The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Javier Bustamante - One of the best experts on this subject based on the ideXlab platform.
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Why Do Kestrels Soar?
PLoS ONE, 2015Co-Authors: Jesús Hernández-pliego, Carlos Rodriguez, Javier BustamanteAbstract:Individuals allocate considerable amounts of energy to movement, which ultimately affects their ability to survive and reproduce. Birds fly by flapping their wings, which is dependent on the chemical energy produced by muscle work, or use soaring-gliding flight, in which chemical energy is replaced with energy harvested from moving air masses, such as thermals. Flapping flight requires more energy than soaring-gliding flight, and this difference in the use of energy increases with body mass. However, soaring-gliding results in lower speeds than flapping, especially for small species. Birds therefore face a trade-off between energy and time costs when deciding which flight strategy to use. Raptors are a group of large birds that typically soar. As relatively light weight raptors, falcons can either soar on weak thermals or fly by flapping with low energy costs. In this paper, we study the flight behavior of the insectivorous lesser Kestrel (Falco naumanni) during foraging trips and the influence of solar radiation, which we have adopted as a proxy for thermal formation, on Kestrel flight variables. We tracked 35 individuals from two colonies using high frequency GPS-dataloggers over four consecutive breeding seasons. Contrary to expectations, Kestrels relied heavily on thermal soaring when foraging, especially during periods of high solar radiation. This produced a circadian pattern in the Kestrel flight strategy that led to a spatial segregation of foraging areas. Kestrels flapped towards foraging areas close to the colony when thermals were not available. However, as soon as thermals were formed, they soared on them towards foraging areas far from the colony, especially when they were surrounded by poor foraging habitats. This reduced the chick provisioning rate at the colony. Given that lesser Kestrels have a preference for feeding on large insects, and considering the average distance they cover to capture them during foraging trips, to commute using flapping flight would result in a negative energy balance for the family group. Our results show that lesser Kestrels prioritize saving energy when foraging, suggesting that Kestrels are more energy than time-constrained during the breeding season.
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patterns of orthoptera abundance and lesser Kestrel conservation in arable landscapes
Biodiversity and Conservation, 2008Co-Authors: Carlos Rodriguez, Javier BustamanteAbstract:The lesser Kestrel Falco naumanni experienced a marked decline during the second half of the 20th century due to changes in land use that influenced breeding success by reducing the abundance and quality of prey. However, the factors governing spatial and temporal variation of prey abundance around lesser Kestrel colonies has not yet been investigated. We sampled Orthoptera abundance in the main crop types and edge habitats surrounding six lesser Kestrel colonies in southern Spain. Samplings focused on Orthoptera because they constitute the main prey during the nestling period. Only those Orthoptera species that are known to be preyed by lesser Kestrels were considered in this study. We found differences in prey density among localities, and crop types. Semi-natural habitats such as grasslands, fallow land, and field margins held the highest densities. However, prey abundance showed a complex pattern that was not possible to explain solely on the basis of crop composition around colonies. Factors determining productivity in individual fields like soil type and productivity or biocide input, and mean size of agricultural fields contributed to explain this complex pattern of prey abundance. Our results highlight the key role of semi-natural and edge habitats in farmed landscapes as prey reservoirs and corridors. Higher conservation priorities for these habitats are suggested to benefit foraging lesser Kestrels, but many other farmland species that also experienced steep population declines due to decreasing food supply resulting from modern agriculture.
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Evaluation of methods for gender determination of Lesser Kestrel nestlings
Journal of Raptor Research, 2005Co-Authors: Carlos Rodriguez, Javier Bustamante, Begoña Martínez-cruz, Juan J. NegroAbstract:-•The traditional method of determining gender of Lesser Kestrel (Falco naumanni) nestlings by visual assessment was tested for accuracy by using data from birds banded as nestlings and recaptured as adults. Concordance between gender assignment by different observers, and between visual and molecular gender determination was also evaluated. We tested whether color measurement of rumps and tails could improve gender determination. Based on recaptured Kestrels, gender determination by eye had a 9.7% error, and was significantly greater for males than for females. Observers mostly relied on rump and tail color to assign gender to nestlings. Assessment of head, shoulders, tail, and rump patterns did not provide additional information that could improve gender determination in nestlings at the time of banding. Gender assignment based on color measurement on digital photos of rumps and tails did not improve determination by eye, but color measurement from a scanned rump feather approached 100% accuracy. We provide a discriminant function equation based on red, green, and blue brightness values (RGB) of a scanned rump feather and propose this as an efficient and effective method for gender determination in Lesser Kestrel nestlings.
