Deterrence of birds with an artificial predator, the RobotFalcon

Collisions between birds and airplanes can damage aircrafts, resulting in delays and cancellation of flights, costing the international civil aviation industry more than 1.4 billion US dollars annually. Driving away birds is therefore crucial, but the effectiveness of current deterrence methods is limited. Live avian predators can be an effective deterrent, because potential prey will not habituate to them, but live predators cannot be controlled entirely. Thus, there is an urgent need for new deterrence methods. We developed the RobotFalcon, a device modelled after the peregrine falcon, and tested its effectiveness to deter flocks of corvids, gulls, starlings and lapwings. We compared its effectiveness with that of a drone, and of conventional methods routinely applied at a military airbase. The RobotFalcon scared away bird flocks from fields immediately, and these fields subsequently remained free of bird flocks for hours. The RobotFalcon outperformed the drone and the best conventional method at the airbase (distress calls). Importantly, there was no evidence that bird flocks habituated to the RobotFalcon over the course of the fieldwork. We conclude that the RobotFalcon is a practical and ethical solution to drive away bird flocks with all advantages of live predators but without their limitations

Innovative Visualizations Shed Light on Avian Nocturnal Migration

We acknowledge the support provided by COST–European Cooperation in Science and Technology through the Action ES1305 ‘European Network for the Radar Surveillance of Animal Movement’ (ENRAM) in facilitating this collaboration. We thank ENRAM members and researchers attending the EOU round table discussion ‘Radar aeroecology: unravelling population scale patterns of avian movement’ for feedback on the visualizations. We thank Arie Dekker for his feedback as jury member of the bird migration visualization challenge & hackathon hosted at the University of Amsterdam, 25–27 March 2015. We thank Willem Bouten and Kevin Winner for discussion of methodological design. We thank Kevin Webb and Jed Irvine for assistance with downloading, managing, and reviewing US radar data. We thank the Royal Meteorological Institute of Belgium for providing weather radar data.Globally, billions of flying animals undergo seasonal migrations, many of which occur at night. The temporal and spatial scales at which migrations occur and our inability to directly observe these nocturnal movements makes monitoring and characterizing this critical period in migratory animals’ life cycles difficult. Remote sensing, therefore, has played an important role in our understanding of large-scale nocturnal bird migrations. Weather surveillance radar networks in Europe and North America have great potential for long-term low-cost monitoring of bird migration at scales that have previously been impossible to achieve. Such long-term monitoring, however, poses a number of challenges for the ornithological and ecological communities: how does one take advantage of this vast data resource, integrate information across multiple sensors and large spatial and temporal scales, and visually represent the data for interpretation and dissemination, considering the dynamic nature of migration? We assembled an interdisciplinary team of ecologists, meteorologists, computer scientists, and graphic designers to develop two different flow visualizations, which are interactive and open source, in order to create novel representations of broad-front nocturnal bird migration to address a primary impediment to long-term, large-scale nocturnal migration monitoring. We have applied these visualization techniques to mass bird migration events recorded by two different weather surveillance radar networks covering regions in Europe and North America. These applications show the flexibility and portability of such an approach. The visualizations provide an intuitive representation of the scale and dynamics of these complex systems, are easily accessible for a broad interest group, and are biologically insightful. Additionally, they facilitate fundamental ecological research, conservation, mitigation of human–wildlife conflicts, improvement of meteorological products, and public outreach, education, and engagement.Yeshttp://www.plosone.org/static/editorial#pee

BIRD STRIKE PREVENTION Version 3.x

Bird strike prevention is dictated by 3 main aspects of human behaviour: •Give the Black Jack (+ the bill) to someone else! •Do something! •Genesis 1:28 Genesis 1:28 God said to them: “….Rule over the fish in the sea and the birds in the sky and over every living creature that moves on the ground…” In Western society this statement has justified and contributed towards a human centered approach towards nature. Bird strike prevention Version 1.x and 2.x are based on this assumption. “Birds have to make way for undisturbed aviation operations” Players in the bird strike prevention Bird Strike Prevention Version 1.x “Do something” : active dispersal of birds Bird Strike Prevention Version 2.x “Do something” : habitat management Bird Strike Prevention Version 1.x / Version 2.x has been successful. But has reached its limits Emphasis needs to be shifted! Not just aimed at birds at or around airports But also at birds overflying the airport coming from A, flying to B Players in the bird strike prevention including overflying birds changes everything Government is asked to “do something” “Do something” = “keep birds out of our way” = pay the bill Spatial planning = how large an area is needed? = in what way is the landscape affected? Population management = culling: to what extend? = is it effective/ feasible? = public acceptance? In other words = how big is aviation’s footprint

Twilight ascents by common swifts, Apus apus, at dawn and dusk: acquisition of orientation cues?

