WorldWideScience

Sample records for bird wing insights

  1. The evolution of HoxD-11 expression in the bird wing: insights from Alligator mississippiensis.

    Directory of Open Access Journals (Sweden)

    Alexander O Vargas

    Full Text Available BACKGROUND: Comparative morphology identifies the digits of the wing of birds as 1,2 and 3, but they develop at embryological positions that become digits 2, 3 and 4 in other amniotes. A hypothesis to explain this is that a homeotic frame shift of digital identity occurred in the evolution of the bird wing, such that digits 1,2 and 3 are developing from embryological positions 2, 3 and 4. Digit 1 of the mouse is the only digit that shows no late expression of HoxD-11. This is also true for the anterior digit of the bird wing, suggesting this digit is actually a digit 1. If this is the case, we can expect closer relatives of birds to show no HoxD-11 expression only in digit 1. To test this prediction we investigate HoxD-11 expression in crocodilians, the closest living relatives of birds. METHODOLOGY/PRINCIPAL FINDINGS: Using degenerate primers we cloned a 606 nucleotide fragment of exon 1 of the alligator HoxD-11 gene and used it for whole-mount in-situ detection in alligator embryos. We found that in the pentadactyl forelimbs of alligator, as in the mouse, late expression of HoxD-11 is absent only in digit 1. CONCLUSIONS/SIGNIFICANCE: The ancestral condition for amniotes is that late-phase HoxD-11 expression is absent only in digit 1. The biphalangeal morphology and lack of HoxD-11 expression of the anterior digit of the wing is like digit 1 of alligator and mouse, but its embryological position as digit 2 is derived. HoxD-11 expression in alligator is consistent with the hypothesis that both digit morphology as well as HoxD-11 expression are shifted towards posterior in the bird wing.

  2. The Evolution of HoxD-11 Expression in the Bird Wing: Insights from Alligator mississippiensis

    Science.gov (United States)

    Vargas, Alexander O.; Kohlsdorf, Tiana; Fallon, John F.; VandenBrooks, John; Wagner, Günter P.

    2008-01-01

    Background Comparative morphology identifies the digits of the wing of birds as 1,2 and 3, but they develop at embryological positions that become digits 2, 3 and 4 in other amniotes. A hypothesis to explain this is that a homeotic frame shift of digital identity occurred in the evolution of the bird wing, such that digits 1,2 and 3 are developing from embryological positions 2, 3 and 4. Digit 1 of the mouse is the only digit that shows no late expression of HoxD-11. This is also true for the anterior digit of the bird wing, suggesting this digit is actually a digit 1. If this is the case, we can expect closer relatives of birds to show no HoxD-11 expression only in digit 1. To test this prediction we investigate HoxD-11 expression in crocodilians, the closest living relatives of birds. Methodology/Principal Findings Using degenerate primers we cloned a 606 nucleotide fragment of exon 1 of the alligator HoxD-11 gene and used it for whole-mount in-situ detection in alligator embryos. We found that in the pentadactyl forelimbs of alligator, as in the mouse, late expression of HoxD-11 is absent only in digit 1. Conclusions/Significance The ancestral condition for amniotes is that late-phase HoxD-11 expression is absent only in digit 1. The biphalangeal morphology and lack of HoxD-11 expression of the anterior digit of the wing is like digit 1 of alligator and mouse, but its embryological position as digit 2 is derived. HoxD-11 expression in alligator is consistent with the hypothesis that both digit morphology as well as HoxD-11 expression are shifted towards posterior in the bird wing. PMID:18833328

  3. Unsteady Aerodynamics of Flapping Wing of a Bird

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    M. Agoes Moelyadi

    2013-04-01

    Full Text Available The unsteady flow behavior and time-dependent aerodynamic characteristics of the flapping motion of a bird’s wing were investigated using a computational method. During flapping, aerodynamic interactions between bird wing surfaces and surrounding flow may occur, generating local time-dependent flow changes in the flow field and aerodynamic load of birds. To study the effect of flapping speed on unsteady aerodynamic load, two kinds of computational simulations were carried out, namely a quasi-steady and an unsteady simulation. To mimic the movement of the down-stroke and the upstroke of a bird, the flapping path accorded to a sinus function, with the wing attitude changing in dihedral angle and time. The computations of time-dependent viscous flow were based on the solution of the Reynolds Averaged Navier-Stokes equations by applying the k-e turbulence model. In addition, the discretization for the computational domain around the model used multi-block structured grid to provide more accuracy in capturing viscous flow, especially in the vicinity of the wing and body surfaces, to obtain a proper wing-body geometry model. For this research, the seagull bird was chosen, which has high aspect ratio wings with pointed wing-tips and a high camber wing section. The results include mesh movement, velocity contours as well as aerodynamic coefficients of the flapping motion of the bird at various flapping frequencies.

  4. Ontogeny of aerial righting and wing flapping in juvenile birds

    CERN Document Server

    Evangelista, Dennis; Huynh, Tony; Krivitskiy, Igor; Dudley, Robert

    2014-01-01

    Mechanisms of aerial righting in juvenile Chukar Partridge (Alectoris chukar) were studied from hatching through 14 days post hatching (dph). Asymmetric movements of the wings were used from 1 to 8 dph to effect progressively more successful righting behaviour via body roll. Following 8 dph, wing motions transitioned to bilaterally symmetric flapping that yielded aerial righting via nose down pitch, along with substantial increases in vertical force production during descent. Ontogenetically, the use of such wing motions to effect aerial righting precedes both symmetric flapping and a previously documented behaviour in chukar (i.e., wing assisted incline running) hypothesized to be relevant to incipient flight evolution in birds. These findings highlight the importance of asymmetric wing activation and controlled aerial manoeuvres during bird development, and are potentially relevant to understanding the origins of avian flight.

  5. Simulating Bird Strike on Aircraft Composite Wing Leading Edge.

    OpenAIRE

    Ericsson, Max

    2012-01-01

    In this master thesis project the possibility to model the response of a wing when subjected to bird strike using finite elements is analyzed. Since this transient event lasts only a few milliseconds the used solution method is explicit time integration. The wing is manufactured using carbon fiber laminate. Carbon fiber laminates have orthotropic material properties with different stiffness in different directions. Accordingly, there are damage mechanisms not considered when using metal that ...

  6. The wings before the bird: an evaluation of flapping-based locomotory hypotheses in bird antecedents

    Directory of Open Access Journals (Sweden)

    T. Alexander Dececchi

    2016-07-01

    Full Text Available Background: Powered flight is implicated as a major driver for the success of birds. Here we examine the effectiveness of three hypothesized pathways for the evolution of the flight stroke, the forelimb motion that powers aerial locomotion, in a terrestrial setting across a range of stem and basal avians: flap running, Wing Assisted Incline Running (WAIR, and wing-assisted leaping. Methods: Using biomechanical mathematical models based on known aerodynamic principals and in vivo experiments and ground truthed using extant avians we seek to test if an incipient flight stroke may have contributed sufficient force to permit flap running, WAIR, or leaping takeoff along the phylogenetic lineage from Coelurosauria to birds. Results: None of these behaviours were found to meet the biomechanical threshold requirements before Paraves. Neither was there a continuous trend of refinement for any of these biomechanical performances across phylogeny nor a signal of universal applicability near the origin of birds. None of these flap-based locomotory models appear to have been a major influence on pre-flight character acquisition such as pennaceous feathers, suggesting non-locomotory behaviours, and less stringent locomotory behaviours such as balancing and braking, played a role in the evolution of the maniraptoran wing and nascent flight stroke. We find no support for widespread prevalence of WAIR in non-avian theropods, but can’t reject its presence in large winged, small-bodied taxa like Microraptor and Archaeopteryx. Discussion: Using our first principles approach we find that “near flight” locomotor behaviors are most sensitive to wing area, and that non-locomotory related selection regimes likely expanded wing area well before WAIR and other such behaviors were possible in derived avians. These results suggest that investigations of the drivers for wing expansion and feather elongation in theropods need not be intrinsically linked to locomotory

  7. Note on the glide of a bird with wings bent downwards

    NARCIS (Netherlands)

    Sparenberg, J. A.

    2006-01-01

    This note considers the influence of the bending down of the wings of a bird on the performance of its glide. The induced drag of bent wings is compared with the induced drag of a corresponding straight wing. Numerical results are given.

  8. The moment of inertia of bird wings and the inertial power requirement for flapping flight

    Science.gov (United States)

    Berg; Rayner

    1995-01-01

    The agility and manoeuvrability of a flying animal and the inertial power required to flap the wings are related to the moment of inertia of the wings. The moments of inertia of the wings of 29 bird species and three bat species were determined using wing strip analysis. We also measured wing length, wing span, wing area, wing mass and body mass. A strong correlation (r2=0.997) was found between the moment of inertia and the product of wing mass and the square of wing length. Using this relationship, it was found that all birds that use their wings for underwater flight had a higher than average moment of inertia. Assuming sinusoidal wing movement, the inertial power requirement was found to be proportional to (body mass)0.799, an exponent close to literature values for both metabolic power output and minimum power required for flight. Ignoring wing retraction, a fairly approximate estimate showed that the inertial power required is 11­15 % of the minimum flight power. If the kinetic energy of the wings is partly converted into aerodynamic (useful) work at stroke reversal, the power loss due to inertial effects may be smaller.

  9. Longitudinal data reveal ontogenetic changes in the wing morphology of a long-distance migratory bird

    NARCIS (Netherlands)

    de la Hera, Ivan; Pulido, Francisco; Visser, Marcel E.

    2014-01-01

    In migratory bird species, juveniles normally have shorter and more rounded wings than adults. The causes of this age-specific difference in wing morphology, however, are largely unknown. Here, we used longitudinal data collected over 3years from a Pied Flycatcher Ficedula hypoleuca population to as

  10. Longitudinal data reveal ontogenetic changes in the wing morphology of a long-distance migratory bird

    NARCIS (Netherlands)

    De la Hera, I.; Pulido, F.; Visser, M.E.

    2014-01-01

    In migratory bird species, juveniles normally have shorter and more rounded wings than adults. The causes of this age-specific difference in wing morphology, however, are largely unknown. Here, we used longitudinal data collected over 3 years from a Pied Flycatcher Ficedula hypoleuca population to a

  11. 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.

  12. 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.

  13. 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.

  14. A study of a three-dimensional self-propelled flying bird with flapping wings

    Science.gov (United States)

    Zhu, LinLin; Guan, Hui; Wu, ChuiJie

    2015-09-01

    In this paper, a study of a three-dimensional (3D) self-propelled bionic flying bird in a viscous flow is carried out. This bionic bird is propelled and lifted through flapping and rotating wings, and better flying can be achieved by adjusting the flapping and rotation motion of wings. In this study, we found that the bird can fly faster forward and upward with appropriate center of rotation and oscillation without more energy consumption and have perfect flight performance at a certain angle of attack by adjusting the center of oscillation. The study utilizes a 3D computational fluid dynamics package which constitutes combined immersed boundary method and the volume of fluid method. In addition, it includes adaptive multigrid finite volume method and control strategy of swimming and flying.

  15. Novel Insights into Chromosome Evolution in Birds, Archosaurs, and Reptiles

    Science.gov (United States)

    Farré, Marta; Narayan, Jitendra; Slavov, Gancho T.; Damas, Joana; Auvil, Loretta; Li, Cai; Jarvis, Erich D.; Burt, David W.; Griffin, Darren K.; Larkin, Denis M.

    2016-01-01

    Homologous synteny blocks (HSBs) and evolutionary breakpoint regions (EBRs) in mammalian chromosomes are enriched for distinct DNA features, contributing to distinct phenotypes. To reveal HSB and EBR roles in avian evolution, we performed a sequence-based comparison of 21 avian and 5 outgroup species using recently sequenced genomes across the avian family tree and a newly-developed algorithm. We identified EBRs and HSBs in ancestral bird, archosaurian (bird, crocodile, and dinosaur), and reptile chromosomes. Genes involved in the regulation of gene expression and biosynthetic processes were preferably located in HSBs, including for example, avian-specific HSBs enriched for genes involved in limb development. Within birds, some lineage-specific EBRs rearranged genes were related to distinct phenotypes, such as forebrain development in parrots. Our findings provide novel evolutionary insights into genome evolution in birds, particularly on how chromosome rearrangements likely contributed to the formation of novel phenotypes. PMID:27401172

  16. On Wings of the Minimum Induced Drag: Spanload Implications for Aircraft and Birds

    Science.gov (United States)

    Bowers, Albion H.; Murillo, Oscar J.; Jensen, Robert (Red); Eslinger, Brian; Gelzer, Christian

    2016-01-01

    For nearly a century Ludwig Prandtl's lifting-line theory remains a standard tool for understanding and analyzing aircraft wings. The tool, said Prandtl, initially points to the elliptical spanload as the most efficient wing choice, and it, too, has become the standard in aviation. Having no other model, avian researchers have used the elliptical spanload virtually since its introduction. Yet over the last half-century, research in bird flight has generated increasing data incongruous with the elliptical spanload. In 1933 Prandtl published a little-known paper presenting a superior spanload: any other solution produces greater drag. We argue that this second spanload is the correct model for bird flight data. Based on research we present a unifying theory for superior efficiency and coordinated control in a single solution. Specifically, Prandtl's second spanload offers the only solution to three aspects of bird flight: how birds are able to turn and maneuver without a vertical tail; why birds fly in formation with their wingtips overlapped; and why narrow wingtips do not result in wingtip stall. We performed research using two experimental aircraft designed in accordance with the fundamentals of Prandtl's second paper, but applying recent developments, to validate the various potentials of the new spanload, to wit: as an alternative for avian researchers, to demonstrate the concept of proverse yaw, and to offer a new method of aircraft control and efficiency.

  17. Development of Bird-like Micro Aerial Vehicle with Flapping and Feathering Wing Motions

    Science.gov (United States)

    Maglasang, Jonathan; Goto, Norihiro; Isogai, Koji

    To investigate the feasibility of a highly efficient flapping system capable of avian maneuvers, such as rapid takeoff, hover and gliding, a full scale bird-like (ornithopter) flapping-wing micro aerial vehicle (MAV) shaped and patterned after a typical pigeon (Columba livia) has been designed and constructed. Both numerical and experimental methods have been used in the development of this vehicle. This flapping-wing micro aerial vehicle utilizes both the flapping and feathering motions of an avian wing by employing a novel flapping-feathering mechanism, which has been synthesized and constructed so as to best describe the properly coordinated flapping and feathering wing motions at phase angle difference of 90° in a horizontal steady level flight condition. This design allows high flapping and feathering amplitudes and is configurable for asymmetric wing motions which are desirable in high-speed flapping flight and maneuvering. The preliminary results indicate its viability as a practical and an efficient flapping-wing micro aerial vehicle.

  18. Origin and diversification of wings: Insights from a neopteran insect.

    Science.gov (United States)

    Medved, Victor; Marden, James H; Fescemyer, Howard W; Der, Joshua P; Liu, Jin; Mahfooz, Najmus; Popadić, Aleksandar

    2015-12-29

    Winged insects underwent an unparalleled evolutionary radiation, but mechanisms underlying the origin and diversification of wings in basal insects are sparsely known compared with more derived holometabolous insects. In the neopteran species Oncopeltus fasciatus, we manipulated wing specification genes and used RNA-seq to obtain both functional and genomic perspectives. Combined with previous studies, our results suggest the following key steps in wing origin and diversification. First, a set of dorsally derived outgrowths evolved along a number of body segments including the first thoracic segment (T1). Homeotic genes were subsequently co-opted to suppress growth of some dorsal flaps in the thorax and abdomen. In T1 this suppression was accomplished by Sex combs reduced, that when experimentally removed, results in an ectopic T1 flap similar to prothoracic winglets present in fossil hemipteroids and other early insects. Global gene-expression differences in ectopic T1 vs. T2/T3 wings suggest that the transition from flaps to wings required ventrally originating cells, homologous with those in ancestral arthropod gill flaps/epipods, to migrate dorsally and fuse with the dorsal flap tissue thereby bringing new functional gene networks; these presumably enabled the T2/T3 wing's increased size and functionality. Third, "fused" wings became both the wing blade and surrounding regions of the dorsal thorax cuticle, providing tissue for subsequent modifications including wing folding and the fit of folded wings. Finally, Ultrabithorax was co-opted to uncouple the morphology of T2 and T3 wings and to act as a general modifier of hindwings, which in turn governed the subsequent diversification of lineage-specific wing forms.

  19. Marginal eyespots on butterfly wings deflect bird attacks under low light intensities with UV wavelengths.

    Directory of Open Access Journals (Sweden)

    Martin Olofsson

    Full Text Available BACKGROUND: Predators preferentially attack vital body parts to avoid prey escape. Consequently, prey adaptations that make predators attack less crucial body parts are expected to evolve. Marginal eyespots on butterfly wings have long been thought to have this deflective, but hitherto undemonstrated function. METHODOLOGY/PRINCIPAL FINDINGS: Here we report that a butterfly, Lopinga achine, with broad-spectrum reflective white scales in its marginal eyespot pupils deceives a generalist avian predator, the blue tit, to attack the marginal eyespots, but only under particular conditions-in our experiments, low light intensities with a prominent UV component. Under high light intensity conditions with a similar UV component, and at low light intensities without UV, blue tits directed attacks towards the butterfly head. CONCLUSIONS/SIGNIFICANCE: In nature, birds typically forage intensively at early dawn, when the light environment shifts to shorter wavelengths, and the contrast between the eyespot pupils and the background increases. Among butterflies, deflecting attacks is likely to be particularly important at dawn when low ambient temperatures make escape by flight impossible, and when insectivorous birds typically initiate another day's search for food. Our finding that the deflective function of eyespots is highly dependent on the ambient light environment helps explain why previous attempts have provided little support for the deflective role of marginal eyespots, and we hypothesize that the mechanism that we have discovered in our experiments in a laboratory setting may function also in nature when birds forage on resting butterflies under low light intensities.

  20. "Bird-Wing" abdominal phalloplasty: A novel surgical technique for penile reconstruction

    Directory of Open Access Journals (Sweden)

    Minu Bajpai

    2013-01-01

    Full Text Available Aim: To describe a technique of phalloplasty that is devoid of donor site scarring and suitable for urethral inlay and penile prosthesis in subsequent stages in cases of aphallia. Materials and Methods: Four patients with various disorders of sex development with 46 XY and severe penile deficiency, including one with complete androgen insensitivity syndrome who was initially raised as female, have been operated using a "Bird Wing" lower abdominal skin crease incision. Results: The patients′ age ranged from 6 to 17 years with preoperative stretched penile lengths between 1 and 2.5 cm. Phallic sizes between 7.5 and 12.5 cm was achieved leaving the donor site unremarkable with lower abdominal skin crease linear scar and excellent postoperative recovery. Conclusions: This phalloplasty technique can be utilized as a definitive procedure in many situations of penile insufficiency. Subsequent stages of urethral repair and insertion of penile prosthesis can be easily added.