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predictive models for lesser Kestrel falco naumanni distribution abundance and extinction in southern spain
Biological Conservation, 1997Co-Authors: Javier BustamanteAbstract:Environmental variables measured on 1:10,000 to 1:3,000,000-scale maps of southern Spain were used to build generalized linear models for presence/absence of lesser Kestrel Falco naumanni colonies, extinction of colonies, and number of breeding pairs, in 6 × 6 km squares. Presence of breeding colonies in a square was positively associated with presence of urban areas, extent of non-irrigated cereal and sunflower crops, and mean annual rainfall, and negatively associated with extent of scrubland and forests. The model was statistically robust and had good predictive ability, correctly classifying 84% of the squares. Two alternative models were obtained for extinction of lesser Kestrel colonies in a square. The first indicated extinctions where there were large areas of scrubland and low annual rainfall, and the second where there were very large or very small areas of non-irrigated cereal and sunflower crops. Although both were statistically significant, neither was very robust or had a good predictive ability. The number of lesser Kestrel pairs breeding in a square showed a negative relationship with altitude, area of forest, and irrigated cultures, and a positive association with total length of rivers and streams. This model was not very robust and explained only 30·3% of the variance in Kestrel numbers. The models indicate that some climatic and land-use variables, as measured on the available maps, are good predictors of the presence of lesser Kestrel colonies in southern Spain, but less good at predicting the probability of extinction of colonies or the number of breeding pairs.
Juan Antonio Fargallo - One of the best experts on this subject based on the ideXlab platform.
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Avian predators as a biological control system of common vole (Microtus arvalis) populations in north-western Spain: Experimental set-up and preliminary results
Pest Management Science, 2013Co-Authors: Alfonso Paz, Daniel Jareño, Francois Mougeot, Beatriz Arroyo, Juan José Luque-larena, Leticia Arroyo, Javier Viñuela, Juan Antonio FargalloAbstract:BACKGROUND: Ecologically based rodent pest management using biological control has never been evaluated for vole plagues in Europe, although it has been successfully tested in other systems. The authors report on the first large-scale replicated experiment to study the usefulness of nest-box installation for increasing the breeding density of common Kestrels (Falco tinnunculus) and barn owls (Tyto alba) as a potential biological control of common vole (Microtus arvalis) abundance in agricultural habitats in north-western Spain.\n\nRESULTS: The results show that: (1) population density of both predator species increased in response to both nest-site availability and vole density; (2) voles are a major prey for the common Kestrels during the breeding period; (3) vole density during the increase phase of a population cycle may be reduced in crop fields near nest boxes.\n\nCONCLUSION: The installation of nest boxes provides nesting sites for barn owls and Kestrels. Kestrel populations increased faster than in areas without artificial nests, and the common vole was one of their main prey during the breeding season. The results suggest that local (field) effects could be found in terms of reduced vole density. If so, this could be an environmentally friendly and cheap vole control technique to be considered on a larger scale.