Common swifts are specialist flyers spending most of their life aloft, including night-time periods when this species roosts on the wing. Nocturnal roosting is preceded by a vertical ascent in twilight conditions towards altitudes of up to 2.5 km, behaviour previously explained as flight altitude selection for sleeping. We examined the nocturnal flight behaviour of swifts, as uniquely identified by a Doppler weather radar in central Netherlands using continuous measurements during two consecutive breeding seasons. Common swifts performed twilight ascents not only at dusk but also at dawn, which casts new light on the purpose of these ascents. Dusk and dawn ascents were mirror images of each other when time-referenced to the moment of sunset and sunrise, suggesting that the acquisition of twilight-specific light-based cues plays an important role in the progression of the ascents. Ascent height was well explained by the altitude of the 280 K isotherm, and was not significantly related to wind, cloud base height, humidity or the presence of nocturnal insects. We hypothesize that swifts profile the state of the atmospheric boundary layer during twilight ascents and/or attempt to maximize their perceptual range for visual access to distant horizontal landmarks, including surrounding weather. We compare twilight profiling by swifts with vertical twilight movements observed in other taxa, proposed to be related to orientation and navigation. (C) 2012 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved

Simulation Model to Calculate Bird-Aircraft Collisions and Near Misses in the Airport Vicinity

Annually, thousands of birds collide with aircraft. The impact usually has lethal consequences for the bird. Depending on the circumstances, also the involved aircraft can suffer severe damage. The highest bird strike risk occurs at low altitudes. Therefore, measures to reduce this risk are widely applied at airports. However, also during flight phases at low altitudes, especially within the adjacent arrival and departure corridors of an airport, there is a higher risk of collisions between birds and aircraft. These areas are typically not reached by the airport's counteracting measures. To analyse risk-reducing measures in all areas with increased collision risk, a fast-time bird strike simulation environment was developed. It uses an open-source Air Traffic Management simulator as a base. The simulator was enhanced with a model to represent bird movements and to recognize collisions between birds and aircraft. Bird strikes depend on various parameters such as season, weather and surrounding ecosystems. In absolute terms, bird strikes represent relatively rare occurrences. To confirm that the simulation environment generates reproducible results even with a limited number of datasets, Monte-Carlo simulations were performed. They included bird movement data from one year and air traffic flight plans for various air traffic volumes. As expected due to the nature of randomness in bird strike occurrences, the number of bird strikes showed variance within the individual replications of the Monte-Carlo simulations. The results indicate that the predictability of the number of occurrences increases with rising number of birds, and rising air traffic intensity. Synthesis and applications. This study evaluated the robustness of a simulation environment for simulating the risk of bird strikes. By considering simulation scenarios including bird movement information from all seasons and a sufficient air traffic volume, the described set-up leads to stable results within the individual replications. Therefore, it can serve as a valuable tool to research novel measures to reduce the risk of bird strikes

Effect of electron contamination on scatter correction factors for photon beam dosimetry

Physical quantities for use in megavoltage photon beam dose calculations which are defined at the depth of maximum absorbed dose are sensitive to electron contamination and are difficult to measure and to calculate. Recently, formalisms have therefore been presented to assess the dose using collimator and phantom scatter correction factors, S(c) and S(p), defined at a reference depth of 10 cm. The data can be obtained from measurements at that depth in a miniphantom and in a full scatter phantom. Equations are presented that show the relation between these quantities and corresponding quantities obtained from measurements at the depth of the dose maximum. It is shown that conversion of S(c) and S(p) determined at a 10 cm depth to quantities defined at the dose maximum such as (normalized) peak scatter factor, (normalized) tissue-air ratio, and vice versa is not possible without quantitative knowledge of the electron contamination. The difference in S(c) at d(max) resulting from this electron contamination compared with S(c) values obtained at a depth of 10 cm in a miniphantom has been determined as a multiplication factor, S(cel), for a number of photon beams of different accelerator types. It is shown that S(cel) may vary up to 5%. Because in the new formalisms output factors are defined at a reference depth of 10 cm, they do not require S(cel) data. The use of S(c) and S(p) values, defined at a 10 cm depth, combined with relative depth-dose data or tissue-phantom ratios is therefore recommended. For a transition period the use of the equations provided in this article and S(cel) data might be required, for instance, if treatment planning systems apply S(c) data normalized at d(max

Dependence of the tray transmission factor on collimator setting and source-surface distance

When blocks are placed on a tray in megavoltage x-ray beams, generally a single correction factor for the attenuation by the tray is applied for each photon beam quality. In this approach, the tray transmission factor is assumed to be independent of field size and source-surface distance (SSD). Analysis of a set of measurements performed in beams of 13 different linear accelerators demonstrates that there is, however, a slight variation of the tray transmission factor with field size and SSD. The tray factor changes about 1.5% for collimator settings varying between 4 x 4 cm and 40 x 40 cm for a 1 cm thick PMMA tray and approximately 3% for a 2 cm thick PMMA tray. The variation with field size is smaller if the source-surface distance is increased. The dependence on the collimator setting is not different, within the experimental uncertainty of about 0.5% (1 s.d.), for the nominal accelerating potentials and accelerator types applied in this study. It is shown that the variation of the tray transmission factor with field size and source-surface distance can easily be taken into account in the dose calculation by considering the volume of the irradiated tray material and the position of the tray in the beam. A relation is presented which can be used to calculate the numerical value of the tray transmission factor directly. These calculated values can be checked with only a few measurements using a cylindrical beam coaxial miniphantom. (C) 2000 American Association of Physicists in Medicine