  1. Anterior maxillary osteotomy: A technical note for superior repositioning: A bird wing segment

    Directory of Open Access Journals (Sweden)

    V Sadesh Kannan

    2014-01-01

    Full Text Available Aim: The aim of this study is to evaluate the efficacy of a single piece bird wing osteotectomy segment during anterior maxillary osteotomy (AMO markedly reduces the duration of the surgery by nearly one-half of the time during bone removal with the conventional method thereby reducing the kinking effect to the palatal pedicle and gives good perfusion to the anterior segment. Materials and Methods: This study was conducted at Karpaga Vinayaga Institute of Dental Sciences composing of 20 patients in which male: female ratio was 8:12, with a mean age of 25-30 years. This bird wing segment technique is performed following presurgical orthodontics under the guidance of clinical assessment of the gummy smile with an incisal show when the lip is at repose (vertical maxillary excess, especially for the calculated amount of superior repositioning. It is calculated by subtracting 2 mm from the total amount of an incisor show when the lip is at repose. The normal incisal show when the lip is at repose is 2 mm. After conventional primary AMO cut was performed, the precise calculated. Results: All our cases were tested positive for pulp vitality, no relapse, and minimal edema and with no changes in the bite or dentoalveolar relation followed until 1 year postoperatively indicating a good perfusion to the anterior segment and all the patients were satisfied esthetically and free of complaints. Conclusion: This simple technique allows the precise amount of calculated bone removal in a single piece from the nasal floor markedly reduces the duration of the surgery by nearly one-half of the time during bone removal with the conventional method there by reducing the kinking effect to the palatal pedicle and maintains good perfusion.

  2. 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.

  3. 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.

  4. Molecular Ecological Insights into Neotropical Bird-Tick Interactions.

    Directory of Open Access Journals (Sweden)

    Matthew J Miller

    Full Text Available In the tropics, ticks parasitize many classes of vertebrate hosts. However, because many tropical tick species are only identifiable in the adult stage, and these adults usually parasitize mammals, most attention on the ecology of tick-host interactions has focused on mammalian hosts. In contrast, immature Neotropical ticks are often found on wild birds, yet difficulties in identifying immatures hinder studies of birds' role in tropical tick ecology and tick-borne disease transmission. In Panama, we found immature ticks on 227 out of 3,498 individually-sampled birds representing 93 host species (24% of the bird species sampled, and 13% of the Panamanian land bird fauna. Tick parasitism rates did not vary with rainfall or temperature, but did vary significantly with several host ecological traits. Likewise, Neotropical-Nearctic migratory birds were significantly less likely to be infested than resident species. Using a molecular library developed from morphologically-identified adult ticks specifically for this study, we identified eleven tick species parasitizing birds, indicating that a substantial portion of the Panamanian avian species pool is parasitized by a diversity of tick species. Tick species that most commonly parasitized birds had the widest diversity of avian hosts, suggesting that immature tick species are opportunistic bird parasites. Although certain avian ecological traits are positively associated with parasitism, we found no evidence that individual tick species show specificity to particular avian host ecological traits. Finally, our data suggest that the four principal vectors of Rocky Mountain Spotted Fever in the Neotropics rarely, if ever, parasitize Panamanian birds. However, other tick species that harbor newly-discovered rickettsial parasites of unknown pathogenicity are frequently found on these birds. Given our discovery of broad interaction between Panamanian tick and avian biodiversity, future work on tick ecology

  5. 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

  6. Tuberculosis in Birds: Insights into the Mycobacterium avium Infections

    Directory of Open Access Journals (Sweden)

    Kuldeep Dhama

    2011-01-01

    Full Text Available Tuberculosis, a List B disease of World Organization for Animal Health, caused by M. avium or M. genavense predominantly affects poultry and pet or captive birds. Clinical manifestations in birds include emaciation, depression and diarrhea along with marked atrophy of breast muscle. Unlike tuberculosis in animals and man, lesions in lungs are rare. Tubercular nodules can be seen in liver, spleen, intestine and bone marrow. Granulomatous lesion without calcification is a prominent feature. The disease is a rarity in organized poultry sector due to improved farm practices, but occurs in zoo aviaries. Molecular techniques like polymerase chain reaction combined with restriction fragment length polymorphism and gene probes aid in rapid identification and characterization of mycobacteria subspecies, and overcome disadvantages of conventional methods which are slow, labour intensive and may at times fail to produce precise results. M. avium subsp. avium with genotype IS901+ and IS1245+ causes infections in animals and human beings too. The bacterium causes sensitivity in cattle to the tuberculin test. The paper discusses in brief the M. avium infection in birds, its importance in a zoonotic perspective, and outlines conventional and novel strategies for its diagnosis, prevention and eradication in domestic/pet birds and humans alike.

  7. The influence of wing morphology on the three-dimensional flow patterns of a flapping wing at bird scale

    NARCIS (Netherlands)

    Thielicke, William; Stamhuis, Eize J.

    2015-01-01

    The effect of airfoil design parameters, such as airfoil thickness and camber, are well understood in steady-state aerodynamics. But this knowledge cannot be readily applied to the flapping flight in insects and birds: flow visualizations and computational analyses of flapping flight have identified

  8. Feathered non-avian dinosaurs from North America provide insight into wing origins.

    Science.gov (United States)

    Zelenitsky, Darla K; Therrien, François; Erickson, Gregory M; DeBuhr, Christopher L; Kobayashi, Yoshitsugu; Eberth, David A; Hadfield, Frank

    2012-10-26

    Previously described feathered dinosaurs reveal a fascinating record of feather evolution, although substantial phylogenetic gaps remain. Here we report the occurrence of feathers in ornithomimosaurs, a clade of non-maniraptoran theropods for which fossilized feathers were previously unknown. The Ornithomimus specimens, recovered from Upper Cretaceous deposits of Alberta, Canada, provide new insights into dinosaur plumage and the origin of the avian wing. Individuals from different growth stages reveal the presence of a filamentous feather covering throughout life and winglike structures on the forelimbs of adults. The appearance of winglike structures in older animals indicates that they may have evolved in association with reproductive behaviors. These specimens show that primordial wings originated earlier than previously thought, among non-maniraptoran theropods.

  9. Reproductive costs in terrestrial male vertebrates: insights from bird studies.

    Science.gov (United States)

    Bleu, Josefa; Gamelon, Marlène; Sæther, Bernt-Erik

    2016-01-27

    Reproduction requires resources that cannot be allocated to other functions resulting in direct reproductive costs (i.e. trade-offs between current reproduction and subsequent survival/reproduction). In wild vertebrates, direct reproductive costs have been widely described in females, but their occurrence in males remains to be explored. To fill this gap, we gathered 53 studies on 48 species testing direct reproductive costs in male vertebrates. We found a trade-off between current reproduction and subsequent performances in 29% of the species and in every clade. As 73% of the studied species are birds, we focused on that clade to investigate whether such trade-offs are associated with (i) levels of paternal care, (ii) polygyny or (iii) pace of life. More precisely for this third question, it is expected that fast species (i.e. short lifespan, early maturity, high fecundity) pay a cost in terms of survival, whereas slow species (with opposite characteristics) do so in terms of fecundity. Our findings tend to support this hypothesis. Finally, we pointed out the potential confounding effects that should be accounted for when investigating reproductive costs in males and strongly encourage the investigation of such costs in more clades to understand to what extent our results are relevant for other vertebrates.

  10. A new specimen of the Early Cretaceous bird Hongshanornis longicresta: insights into the aerodynamics and diet of a basal ornithuromorph

    Directory of Open Access Journals (Sweden)

    Luis M. Chiappe

    2014-01-01

    Full Text Available The discovery of Hongshanornis longicresta, a small ornithuromorph bird with unusually long hindlimb proportions, was followed by the discovery of two closely related species, Longicrusavis houi and Parahongshanornis chaoyangensis. Together forming the Hongshanornithidae, these species reveal important information about the early diversity and morphological specialization of ornithuromorphs, the clade that contains all living birds. Here we report on a new specimen (DNHM D2945/6 referable to Hongshanornis longicresta that contributes significant information to better understand the morphology, trophic ecology, and aerodynamics of this species, as well as the taxonomy of the Hongshanornithidae. Most notable are the well-preserved wings and feathered tail of DNHM D2945/6, which afford an accurate reconstruction of aerodynamic parameters indicating that as early as 125 million years ago, basal ornithuromorphs had evolved aerodynamic surfaces comparable in size and design to those of many modern birds, and flight modes alike to those of some small living birds.

  11. Avian Wings

    Science.gov (United States)

    Liu, Tianshu; Kuykendoll, K.; Rhew, R.; Jones, S.

    2004-01-01

    This paper describes the avian wing geometry (Seagull, Merganser, Teal and Owl) extracted from non-contact surface measurements using a three-dimensional laser scanner. The geometric quantities, including the camber line and thickness distribution of airfoil, wing planform, chord distribution, and twist distribution, are given in convenient analytical expressions. Thus, the avian wing surfaces can be generated and the wing kinematics can be simulated. The aerodynamic characteristics of avian airfoils in steady inviscid flows are briefly discussed. The avian wing kinematics is recovered from videos of three level-flying birds (Crane, Seagull and Goose) based on a two-jointed arm model. A flapping seagull wing in the 3D physical space is re-constructed from the extracted wing geometry and kinematics.

  12. Study of the Bionic Design of Bird Flapping Wing Mechanism%机器鸟扑翼仿生机构研究

    Institute of Scientific and Technical Information of China (English)

    王旭光; 崔建昆; 范建华

    2013-01-01

    通过对鸟类翅膀的生理结构和运动特征的分析,分别从扑翼鸟的翅膀骨骼机构和飞行中翅膀运动规律两个仿生学角度设计了鸟类翅膀的驱动平面机构.并利用机构设计软件SAM6.0对其进行了运动学的仿真,仿真效果优异,从而为仿生大型鸟类机体设计提供了参考.%The drive plane mechanism of the birds wing is designed respectively from two bionic perspectives of bone institutions of the bird wing and the motion law of the flapping wing. The simulation effect is excellent on the kinematics simulation by the mechanical design software SAM6.0. The reference for design the body of large bionic flapping wing mechanism in our country is provided.

  13. 机翼前缘结构鸟撞仿真分析与试验验证%Bird Strike Simulation and Test Validation for Wing Leading Edge

    Institute of Scientific and Technical Information of China (English)

    王会利

    2015-01-01

    Bird strike simulation by using instantaneous non-linear FEM is an important work in the process of the bird strike design.In this paper, the bird strike simulation of four different wing leading edge structures with FE software PAM-CRASH is presented, the optimum structure was chosen in four structures.Meanwhile, the bird strike test is done to the optimum structure, the strain curves and clash-force curves were compared with simulation results, the curvilinear trends were in concordance, which indicate experimental results were reasonable, and provided the reference for the design and promotion of bird-strike resistance of wing leading edge.%采用瞬态非线性有限元方法进行鸟撞仿真已成为鸟撞设计工作的主要内容。运用PAM-CRASH软件对四种不同前缘结构进行了仿真计算分析,选出了四种结构中的最优结构。同时,对选出的最优前缘结构进行了鸟撞试验,将试验得到的应变曲线和撞击力曲线与仿真结果进行对比,曲线趋势基本一致,说明仿真计算结果是合理的,为前缘结构的抗鸟撞设计及改型提供了参考。

  14. New Insights on Insect's Silent Flight. Part I: Vortex Dynamics and Wing Morphing

    Science.gov (United States)

    Ren, Yan; Liu, Geng; Dong, Haibo; Geng, Biao; Zheng, Xudong; Xue, Qian

    2016-11-01

    Insects are capable of conducting silent flights. This is attributed to its specially designed wing material properties for the control of vibration and surface morphing during the flapping flight. In current work, we focus on the roles of dynamic wing morphing on the unsteady vortex dynamics of a cicada in steady flight. A 3D image-based surface reconstruction method is used to obtain kinematical and morphological data of cicada wings from high-quality high-speed videos. The observed morphing wing kinematics is highly complex and a singular value decomposition method is used to decompose the wing motion to several dominant modes with distinct motion features. A high-fidelity immersed-boundary-based flow solver is then used to study the vortex dynamics in details. The results show that vortical structures closely relate to the morphing mode, which plays key role in the development and attachment of leading-edge vortex (LEV), thus helps the silent flapping of the cicada wings. This work is supported by AFOSR FA9550-12-1-0071 and NSF CBET-1313217.

  15. Agricultural Set-aside Programs and Grassland Birds: Insights from Broad-scale Population Trends

    Directory of Open Access Journals (Sweden)

    S. Riffell

    2008-10-01

    Full Text Available The Conservation Reserve Program (CRP is a voluntary set-aside program in the United States designed to amelioratesoil erosion, control crop overproduction, enhance water quality, and provide wildlife habitat by replacing crops with other forms of land cover. Because CRP includes primarily grass habitats, it has great potential to benefitdeclining North American grassland bird populations. We looked at the change in national and state population trends of grassland birds and related changes to cover-specific CRP variables (previous research grouped all CRP practices. Changes in national trends after the initiation of the CRP were inconclusive, but we observed signficant bird-CRP relations at the state level. Most bird-CRP relations were positive, except for some species associated with habitats that CRP replaced. Practice- and configuration-specific CRP variables were related to grassland bird trends, rather than a generic measure of all CRP types combined. Considering all CRP land as a single, distinct habitat type may obscure actual relations between birds and set-aside characteristics. Understanding and predictingthe effects of set-aside programs (like CRP or agri-environment schemes on grassland birds is complex and difficult. Because available broad-scale datasets are less than adequate, studies should be conducted at a variety of spatial and temporal scales.

  16. Anatomy and histochemistry of flight muscles in a wing-propelled diving bird, the Atlantic puffin, Fratercula arctica.

    Science.gov (United States)

    Kovacs, C E; Meyers, R A

    2000-05-01

    Twenty-three species within the avian family Alcidae are capable of wing-propelled flight in the air and underwater. Alcids have been viewed as Northern Hemisphere parallels to penguins, and have often been studied to see if their underwater flight comes at a cost, compromising their aerial flying ability. We examined the anatomy and histochemistry of select wing muscles (Mm. pectoralis, supracoracoideus, latissimus dorsi caudalis, coracobrachialis caudalis, triceps scapularis, and scapulohumeralis caudalis) from Atlantic puffins (Fratercula arctica) to assess if the muscle fiber types reveal the existence of a compromise associated with "dual-medium" flight. Pectoralis was found to be proportional in size with that of nondiving species, although the supracoracoideus was proportionally larger in puffins. Muscle fiber types were largely aerobic in both muscles, with two distinct fast-twitch types demonstrable: a smaller, aerobic, moderately glycolytic population (FOg), and a larger, moderately aerobic, glycolytic population (FoG). The presence of these two fiber types in the primary flight muscles of puffins suggests that aerial and underwater flight necessitate a largely aerobic fiber complement. We suggest that alcids do not represent an adaptive compromise, but a stable adaptation for wing-propelled locomotion both in the air and underwater.

  17. Natural history traits associated with detecting mortality within residential bird communities: can citizen science provide insights?

    Science.gov (United States)

    Cooper, Caren Beth; Loyd, Kerrie Anne Therese; Murante, Tessa; Savoca, Matthew; Dickinson, Janis

    2012-07-01

    Cat predation of birds in residential landscapes is ephemeral, unpredictable, and spatially dispersed, and thus requires many person-hours to observe. We sought to identify whether specific behaviors, traits, or feeding ecologies of birds contribute to their probability of cat-caused mortality around residences across temperate North America. In addressing this question, we evaluated citizen science data with respect to peer-reviewed species accounts (Birds of North America, BNA). Using information on cat predation from the BNA, we found that species that glean their prey from the ground or breed in nest boxes were three times more likely to be depredated by cats, while birds that hawk were over two times less likely to become cat prey than would be predicted by random chance. Data from citizen science sources also showed that birds using nest boxes had increased susceptibility to cat predation, as did those that use feeders and that glean from foliage. We caution that observations of predation by citizen science volunteers may be biased towards detection at feeders. Future research should focus on developing volunteer survey techniques for improving estimates of bird mortality rates and sources.

  18. Kinematic Optimization in Birds, Bats and Ornithopters

    Science.gov (United States)

    Reichert, Todd

    Birds and bats employ a variety of advanced wing motions in the efficient production of thrust. The purpose of this thesis is to quantify the benefit of these advanced wing motions, determine the optimal theoretical wing kinematics for a given flight condition, and to develop a methodology for applying the results in the optimal design of flapping-wing aircraft (ornithopters). To this end, a medium-fidelity, combined aero-structural model has been developed that is capable of simulating the advanced kinematics seen in bird flight, as well as the highly non-linear structural deformations typical of high-aspect ratio wings. Five unique methods of thrust production observed in natural species have been isolated, quantified and thoroughly investigated for their dependence on Reynolds number, airfoil selection, frequency, amplitude and relative phasing. A gradient-based optimization algorithm has been employed to determined the wing kinematics that result in the minimum required power for a generalized aircraft or species in any given flight condition. In addition to the theoretical work, with the help of an extended team, the methodology was applied to the design and construction of the world's first successful human-powered ornithopter. The Snowbird Human-Powered Ornithopter, is used as an example aircraft to show how additional design constraints can pose limits on the optimal kinematics. The results show significant trends that give insight into the kinematic operation of natural species. The general result is that additional complexity, whether it be larger twisting deformations or advanced wing-folding mechanisms, allows for the possibility of more efficient flight. At its theoretical optimum, the efficiency of flapping-wings exceeds that of current rotors and propellers, although these efficiencies are quite difficult to achieve in practice.

  19. Micromagnetic insight into a magnetoreceptor in birds: existence of magnetic field amplifiers in the beak

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Greiner, Walter

    2009-01-01

    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...... of the ophthalmic nerves in the skin of the upper beak of homing pigeons and were shown to fulfill the special prerequisites of a biological receptor. Here we study the proposed receptor theoretically and formulate the criteria for which it becomes operational and can be used for registering the weak magnetic...

  20. How do frugivores track resources? Insights from spatial analyses of bird foraging in a tropical forest

    Science.gov (United States)

    Saracco, J.F.; Collazo, J.A.; Groom, M.J.

    2004-01-01

    Frugivores often track ripe fruit abundance closely across local areas despite the ephemeral and typically patchy distributions of this resource. We use spatial auto- and cross-correlation analyses to quantify spatial patterns of fruit abundance and avian frugivory across a 4-month period within a forested 4.05-ha study grid in Puerto Rico. Analyses focused on two tanager species, Spindalis portoricensis and Nesospingus speculiferus, and their principal food plants. Three broad questions are addressed: (1) at what spatial scales is fruit abundance and frugivory patchy; (2) at what spatial scales do frugivores respond to fruit abundance; and (3) to what extent do spatial patterns of frugivory overlap between bird species? Fruit patch size, species composition, and heterogeneity was variable among months, despite fruit patch locations remaining relatively consistent between months. Positive correlations between frugivory and fruit abundance suggested tanagers successfully tracked fruit abundance. Frugivory was, however, more localized than fruit abundance. Scales of spatial overlap in frugivory and monthly variation in the foraging locations of the two tanager species suggested that interspecific facilitation may have been important in determining bird foraging locations. In particular, S. portoricensis, a specialist frugivore, may have relied on the loud calls of the gregarious generalist, N. speculiferus, to find new foraging areas. Such a mechanism could help explain the formation of mixed species feeding flocks and highlights the potential importance of facilitation between species that share resources. ?? Springer-Verlag 2004.