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Kestrel prey dynamic in a mediterranean region the effect of generalist predation and climatic factors
PLOS ONE, 2009Co-Authors: Juan Antonio Fargallo, Javier Viñuela, Guillermo Blanco, Jesus Martinezpadilla, Ignasi Torre, Pablo Vergara, Liesbeth De NeveAbstract:Background: Most hypotheses on population limitation of small mammals and their predators come from studies carried out in northern latitudes, mainly in boreal ecosystems. In such regions, many predators specialize on voles and predator-prey systems are simpler compared to southern ecosystems where predator communities are made up mostly of generalists and predator-prey systems are more complex. Determining food limitation in generalist predators is difficult due to their capacity to switch to alternative prey when the basic prey becomes scarce. Methodology: We monitored the population density of a generalist raptor, the Eurasian Kestrel Falco tinnunculus over 15 years in a mountainous Mediterranean area. In addition, we have recorded over 11 years the inter-annual variation in the abundance of two main prey species of Kestrels, the common vole Microtus arvalis and the eyed lizard Lacerta lepida and a third species scarcely represented in Kestrel diet, the great white-toothed shrew Crocidura russula. We estimated the per capita growth rate (PCGR) to analyse population dynamics of Kestrel and predator species. Principal Findings: Multimodel inference determined that the PCGR of Kestrels was better explained by a model containing the population density of only one prey species (the common vole) than a model using a combination of the densities of the three prey species. The PCGR of voles was explained by Kestrel abundance in combination with annual rainfall and mean annual temperature. In the case of shrews, growth rate was also affected by Kestrel abundance and temperature. Finally, we did not find any correlation between Kestrel and lizard abundances. Significance: Our study showed for the first time vertebrate predator-prey relationships at southern latitudes and determined that only one prey species has the capacity to modulate population dynamics of generalist predators and reveals the importance of climatic factors in the dynamics of micromammal species and lizards in the Mediterranean region.
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Fear in grasslands: The effect of Eurasian Kestrels on skylark abundances
Naturwissenschaften, 2008Co-Authors: Jesús Martínez-padilla, Juan Antonio FargalloAbstract:Predation has received considerable theoretical and empirical support in population regulation. The effect of predators, however, could be achieved in direct (killing) or indirect effects (such as displacement). In this paper, we explored the relationship between Eurasian Kestrels Falco tinnunculus and skylarks Alauda arvensis in Mediterranean grasslands. First, we analysed the presence of skylarks in the Kestrel diet over 9 years. We also compared a grassland area of experimentally increased Kestrel density and a second grassland as control area to evaluate the direct or indirect effect on skylark abundance. We also considered two different habitats, grazed and ungrazed plots. If skylark abundance decreased as the Kestrel breeding season progressed in high-density Kestrel area compared with the control area, it would suggest a direct effect (predator hypothesis). If skylark abundance remains constant in both areas of contrasting Kestrel density, it would suggest that skylarks avoid Kestrels (avoidance hypothesis). We found that skylark abundance decreased in the Kestrel area from the beginning of Kestrel nest-box installation to recent years. The rate of skylark consumption decreased in a 9-year period as Kestrel abundance increased, although the total amount skylark consumption did not show a decreasing trend. In addition, skylarks were more abundant in the Kestrel-free area than in the Kestrel area. Finally, we found that skylark abundance did not change through the Kestrel breeding period in relation to grazing. We suggest that an increased breeding density of Kestrels during their breeding period may force the skylarks to breed in other areas, which may explain the decline of their abundance.
David M. Bird - One of the best experts on this subject based on the ideXlab platform.
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The Use of Captive American Kestrels (Falco sparverius) as Wildlife Models: A Review
Journal of Raptor Research, 2009Co-Authors: Lina Bardo, David M. BirdAbstract:Abstract The American Kestrel (Falco sparverius) is a common North American falcon. As a result of a number of characteristics, including small size, annual reproduction, ability to be housed in large numbers, and ease of breeding in captivity, these falcons have been used as wildlife models for over four decades. Kestrels are best known for their use in the demonstration that 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), and 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) caused eggshell thinning and reproductive failure in birds, and their use in the amelioration of captive propagation programs for the Peregrine Falcon (F. peregrinus). Since that time, Kestrels have continued to play a prominent role in wildlife research, particularly in the field of toxicology, where they remain the only raptor species to be bred in sufficient numbers in captivity for statistically significant research. Kestrels have also been used for studies of avian biology, physiology, nutrition, and behavior. In recent y...
