nested sampling design, and used linear mixed models to analyze changes in bird assemblages along an exposure gradient in South China. Total bird abundance and species diversity decreased with e-waste severity (exposed e-waste polluted sites. A high pairwise similarity between exposed and surrounding sites indicates a diffuse effect of pollutants on the species assembly at local scale. We show that sensitivity to e-waste severity varies substantially across functional guild, with the prevalence of woodland insectivorous and grassland specialists declining, while some open farmland generalists such as arboreal frugivores, and terrestrial granivores were also rare. By contrast, the response of waterbirds, omnivorous and non-breeding visitors seem to be tolerable to a wide range of pollution so far. These findings underscore that improper e-waste dismantling results in a severe decline of bird diversity, and the different bird assemblages on polluted and natural farmlands imply species- and guild-dependent susceptibility with functional traits. Moreover, a better understanding of the impact of e-waste with different pollution levels, combined multiple pollutants, and in a food-web context on bird is required in future.

  15. Do bird assemblages predict susceptibility by e-waste pollution? A comparative study based on species- and guild-dependent responses in China agroecosystems.

    Directory of Open Access Journals (Sweden)

    Qiang Zhang

    Full Text Available Indirect effects of electronic waste (e-waste have been proposed as a causal factor in the decline of bird populations, but analyses of the severity impacts on community assembly are currently lacking. To explore how population abundance/species diversity are influenced, and which functional traits are important in determining e-waste susceptibility, here we surveyed breeding and overwintering birds with a hierarchically nested sampling design, and used linear mixed models to analyze changes in bird assemblages along an exposure gradient in South China. Total bird abundance and species diversity decreased with e-waste severity (exposed < surrounding < reference, reflecting the decreasing discharge and consequent side effects. Twenty-five breeding species exclusively used natural farmland, and nine species decreased significantly in relative abundance at e-waste polluted sites. A high pairwise similarity between exposed and surrounding sites indicates a diffuse effect of pollutants on the species assembly at local scale. We show that sensitivity to e-waste severity varies substantially across functional guild, with the prevalence of woodland insectivorous and grassland specialists declining, while some open farmland generalists such as arboreal frugivores, and terrestrial granivores were also rare. By contrast, the response of waterbirds, omnivorous and non-breeding visitors seem to be tolerable to a wide range of pollution so far. These findings underscore that improper e-waste dismantling results in a severe decline of bird diversity, and the different bird assemblages on polluted and natural farmlands imply species- and guild-dependent susceptibility with functional traits. Moreover, a better understanding of the impact of e-waste with different pollution levels, combined multiple pollutants, and in a food-web context on bird is required in future.

  16. Modeling the impact of immigration on the epidemiology of tuberculosis.

    Science.gov (United States)

    Jia, Zhong-Wei; Tang, Gong-You; Jin, Zhen; Dye, Christopher; Vlas, Sake J; Li, Xiao-Wen; Feng, Dan; Fang, Li-Qun; Zhao, Wen-Juan; Cao, Wu-Chun

    2008-05-01

    This paper presents two new theoretical frameworks to investigate the impact of immigration on the transmission dynamics of tuberculosis. For the basic model, we present new analysis on the existence and stability of equilibria. Then, we use numerical simulations of the model to illustrate the behavior of the system. We apply the model to Canadian reported data on tuberculosis and observe a good agreement between the model prediction and the data. For the extended model, which incorporated the recruitment of the latent and infectious in immigrants to the basic model, we find that the usual threshold condition does not apply and a unique equilibrium exists for all parameter values. This indicates that the disease does not disappear and becomes endemic in host areas. This finding is also supported by numerical simulations with the extended model. Our study suggests that immigrants have a considerable influence on the overall transmission dynamics behavior of tuberculosis.

  17. Impact of GOCE on Regional Geoid Modelling: Finnish Territory

    Science.gov (United States)

    Saari, Timo; Bilker-Koivula, Mirjam; Poutanen, Markku

    2016-08-01

    In the Dragon 3 project 10519 "Case study on heterogeneous geoid/quasigeoid based on space borne and terrestrial data combination with special consideration of GOCE mission data impact" we combined the latest GOCE models with the terrestrial gravity data of Finland and surrounding areas to calculate a quasi-geoid model for Finland. Altogether 249 geoid models with different modifications were calculated using the GOCE DIR5 models up to spherical harmonic degree and order 240 and 300 and the EIGEN-6C4 up to degree and order 1000 and 2190.The calculated quasi-geoid models were compared against the ground truth in Finland with two independent GPS-levelling datasets. The best GOCE- only models gave standard deviations of 2.8 cm, 2.6 cm (DIR5 d/o 240) and 2.7 cm, 2.3 cm (DIR5 d/o 300) in Finnish territory for NLS-FIN and EUVN-DA datasets, respectively. For the high resolution model EIGEN-6C4 (which includes the full cycle of the GOCE data), the results were 2.4 cm, 1.8 cm (d/o 1000) and 2.5 cm, 1.7 (d/o 2190). The sub-2-centimetre (and near 2 cm with GOCE-only) accuracy is an improvement over the previous and current Finnish geoid models, thus leading to a conclusion of the great impact of the GOCE- mission on regional geoid modelling.

  18. Continental scale analysis of bird migration timing: influences of climate and life history traits—a generalized mixture model clustering and discriminant approach

    Science.gov (United States)

    Chambers, Lynda E.; Beaumont, Linda J.; Hudson, Irene L.

    2014-08-01

    There is substantial evidence of climate-related shifts to the timing of avian migration. Although spring arrival has generally advanced, variable species responses and geographical biases in data collection make it difficult to generalise patterns. We advance previous studies by using novel multivariate statistical techniques to explore complex relationships between phenological trends, climate indices and species traits. Using 145 datasets for 52 bird species, we assess trends in first arrival date (FAD), last departure date (LDD) and timing of peak abundance at multiple Australian locations. Strong seasonal patterns were found, i.e. spring phenological events were more likely to significantly advance, while significant advances and delays occurred in other seasons. However, across all significant trends, the magnitude of delays exceeded that of advances, particularly for FAD (+22.3 and -9.6 days/decade, respectively). Geographic variations were found, with greater advances in FAD and LDD, in south-eastern Australia than in the north and west. We identified four species clusters that differed with respect to species traits and climate drivers. Species within bird clusters responded in similar ways to local climate variables, particularly the number of raindays and rainfall. The strength of phenological trends was more strongly related to local climate variables than to broad-scale drivers (Southern Oscillation Index), highlighting the importance of precipitation as a driver of movement in Australian birds.

  19. FAQ: West Nile Virus and Dead Birds

    Science.gov (United States)

    ... Education Public Service Videos West Nile Virus & Dead Birds Recommend on Facebook Tweet Share Compartir On This ... dead bird sightings to local authorities. How do birds get infected with West Nile virus? West Nile ...

  20. Migration Helps Spread Bird Flu Worldwide

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_161473.html Migration Helps Spread Bird Flu Worldwide Scientists recommend keeping ... birds can spread bird flu worldwide and monitoring migration routes could provide early warning of outbreaks, researchers ...