  1. How cooperatively breeding birds identify relatives and avoid incest: New insights into dispersal and kin recognition.

    Science.gov (United States)

    Riehl, Christina; Stern, Caitlin A

    2015-12-01

    Cooperative breeding in birds typically occurs when offspring - usually males - delay dispersal from their natal group, remaining with the family to help rear younger kin. Sex-biased dispersal is thought to have evolved in order to reduce the risk of inbreeding, resulting in low relatedness between mates and the loss of indirect fitness benefits for the dispersing sex. In this review, we discuss several recent studies showing that dispersal patterns are more variable than previously thought, often leading to complex genetic structure within cooperative avian societies. These empirical findings accord with recent theoretical models suggesting that sex- biased dispersal is neither necessary, nor always sufficient, to prevent inbreeding. The ability to recognize relatives, primarily by learning individual or group-specific vocalizations, may play a more important role in incest avoidance than currently appreciated.

  2. An advanced, new long-legged bird from the Early Cretaceous of the Jehol Group (northeastern China): insights into the temporal divergence of modern birds.

    Science.gov (United States)

    Liu, Di; Chiappe, Luis M; Zhang, Yuguang; Bell, Alyssa; Meng, Qingjin; Ji, Qiang; Wang, Xuri

    2014-11-14

    We describe a new ornithuromorph bird species, Gansus zheni from the Lower Cretaceous lacustrine deposits of the Jiufotang Formation (Jehol Group), Liaoning Province, China. A cladistic analysis resolves Gansus zheni as the sister taxon of the roughly contemporaneous Gansus yumenensis (Xiagou Formation, Gansu Province), and together as the most immediate outgroup to Ornithurae. Gansus zheni is the most advanced bird known today for the Jehol Biota. Its discovery provides the best-documented case of inter-basinal correlations (Jehol and Changma basins of Liaoning and Gansu provinces, respectively) using low-taxonomic clades of fossil birds. The existence of close relatives of Ornithurae in deposits formed at about 120 million years ago helps to mitigate the long-standing controversy between molecular and paleontological evidence for the temporal divergence of modern birds (Neornithes).

  3. Role of wing morphing in thrust generation

    Directory of Open Access Journals (Sweden)

    Mehdi Ghommem

    2014-01-01

    Full Text Available In this paper, we investigate the role of morphing on flight dynamics of two birds by simulating the flow over rigid and morphing wings that have the characteristics of two different birds, namely the Giant Petrel and Dove Prion. The simulation of a flapping rigid wing shows that the root of the wing should be placed at a specific angle of attack in order to generate enough lift to balance the weight of the bird. However, in this case the generated thrust is either very small, or even negative, depending on the wing shape. Further, results show that morphing of the wing enables a significant increase in the thrust and propulsive efficiency. This indicates that the birds actually utilize some sort of active wing twisting and bending to produce enough thrust. This study should facilitate better guidance for the design of flapping air vehicles.

  4. How swifts control their glide performance with morphing wings

    NARCIS (Netherlands)

    Lentink, D.; Muller, U. K.; Stamhuis, E. J.; de Kat, R.; van Gestel, W.; Veldhuis, L. L. M.; Henningsson, P.; Hedenstrom, A.; Videler, J. J.

    2007-01-01

    Gliding birds continually change the shape and size of their wings(1-6), presumably to exploit the profound effect of wing morphology on aerodynamic performance(7-9). That birds should adjust wing sweep to suit glide speed has been predicted qualitatively by analytical glide models(2,10), which extr

  5. How swifts control their glide performance with morphing wings

    NARCIS (Netherlands)

    Lentink, D.; Müller, U.K.; Stamhuis, E.J.; Kat, de R.; Gestel, van W.J.H.; Veldhuis, L.L.M.; Henningsson, P.; Hedenström, A.; Videler, J.J.; Leeuwen, van J.L.

    2007-01-01

    Gliding birds continually change the shape and size of their wings1, 2, 3, 4, 5, 6, presumably to exploit the profound effect of wing morphology on aerodynamic performance7, 8, 9. That birds should adjust wing sweep to suit glide speed has been predicted qualitatively by analytical glide models2, 10

  6. AERODYNAMICS OF WING TIP SAILS

    Directory of Open Access Journals (Sweden)

    MUSHTAK AL-ATABI

    2006-06-01

    Full Text Available Observers have always been fascinated by soaring birds. An interesting feature of these birds is the existence of few feathers extending from the tip of the wing. In this paper, small lifting surfaces were fitted to the tip of a NACA0012 wing in a fashion similar to that of wing tip feathers. Experimental measurements of induced drag, longitudinal static stability and trailing vortex structure were obtained.The tests showed that adding wing tip surfaces (sails decreased the induced drag factor and increased the longitudinal static stability. Results identified two discrete appositely rotated tip vortices and showed the ability of wing tip surfaces to break them down and to diffuse them.

  7. Ornithopter type flapping wings for autonomous micro air vehicles

    OpenAIRE

    2015-01-01

    In this paper, an ornithopter prototype that mimics the flapping motion of bird flight is developed, and the lift and thrust generation characteristics of different wing designs are evaluated. This project focused on the spar arrangement and material used for the wings that could achieves improved performance. Various lift and thrust measurement techniques are explored and evaluated. Various wings of insects and birds were evaluated to understand how these natural flyers with flapping wings a...

  8. Insights into Airframe Aerodynamics and Rotor-on-Wing Interactions from a 0.25-Scale Tiltrotor Wind Tunnel Model

    Science.gov (United States)

    Young, L. A.; Lillie, D.; McCluer, M.; Yamauchi, G. K.; Derby, M. R.

    2001-01-01

    A recent experimental investigation into tiltrotor aerodynamics and acoustics has resulted in the acquisition of a set of data related to tiltrotor airframe aerodynamics and rotor and wing interactional aerodynamics. This work was conducted in the National Full-scale Aerodynamics Complex's (NFAC) 40-by-80 Foot Wind Tunnel, at NASA Ames Research Center, on the Full-Span Tilt Rotor Aeroacoustic Model (TRAM). The full-span TRAM wind tunnel test stand is nominally based on a quarter-scale representation of the V-22 aircraft. The data acquired will enable the refinement of analytical tools for the prediction of tiltrotor aeromechanics and aeroacoustics.

  9. Synchrotron imaging of dentition provides insights into the biology of Hesperornis and Ichthyornis, the “last” toothed birds

    OpenAIRE

    Dumont, Maïtena; Tafforeau, Paul; Bertin, Thomas; Bhullar, Bhart-Anjan; Field, Daniel; Schulp, Anne; Strilisky, Brandon; Thivichon-Prince, Béatrice; Viriot, Laurent; Louchart, Antoine

    2016-01-01

    Background The dentitions of extinct organisms can provide pivotal information regarding their phylogenetic position, as well as paleobiology, diet, development, and growth. Extant birds are edentulous (toothless), but their closest relatives among stem birds, the Cretaceous Hesperornithiformes and Ichthyornithiformes, retained teeth. Despite their significant phylogenetic position immediately outside the avian crown group, the dentitions of these taxa have never been studied in detail. To ob...

  10. 基于欧拉—拉格朗日方法的复合材料机翼前缘鸟撞模拟%Finite element analysis of bird striking on a composite wing leading edge based on eulerian-lagrangian method

    Institute of Scientific and Technical Information of China (English)

    杜龙

    2012-01-01

    Along with large-scale application of composite materials in aircraft structures,a bird striking problem has become more prominent. Numerical simulations for bird striking on a composite wing leading edge were performed using ABAQUS based on Eulerian-Lagrangian method. Parametric analyses for the dynamic response of bird striking were performed with different bird velocities,densities and wing skin ply arrangements. The damage due to bird striking in the composite wing was simulated when the leading edge was filled with foam core. The destructive mechanism due to bird striking of the composite wing skin was analysed. The results gave a reference for engineering designs.%复合材料大面积用于飞机结构后,其鸟撞问题变得更加突出.利用大型通用有限元程序ABAQUS,采用耦合欧拉-拉格朗日方法(CEL)对某型无人机复合材料机翼前缘的鸟撞问题进行模拟,研究鸟体速度、密度和蒙皮铺层形式等对鸟撞动响应的影响,计算机翼前缘填充泡沫后的鸟撞损伤,对复合材料蒙皮的鸟撞破坏机理进行分析,所得结果对工程设计具有参考意义.

  11. 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。

  12. An amphioxus winged helix/forkhead gene, AmphiFoxD: insights into vertebrate neural crest evolution

    Science.gov (United States)

    Yu, Jr-Kai; Holland, Nicholas D.; Holland, Linda Z.

    2002-01-01

    During amphioxus development, the neural plate is bordered by cells expressing many genes with homologs involved in vertebrate neural crest induction. However, these amphioxus cells evidently lack additional genetic programs for the cell delaminations, migrations, and differentiations characterizing definitive vertebrate neural crest. We characterize an amphioxus winged helix/forkhead gene (AmphiFoxD) closely related to vertebrate FoxD genes. Phylogenetic analysis indicates that the AmphiFoxD is basal to vertebrate FoxD1, FoxD2, FoxD3, FoxD4, and FoxD5. One of these vertebrate genes (FoxD3) consistently marks neural crest during development. Early in amphioxus development, AmphiFoxD is expressed medially in the anterior neural plate as well as in axial (notochordal) and paraxial mesoderm; later, the gene is expressed in the somites, notochord, cerebral vesicle (diencephalon), and hindgut endoderm. However, there is never any expression in cells bordering the neural plate. We speculate that an AmphiFoxD homolog in the common ancestor of amphioxus and vertebrates was involved in histogenic processes in the mesoderm (evagination and delamination of the somites and notochord); then, in the early vertebrates, descendant paralogs of this gene began functioning in the presumptive neural crest bordering the neural plate to help make possible the delaminations and cell migrations that characterize definitive vertebrate neural crest. Copyright 2002 Wiley-Liss, Inc.

  13. Homology of the cranial vault in birds: new insights based on embryonic fate-mapping and character analysis

    Science.gov (United States)

    Maddin, Hillary C.; Piekarski, Nadine; Sefton, Elizabeth M.; Hanken, James

    2016-08-01

    Bones of the cranial vault appear to be highly conserved among tetrapod vertebrates. Moreover, bones identified with the same name are assumed to be evolutionarily homologous. However, recent developmental studies reveal a key difference in the embryonic origin of cranial vault bones between representatives of two amniote lineages, mammals and birds, thereby challenging this view. In the mouse, the frontal is derived from cranial neural crest (CNC) but the parietal is derived from mesoderm, placing the CNC-mesoderm boundary at the suture between these bones. In the chicken, this boundary is located within the frontal. This difference and related data have led several recent authors to suggest that bones of the avian cranial vault are misidentified and should be renamed. To elucidate this apparent conflict, we fate-mapped CNC and mesoderm in axolotl to reveal the contributions of these two embryonic cell populations to the cranial vault in a urodele amphibian. The CNC-mesoderm boundary in axolotl is located between the frontal and parietal bones, as in the mouse but unlike the chicken. If, however, the avian frontal is regarded instead as a fused frontal and parietal (i.e. frontoparietal) and the parietal as a postparietal, then the cranial vault of birds becomes developmentally and topologically congruent with those of urodeles and mammals. This alternative hypothesis of cranial vault homology is also phylogenetically consistent with data from the tetrapod fossil record, where frontal, parietal and postparietal bones are present in stem lineages of all extant taxa, including birds. It further implies that a postparietal may be present in most non-avian archosaurs, but fused to the parietal or supraoccipital as in many extant mammals.

  14. Migration on Wings Aerodynamics and Energetics

    CERN Document Server

    Kantha, Lakshmi

    2012-01-01

    This book is an effort to explore the technical aspects associated with bird flight and migration on wings. After a short introduction on the birds migration, the book reviews the aerodynamics and Energetics of Flight and presents the calculation of the Migration Range. In addition, the authors explains aerodynamics of the formation flight and finally introduces great flight diagrams.

  15. 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...

  16. Design, fabrication, and characterization of multifunctional wings to harvest solar energy in flapping wing air vehicles

    Science.gov (United States)

    Perez-Rosado, Ariel; Gehlhar, Rachel D.; Nolen, Savannah; Gupta, Satyandra K.; Bruck, Hugh A.

    2015-06-01

    Currently, flapping wing unmanned aerial vehicles (a.k.a., ornithopters or robotic birds) sustain very short duration flight due to limited on-board energy storage capacity. Therefore, energy harvesting elements, such as flexible solar cells, need to be used as materials in critical components, such as wing structures, to increase operational performance. In this paper, we describe a layered fabrication method that was developed for realizing multifunctional composite wings for a unique robotic bird we developed, known as Robo Raven, by creating compliant wing structure from flexible solar cells. The deformed wing shape and aerodynamic lift/thrust loads were characterized throughout the flapping cycle to understand wing mechanics. A multifunctional performance analysis was developed to understand how integration of solar cells into the wings influences flight performance under two different operating conditions: (1) directly powering wings to increase operation time, and (2) recharging batteries to eliminate need for external charging sources. The experimental data is then used in the analysis to identify a performance index for assessing benefits of multifunctional compliant wing structures. The resulting platform, Robo Raven III, was the first demonstration of a robotic bird that flew using energy harvested from solar cells. We developed three different versions of the wing design to validate the multifunctional performance analysis. It was also determined that residual thrust correlated to shear deformation of the wing induced by torsional twist, while biaxial strain related to change in aerodynamic shape correlated to lift. It was also found that shear deformation of the solar cells induced changes in power output directly correlating to thrust generation associated with torsional deformation. Thus, it was determined that multifunctional solar cell wings may be capable of three functions: (1) lightweight and flexible structure to generate aerodynamic forces, (2

  17. Intra-specific variation in wing morphology and its impact on take-off performance in blue tits (Cyanistes caeruleus) during escape flights.

    Science.gov (United States)

    McFarlane, Laura; Altringham, John D; Askew, Graham N

    2016-05-01

    Diurnal and seasonal increases in body mass and seasonal reductions in wing area may compromise a bird's ability to escape, as less of the power available from the flight muscles can be used to accelerate and elevate the animal's centre of mass. Here, we investigated the effects of intra-specific variation in wing morphology on escape take-off performance in blue tits (Cyanistes caeruleus). Flights were recorded using synchronised high-speed video cameras and take-off performance was quantified as the sum of the rates of change of the kinetic and potential energies of the centre of mass. Individuals with a lower wing loading, WL (WL=body weight/wing area) had higher escape take-off performance, consistent with the increase in lift production expected from relatively larger wings. Unexpectedly, it was found that the total power available from the flight muscles (estimated using an aerodynamic analysis) was inversely related to WL. This could simply be because birds with a higher WL have relatively smaller flight muscles. Alternatively or additionally, variation in the aerodynamic load on the wing resulting from differences in wing morphology will affect the mechanical performance of the flight muscles via effects on the muscle's length trajectory. Consistent with this hypothesis is the observation that wing beat frequency and relative downstroke duration increase with decreasing WL; both are factors that are expected to increase muscle power output. Understanding how wing morphology influences take-off performance gives insight into the potential risks associated with feather loss and seasonal and diurnal fluctuations in body mass.

  18. DNA from bird-dispersed seed and wind-disseminated pollen provides insights into postglacial colonization and population genetic structure of whitebark pine (Pinus albicaulis).

    Science.gov (United States)

    Richardson, B A; Brunsfeld, S J; Klopfenstein, N B

    2002-02-01

    Uniparentally inherited mitochondrial (mt)DNA and chloroplast (cp)DNA microsatellites (cpSSRs) were used to examine population genetic structure and biogeographic patterns of bird-dispersed seed and wind-disseminated pollen of whitebark pine (Pinus albicaulis Engelm.). Sampling was conducted from 41 populations throughout the range of the species. Analyses provide evidence for an ancestral haplotype and two derived mtDNA haplotypes with distinct regional distributions. An abrupt contact zone between mtDNA haplotypes in the Cascade Range suggests postglacial biogeographic movements. Among three cpSSR loci, 42 haplotypes were detected within 28 cpSSR sample populations that were aggregated into six regions. Analysis of molecular variance (amova) was used to determine the hierarchical genetic structure of cpSSRs. amova and population pairwise comparisons (FST ) of cpSSR, and geographical distribution of mtDNA haplotypes provide insights into historical changes in biogeography. The genetic data suggest that whitebark pine has been intimately tied to climatic change and associated glaciation, which has led to range movements facilitated by seed dispersal by Clark's nutcracker (Nucifraga columbiana Wilson). The two hypotheses proposed to explain the genetic structure are: (i) a northward expansion into Canada and the northern Cascades in the early Holocene; and (ii) historical gene flow between Idaho and the Oregon Cascades when more continuous habitat existed in Central Oregon during the late Pleistocene. Genetic structure and insights gained from historical seed movements provide a basis on which to develop recovery plans for a species that is at risk from multiple threats.

  19. 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...

  20. Micro-Scale Flapping Wings for the Advancement of Flying MEMS

    Science.gov (United States)

    2009-03-01

    wings. These devices are often called entomopters, winged in- sect machines, or ornithopter , winged bird machines. The flapping wing benefits from both...minutes of flight before refueling is required [26–28]. An ornithopter from Tamkang University was reviewed. It was constructed using titanium alloy...Grasmeyer, Y. C. Tai, C. M. Ho, and M. Keennon, “Mems wing technology for a battery-powered ornithopter ,” Proceedings of the IEEE Micro Electro Mechanical

  1. Method for Force Analysis of Spatial Four Bar Linkage Bird-like Flapping-wing Mechanism Based on ProE%基于 ProE 的空间四连杆仿鸟扑翼机构的受力分析方法

    Institute of Scientific and Technical Information of China (English)

    梁俊杰; 黄文恺; 伍冯洁; 朱静

    2016-01-01

    According to the strict requirements of air drag and the strength of mechanical parts of the design of bird -like flapping-wing mechanism , we propose a method for Force Analysis of spatial four bar linkage flapping-wing mechanism based on ProE.Firstly, make a necessary simplification for the bird-like flapping-wing mechanism and the bird-like.Next, analyze the move-ment of the mechanism and the moment of resistance caused by air drag , and find out the moment function of follower motion speed . Finally, set parameter values in ProE to realize the force analysis , and then obtain the data which can be helpful to checking the strength of mechanical parts .The results show that this method for force analysis of spatial four bar linkage bird-like flapping-wing mechanism can simplify the design process and improve the design efficiency .%针对仿鸟扑翼机构设计中对空气阻力以及机构零件强度的严格要求,提出了一种基于ProE的对空间四连杆扑翼机构的受力分析方法。首先,对仿鸟扑翼机构及翅翼进行必要的简化;其次,将机构运动情况和空气阻力引起的阻力矩进行耦合,得出阻力矩关于从动件运动速度的函数;最后在ProE中设置参数,实现受力分析,并得出可用于校核零件强度的受力分析数据。结果表明,该方法应用于仿鸟扑翼机构的受力分析可以简化设计流程,提高设计效率。

  2. Mother Nature inspires new wind turbine wing

    DEFF Research Database (Denmark)

    Sønderberg Petersen, L.