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changes in reproductive courtship behaviors of adult american Kestrels falco sparverius exposed to environmentally relevant levels of the polybrominated diphenyl ether mixture de 71
Toxicological Sciences, 2008Co-Authors: Kim J Fernie, John L Shutt, Robert J Letcher, James I Ritchie, Katrina M Sullivan, David M. BirdAbstract:Polybrominated diphenyl ethers (PBDEs) are increasing in biota. Here, captive adult American Kestrels were exposed daily by diet to safflower oil (controls), or one of two levels of a pentaBDE technical formulation, DE-71 (0.3 or 1.6 ppm), for approximately 75 days, commencing 21 days before breeding. This exposure resulted in eggs having PBDE concentrations similar (low exposure) or within the same order of magnitude (high exposure) reported for wild American Kestrels and gulls in the Great Lakes. Compared to controls, Kestrels in both exposure groups copulated less, spent less time in their nest boxes, and participated in fewer pairbonding behaviors. Furthermore, the timing of these behaviors, which is important to creating and maintaining the pair-bond, also differed significantly from the controls. The females in the lowexposure group made fewer compatible trilling calls and ate less frequently. These behavioral changes were compounded by increasing exposure to DE-71 during the 9-day courtship period immediately preceding egg laying, a standard measure of the Kestrel courtship period. The birds in the high-exposure group made more food transfers, excited ‘‘klee’’ calls, and copulations, the latter only when compared to the low-exposure birds, whereas the low-exposure males performed fewer pair-bonding behaviors. This study demonstrates that the exposure of Kestrels to environmentally relevant levels of DE-71 modifies the quality of the pair-bond, affects the reproductive behavior of both sexes, and occurs when birds are exposed for a short period as adults. In addition, these behavioral effects are consistent with the observed reproductive changes in these birds.
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plasma corticosterone in american Kestrel siblings effects of age hatching order and hatching asynchrony
Hormones and Behavior, 2003Co-Authors: Oliver P Love, David M. Bird, Laird J ShuttAbstract:Although it is well documented that hatching asynchrony in birds can lead to competitive and developmental hierarchies, potentially greatly affecting growth and survival of nestlings, hatching asynchrony may also precipitate modulations in neuroendocrine development or function. Here we examine sibling variation in adrenocortical function in postnatally developing, asynchronously hatching American Kestrels (Falco sparverius) by measurements of baseline and stress-induced levels of corticosterone at ages 10, 16, 22, and 28 days posthatching. There was a significant effect of hatching order on both baseline and stress-induced corticosterone levels during development and these effects grew stronger through development. First-hatched chicks exhibited higher baseline levels than later-hatched chicks throughout development and higher stress-induced levels during the latter half of development. Furthermore, there was significant hatching span (difference in days between first- and last-hatched chicks) × hatching order interaction on both baseline and stress-induced corticosterone levels during development. Hatching span was also positively correlated with both measures of corticosterone and body mass in first-hatched chicks, but was negatively correlated with these factors through most of the development in last-hatched chicks. It is known that hatching asynchrony creates mass and size hierarchies within Kestrel broods and we suggest that hierarchies in adrenocortical function among siblings may be one physiological mechanism by which these competitive hierarchies are maintained.
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Variations in blood packed cell volume of captive american Kestrels
Comparative Biochemistry and Physiology Part A: Physiology, 2003Co-Authors: N.b. Rehder, David M. Bird, Paul C. LaguëAbstract:Abstract 1. 1. Taking 0.9ml of blood (10% TBV) from American Kestrels weekly for 20 weeks did not affect PCV. 2. 2. American Kestrel PCV decreased when air temperature increased, and when the birds molted, laid eggs or were inactive. 3. 3. American Kestrel PCV did not vary with age after matu ity or between 0900 and 1200 hr. 4. 4. From 25 April to 10 September. PCV of female American Kestrels was lower than that of males only during egg-laying.