    2007-01-01

    The sight of a bird of prey hanging immobile in the air while its wings continuously adjust themselves slightly in relation to the wind in order to keep the bird in the same position in the air, is a sight that most of us have admired, including the windenergy scientists at Risø DTU. They have st...... started transferring the principle to wind turbine blades to make them adaptive...

  3. Experimental Methods to Characterize Nonlinear Vibration of Flapping Wing Micro Air Vehicles

    Science.gov (United States)

    2007-03-01

    the following terminology when referring to flapping wing MAVs; bird flight machines are also known as ornithopters and robotic insects are also...15. SUBJECT TERMS Flapping Wing Micro Air Vehicle, flapping-wing MAV, MAV, ornithopter , entomopter, nonlinear vibration, beam resonance

  4. 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....

  5. Angel's Wings

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ Angel's wings had fallen off. It started slowly,a couple of feathers breaking loose in the wind,floating away in carefree spirals, then in clumps in the shower, matted wet and clogging the drain,until one day he woke in a thick layer of white plumage, quills snagging on the stained sheets.

  6. Poisonous birds: A timely review.

    Science.gov (United States)

    Ligabue-Braun, Rodrigo; Carlini, Célia Regina

    2015-06-01

    Until very recently, toxicity was not considered a trait observed in birds, but works published in the last two decades started to shed light on this subject. Poisonous birds are rare (or little studied), and comprise Pitohui and Ifrita birds from Papua New Guinea, the European quail, the Spoor-winged goose, the Hoopees, the North American Ruffed grouse, the Bronzewings, and the Red warbler. A hundred more species are considered unpalatable or malodorous to humans and other animals. The present review intends to present the current understanding of bird toxicity, possibly pointing to an ignored research field. Whenever possible, biochemical characteristics of these poisons and their effects on humans and other animals are discussed, along with historical aspects of poison discovery and evolutionary hypothesis regarding their function.

  7. Design and Construction of Passively Articulated Ornithopter Wings

    Science.gov (United States)

    Mastro, Alexander Timothy

    Birds, bats, and insects are able to fly efficiently and execute impressive in-flight, landing, and takeoff maneuvers with apparent ease through actuation of their highly articulated wings. This contrasts the approach used to enable the flight of comparatively simple man-made rotary and fixed wing aircraft. The complex aerodynamics underlying flapping-based flight pose an everpresent challenge to scientists hoping to reveal the secrets of animal flight. Despite this, interest in engineering aircraft on the bird and insect scale is higher than ever. Herein, I present my attempt to design and construct bioinspired passively articulated ornithopter wings. Two different hinge-based joint design concepts are investigated across several design iterations. The advantages and disadvantages of each implementation are discussed. Finally, the necessary instrumentation to analyze the performance of the wings is designed and fabricated, followed by testing of the wings.

  8. Comparative Analysis of Uninhibited and Constrained Avian Wing Aerodynamics

    Science.gov (United States)

    Cox, Jordan A.

    The flight of birds has intrigued and motivated man for many years. Bird flight served as the primary inspiration of flying machines developed by Leonardo Da Vinci, Otto Lilienthal, and even the Wright brothers. Avian flight has once again drawn the attention of the scientific community as unmanned aerial vehicles (UAV) are not only becoming more popular, but smaller. Birds are once again influencing the designs of aircraft. Small UAVs operating within flight conditions and low Reynolds numbers common to birds are not yet capable of the high levels of control and agility that birds display with ease. Many researchers believe the potential to improve small UAV performance can be obtained by applying features common to birds such as feathers and flapping flight to small UAVs. Although the effects of feathers on a wing have received some attention, the effects of localized transient feather motion and surface geometry on the flight performance of a wing have been largely overlooked. In this research, the effects of freely moving feathers on a preserved red tailed hawk wing were studied. A series of experiments were conducted to measure the aerodynamic forces on a hawk wing with varying levels of feather movement permitted. Angle of attack and air speed were varied within the natural flight envelope of the hawk. Subsequent identical tests were performed with the feather motion constrained through the use of externally-applied surface treatments. Additional tests involved the study of an absolutely fixed geometry mold-and-cast wing model of the original bird wing. Final tests were also performed after applying surface coatings to the cast wing. High speed videos taken during tests revealed the extent of the feather movement between wing models. Images of the microscopic surface structure of each wing model were analyzed to establish variations in surface geometry between models. Recorded aerodynamic forces were then compared to the known feather motion and surface

  9. Actogram analysis of free-flying migratory birds: new perspectives based on acceleration logging.

    Science.gov (United States)

    Bäckman, Johan; Andersson, Arne; Pedersen, Lykke; Sjöberg, Sissel; Tøttrup, Anders P; Alerstam, Thomas

    2017-03-25

    The use of accelerometers has become an important part of biologging techniques for large-sized birds with accelerometer data providing information about flight mode, wing-beat pattern, behaviour and energy expenditure. Such data show that birds using much energy-saving soaring/gliding flight like frigatebirds and swifts can stay airborne without landing for several months. Successful accelerometer studies have recently been conducted also for free-flying small songbirds during their entire annual cycle. Here we review the principles and possibilities for accelerometer studies in bird migration. We use the first annual actograms (for red-backed shrike Lanius collurio) to explore new analyses and insights that become possible with accelerometer data. Actogram data allow precise estimates of numbers of flights, flight durations as well as departure/landing times during the annual cycle. Annual and diurnal rhythms of migratory flights, as well as prolonged nocturnal flights across desert barriers are illustrated. The shifting balance between flight, rest and different intensities of activity throughout the year as revealed by actogram data can be used to analyse exertion levels during different phases of the life cycle. Accelerometer recording of the annual activity patterns of individual birds will open up a new dimension in bird migration research.

  10. Bat predation on nocturnally migrating birds.

    Science.gov (United States)

    Ibáñez, C; Juste, J; García-Mudarra, J L; Agirre-Mendi, P T

    2001-08-14

    Bat predation on birds is a very rare phenomenon in nature. Most documented reports of bird-eating bats refer to tropical bats that occasionally capture resting birds. Millions of small birds concentrate and cross over the world's temperate regions during migration, mainly at night, but no nocturnal predators are known to benefit from this enormous food resource. An analysis of 14,000 fecal pellets of the greater noctule bat (Nyctalus lasiopterus) reveals that this species captures and eats large numbers of migrating passerines, making it the only bat species so far known that regularly preys on birds. The echolocation characteristics and wing morphology of this species strongly suggest that it captures birds in flight.

  11. Hovering and intermittent flight in birds

    Energy Technology Data Exchange (ETDEWEB)

    Tobalske, Bret W, E-mail: bret.tobalske@mso.umt.ed [Field Research Station at Fort Missoula, Division of Biological Sciences, University of Montana, Missoula, MT 59812 (United States)

    2010-12-15

    Two styles of bird locomotion, hovering and intermittent flight, have great potential to inform future development of autonomous flying vehicles. Hummingbirds are the smallest flying vertebrates, and they are the only birds that can sustain hovering. Their ability to hover is due to their small size, high wingbeat frequency, relatively large margin of mass-specific power available for flight and a suite of anatomical features that include proportionally massive major flight muscles (pectoralis and supracoracoideus) and wing anatomy that enables them to leave their wings extended yet turned over (supinated) during upstroke so that they can generate lift to support their weight. Hummingbirds generate three times more lift during downstroke compared with upstroke, with the disparity due to wing twist during upstroke. Much like insects, hummingbirds exploit unsteady mechanisms during hovering including delayed stall during wing translation that is manifest as a leading-edge vortex (LEV) on the wing and rotational circulation at the end of each half stroke. Intermittent flight is common in small- and medium-sized birds and consists of pauses during which the wings are flexed (bound) or extended (glide). Flap-bounding appears to be an energy-saving style when flying relatively fast, with the production of lift by the body and tail critical to this saving. Flap-gliding is thought to be less costly than continuous flapping during flight at most speeds. Some species are known to shift from flap-gliding at slow speeds to flap-bounding at fast speeds, but there is an upper size limit for the ability to bound ({approx}0.3 kg) and small birds with rounded wings do not use intermittent glides.

  12. THE BIODIVERSITY AT SANDI BIRD SANCTUARY, HARDOI WITH SPECIAL REFERENCE TO MIGRATORY BIRDS

    Directory of Open Access Journals (Sweden)

    Ashok Kumar

    2013-09-01

    heron, pond heron, night heron, large, medium and little egrets, painted stork, open billed stork, cattle egret, black necked stork(endangered, combduck, lesser whistling teal, common pariah kite, brahminy kite, shikra, sparrow, hawk, tawny eagle, greater spotted eagle, crested hawk eagle, lagger falcon rain quail, jungle bush quail, painted bush quail, black partridge, grey partridge, common peafowl, water hens, purple moor hens, jacanas, black winged stilt, lap wing, blue rock pigeon, dove spp., parakeets, crow pheasants, owl, swifts, kingfishers, blue jay, hoopoe, mynas, crow, drongo, bulbul, babblers, cormorants, sarus cranes, etc. There are 38195 local birds and 11378 migratory birds (total 49572 observed during period of study. The migratory birds represent the economic importance of that particular area and faunal biodiversity along with health of ecosystem.

  13. 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.

  14. Flapping wing aerodynamics: from insects to vertebrates.

    Science.gov (United States)

    Chin, Diana D; Lentink, David

    2016-04-01

    More than a million insects and approximately 11,000 vertebrates utilize flapping wings to fly. However, flapping flight has only been studied in a few of these species, so many challenges remain in understanding this form of locomotion. Five key aerodynamic mechanisms have been identified for insect flight. Among these is the leading edge vortex, which is a convergent solution to avoid stall for insects, bats and birds. The roles of the other mechanisms - added mass, clap and fling, rotational circulation and wing-wake interactions - have not yet been thoroughly studied in the context of vertebrate flight. Further challenges to understanding bat and bird flight are posed by the complex, dynamic wing morphologies of these species and the more turbulent airflow generated by their wings compared with that observed during insect flight. Nevertheless, three dimensionless numbers that combine key flow, morphological and kinematic parameters - the Reynolds number, Rossby number and advance ratio - govern flapping wing aerodynamics for both insects and vertebrates. These numbers can thus be used to organize an integrative framework for studying and comparing animal flapping flight. Here, we provide a roadmap for developing such a framework, highlighting the aerodynamic mechanisms that remain to be quantified and compared across species. Ultimately, incorporating complex flight maneuvers, environmental effects and developmental stages into this framework will also be essential to advancing our understanding of the biomechanics, movement ecology and evolution of animal flight.

  15. The morphological basis of the arm-to-wing transition.

    Science.gov (United States)

    Poore, Samuel O

    2008-02-01

    Human-powered flight has fascinated scientists, artists, and physicians for centuries. This history includes Abbas Ibn Firnas, a Spanish inventor who attempted the first well-documented human flight; Leonardo da Vinci and his flying machines; the Turkish inventor Hezarfen Ahmed Celebi; and the modern aeronautical pioneer Otto Lilienthal. These historic figures held in common their attempts to construct wings from man-made materials, and though their human-powered attempts at flight never came to fruition, the ideas and creative elements contained within their flying machines were essential to modern aeronautics. Since the time of these early pioneers, flight has continued to captivate humans, and recently, in a departure from creating wings from artificial elements, there has been discussion of using reconstructive surgery to fabricate human wings from human arms. This article is a descriptive study of how one might attempt such a reconstruction and in doing so calls upon essential evidence in the evolution of flight, an understanding of which is paramount to constructing human wings from arms. This includes a brief analysis and exploration of the anatomy of the 150-million-year-old fossil Archaeopteryx lithographica, with particular emphasis on the skeletal organization of this primitive bird's wing and wrist. Additionally, certain elements of the reconstruction must be drawn from an analysis of modern birds including a description of the specialized shoulder of the European starling, Sturnus vulgaris. With this anatomic description in tow, basic calculations regarding wing loading and allometry suggest that human wings would likely be nonfunctional. However, with the proper reconstructive balance between primitive (Archaeopteryx) and modern (Sturnus), and in attempting to integrate a careful analysis of bird anatomy with modern surgical techniques, the newly constructed human wings could function as cosmetic features simulating, for example, the nonfunctional

  16. The energetic cost of variations in wing span and wing asymmetry in the zebra finch Taeniopygia guttata.

    Science.gov (United States)

    Hambly, C; Harper, E J; Speakman, J R

    2004-10-01

    Asymmetry is a difference in the sizes of bilaterally paired structures. Wing asymmetry may have an effect on the kinematics of flight, with knock-on effects for the energetic cost of flying. In this study the 13C-labelled bicarbonate technique was used to measure the energy expended during the flight of zebra finches Taeniopygia guttata, prior to and after experimental manipulation to generate asymmetry and a change in wing span by trimming the primary feathers. In addition, simultaneous high-speed video footage enabled differences in flight kinematics such as flight speed, wing amplitude, up- and downstroke duration and wing beat frequency to be examined. In 10 individuals, the primary feathers on the right wing were trimmed first, by 0.5 cm, and then by an additional 0.5 cm in six of these individuals. In a separate 'control' group (N=7), approximately 0.25 cm was trimmed off the primary feathers of both wings, to produce the same reduction in wing span as 0.5 cm trimmed from one wing, while maintaining symmetry. When birds were manipulated to become asymmetric they maintained flight speed. They also increased the left wing amplitude and decreased the right up- and downstroke durations to counteract the changes in wing shape, which meant that they had an increase in wing beat frequency. When the wing area was reduced while maintaining symmetry, birds flew with slower flight speed. In this case wing amplitude did not change and wing upstroke slightly decreased, causing an increased wing beat frequency. The mean flight cost in the pre-manipulated birds was 1.90+/-0.1 W. There was a slight increase in flight cost with both of the asymmetry manipulations (0.5 cm, increase of 0.04 W; 1.0 cm, increase of 0.12 W), neither of which reached statistical significance. There was, however, a significantly increased flight cost when the wing span was reduced without causing asymmetry (increase of 0.45 W; paired t-test T=2.3, P=0.03).

  17. Principle of bio-inspired insect wing rotational hinge design

    Science.gov (United States)

    Fei, Fan

    A principle for designing and fabricating bio-inspired miniature artificial insect flapping wing using flexure rotational hinge design is presented. A systematic approach of selecting rotational hinge stiffness value is proposed. Based on the understanding of flapping wing aerodynamics, a dynamic simulation is constructed using the established quasi-steady model and the wing design. Simulations were performed to gain insight on how different parameters affect the wing rotational response. Based on system resonance a model to predict the optimal rotational hinge stiffness based on given wing parameter and flapping wing kinematic is proposed. By varying different wing parameters, the proposed method is shown to be applicable to a wide range of wing designs with different sizes and shapes. With the selected hinge stiffness value, aspects of the rotational joint design is discussed and an integrated wing-hinge structure design using laminated carbon fiber and polymer film is presented. Manufacturing process of such composite structure is developed to achieve high accuracy and repeatability. The yielded hinge stiffness is verified by measurements. To validate the proposed model, flapping wing experiments were conducted. A flapping actuation set up is built using DC motor and a controller is implemented on a microcontroller to track desired wing stroke kinematic. Wing stroke and rotation kinematic were extracted using a high speed camera and the lift generation is evaluated. A total of 49 flapping experiments were presented, experimental data shows good correlation with the model's prediction. With the wing rotational hinge stiffness designed so that the rotational resonant frequency is twice as the stroke frequency, the resulting wing rotation generates near optimal lift. With further simulation, the proposed model shows low sensitivity to wing parameter variation. As a result, giving a design parameter of a flapping wing robot platform, the proposed principle can

  18. Fossil evidence of wing shape in a stem relative of swifts and hummingbirds (Aves, Pan-Apodiformes).

    Science.gov (United States)

    Ksepka, Daniel T; Clarke, Julia A; Nesbitt, Sterling J; Kulp, Felicia B; Grande, Lance

    2013-06-22

    A feathered specimen of a new species of Eocypselus from the Early Eocene Green River Formation of Wyoming provides insight into the wing morphology and ecology in an early part of the lineage leading to extant swifts and hummingbirds. Combined phylogenetic analysis of morphological and molecular data supports placement of Eocypselus outside the crown radiation of Apodiformes. The new specimen is the first described fossil of Pan-Apodiformes from the pre-Pleistocene of North America and the only reported stem taxon with informative feather preservation. Wing morphology of Eocypselus rowei sp. nov. is intermediate between the short wings of hummingbirds and the hyper-elongated wings of extant swifts, and shows neither modifications for the continuous gliding used by swifts nor modifications for the hovering flight style used by hummingbirds. Elongate hindlimb elements, particularly the pedal phalanges, also support stronger perching capabilities than are present in Apodiformes. The new species is the smallest bird yet described from the Green River Formation, and supports the hypothesis that a decrease in body size preceded flight specializations in Pan-Apodiformes. The specimen also provides the first instance of melanosome morphology preserved in association with skeletal remains from the Green River Formation.

  19. Comparing aerodynamic efficiency in birds and bats suggests better flight performance in birds.

    Science.gov (United States)

    Muijres, Florian T; Johansson, L Christoffer; Bowlin, Melissa S; Winter, York; Hedenström, Anders

    2012-01-01

    Flight is one of the energetically most costly activities in the animal kingdom, suggesting that natural selection should work to optimize flight performance. The similar size and flight speed of birds and bats may therefore suggest convergent aerodynamic performance; alternatively, flight performance could be restricted by phylogenetic constraints. We test which of these scenarios fit to two measures of aerodynamic flight efficiency in two passerine bird species and two New World leaf-nosed bat species. Using time-resolved particle image velocimetry measurements of the wake of the animals flying in a wind tunnel, we derived the span efficiency, a metric for the efficiency of generating lift, and the lift-to-drag ratio, a metric for mechanical energetic flight efficiency. We show that the birds significantly outperform the bats in both metrics, which we ascribe to variation in aerodynamic function of body and wing upstroke: Bird bodies generated relatively more lift than bat bodies, resulting in a more uniform spanwise lift distribution and higher span efficiency. A likely explanation would be that the bat ears and nose leaf, associated with echolocation, disturb the flow over the body. During the upstroke, the birds retract their wings to make them aerodynamically inactive, while the membranous bat wings generate thrust and negative lift. Despite the differences in performance, the wake morphology of both birds and bats resemble the optimal wake for their respective lift-to-drag ratio regimes. This suggests that evolution has optimized performance relative to the respective conditions of birds and bats, but that maximum performance is possibly limited by phylogenetic constraints. Although ecological differences between birds and bats are subjected to many conspiring variables, the different aerodynamic flight efficiency for the bird and bat species studied here may help explain why birds typically fly faster, migrate more frequently and migrate longer distances

  20. Comparing aerodynamic efficiency in birds and bats suggests better flight performance in birds.

    Directory of Open Access Journals (Sweden)

    Florian T Muijres

    Full Text Available Flight is one of the energetically most costly activities in the animal kingdom, suggesting that natural selection should work to optimize flight performance. The similar size and flight speed of birds and bats may therefore suggest convergent aerodynamic performance; alternatively, flight performance could be restricted by phylogenetic constraints. We test which of these scenarios fit to two measures of aerodynamic flight efficiency in two passerine bird species and two New World leaf-nosed bat species. Using time-resolved particle image velocimetry measurements of the wake of the animals flying in a wind tunnel, we derived the span efficiency, a metric for the efficiency of generating lift, and the lift-to-drag ratio, a metric for mechanical energetic flight efficiency. We show that the birds significantly outperform the bats in both metrics, which we ascribe to variation in aerodynamic function of body and wing upstroke: Bird bodies generated relatively more lift than bat bodies, resulting in a more uniform spanwise lift distribution and higher span efficiency. A likely explanation would be that the bat ears and nose leaf, associated with echolocation, disturb the flow over the body. During the upstroke, the birds retract their wings to make them aerodynamically inactive, while the membranous bat wings generate thrust and negative lift. Despite the differences in performance, the wake morphology of both birds and bats resemble the optimal wake for their respective lift-to-drag ratio regimes. This suggests that evolution has optimized performance relative to the respective conditions of birds and bats, but that maximum performance is possibly limited by phylogenetic constraints. Although ecological differences between birds and bats are subjected to many conspiring variables, the different aerodynamic flight efficiency for the bird and bat species studied here may help explain why birds typically fly faster, migrate more frequently and migrate

  1. Biaxial mechanical characterization of bat wing skin.

    Science.gov (United States)

    Skulborstad, A J; Swartz, S M; Goulbourne, N C

    2015-04-21

    The highly flexible and stretchable wing skin of bats, together with the skeletal structure and musculature, enables large changes in wing shape during flight. Such compliance distinguishes bat wings from those of all other flying animals. Although several studies have investigated the aerodynamics and kinematics of bats, few have examined the complex histology and mechanical response of the wing skin. This work presents the first biaxial characterization of the local deformation, mechanical properties, and fiber kinematics of bat wing skin. Analysis of these data has provided insight into the relationships among the structural morphology, mechanical properties, and functionality of wing skin. Large spatial variations in tissue deformation and non-negligible fiber strains in the cross-fiber direction for both chordwise and spanwise fibers indicate fibers should be modeled as two-dimensional elements. The macroscopic constitutive behavior was anisotropic and nonlinear, with very low spanwise and chordwise stiffness (hundreds of kilopascals) in the toe region of the stress-strain curve. The structural arrangement of the fibers and matrix facilitates a low energy mechanism for wing deployment and extension, and we fabricate examples of skins capturing this mechanism. We propose a comprehensive deformation map for the entire loading regime. The results of this work underscore the importance of biaxial field approaches for soft heterogeneous tissue, and provide a foundation for development of bio-inspired skins to probe the effects of the wing skin properties on aerodynamic performance.

  2. 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...

  3. Birds caught inspider webs inAsia

    Institute of Scientific and Technical Information of China (English)

    Bruno A. Walther

    2016-01-01

    A recent global review of birds caught in spider webs reported only three Asian cases. Given this surprisingly low number, I made a concerted effort to obtain additional Asian cases from the literature, the internet, and ifeld workers. I present a total of 56 Asian cases which pertain to 33 bird species. As in the global dataset, mostly small bird species were caught in spider webs, with a mean body mass of 17.5 g and a mean wing chord length of 73.1 mm. Conse‑quently, birds with a body mass >30 g were very rarely caught. This Asian review corroborates the global review that smaller birds are more likely to be caught and thatNephila spiders are most likely to be the predators. Continuous monitoring of spider webs is recommended to ascertain the frequency of these events.

  4. The influence of flight style on the aerodynamic properties of avian wings as fixed lifting surfaces

    Directory of Open Access Journals (Sweden)

    John J. Lees

    2016-10-01

    Full Text Available The diversity of wing morphologies in birds reflects their variety of flight styles and the associated aerodynamic and inertial requirements. Although the aerodynamics underlying wing morphology can be informed by aeronautical research, important differences exist between planes and birds. In particular, birds operate at lower, transitional Reynolds numbers than do most aircraft. To date, few quantitative studies have investigated the aerodynamic performance of avian wings as fixed lifting surfaces and none have focused upon the differences between wings from different flight style groups. Dried wings from 10 bird species representing three distinct flight style groups were mounted on a force/torque sensor within a wind tunnel in order to test the hypothesis that wing morphologies associated with different flight styles exhibit different aerodynamic properties. Morphological differences manifested primarily as differences in drag rather than lift. Maximum lift coefficients did not differ between groups, whereas minimum drag coefficients were lowest in undulating flyers (Corvids. The lift to drag ratios were lower than in conventional aerofoils and data from free-flying soaring species; particularly in high frequency, flapping flyers (Anseriformes, which do not rely heavily on glide performance. The results illustrate important aerodynamic differences between the wings of different flight style groups that cannot be explained solely by simple wing-shape measures. Taken at face value, the results also suggest that wing-shape is linked principally to changes in aerodynamic drag, but, of course, it is aerodynamics during flapping and not gliding that is likely to be the primary driver.

  5. The influence of flight style on the aerodynamic properties of avian wings as fixed lifting surfaces

    Science.gov (United States)

    Dimitriadis, Grigorios; Nudds, Robert L.

    2016-01-01

    The diversity of wing morphologies in birds reflects their variety of flight styles and the associated aerodynamic and inertial requirements. Although the aerodynamics underlying wing morphology can be informed by aeronautical research, important differences exist between planes and birds. In particular, birds operate at lower, transitional Reynolds numbers than do most aircraft. To date, few quantitative studies have investigated the aerodynamic performance of avian wings as fixed lifting surfaces and none have focused upon the differences between wings from different flight style groups. Dried wings from 10 bird species representing three distinct flight style groups were mounted on a force/torque sensor within a wind tunnel in order to test the hypothesis that wing morphologies associated with different flight styles exhibit different aerodynamic properties. Morphological differences manifested primarily as differences in drag rather than lift. Maximum lift coefficients did not differ between groups, whereas minimum drag coefficients were lowest in undulating flyers (Corvids). The lift to drag ratios were lower than in conventional aerofoils and data from free-flying soaring species; particularly in high frequency, flapping flyers (Anseriformes), which do not rely heavily on glide performance. The results illustrate important aerodynamic differences between the wings of different flight style groups that cannot be explained solely by simple wing-shape measures. Taken at face value, the results also suggest that wing-shape is linked principally to changes in aerodynamic drag, but, of course, it is aerodynamics during flapping and not gliding that is likely to be the primary driver.

  6. Insight into live bird markets of Bangladesh: an overview of the dynamics of transmission of H5N1 and H9N2 avian influenza viruses.

    Science.gov (United States)

    Turner, Jasmine C M; Feeroz, Mohammed M; Hasan, M Kamrul; Akhtar, Sharmin; Walker, David; Seiler, Patrick; Barman, Subrata; Franks, John; Jones-Engel, Lisa; McKenzie, Pamela; Krauss, Scott; Webby, Richard J; Kayali, Ghazi; Webster, Robert G

    2017-03-08

    Highly pathogenic avian influenza (HPAI) H5N1 and low pathogenic avian influenza (LPAI) H9N2 viruses have been recognized as threats to public health in Bangladesh since 2007. Although live bird markets (LBMs) have been implicated in the transmission, dissemination, and circulation of these viruses, an in-depth analysis of the dynamics of avian transmission of H5N1 and H9N2 viruses at the human-animal interface has been lacking. Here we present and evaluate epidemiological findings from active surveillance conducted among poultry in various production sectors in Bangladesh from 2008 to 2016. Overall, the prevalence of avian influenza viruses (AIVs) in collected samples was 24%. Our data show that AIVs are more prevalent in domestic birds within LBMs (30.4%) than in farms (9.6%). Quail, chickens and ducks showed a high prevalence of AIVs (>20%). The vast majority of AIVs detected (99.7%) have come from apparently healthy birds and poultry drinking water served as a reservoir of AIVs with a prevalence of 32.5% in collected samples. HPAI H5N1 was more frequently detected in ducks while H9N2 was more common in chickens and quail. LBMs, particularly wholesale markets, have become a potential reservoir for various types of AIVs, including HPAI H5N1 and LPAI H9N2. The persistence of AIVs in LBMs is of great concern to public health, and this study highlights the importance of regularly reviewing and implementing infection control procedures as a means of reducing the exposure of the general public to AIVs.Emerging Microbes & Infections (2017) 6, e12; doi:10.1038/emi.2016.142; published online 8 March 2017.

  7. Resilin in dragonfly and damselfly wings and its implications for wing flexibility.

    Science.gov (United States)

    Donoughe, Seth; Crall, James D; Merz, Rachel A; Combes, Stacey A

    2011-12-01

    Although there is mounting evidence that passive mechanical dynamics of insect wings play an integral role in insect flight, our understanding of the structural details underlying insect wing flexibility remains incomplete. Here, we use comparative morphological and mechanical techniques to illuminate the function and diversity of two mechanisms within Odonata wings presumed to affect dynamic wing deformations: flexible resilin vein-joints and cuticular spikes. Mechanical tests show that joints with more resilin have lower rotational stiffness and deform more in response to a load applied to an intact wing. Morphological studies of 12 species of Odonata reveal that resilin joints and cuticular spikes are widespread taxonomically, yet both traits display a striking degree of morphological and functional diversity that follows taxonomically distinct patterns. Interestingly, damselfly wings (suborder Zygoptera) are mainly characterized by vein-joints that are double-sided (containing resilin both dorsally and ventrally), whereas dragonfly wings (suborder Epiprocta) are largely characterized by single-sided vein-joints (containing resilin either ventrally or dorsally, but not both). The functional significance and diversity of resilin joints and cuticular spikes could yield insight into the evolutionary relationship between form and function of wings, as well as revealing basic principles of insect wing mechanical design.

  8. Mimicking unfolding motion of a beetle hind wing

    Institute of Scientific and Technical Information of China (English)

    MUHAMMAD Azhar; PARK Hoon C; HWANG Do Y; BYUN Doyoung; GOO Nam S

    2009-01-01

    This paper presents an experimental research aiming to realize an artificial hind wing that can mimic the wing unfolding motion of Allomyrina dichotoma, an insect in coleopteran order. Based on the understanding of working principles of beetle wing folding/unfolding mechanisms, the hind wing unfolding motion is mimicked by a combination of creative ideas and state-of-art artificial muscle actuator. In this work, we devise two types of artificial wings and the successfully demonstrate that they can be unfolded by actuation of shape memory alloy wires to provide actuation force at the wing base and along the leading edge vein. The folding/unfolding mechanisms may provide an insight for portable nano/micro air vehicles with morphing wings.

  9. Folding in and out: passive morphing in flapping wings.

    Science.gov (United States)

    Stowers, Amanda K; Lentink, David

    2015-03-25

    We present a new mechanism for passive wing morphing of flapping wings inspired by bat and bird wing morphology. The mechanism consists of an unactuated hand wing connected to the arm wing with a wrist joint. Flapping motion generates centrifugal accelerations in the hand wing, forcing it to unfold passively. Using a robotic model in hover, we made kinematic measurements of unfolding kinematics as functions of the non-dimensional wingspan fold ratio (2-2.5) and flapping frequency (5-17 Hz) using stereo high-speed cameras. We find that the wings unfold passively within one to two flaps and remain unfolded with only small amplitude oscillations. To better understand the passive dynamics, we constructed a computer model of the unfolding process based on rigid body dynamics, contact models, and aerodynamic correlations. This model predicts the measured passive unfolding within about one flap and shows that unfolding is driven by centrifugal acceleration induced by flapping. The simulations also predict that relative unfolding time only weakly depends on flapping frequency and can be reduced to less than half a wingbeat by increasing flapping amplitude. Subsequent dimensional analysis shows that the time required to unfold passively is of the same order of magnitude as the flapping period. This suggests that centrifugal acceleration can drive passive unfolding within approximately one wingbeat in small and large wings. Finally, we show experimentally that passive unfolding wings can withstand impact with a branch, by first folding and then unfolding passively. This mechanism enables flapping robots to squeeze through clutter without sophisticated control. Passive unfolding also provides a new avenue in morphing wing design that makes future flapping morphing wings possibly more energy efficient and light-weight. Simultaneously these results point to possible inertia driven, and therefore metabolically efficient, control strategies in bats and birds to morph or recover

  10. 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,...

  11. The costae presenting in high-temperature-induced vestigial wings of Drosophila: implications for anterior wing margin formation

    Indian Academy of Sciences (India)

    Daxiang Yang

    2007-01-01

    It has long been noted that high temperature produces great variation in wing forms of the vestigial mutant of Drosophila. Most of the wings have defects in the wing blade and partially formed wing margin, which are the result of autonomous cell death in the presumptive wing blade or costal region of the wing disc. The vestigial gene ($vg$) and the interaction of Vg protein with other gene products are well understood. With this biochemical knowledge, reinvestigations of the high-temperature-induced vestigial wings and the elucidation of the molecular mechanism underlying the large-scale variation of the wing forms may provide insight into further understanding of development of the wing of Drosophila. As a first step of such explorations, I examined high-temperature-induced (29°C) vestigial wings. In the first part of this paper, I provide evidences to show that the proximal and distal costae in these wings exhibit regular and continuous variation, which suggests different developmental processes for the proximal and distal costal sections. Judging by the costae presenting in the anterior wing margin, I propose that the proximal and distal costal sections are independent growth units. The genes that regulate formation of the distal costal section also strongly affect proliferation of cells nearby; however, the same phenomenon has not been found in the proximal costal section. The distal costal section seems to be an extension of the radius vein. vestigial, one of the most intensely researched temperature-sensitive mutations, is a good candidate for the study of marginal vein formation. In the second part of the paper, I regroup the wing forms of these wings, chiefly by comparison of venation among these wings, and try to elucidate the variation of the wing forms according to the results of previous work and the conclusions reached in the first part of this paper, and provide clues for further researches.

  12. Current perspectives on the evolution of birds

    NARCIS (Netherlands)

    Ericson, P.G.P.

    2008-01-01

    The paper summarizes the current understanding of the evolution and diversification of birds. New insights into this field have mainly come from two fundamentally different, but complementary sources of information: the many newly discovered Mesozoic bird fossils and the wealth of genetic analyses o

  13. 76 FR 59298 - Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations...

    Science.gov (United States)

    2011-09-26

    ... Survey; population status reports for blue-winged teal, sandhill cranes, woodcock, mourning doves, white... has reviewed this rule under Executive Order 12866. OMB bases its determination of regulatory... of age or older must carry on his/her person a valid Migratory Bird Hunting and Conservation...

  14. Assessing collision risk for birds and bats : radar survey

    Energy Technology Data Exchange (ETDEWEB)

    Brunet, R. [Genivar SEC, Sherbrooke, PQ (Canada)

    2010-07-01

    This PowerPoint presentation described some of the inventories and instrumentation available for monitoring winged fauna in and around wind farms. In addition to visual observations, bird calls and songs can be recorded to determine the amount and different types of birds located at wind farm sites. Radio-telemetry devices are also used to evaluate bird activities, and nest searches are conducted to determine the amount of eggs or young birds that will soon add to the bird population. Between 90 and 100 percent of birds and bats migrate at night. Acoustic radar, Doppler radar, and maritime surveillance radar instruments are used to monitor night-time activities in wind farm locations. Doppler radar is also used to detect bird and bat migration corridors. Screen-shots of various radar interfaces were presented. tabs., figs.

  15. 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...

  16. 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...

  17. Vortices around Dragonfly Wings

    OpenAIRE

    Kweon, Jihoon; Choi, Haecheon

    2009-01-01

    Dragonfly beats its wings independently, resulting in its superior maneuverability. Depending on the magnitude of phase difference between the fore- and hind-wings of dragonfly, the vortical structures and their interaction with wings become significantly changed, and so does the aerodynamic performance. In this study, we consider hovering flights of modelled dragonfly with three different phase differences (phi=-90, 90, 180 degrees). The three-dimensional wing shape is based on that of Aesch...

  18. 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.

  19. 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].

  20. Features of owl wings that promote silent flight.

    Science.gov (United States)

    Wagner, Hermann; Weger, Matthias; Klaas, Michael; Schröder, Wolfgang

    2017-02-06

    Owls are an order of birds of prey that are known for the development of a silent flight. We review here the morphological adaptations of owls leading to silent flight and discuss also aerodynamic properties of owl wings. We start with early observations (until 2005), and then turn to recent advances. The large wings of these birds, resulting in low wing loading and a low aspect ratio, contribute to noise reduction by allowing slow flight. The serrations on the leading edge of the wing and the velvet-like surface have an effect on noise reduction and also lead to an improvement of aerodynamic performance. The fringes at the inner feather vanes reduce noise by gliding into the grooves at the lower wing surface that are formed by barb shafts. The fringed trailing edge of the wing has been shown to reduce trailing edge noise. These adaptations to silent flight have been an inspiration for biologists and engineers for the development of devices with reduced noise production. Today several biomimetic applications such as a serrated pantograph or a fringed ventilator are available. Finally, we discuss unresolved questions and possible future directions.

  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. Birds of Swale Marshes on John F. Kennedy Space Center

    Science.gov (United States)

    Breininger, David R.

    1992-01-01

    Birds were surveyed in several isolated freshwater wetlands on John F. Kennedy Space Center to determine species composition and the importance of these wet- lands to birds. The Red-winged Blackbird and Green-backed Heron were the two most abundant breeders in the swale marshes. The Common Yellowthroat was the most common winter resident but was rare in summer. These marshes are important features within landscapes dominated by uplands particularly because of their significance to amphibians and reptiles.