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BEHAVIOR OF FREE-RANGING AND CAPTIVE AMERICAN KestrelS UNDER ELECTROMAGNETIC FIELDS
Journal of Toxicology and Environmental Health, 2000Co-Authors: Kimberly J Fernie, Nancy J. Leonard, David M. BirdAbstract:Wild birds, particularly raptors, commonly use electrical transmission structures for nesting, perching, hunting, and roosting. Consequently, birds are exposed to electromagnetic fields (EMFs). The amount of time that wild reproducing American Kestrels (Falco sparverius) were exposed to EMFs was determined, and the effects of EMFs on the behavior of captive reproducing Kestrels were examined. Wild Kestrels were exposed to EMFs for 25% to 75% of the observed time. On a 24-h basis, estimated EMF exposure of wild Kestrels ranged from 71% during courtship, to 90% during incubation, similar to that experienced by captive Kestrels (88% of a 24-h period). Additionally, captive Kestrels were exposed to EMF levels experienced by wild Kestrels nesting under 735-kV power lines. Captive EMF females were more active, more alert, and perched on the pen roof more frequently than control females during courtship. EMF females preened and rested less often during brood rearing. EMF male Kestrels were more active than contr...
Pedro P Olea - One of the best experts on this subject based on the ideXlab platform.
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the role of fallow in habitat use by the lesser Kestrel during the post fledging period inferring potential conservation implications from the abolition of obligatory set aside
European Journal of Wildlife Research, 2010Co-Authors: A De Frutos, Pedro P Olea, Patricia Mateotomas, Francisco J PurroyAbstract:The maintenance of fallows has been shown to prevent the loss of farmland biodiversity caused by agricultural intensification. These are mainly introduced as part of both obligatory and voluntary set-aside schemes. However, the obligatory set-aside has recently been abolished by the Common Agricultural Policy Health Check. In this study, we examine the role of fallow in fine-grained habitat use by a threatened farmland bird (Lesser Kestrel) during summer in northwestern Spain. To analyze Lesser Kestrel occurrence, we used generalized linear models, a theoretic-information approach and a hierarchical partitioning analysis. The best AIC-based models explaining occurrence of Lesser Kestrels showed that fallow was the more important habitat type followed, to a lesser extent, by dry cereal stubble and field margin. In contrast, irrigated crops negatively influenced occurrence. Heterogeneity of crop mosaic was not important in explaining occurrence of Lesser Kestrel. Fallows, like dry cereal stubbles and field margins, seem to be suitable for foraging given the abundance of high food resources and their availability due to shorter vegetation cover. The abolition of the obligatory set-aside could reduce the total surface of fallow land (approximately 40.9%), likely affecting habitat use by Lesser Kestrel through an increase of other non-preferred crops (e.g., irrigated crops) or by decreasing food resources. Agri-environment schemes focusing on the maintenance of low-intensive farming systems with a mosaic of crops and semi-natural habitats interspersed should be promoted in premigratory areas to maintain Lesser Kestrel.
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importance of the premigratory areas for the conservation of lesser Kestrel space use and habitat selection during the post fledging period
Animal Conservation, 2008Co-Authors: A De Frutos, Pedro P OleaAbstract:The conservation importance of the post-fledging period in migratory birds has been scarcely assessed. In this study, we examined the space use and habitat selection of radio-tagged lesser Kestrels Falco naumanni at two spatial scales during summer in north-western Spain, where premigratory aggregations of around 1000 lesser Kestrels occur. Space use was estimated by kernel accounting for the spatiotemporal autocorrelation of the radio locations, and habitat selection was analysed by weighted compositional analysis accounting for the intensity of use. Kestrels moved within 9 km around roosts during daylight and returned daily during sunset to the same roosts, exhibiting refuging behaviour. They foraged on average 3.7 km from the roost in an area of 346.8 ha (home range), 92.7 ha of which were used intensively (core area). Within these areas, lesser Kestrels intensively used more farmland than any land-scale habitat. Within farmland, Kestrels significantly avoided the irrigated crops. This avoidance seemed to be due to the difficulty of prey access and/or scarcity of prey available. Conservation plans of lesser Kestrel should include the post-fledging period by legally protecting roost sites and maintaining dry farmland systems around the communal roosts.