  3. Bird or bat: comparing airframe design and flight performance.

    Science.gov (United States)

    Hedenström, Anders; Johansson, L Christoffer; Spedding, Geoffrey R

    2009-03-01

    Birds and bats have evolved powered flight independently, which makes a comparison of evolutionary 'design' solutions potentially interesting. In this paper we highlight similarities and differences with respect to flight characteristics, including morphology, flight kinematics, aerodynamics, energetics and flight performance. Birds' size range is 0.002-15 kg and bats' size range is 0.002-1.5 kg. The wingbeat kinematics differ between birds and bats, which is mainly due to the different flexing of the wing during the upstroke and constraints by having a wing of feathers and a skin membrane, respectively. Aerodynamically, bats appear to generate a more complex wake than birds. Bats may be more closely adapted for slow maneuvering flight than birds, as required by their aerial hawking foraging habits. The metabolic rate and power required to fly are similar among birds and bats. Both groups share many characteristics associated with flight, such as for example low amounts of DNA in cells, the ability to accumulate fat as fuel for hibernation and migration, and parallel habitat-related wing shape adaptations.

  4. 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)

  5. 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.

  6. Insights into the evolution of mammalian telomerase: Platypus TERT shares similarities with genes of birds and other reptiles and localizes on sex chromosomes

    Directory of Open Access Journals (Sweden)

    Hrdličková Radmila

    2012-06-01

    Full Text Available Abstract Background The TERT gene encodes the catalytic subunit of the telomerase complex and is responsible for maintaining telomere length. Vertebrate telomerase has been studied in eutherian mammals, fish, and the chicken, but less attention has been paid to other vertebrates. The platypus occupies an important evolutionary position, providing unique insight into the evolution of mammalian genes. We report the cloning of a platypus TERT (OanTERT ortholog, and provide a comparison with genes of other vertebrates. Results The OanTERT encodes a protein with a high sequence similarity to marsupial TERT and avian TERT. Like the TERT of sauropsids and marsupials, as well as that of sharks and echinoderms, OanTERT contains extended variable linkers in the N-terminal region suggesting that they were present already in basal vertebrates and lost independently in ray-finned fish and eutherian mammals. Several alternatively spliced OanTERT variants structurally similar to avian TERT variants were identified. Telomerase activity is expressed in all platypus tissues like that of cold-blooded animals and murine rodents. OanTERT was localized on pseudoautosomal regions of sex chromosomes X3/Y2, expanding the homology between human chromosome 5 and platypus sex chromosomes. Synteny analysis suggests that TERT co-localized with sex-linked genes in the last common mammalian ancestor. Interestingly, female platypuses express higher levels of telomerase in heart and liver tissues than do males. Conclusions OanTERT shares many features with TERT of the reptilian outgroup, suggesting that OanTERT represents the ancestral mammalian TERT. Features specific to TERT of eutherian mammals have, therefore, evolved more recently after the divergence of monotremes.

  7. Slotted Aircraft Wing

    Science.gov (United States)

    McLean, James D. (Inventor); Witkowski, David P. (Inventor); Campbell, Richard L. (Inventor)

    2006-01-01

    A swept aircraft wing includes a leading airfoil element and a trailing airfoil element. At least one full-span slot is defined by the wing during at least one transonic condition of the wing. The full-span slot allows a portion of the air flowing along the lower surface of the leading airfoil element to split and flow over the upper surface of the trailing airfoil element so as to achieve a performance improvement in the transonic condition.

  8. Dynamic distributions and population declines of Golden-winged Warblers

    Science.gov (United States)

    Rosenberg, Kenneth V.; Will, Tom; Buehler, David A.; Barker Swarthout, Sara; Thogmartin, Wayne E.; Chandler, Richard

    2016-01-01

    With an estimated breeding population in 2010 of 383,000 pairs, the Golden-winged Warbler (Vermivora chrysoptera) is among the most vulnerable and steeply declining of North American passerines. This species also has exhibited among the most dynamic breeding distributions, with populations expanding and then contracting over the past 150 years in response to regional habitat changes, interactions with closely related Blue-winged Warblers (V. cyanoptera), and possibly climate change. Since 1966, the rangewide population has declined by >70% (-2.3% per year; latest North American Breeding Bird Survey data), with much steeper declines in the Appalachian Mountains bird conservation region (-8.3% per year, 98% overall decline). Despite apparently stable or increasing populations in the northwestern part of the range (Minnesota, Manitoba), population estimates for Golden-winged Warbler have continued to decline by 18% from the decade of the 1990s to the 2000s. Population modeling predicts a further decline to roughly 37,000 individuals by 2100, with the species likely to persist only in Manitoba, Minnesota, and possibly Ontario. To delineate the present-day distribution and to identify population concentrations that could serve as conservation focus areas, we compiled rangewide survey data collected in 2000-2006 in 21 states and 3 Canadian provinces, as part of the Golden-winged Warbler Atlas Project (GOWAP), supplemented by state and provincial Breeding Bird Atlas data and more recent observations in eBird. Based on >8,000 GOWAP surveys for Golden-winged and Blue-winged warblers and their hybrids, we mapped occurrence of phenotypically pure and mixed populations in a roughly 0.5-degree grid across the species’ ranges. Hybrids and mixed Golden-winged-Blue-winged populations occurred in a relatively narrow zone across Minnesota, Wisconsin, Michigan, southern Ontario, and northern New York. Phenotypically pure Golden-winged Warbler populations occurred north of this

  9. Wing Kinematics and Wake Velocity Characteristics of Bat Flight

    Science.gov (United States)

    Swartz, Sharon

    2005-11-01

    Bats demonstrate unequalled flight characteristics and are capable of highly efficient flight as well as extreme maneuverability at high speeds. They have morphological properties that are unique in the animal world including jointed wings skeletons, elastic wing membranes and very complex wing motions. We report on a series of experiments on bats flying in a flight cage along both a straight path and through a 90-degree turn. Measurements of their kinematic wing motion (using high speed photography) and wake velocity structures (using stereo PIV) are reported. The live animal measurements are also interpreted with the help of a series of companion wind tunnel experiments using model structures that mimic some key features of bat flight mechanics. The results reveal a complex vortex wake structure which is compared and contrasted to that found in bird and insect flight.

  10. Wake patterns of the wings and tail of hovering hummingbirds

    Science.gov (United States)

    Altshuler, Douglas L.; Princevac, Marko; Pan, Hansheng; Lozano, Jesse

    The flow fields of slowly flying bats and fasterflying birds differ in that bats produce two vortex loops during each stroke, one per wing, and birds produce a single vortex loop per stroke. In addition, the circulation at stroke transition approaches zero in bats but remains strong in birds. It is unknown if these difference derive from fundamental differences in wing morphology or are a consequence of flight speed. Here, we present an analysis of the horizontal flow field underneath hovering Anna's hummingbirds (Calypte anna) to describe the wake of a bird flying at zero forward velocity. We also consider how the hummingbird tail interacts with the wake generated by the wings. High-speed image recording and analysis from three orthogonal perspectives revealed that the wing tips reach peak velocities in the middle of each stroke and approach zero velocity at stroke transition. Hummingbirds use complex tail kinematic patterns ranging from in phase to antiphase cycling with respect to the wings, covering several phase shifted patterns. We employed particle image velocimetry to attain detailed horizontal flow measurements at three levels with respect to the tail: in the tail, at the tail tip, and just below the tail. The velocity patterns underneath the wings indicate that flow oscillates along the ventral-dorsal axis in response to the down- and up-strokes and that the sideways flows with respect to the bird are consistently from the lateral to medial. The region around the tail is dominated by axial flows in dorsal to ventral direction. We propose that these flows are generated by interaction between the wakes of the two wings at the end of the upstroke, and that the tail actively defects flows to generate moments that contribute to pitch stability. The flow fields images also revealed distinct vortex loops underneath each wing, which were generated during each stroke. From these data, we propose a model for the primary flow structures of hummingbirds that more

  11. 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 ...

  12. 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...

  13. Feather isotope analysis reveals differential patterns of habitat and resource use in populations of white-winged doves

    Science.gov (United States)

    Carleton, Scott A.; Martinez Del Rio, Carlos; Robinson, Timothy J.

    2015-01-01

    The white-winged dove (Zenaida asiatica) serves an important ecological role as a diurnal pollinator of the saguaro cactus in the Sonoran desert and an economic role as a highly sought after game bird in North America. White-winged doves are intimately linked to anthropogenic changes on the landscape and because of this, have experienced dramatic population fluctuations over the last 75 years in response, both positively and negatively, to anthropogenic changes on the landscape. To understand the factors driving population growth and decline of migratory species like the white-winged dove, it is imperative we study resource use on both their breeding and wintering grounds. To understand how populations are distributed on the wintering grounds, we tested an alternative to band recovery approaches by using stable isotope analysis. Before we could use isotope analysis to link breeding and wintering locations for this species, we first needed to determine if hydrogen (δ2H) and carbon (δ13C) stable isotopes in feather tissue (δ2Hf and δ13Cf, respectively) could differentiate among populations of white-winged doves across their breeding range in Texas, New Mexico, and Arizona. δ2Hf and δ13Cf not only differentiated between populations of white-winged doves that breed in the United States, but δ2Hf also provided further differentiation in white-winged doves that breed in native Sonoran Desert and agricultural habitats in the western portion of their range. Ecological processes associated with desert resources and anthropogenic influences, specifically saguaro cacti and irrigated crops, largely determined δ2Hf in some white-winged doves in Arizona whereas δ2H of precipitation (δ2Hp) largely determined δ2Hfof doves in New Mexico and Texas. This study highlights the usefulness of stable isotope analysis to differentiate populations of animals across the landscape and the insight isotopes can provide into habitat and resource use. Published 2015. This article

  14. Application of fractional algorithms in the control of a robotic bird

    Science.gov (United States)

    Couceiro, Micael S.; Fonseca Ferreira, N. M.; Tenreiro Machado, J. A.

    2010-04-01

    In this paper, it is studied the dynamics of the robotic bird in terms of time response and robustness. It is analyzed the wing angle of attack and the velocity of the bird, the tail influence, the gliding flight and the flapping flight. The results are positive for the construction of flying robots. The development of computational simulation based on the dynamic of the robotic bird should allow testing strategies and different algorithms of control such as integer and fractional controllers.

  15. Dynamics and control of robotic aircraft with articulated wings

    Science.gov (United States)

    Paranjape, Aditya Avinash

    There is a considerable interest in developing robotic aircraft, inspired by birds, for a variety of missions covering reconnaissance and surveillance. Flapping wing aircraft concepts have been put forth in light of the efficiency of flapping flight at small scales. These aircraft are naturally equipped with the ability to rotate their wings about the root, a form of wing articulation. This thesis covers some problems concerning the performance, stability and control of robotic aircraft with articulated wings in gliding flight. Specifically, we are interested in aircraft without a vertical tail, which would then use wing articulation for longitudinal as well as lateral-directional control. Although the dynamics and control of articulated wing aircraft share several common features with conventional fixed wing aircraft, the presence of wing articulation presents several unique benefits as well as limitations from the perspective of performance and control. One of the objective of this thesis is to understand these features using a combination of theoretical and numerical tools. The aircraft concept envisioned in this thesis uses the wing dihedral angles for longitudinal and lateral-directional control. Aircraft with flexible articulated wings are also investigated. We derive a complete nonlinear model of the flight dynamics incorporating dynamic CG location and the changing moment of inertia. We show that symmetric dihedral configuration, along with a conventional horizontal tail, can be used to control flight speed and flight path angle independently of each other. This characteristic is very useful for initiating an efficient perching maneuver. It is shown that wing dihedral angles alone can effectively regulate sideslip during rapid turns and generate a wide range of equilibrium turn rates while maintaining a constant flight speed and regulating sideslip. We compute the turning performance limitations that arise due to the use of wing dihedral for yaw control

  16. Ornithopter Type Flapping Wings for Autonomous Micro Air Vehicles

    Directory of Open Access Journals (Sweden)

    Sutthiphong Srigrarom

    2015-05-01

    Full Text Available In this paper, an ornithopter prototype that mimics the flapping motion of bird flight is developed, and the lift and thrust generation characteristics of different wing designs are evaluated. This project focused on the spar arrangement and material used for the wings that could achieves improved performance. Various lift and thrust measurement techniques are explored and evaluated. Various wings of insects and birds were evaluated to understand how these natural flyers with flapping wings are able to produce sufficient lift to fly. The differences in the flapping aerodynamics were also detailed. Experiments on different wing designs and materials were conducted and a paramount wing was built for a test flight. The first prototype has a length of 46.5 cm, wing span of 88 cm, and weighs 161 g. A mechanism which produced a flapping motion was fabricated and designed to create flapping flight. The flapping flight was produced by using a single motor and a flexible and light wing structure. A force balance made of load cell was then designed to measure the thrust and lift force of the ornithopter. Three sets of wings varying flexibility were fabricated, therefore lift and thrust measurements were acquired from each different set of wings. The lift will be measured in ten cycles computing the average lift and frequency in three different speeds or frequencies (slow, medium and fast. The thrust measurement was measure likewise but in two cycles only. Several observations were made regarding the behavior of flexible flapping wings that should aid in the design of future flexible flapping wing vehicles. The wings angle or phase characteristic were analyze too and studied. The final ornithopter prototype weighs only 160 g, has a wing span of 88.5 cm, that could flap at a maximum flapping frequency of 3.869 Hz, and produce a maximum thrust and lift of about 0.719 and 0.264 N respectively. Next, we proposed resonance type flapping wing utilizes the near

  17. Relationship between osteology and aquatic locomotion in birds: determining modes of locomotion in extinct Ornithurae.

    Science.gov (United States)

    Hinić-Frlog, S; Motani, R

    2010-02-01

    The evolutionary history of aquatic invasion in birds would be incomplete without incorporation of extinct species. We show that aquatic affinities in fossil birds can be inferred by multivariate analysis of skeletal features and locomotion of 245 species of extant birds. Regularized discriminant analyses revealed that measurements of appendicular skeletons successfully separated diving birds from surface swimmers and flyers, while also discriminating among different underwater modes of swimming. The high accuracy of this method allows detection of skeletal characteristics that are indicative of aquatic locomotion and inference of such locomotion in bird species with insufficient behavioural information. Statistical predictions based on the analyses confirm qualitative assessments for both foot-propelled (Hesperornithiformes) and wing-propelled (Copepteryx) underwater locomotion in fossil birds. This is the first quantitative inference of underwater modes of swimming in fossil birds, enabling future studies of locomotion in extinct birds and evolutionary transitions among locomotor modes in avian lineage.

  18. Flight mode affects allometry of migration range in birds.

    Science.gov (United States)

    Watanabe, Yuuki Y

    2016-08-01

    Billions of birds migrate to exploit seasonally available resources. The ranges of migration vary greatly among species, but the underlying mechanisms are poorly understood. I hypothesise that flight mode (flapping or soaring) and body mass affect migration range through their influence on flight energetics. Here, I compiled the tracks of migratory birds (196 species, weighing 12-10 350 g) recorded by electronic tags in the last few decades. In flapping birds, migration ranges decreased with body mass, as predicted from rapidly increasing flight cost with increasing body mass. The species with higher aspect ratio and lower wing loading had larger migration ranges. In soaring birds, migration ranges were mass-independent and larger than those of flapping birds, reflecting their low flight costs irrespective of body mass. This study demonstrates that many animal-tracking studies are now available to explore the general patterns and the underlying mechanisms of animal migration.

  19. Viscous-Inviscid Methods in Unsteady Aerodynamic Analysis of Bio-Inspired Morphing Wings

    Science.gov (United States)

    Dhruv, Akash V.

    over the upper and lower surfaces of a standard airfoil, proves to be an effective alternative to standard control surfaces by increasing the flight capability of bird-scale UAVs. The results obtained for this wing design under various flight and flap configurations provide insight into its aerodynamic behavior, which enhance the maneuverability and controllability. The overall method acts as an important tool to create an aerodynamic database to develop a distributed control system for autonomous operation of the multi-flap morphing wing, supporting the use of viscous-inviscid methods as a tool in rapid aerodynamic analysis.

  20. 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.

  1. Drag reduction by wing tip slots in a gliding Harris' hawk, Parabuteo unicinctus

    Science.gov (United States)

    Tucker

    1995-01-01

    The anterior-most primary feathers of many birds that soar over land bend upwards and separate vertically to form slotted wing tips during flight. The slots are thought to reduce aerodynamic drag, although drag reduction has never been demonstrated in living birds. Wing theory explains how the feathers that form the tip slots can reduce induced drag by spreading vorticity horizontally along the wing and by acting as winglets, which are used on aircraft to make wings non-planar and to spread vorticity vertically. This study uses the induced drag factor to measure the induced drag of a wing relative to that of a standard planar wing with the same span, lift and speed. An induced drag factor of less than 1 indicates that the wing is non-planar. The minimum drag of a Harris' hawk gliding freely in a wind tunnel was measured before and after removing the slots by clipping the tip feathers. The unclipped hawk had 70­90 % of the drag of the clipped hawk at speeds between 7.3 and 15.0 m s-1. At a wing span of 0.8 m, the unclipped hawk had a mean induced drag factor of 0.56, compared with the value of 1.10 assumed for the clipped hawk. A Monte Carlo simulation of error propagation and a sensitivity analysis to possible errors in measured and assumed values showed that the true mean value of the induced drag factor for the unclipped hawk was unlikely to be more than 0.93. These results for a living bird support the conclusions from a previous study of a feathered tip on a model wing in a wind tunnel: the feathers that form the slotted tips reduce induced drag by acting as winglets that make the wings non-planar and spread vorticity both horizontally and vertically.

  2. Butterfly wing coloration studied with a novel imaging scatterometer

    Science.gov (United States)

    Stavenga, Doekele

    2010-03-01

    Animal coloration functions for display or camouflage. Notably insects provide numerous examples of a rich variety of the applied optical mechanisms. For instance, many butterflies feature a distinct dichromatism, that is, the wing coloration of the male and the female differ substantially. The male Brimstone, Gonepteryx rhamni, has yellow wings that are strongly UV iridescent, but the female has white wings with low reflectance in the UV and a high reflectance in the visible wavelength range. In the Small White cabbage butterfly, Pieris rapae crucivora, the wing reflectance of the male is low in the UV and high at visible wavelengths, whereas the wing reflectance of the female is higher in the UV and lower in the visible. Pierid butterflies apply nanosized, strongly scattering beads to achieve their bright coloration. The male Pipevine Swallowtail butterfly, Battus philenor, has dorsal wings with scales functioning as thin film gratings that exhibit polarized iridescence; the dorsal wings of the female are matte black. The polarized iridescence probably functions in intraspecific, sexual signaling, as has been demonstrated in Heliconius butterflies. An example of camouflage is the Green Hairstreak butterfly, Callophrys rubi, where photonic crystal domains exist in the ventral wing scales, resulting in a matte green color that well matches the color of plant leaves. The spectral reflection and polarization characteristics of biological tissues can be rapidly and with unprecedented detail assessed with a novel imaging scatterometer-spectrophotometer, built around an elliptical mirror [1]. Examples of butterfly and damselfly wings, bird feathers, and beetle cuticle will be presented. [4pt] [1] D.G. Stavenga, H.L. Leertouwer, P. Pirih, M.F. Wehling, Optics Express 17, 193-202 (2009)

  3. Anisotropism of the Non-Smooth Surface of Butterfly Wing

    Institute of Scientific and Technical Information of China (English)

    Gang Sun; Yan Fang; Qian Cong; Lu-quan Ren

    2009-01-01

    Twenty-nine species of butterflies were collected for observation and determination of the wing surfaces using a Scanning Electron Microscope (SEM). Butterfly wing surface displays structural anisotropism in micro-, submicro- and nano-scales. The scales on butterfly wing surface arrange like overlapping roof tiles. There are submicrometric vertical gibbosities, horizontal links, and nano-protuberances on the scales. First-incline-then-drip method and first-drip-then-incline method were used to measure the Sliding Angle (SA) of droplet on butterfly wing surface by an optical Contact Angle (CA) measuring system.Relatively smaller sliding angles indicate that the butterfly wing surface has fine self-cleaning property. Significantly different SAs in various directions indicate the anisotropic self-cleaning property of butterfly wing surface. The SAs on the butterfly wing surface without scales are remarkably larger than those with scales, which proves the crucial role of scales in determining the self-cleaning property. Butterfly wing surface is a template for design and fabrication of biomimetic materials and self-cleaning substrates. This work may offer insights into how to design directional self-cleaning coatings and anisotropic wetting surface.

  4. Age-class separation of blue-winged ducks

    Science.gov (United States)

    Hohman, W.L.; Moore, J.L.; Twedt, D.J.; Mensik, John G.; Logerwell, E.

    1995-01-01

    Accurate determination of age is of fundamental importance to population and life history studies of waterfowl and their management. Therefore, we developed quantitative methods that separate adult and immature blue-winged teal (Anas discors), cinnamon teal (A. cyanoptera), and northern shovelers (A. clypeata) during spring and summer. To assess suitability of discriminant models using 9 remigial measurements, we compared model performance (% agreement between predicted age and age assigned to birds on the basis of definitive cloacal or rectral feather characteristics) in different flyways (Mississippi and Pacific) and between years (1990-91 and 1991-92). We also applied age-classification models to wings obtained from U.S. Fish and Wildlife Service harvest surveys in the Mississippi and Central-Pacific flyways (wing-bees) for which age had been determined using qualitative characteristics (i.e., remigial markings, shape, or wear). Except for male northern shovelers, models correctly aged lt 90% (range 70-86%) of blue-winged ducks. Model performance varied among species and differed between sexes and years. Proportions of individuals that were correctly aged were greater for males (range 63-86%) than females (range 39-69%). Models for northern shovelers performed better in flyway comparisons within year (1991-92, La. model applied to Calif. birds, and Calif. model applied to La. birds: 90 and 94% for M, and 89 and 76% for F, respectively) than in annual comparisons within the Mississippi Flyway (1991-92 model applied to 1990-91 data: 79% for M, 50% for F). Exclusion of measurements that varied by flyway or year did not improve model performance. Quantitative methods appear to be of limited value for age separation of female blue-winged ducks. Close agreement between predicted age and age assigned to wings from the wing-bees suggests that qualitative and quantitative methods may be equally accurate for age separation of male blue-winged ducks. We interpret annual

  5. 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.

  6. The Flight of Birds and Other Animals

    Directory of Open Access Journals (Sweden)

    Colin J. Pennycuick

    2015-09-01

    Flight programme, which does these comparisons, also had provision for including contributions due to extracting energy from the atmosphere (soaring, or intermittent bounding flight in small birds (Passerines. It has been known for some time that the feathered surface allows the bird to delay or reverse detachment of the boundary layer, although exactly how this works remains a mystery, which might have practical applications. The bird wing was in use in past times, when birds were still competing with pterosaurs, although these had less efficient wings. The birds that survived the extinction that killed the pterosaurs and dinosaurs have (today an automatic spherical navigator, which enables them to cross the Pacific and find New Zealand on the other side. Bats have never had such a device, and pterosaurs probably did not either. Animals, when seen from a zoological point of view, are adapted to whatever problems they had to deal with in earlier times.

  7. Analysis of Kinematics of Flapping Wing UAV Using OptiTrack Systems

    Directory of Open Access Journals (Sweden)

    Matthew Ng Rongfa

    2016-07-01

    Full Text Available An analysis of the kinematics of a flapping membrane wing using experimental kinematic data is presented. This motion capture technique tracks the positon of the retroreflective marker(s placed on the left wing of a 1.3-m-wingspan ornithopter. The time-varying three-dimensional data of the wing kinematics were recorded for a single frequency. The wing shape data was then plotted on a two-dimensional plane to understand the wing dynamic behaviour of an ornithopter. Specifically, the wing tip path, leading edge bending, wing membrane shape, local twist, stroke angle and wing velocity were analyzed. As the three characteristic angles can be expressed in the Fourier series as a function of time, the kinematics of the wing can be computationally generated for the aerodynamic study of flapping flight through the Fourier coefficients presented. Analysis of the ornithopter wing showed how the ornithopter closely mimics the flight motions of birds despite several physical limitations.

  8. Application of Piezoelectrics to Flapping-Wing MAVs

    Science.gov (United States)

    Widstrand, Alex; Hubner, J. Paul

    2015-11-01

    Micro air vehicles (MAVs) are a class of unmanned aerial vehicles that are size-restricted and operate at low velocities and low Reynolds numbers. An ongoing challenge with MAVs is that their flight-related operations are highly constrained by their size and weight, which limits battery size and, therefore, available power. One type of MAV called an ornithopter flies using flapping wings to create both lift and thrust, much like birds and insects do. Further bio-inspiration from bats led to the design of membrane wings for these vehicles, which provide aerodynamic benefits through passive vibration. In an attempt to capitalize on this vibration, a piezoelectric film, which generates a voltage when stressed, was investigated as the wing surface. Two wing planforms with constant area were designed and fabricated. The goal was to measure the wings' flight characteristics and output energy in freestream conditions. Complications with the flapper arose which prevented wind tunnel tests from being performed; however, energy data was obtained from table-top shaker tests. Preliminary results indicate that wing shape affects the magnitude of the charge generated, with a quarter-elliptic planform outperforming a rectangular planform. Funding provided by NSF REU Site Award number 1358991.

  9. Wing Warping, Roll Control and Aerodynamic Optimization of Inflatable Wings

    Science.gov (United States)

    Simpson, Andrew

    2005-11-01

    The research presents work on aerodynamic control by warping inflatable wings. Inflatable wings are deformable by their nature. Mechanical manipulation of the wing's shape has been demonstrated to alter the performance and control the vehicle in flight by deforming the trailing edge of the wing near the wing tip. Predicting and correlating the forces required in deforming the wings to a particular shape and the deformation generated for a given internal pressure were conducted through the use of photogrammetry. This research focuses on optimizing the roll moments and aerodynamic performance of the vehicle, given the current level of wing warping ability. Predictions from lifting line theory applied to wing shape changes are presented. Comparisons from the experimental results are made with lifting line analysis for wings with arbitrary twist and the solutions are used to determine rolling moment and optimum L/D. Results from flight tests will also be presented.

  10. Blue-winged teals in the waters around KSC

    Science.gov (United States)

    1999-01-01

    The furious beating wings of a blue-winged teal launch it from the water as another swims calmly beneath it in the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. Inhabiting marshes, shallow ponds and lakes from British Columbia, Quebec and Newfoundland to North Carolina, the Gulf Coast and southern California, the teal winters as far south as South America. The 92,000-acre refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

  11. Osteology and myology of the wing of the Emu (Dromaius novaehollandiae), and its bearing on the evolution of vestigial structures.

    Science.gov (United States)

    Maxwell, Erin E; Larsson, Hans C E

    2007-05-01

    Emus have reduced their wing skeleton to only a single functional digit, but the myological changes associated with this reduction have never been properly described. Moreover, the intraspecific variability associated with these changes has not previously been examined, dissections having been restricted in the past to only one or two individuals. In this paper, the myology and osteology of the Emu wing is described for a sample of five female birds. The Emu showed a marked reduction in the number of muscles in the wing, even compared with other ratites. Many wing muscles showed diversity in structure, origin and insertion sites, number of heads, as well as presence-absence variation. This variability dramatically exceeds that found in flying birds. Evolutionary theory predicts that relaxed selection on vestigial organs should allow more variation to persist in the population, and corresponds to what is observed here. A large amount of fluctuating asymmetry was also detected, indicating reduced canalization of the wing during development.

  12. Wings of Stretched Metal

    Science.gov (United States)

    Nelken, Miranda

    2010-01-01

    This article presents a lesson that allows students to make bird ornaments using a metal tooling as it can be textured, cut, and colored. In this lesson, students choose a bird and sketch it on a piece of paper. Once the sketches are complete, students copy their pictures on a second piece of paper by taping the sketch over a sheet of blank paper…

  13. Aerodynamic tricks for pitching oscillation and visual stabilization in a hovering bird

    Science.gov (United States)

    Su, Jian-Yuan; Ting, Shang-Chieh; Yang, Jing-Tang

    2010-11-01

    We experimentally investigate how small birds attain a stabilized vision and body posture during hovering. Wing-beats of finches and passerines executing asymmetrical hovering provide lift merely during the downstroke. The downstroke lift is significantly greater than the bird weight, thereby causing a pitch-up swing of the bird body. A hovering bird skillfully and unceasingly tunes the position and orientation of lift force to stabilize its vision, so that the eye displacement is approximately one-tenth less than the tail, causing an illusion that the bird body is rotating about the eye. The hovering birds also spread and fold periodically their tail with an evident phase relationship with respect to the beating wings. We found that hovering birds use their tail to intercept the strong downward air-flow induced by the downstroking wings, and sophisticatedly spread their tail upon the arrival of the downward air-flow, rendering a pitch-up moment that effectively counteracts the pitch-down body rotation. Hence during hovering the bird essentially undergoes a dynamically-stable pitching oscillation, and concurrently attains a stabilized vision.

  14. Manufacturing and Evaluation of a Biologically Inspired Engineered MAV Wing Compared to the Manduca Sexta Wing Under Simulated Flapping Conditions

    Science.gov (United States)

    2011-03-24

    flexion can be considered a method of energy storage , making the span- wise rigid wings more efficient than those of birds and bats who actively manipulate...3.30. Push Rod Shown as L5 . . . . . . . . . . . . . . . . . . . . . . 94 3.31. Driving Link L1 as Rotating Flywheel . . . . . . . . . . . . . . 94...3.32. Diving Link L1 as Rotating Flywheel . . . . . . . . . . . . . . . 95 3.33. Motor Mount and Associated Annotations . . . . . . . . . . . . 96 3.34

  15. Utilization of Optimization for Design of Morphing Wing Structures for Enhanced Flight

    Science.gov (United States)

    Detrick, Matthew Scott

    Conventional aircraft control surfaces constrain maneuverability. This work is a comprehensive study that looks at both smart material and conventional actuation methods to achieve wing twist to potentially improve flight capability using minimal actuation energy while allowing minimal wing deformation under aerodynamic loading. A continuous wing is used in order to reduce drag while allowing the aircraft to more closely approximate the wing deformation used by birds while loitering. The morphing wing for this work consists of a skin supported by an underlying truss structure whose goal is to achieve a given roll moment using less actuation energy than conventional control surfaces. A structural optimization code has been written in order to achieve minimal wing deformation under aerodynamic loading while allowing wing twist under actuation. The multi-objective cost function for the optimization consists of terms that ensure small deformation under aerodynamic loading, small change in airfoil shape during wing twist, a linear variation of wing twist along the length of the wing, small deviation from the desired wing twist, minimal number of truss members, minimal wing weight, and minimal actuation energy. Hydraulic cylinders and a two member linkage driven by a DC motor are tested separately to provide actuation. Since the goal of the current work is simply to provide a roll moment, only one actuator is implemented along the wing span. Optimization is also used to find the best location within the truss structure for the actuator. The active structure produced by optimization is then compared to simulated and experimental results from other researchers as well as characteristics of conventional aircraft.

  16. Analysis and Experiment of an Ultra-light Flapping Wing Aircraft

    OpenAIRE

    Hu, Xiaowei

    2013-01-01

    II Inspired by flying animals in nature especially birds, human has designed and attempted to achieve man-powered flapping wing aircraft in very early aviation history. Limited by the understanding of the aerodynamic theory and materials in practise, the bird-like aircraft remains as a dream and ambition for over a contrary. As the relevant knowledge and technology are fast developing in the last decade, the research topic becomes attractive again with encouraging results fr...

  17. 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...

  18. Avian Influenza in Birds

    Science.gov (United States)

    ... this? Submit Button Past Newsletters Avian Influenza in Birds Language: English Español Recommend on Facebook Tweet ... illness. Top of Page Avian Influenza in Wild Birds Avian influenza A viruses have been isolated from ...

  19. Birds Kept as Pets

    Science.gov (United States)

    ... Patients Infants and Young Children Publications & Materials Announcements Birds Kept as Pets Recommend on Facebook Tweet Share ... your hands whenever you play or work with birds Person washing their hands with soap and water. ...

  20. 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

  1. Low Dimensional Analysis of Wing Surface Morphology in Hummingbird Free Flight

    Science.gov (United States)

    Shallcross, Gregory; Ren, Yan; Liu, Geng; Dong, Haibo; Tobalske, Bret

    2015-11-01

    Surface morphing in flapping wings is a hallmark of bird flight. In current work, the role of dynamic wing morphing of a free flying hummingbird is studied in detail. A 3D image-based surface reconstruction method is used to obtain the kinematics and deformation of hummingbird wings from high-quality high-speed videos. The observed wing surface morphing is highly complex and a number of modeling methods including singular value decomposition (SVD) are used to obtain the fundamental kinematical modes with distinct motion features. Their aerodynamic roles are investigated by conducting immersed-boundary-method based flow simulations. The results show that the chord-wise deformation modes play key roles in the attachment of leading-edge vortex, thus improve the performance of the flapping wings. This work is supported by NSF CBET-1313217 and AFOSR FA9550-12-1-0071.

  2. Bioinspired morphing wings for extended flight envelope and roll control of small drones

    Science.gov (United States)

    Heitz, G.; Noca, F.; Floreano, D.

    2017-01-01

    Small-winged drones can face highly varied aerodynamic requirements, such as high manoeuvrability for flight among obstacles and high wind resistance for constant ground speed against strong headwinds that cannot all be optimally addressed by a single aerodynamic profile. Several bird species solve this problem by changing the shape of their wings to adapt to the different aerodynamic requirements. Here, we describe a novel morphing wing design composed of artificial feathers that can rapidly modify its geometry to fulfil different aerodynamic requirements. We show that a fully deployed configuration enhances manoeuvrability while a folded configuration offers low drag at high speeds and is beneficial in strong headwinds. We also show that asymmetric folding of the wings can be used for roll control of the drone. The aerodynamic performance of the morphing wing is characterized in simulations, in wind tunnel measurements and validated in outdoor flights with a small drone. PMID:28163882

  3. Bioinspired morphing wings for extended flight envelope and roll control of small drones.

    Science.gov (United States)

    Di Luca, M; Mintchev, S; Heitz, G; Noca, F; Floreano, D

    2017-02-06

    Small-winged drones can face highly varied aerodynamic requirements, such as high manoeuvrability for flight among obstacles and high wind resistance for constant ground speed against strong headwinds that cannot all be optimally addressed by a single aerodynamic profile. Several bird species solve this problem by changing the shape of their wings to adapt to the different aerodynamic requirements. Here, we describe a novel morphing wing design composed of artificial feathers that can rapidly modify its geometry to fulfil different aerodynamic requirements. We show that a fully deployed configuration enhances manoeuvrability while a folded configuration offers low drag at high speeds and is beneficial in strong headwinds. We also show that asymmetric folding of the wings can be used for roll control of the drone. The aerodynamic performance of the morphing wing is characterized in simulations, in wind tunnel measurements and validated in outdoor flights with a small drone.

  4. The effects of wing loading and gender on the escape flights of least sandpipers (Calidris minutilla) and western sandpipers (Calidris mauri)

    NARCIS (Netherlands)

    Burns, J.G.; Ydenberg, R.C.

    2002-01-01

    High body mass caused by fat storage during migration is believed to increase a bird's risk of predation by decreasing its ability to escape predators. We demonstrate the negative effect of wing loading (mass/wing area) on escape speed and angle of two migrating species of shorebird. We also show si

  5. Flapping Wing Micro Air Vehicle Wing Manufacture and Force Testing

    Science.gov (United States)

    2011-03-03

    include: stroke amplitude, wing beat frequency, wing angle of attack, stroke plane angle, downstroke/upstroke ratio, wing tip trajectory and timing for...Analogous to the Magnus effect 9 (production of lift by surface rotation), it was found that the lift force peaked at the termination of the half

  6. 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,…

  7. 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.

  8. Survival, fidelity, and recovery rates of white-winged doves in Texas

    KAUST Repository

    Collier, Bret A.

    2012-03-12

    Management of migratory birds at the national level has historically relied on regulatory boundaries for definition of harvest restrictions and estimation of demographic parameters. Most species of migratory game birds are not expanding their ranges, so migratory corridors are approximately fixed. White-winged doves (Zenaida asiatica), however, have undergone significant variation in population structure with marked range expansion occurring in Texas, and range contraction in Arizona, during the last 30 years. Because >85% of white-winged dove harvest in the United States (approx. 1.3 million annually) now occurs in Texas, information on vital rates of expanding white-winged dove populations is necessary for informed management. We used band recovery and mark-recapture data to investigate variation in survival and harvest across 3 geographic strata for white-winged doves banded in the pre-hunting season in Texas during 2007-2010. We banded 60,742 white-winged doves, recovered 2,458 bands via harvest reporting, and recaptured 455 known-age birds between 2007 and 2010. The best supporting model found some evidence for geographic differences in survival rates among strata (A-C) in both hatch-year (juvenile; A = 0.205 [SE = 0.0476], B = 0.213 [SE = 0.0278], C = 0.364 [SE = 0.0254]) and after-hatch year (adult; A = 0.483 [SE = 0.0775], B = 0.465 [SE = 0.0366], C = 0.538 [SE = 0.251]) birds. White-winged doves had a low probability of moving among strata (0.009) or being recaptured (0.002) across all strata. Harvest recovery rates were concordant with estimates for other dove species, but were variable across geographic strata. Based on our results, harvest management strategies for white-winged doves in Texas and elsewhere should consider differences in population vital rates among geographic strata. © 2012 The Wildlife Society.