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analyzing and modelling spatial distribution of summering lesser Kestrel the role of spatial autocorrelation
Ecological Modelling, 2007Co-Authors: A De Frutos, Pedro P Olea, Ruben VeraAbstract:Abstract In modelling spatial distribution of species, ignoring spatial autocorrelation (SA) and multicollinearity may lead to false ecological conclusions. Here we take into account both issues for examining and modelling the spatial pattern of abundance of the globally threatened lesser Kestrel ( Falco naumanni ) during summer in a 38,400 ha area of northwestern Spain where large premigratory aggregations of the species occur. Spatial pattern was examined using Moran's correlogram, and models were built including geographical coordinates and autocovariate terms (which account for SA) in generalized linear models (GLM) and hierarchical partitioning (HP) models. HP models allow to alleviate multicollinearity. A grid-based approach was used by dividing the study area in 24 contiguous 4 km × 4 km squares where birds were counted in 2–3 visits per square (response variable). Environmental coarse-grained variables were extracted from a geographic information system (GIS) at three spatial extents. Moran's correlogram showed that lesser Kestrel mean abundance per square was spatially autocorrelated up to 4–8 km. The results from both GLM and HP analyses were roughly compatible. The GLM models explained 80.0% of the variation in Kestrel abundance and were the same at the three spatial extents. Lesser Kestrel abundance was not significantly explained by landscape variables, but was negatively related to both the distance to the nearest communal roost and distance to the nearest breeding colony with more of 10 breeding pairs of lesser Kestrel. An autocovariate term added later in the GLM models improved both their explanatory power (from 74.5 to 80.0%) and model residuals, which were not longer spatially autocorrelated, fulfilling thus the statistical assumption of independent errors. Findings suggest that the spatial distribution of abundance of summering lesser Kestrel is, at least, partially driven by endogenous causes, such as conspecific attraction. Exogenous causes such as finer-scale variables (e.g. type of crops and food available) are yet likely needed for lesser Kestrel-environment relationships.
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Postfledging dispersal in the endangered Lesser Kestrel Falco naumanni
Bird Study, 2001Co-Authors: Pedro P OleaAbstract:Much is known about the breeding period of the threatened Lesser Kestrel, but little of the postfledging period. Here, I examine the postfledging dispersal of juvenile Lesser Kestrels, based on all ringing recoveries of Lesser Kestrels ringed as nestlings in Spain and recovered before September (migration) of the same year. Of 28 juveniles recovered, 19 (67.9%) dispersed and their median recovery distance was 210 km (range 41–578 km), with significantly northern directions. No difference was found in the dispersal distance between individuals ringed as nestlings in mid-north and mid-south Spain, nor was any correlation found between the recovery distance and ringing latitude. These findings for postfledging dispersal in juvenile Lesser Kestrels seem in accordance with predictions of a mental map hypothesis for homing, but they do not exclude food as a potential factor influencing such movements. However, these postfledging movements cannot be explained by the hypothesis of gathering information for identi...
Scott A Morton - One of the best experts on this subject based on the ideXlab platform.
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A Fixed-Wing Aircraft Simulation Tool for Improving DoD Acquisition Efficiency
Computing in Science & Engineering, 2016Co-Authors: Scott A Morton, David R McdanielAbstract:The HPCMP CREATE-AV Kestrel software product is a modularized, multidisciplinary, fixed-wing virtual aircraft simulation tool incorporating aerodynamics, structural dynamics, kinematics, and kinetics. Kestrel allows cross-over between simulation of aerodynamics, dynamic stability and control, structures, propulsion, and store separation. It's written in modular form with a Python infrastructure to allow growth to additional capabilities as needed. The current version of Kestrel is being used extensively in the government aircraft acquisition process and is being evaluated by industry for suitability to aircraft acquisition. Current capability is demonstrated for a maneuvering aircraft coupled with control surface movements, aeroelastic effects, store separation, and cargo deployment. In addition, several future capabilities currently in prototype are discussed.
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static and dynamic aeroelastic simulations using Kestrel a create aircraft simulation tool
53rd AIAA ASME ASCE AHS ASC Structures Structural Dynamics and Materials Conference<BR>20th AIAA ASME AHS Adaptive Structures Conference<BR&g, 2012Co-Authors: Scott A Morton, Steven E Lamberson, David R McdanielAbstract:This paper documents aeroelastic results from a new integrating product that allows cross-over between simulation of aerodynamics, dynamic stability and control, and structures in the current version, as well as propulsion and store separation in later versions. The Kestrel software product is an integrating product written in modular form with a Python infrastructure to allow growth to additional capabilities as needed. The Kestrel software product has been designed from the ground up to address fixed-wing aircraft in flight regimes ranging from subsonic through supersonic flight, including maneuvers, multi-aircraft configurations, and operational conditions. Kestrel v2.0 has nine simulation capabilities, static rigid body aircraft, rigid body maneuvering aircraft, aeroelastic aircraft, aircraft with control surface motion, predictive 6DoF aircraft motion, and combinations of the previous capabilities. Aeroelastic results for two wings and a generic fighter configuration are presented with comparison to experiment and other researcher’s data.
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aerodynamic control surface implementation in Kestrel v2 0
49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2011Co-Authors: David R Mcdaniel, David R Sears, Todd Tuckey, Brett Tillman, Scott A MortonAbstract:Kestrel is an integrating software product in the CREATE program that allows crossover between simulation of aerodynamics, dynamic stability and control, structures, propulsion, and store separation. It is written in a modular form with a Python infrastructure to allow growth to additional capabilities as needed. The second version of the Kestrel product includes the addition of two new components that enable both static and dynamic movement of aerodynamic control surfaces to be included in a fixed-wing simulation. This paper documents the design and implementation of these new components as well as their integration into the overall Kestrel environment. Both components are fully parallel and capable of handling any number of conventional control surfaces in a single unstructured mesh. Results from the Kestrel v2.0 testing involving a NACA 0015 wing with a single trailing edge control surface are presented.
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Kestrel v2 0 6dof and control surface additions to a create simulation tool
48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition, 2010Co-Authors: Scott A Morton, David R Mcdaniel, David R Sears, Brett Tillman, Todd TuckeyAbstract:This paper documents the second version of a new integrating product that allows crossover between simulation of aerodynamics, dynamic stability and control, structures, propulsion, and store separation. The Kestrel software product is an integrating product written in modular form with a Python infrastructure to allow growth to additional capabilities as needed. Computational efficiency will also be improved by targeting the next generation peta-flop architectures envisioned for the 2010+ time frame. The need for Kestrel developed from the fact that existing computational resources (hardware and CSE software) are insufficient to generate decision data in a timely enough way to impact early-phase and even many sustainment phase acquisition processes. Kestrel is also targeted to the need of simulating multi-disciplinary physics such as fluid-structure interactions, inclusion of propulsion effects, moving control surfaces, and coupled flight control systems. The Kestrel software product is to address these needs for fixed-wing aircraft in flight regimes ranging from subsonic through supersonic flight, including maneuvers, multi-aircraft configurations, and operational conditions. Version 2.0 adds a 6 Degree of Freedom (6DoF) component to provide a predictive motion capability and a moving control surface capability to allow more realistic aircraft simulations. Version 2.0 also provides parallel scalability performance improvements for moving and deforming mesh use cases.
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Kestrel -- A Fixed Wing Virtual Aircraft Product of the CREATE Program
2009 DoD High Performance Computing Modernization Program Users Group Conference, 2009Co-Authors: Scott A Morton, David R Mcdaniel, David R Sears, Brett Tillman, Todd TuckeyAbstract:This paper documents a new integrating product that allows cross-over between simulation of aerodynamics, dynamic stability and control, structures, propulsion, and store separation. The Kestrel software product is an integrating product written in modular form with a Python infrastructure to allow growth to additional capabilities as needed. Computational efficiency will also be improved by targeting the next generation peta-flop architectures envisioned for the 2010+ timeframe. Kestrel is also targeted to the need of simulating multidisciplinary physics, such as fluid-structure interactions, inclusion of propulsion effects, moving control surfaces, and coupled flight control systems. The Kestrel software product is to address these needs for fixed-wing aircraft in flight regimes ranging from subsonic through supersonic flight, including maneuvers, multi-aircraft configurations, and operational conditions. Preliminary results of the F-16C with comparison to experiments are provided. Parallel scalability analysis of the initial version of Kestrel is also presented.