  9. The Aerodynamics of Deforming Wings at Low Reynolds Number

    Science.gov (United States)

    Medina, Albert

    Flapping flight has gained much attention in the past decade driven by the desire to understand capabilities observed in nature and the desire to develop agile small-scale aerial vehicles. Advancing our current understanding of unsteady aerodynamics is an essential component in the development of micro-air vehicles (MAV) intended to utilize flight mechanics akin to insect flight. Thus the efforts undertaken that of bio-mimicry. The complexities of insect wing motion are dissected and simplified to more tractable problems to elucidate the fundamentals of unsteady aerodynamics in biologically inspired kinematics. The MAV's fruition would satisfy long established needs in both the military and civilian sectors. Although recent studies have provided great insight into the lift generating mechanisms of flapping wings the deflection response of such wings remains poorly understood. This dissertation numerically and experimentally investigates the aerodynamic performance of passively and actively deflected wings in hover and rotary kinematics. Flexibility is distilled to discrete lines of flexion which acknowledging major flexion lines in insect wings to be the primary avenue for deformation. Of primary concern is the development of the leading-edge vortex (LEV), a high circulation region of low pressure above the wing to which much of the wing's lift generation is attributed. Two-dimensional simulations of wings with chord-wise flexibility in a freestream reveal a lift generating mechanism unavailable to rigid wings with origins in vortical symmetry breaking. The inclusion of flexibility in translating wings accelerated from rest revealed the formation time of the initial LEV was very weakly dependent on the flexible stiffness of the wing, maintaining a universal time scale of four to five chords of travel before shedding. The frequency of oscillatory shedding of the leading and trailing-edge vortices that develops after the initial vortex shedding was shown to be

  10. Anatomy of a Bird

    Science.gov (United States)

    2007-12-01

    Using ESO's Very Large Telescope, an international team of astronomers [1] has discovered a stunning rare case of a triple merger of galaxies. This system, which astronomers have dubbed 'The Bird' - albeit it also bears resemblance with a cosmic Tinker Bell - is composed of two massive spiral galaxies and a third irregular galaxy. ESO PR Photo 55a/07 ESO PR Photo 55a/07 The Tinker Bell Triplet The galaxy ESO 593-IG 008, or IRAS 19115-2124, was previously merely known as an interacting pair of galaxies at a distance of 650 million light-years. But surprises were revealed by observations made with the NACO instrument attached to ESO's VLT, which peered through the all-pervasive dust clouds, using adaptive optics to resolve the finest details [2]. Underneath the chaotic appearance of the optical Hubble images - retrieved from the Hubble Space Telescope archive - the NACO images show two unmistakable galaxies, one a barred spiral while the other is more irregular. The surprise lay in the clear identification of a third, clearly separate component, an irregular, yet fairly massive galaxy that seems to be forming stars at a frantic rate. "Examples of mergers of three galaxies of roughly similar sizes are rare," says Petri Väisänen, lead author of the paper reporting the results. "Only the near-infrared VLT observations made it possible to identify the triple merger nature of the system in this case." Because of the resemblance of the system to a bird, the object was dubbed as such, with the 'head' being the third component, and the 'heart' and 'body' making the two major galaxy nuclei in-between of tidal tails, the 'wings'. The latter extend more than 100,000 light-years, or the size of our own Milky Way. ESO PR Photo 55b/07 ESO PR Photo 55b/07 Anatomy of a Bird Subsequent optical spectroscopy with the new Southern African Large Telescope, and archive mid-infrared data from the NASA Spitzer space observatory, confirmed the separate nature of the 'head', but also added

  11. 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.

  12. Twin Flavor Chicken Wings

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Ingredients:1000g chicken wings,about,100g Shredded rape-seedleaves,100g black sesame seeds,7g salt,5g sugar,3gMSG,10g cooking wine,5g cassia bark,1000g cookingoil(actual consumption only 100 grams),one egg,anoptional amount of scallion,ginger root,starch and

  13. 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...

  14. International trade of CITES listed bird species in China.

    Science.gov (United States)

    Li, Linlin; Jiang, Zhigang

    2014-01-01

    Commercial trade of wild birds may devastate wild bird populations. Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) controls the trade of wild species listed in its appendices to avoid these species being threatened by international trade. China used to be one of the major trading countries with significant bird trade with foreign countries; on the other hand, China is a country with unique avian fauna, many Important Bird Areas and critically endangered bird species. What is the role of the country in world wild bird trade? What kind of insights can we extract from trade records for improving future management of wild bird trade in the country? We retrieved and analyzed international trade records of the CITES listed bird species of China from 1981 to 2010 from the CITES Trade Database maintained by United Nations Environment Program and World Conservation Monitoring Centre (UNEP-WCMC). We found that: (1) International trade of live birds in China peaked during the late 1990s, then decreased to the level before the surge of trade in a few years, the trade dynamics of wild birds may be affected by governmental policy and the outbreak of avian influenza during the period. (2) Most frequently traded CITES Appendix listed birds in China were parrots, most of which were exotic species to the country. (3) Birds were mainly traded for commercial purpose. Exotic birds in trade were mainly captive-bred while the most Chinese birds traded internationally were captured from the wild. Since many bird species in international trade are threatened to extinction, China should take stricter measures on importing of wild-captured birds and should collaborate with the countries of original in the international bird trade to avoid unsustainable harvesting of wild birds. It is urgent for China to carry out population surveys on those domestic bird species once in significant international trade and to make better conservation decisions based on

  15. International trade of CITES listed bird species in China.

    Directory of Open Access Journals (Sweden)

    Linlin Li

    Full Text Available Commercial trade of wild birds may devastate wild bird populations. Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES controls the trade of wild species listed in its appendices to avoid these species being threatened by international trade. China used to be one of the major trading countries with significant bird trade with foreign countries; on the other hand, China is a country with unique avian fauna, many Important Bird Areas and critically endangered bird species. What is the role of the country in world wild bird trade? What kind of insights can we extract from trade records for improving future management of wild bird trade in the country? We retrieved and analyzed international trade records of the CITES listed bird species of China from 1981 to 2010 from the CITES Trade Database maintained by United Nations Environment Program and World Conservation Monitoring Centre (UNEP-WCMC. We found that: (1 International trade of live birds in China peaked during the late 1990s, then decreased to the level before the surge of trade in a few years, the trade dynamics of wild birds may be affected by governmental policy and the outbreak of avian influenza during the period. (2 Most frequently traded CITES Appendix listed birds in China were parrots, most of which were exotic species to the country. (3 Birds were mainly traded for commercial purpose. Exotic birds in trade were mainly captive-bred while the most Chinese birds traded internationally were captured from the wild. Since many bird species in international trade are threatened to extinction, China should take stricter measures on importing of wild-captured birds and should collaborate with the countries of original in the international bird trade to avoid unsustainable harvesting of wild birds. It is urgent for China to carry out population surveys on those domestic bird species once in significant international trade and to make better conservation

  16. The bizarre wing of the Jamaican flightless ibis Xenicibis xympithecus: a unique vertebrate adaptation.

    Science.gov (United States)

    Longrich, Nicholas R; Olson, Storrs L

    2011-08-07

    Birds have frequently evolved to exploit insular environments by becoming adapted to a terrestrial lifestyle and losing the ability to fly, usually via reducing the wings and pectoral girdle. The enigmatic flightless ibis Xenicibis xympithecus (Threskiornithidae) from the Quaternary of Jamaica provides a rare example of flight loss in ibises. We report on previously undescribed fossils of Xenicibis, and show that the wing differed radically from that of all other birds, flightless or volant. The metacarpus is elongate, grotesquely inflated and has extremely thick walls; phalanges are short and block-like; the radius is distally expanded; and the humerus is elongate. The furcula, coracoid and sternum are all well developed. We propose that the elongate forelimb and massive hand functioned in combat as a jointed club or flail. This hypothesis is supported by the morphology of the carpometacarpus, by features permitting rapid extension of the wing and by the presence of fractures in wing bones. Although other birds use the wings as weapons, none resemble Xenicibis, which represents a unique and extraordinary morphological solution to this functional problem. Xenicibis strikingly illustrates how similar selective pressures, acting on a similar starting point, can result in novel outcomes.

  17. A Review on Fish Swimming and Bird/Insect Flight

    CERN Document Server

    Wu, Theodore Yaotsu

    2010-01-01

    This expository review is devoted to fish swimming and bird/insect flight. (i) The simple waving motion of an elongated flexible ribbon plate of constant width, immersed in a fluid at rest, propagating a wave distally down the plate to swim forward is first considered to provide a fundamental concept on energy conservation. It is generalized to include variations in body width and thickness, vortex shedding from appended dorsal, ventral and caudal fins to closely simulate fish swimming for which a nonlinear theory is presented for large-amplitude propulsion. (ii) For bird flight, the pioneering studies on oscillating rigid wings are briefed, followed by presenting a nonlinear unsteady theory for flexible wing with arbitrary variations in shape and trajectory with a comparative study with experiments. (iii) For insect flight, more recent advances are reviewed under aerodynamic theory and modeling, computational methods, and experiments, on forward and hovering flights with producing leading-edge vortex to give...

  18. A new raptorial dinosaur with exceptionally long feathering provides insights into dromaeosaurid flight performance.

    Science.gov (United States)

    Han, Gang; Chiappe, Luis M; Ji, Shu-An; Habib, Michael; Turner, Alan H; Chinsamy, Anusuya; Liu, Xueling; Han, Lizhuo

    2014-07-15

    Microraptorines are a group of predatory dromaeosaurid theropod dinosaurs with aerodynamic capacity. These close relatives of birds are essential for testing hypotheses explaining the origin and early evolution of avian flight. Here we describe a new 'four-winged' microraptorine, Changyuraptor yangi, from the Early Cretaceous Jehol Biota of China. With tail feathers that are nearly 30 cm long, roughly 30% the length of the skeleton, the new fossil possesses the longest known feathers for any non-avian dinosaur. Furthermore, it is the largest theropod with long, pennaceous feathers attached to the lower hind limbs (that is, 'hindwings'). The lengthy feathered tail of the new fossil provides insight into the flight performance of microraptorines and how they may have maintained aerial competency at larger body sizes. We demonstrate how the low-aspect-ratio tail of the new fossil would have acted as a pitch control structure reducing descent speed and thus playing a key role in landing.

  19. Hummingbird wing efficacy depends on aspect ratio and compares with helicopter rotors

    NARCIS (Netherlands)

    Kruyt, J.W.; Quicazan Rubio, E.M.; Heijst, van G.J.F.; Altshuler, D.L.; Lentink, D.

    2014-01-01

    Hummingbirds are the only birds that can sustain hovering. This unique flight behaviour comes, however, at high energetic cost. Based on helicopter and aeroplane design theory, we expect that hummingbird wing aspect ratio (AR), which ranges from about 3.0 to 4.5, determines aerodynamic efficacy. Pre

  20. SMA actuators for morphing wings

    Science.gov (United States)

    Brailovski, V.; Terriault, P.; Georges, T.; Coutu, D.

    An experimental morphing laminar wing was developed to prove the feasibility of aircraft fuel consumption reduction through enhancement of the laminar flow regime over the wing extrados. The morphing wing prototype designed for subsonic cruise flight conditions (Mach 0.2 … 0.3; angle of attack - 1 … +2∘), combines three principal subsystems: (1) flexible extrados, (2) rigid intrados and (3) an actuator group located inside the wing box. The morphing capability of the wing relies on controlled deformation of the wing extrados under the action of shape memory alloys (SMA) actuators. A coupled fluid-structure model of the morphing wing was used to evaluate its mechanical and aerodynamic performances in different flight conditions. A 0.5 m chord and 1 m span prototype of the morphing wing was tested in a subsonic wind tunnel. In this work, SMA actuators for morphing wings were modeled using a coupled thermo-mechanical finite element model and they were windtunnel validated. If the thermo-mechanical model of SMA actuators presented in this work is coupled with the previously developed structureaerodynamic model of the morphing wing, it could serve for the optimization of the entire morphing wing system.

  1. Variation in wing characteristics of monarch butterflies during migration: Earlier migrants have redder and more elongated wings

    Directory of Open Access Journals (Sweden)

    Satterfield Dara A.

    2014-01-01

    Full Text Available The migration of monarch butterflies (Danaus plexippus in North America has a number of parallels with long-distance bird migration, including the fact that migratory populations of monarchs have larger and more elongated forewings than residents. These characteristics likely serve to optimize flight performance in monarchs, as they also do with birds. A question that has rarely been addressed thus far in birds or monarchs is if and how wing characteristics vary within a migration season. Individuals with superior flight performance should migrate quickly, and/or with minimal stopovers, and these individuals should be at the forefront of the migratory cohort. Conversely, individuals with poor flight performance and/or low endurance would be more likely to fall behind, and these would comprise the latest migrants. Here we examined how the wing morphology of migrating monarchs varies to determine if wing characteristics of early migrants differ from late migrants. We measured forewing area, elongation (length/width, and redness, which has been shown to predict flight endurance in monarchs. Based on a collection of 75 monarchs made one entire season (fall 2010, results showed that the earliest migrants (n = 20 in this cohort had significantly redder and more elongated forewings than the latest migrants (n = 17. There was also a non-significant tendency for early migrants to have larger forewing areas. These results suggest that the pace of migration in monarchs is at least partly dependent on the properties of their wings. Moreover, these data also raise a number of questions about the ultimate fate of monarchs that fall behind

  2. When wings touch wakes: understanding locomotor force control by wake wing interference in insect wings.

    Science.gov (United States)

    Lehmann, Fritz-Olaf

    2008-01-01

    Understanding the fluid dynamics of force control in flying insects requires the exploration of how oscillating wings interact with the surrounding fluid. The production of vorticity and the shedding of vortical structures within the stroke cycle thus depend on two factors: the temporal structure of the flow induced by the wing's own instantaneous motion and the flow components resulting from both the force production in previous wing strokes and the motion of other wings flapping in close proximity. These wake-wing interactions may change on a stroke-by-stroke basis, confronting the neuro-muscular system of the animal with a complex problem for force control. In a single oscillating wing, the flow induced by the preceding half stroke may lower the wing's effective angle of attack but permits the recycling of kinetic energy from the wake via the wake capture mechanism. In two-winged insects, the acceleration fields produced by each wing may strongly interact via the clap-and-fling mechanism during the dorsal stroke reversal. Four-winged insects must cope with the fact that the flow over their hindwings is affected by the presence of the forewings. In these animals, a phase-shift between the stroke cycles of fore- and hindwing modulates aerodynamic performance of the hindwing via leading edge vortex destruction and changes in local flow condition including wake capture. Moreover, robotic wings demonstrate that phase-lag during peak performance and the strength of force modulation depend on the vertical spacing between the two stroke planes and the size ratio between fore- and hindwing. This study broadly summarizes the most prominent mechanisms of wake-wing and wing-wing interactions found in flapping insect wings and evaluates the consequences of these processes for the control of locomotor forces in the behaving animal.

  3. Effect of salt on the response of birds to sucrose

    Science.gov (United States)

    Rogers, J.G.; Maller, O.

    1973-01-01

    The preference of male red-winged blackbirds for solutions of sucrose and sucrose with 0.03 M sodium chloride was tested, using a two-bottle choice test. Preliminary experiments demonstrated that the birds were indifferent to 0.03 M NaCl in water. Both control and experimental animals exhibited indifference to the solutions at the lowest concentration and aversion at the highest. The data suggest that the added sodium chloride makes the sucrose stimulus more discriminable.

  4. Passively morphing ornithopter wings constructed using a novel compliant spine: design and testing

    Science.gov (United States)

    Wissa, A. A.; Tummala, Y.; Hubbard, J. E., Jr.; Frecker, M. I.

    2012-09-01

    Ornithopters or flapping wing uncrewed aerial vehicles (UAVs) have potential applications in civil and military sectors. Amongst the UAVs, ornithopters have a unique ability to fly in low Reynolds number flight regimes and also have the agility and maneuverability of rotary wing aircraft. In nature, birds achieve such performance by exploiting various wing kinematics known as gaits. The objective of this work is to improve the steady level flight performance of an ornithopter by implementing a continuous vortex gait using a novel passive compliant spine inserted in the ornithopter’s wings. This paper presents an optimal compliant spine concept for ornithopter applications. A quasi-static design optimization procedure was formulated to design the compliant spine. Finite element analysis was performed on a first generation spine and the spine was fabricated. This prototype was then tested by inserting it into an ornithopter’s wing leading edge spar. The effect of inserting the compliant spine into the wings on the electric power required, the aerodynamic loads and the wing kinematics was studied. The ornithopter with the compliant spines inserted in its wings consumed 45% less power and produced an additional 16% of its weight in mean lift compared to the same ornithopter without the compliant spine. The results indicate that this passive morphing approach is promising for improved steady level flight performance.

  5. Conserved syntenic clusters of protein coding genes are missing in birds

    OpenAIRE

    Lovell, Peter V.; Wirthlin, Morgan; Wilhelm, Larry; Minx, Patrick; Lazar, Nathan H.; Carbone, Lucia; Warren, Wesley C.; Mello, Claudio V.

    2014-01-01

    Background Birds are one of the most highly successful and diverse groups of vertebrates, having evolved a number of distinct characteristics, including feathers and wings, a sturdy lightweight skeleton and unique respiratory and urinary/excretion systems. However, the genetic basis of these traits is poorly understood. Results Using comparative genomics based on extensive searches of 60 avian genomes, we have found that birds lack approximately 274 protein coding genes that are present in th...

  6. Circulation Produced by a Flapping Wing During Stroke Reversal

    Science.gov (United States)

    Burge, Matthew; Ringuette, Matthew

    2016-11-01

    We investigate the circulation behavior of the 3D flow structures formed during the stroke-reversal of a 2-degree-of-freedom flapping wing in hover. Previous work has related circulation peaks to the unsteady wing kinematics and forces. However, information from experiments detailing contributions from the multiple, 3D flow structures is lacking. The objective of this work is to quantitatively study the spanwise circulation as well as the spanwise flow which advects vorticity in the complex loop topology of a flapping wing during stroke reversal. We analyze the flow features of a scaled wing model using multi-plane stereo digital particle image velocimetry in a glycerin-water mixture. Data plane locations along the wing span are inspired by the time-resolved behavior of the 3D vortex structures observed in our earlier flow visualization studies. As with our prior work, we vary dimensionless parameters such as the pitching reduced frequency to understand their effect on the circulation. This research provides insight into the vortex dynamics produced by the coupled rotational and pitching wing motions during stroke reversal, when lift generation is challenging. This work is supported by the National Science Foundation, Award Number 1336548, supervised by Dr. Dimitrios Papavassiliou.

  7. Immunogenic proteins specific to different bird species in bird fancier's lung.

    Science.gov (United States)

    Rouzet, Adeline; Reboux, Gabriel; Rognon, Bénédicte; Barrera, Coralie; De Vuyst, Paul; Dalphin, Jean-Charles; Millon, Laurence; Roussel, Sandrine

    2014-01-01

    Bird fancier's lung (BFL) is a disease produced by exposure to avian proteins present in droppings, blooms, and serum of a variety of birds. Although serological test results are currently used to confirm clinical diagnosis of the disease, bird species specificity is poorly understood. This study aimed to contribute to a better understanding of the specificity of immunogenic proteins revealed from the droppings of three bird species. Sera from four patients with BFL and two controls without exposure were analyzed by Western blotting with antigens from droppings of two pigeon and budgerigar strains and two hen species. When the antigens from the droppings of the three bird species were compared, the profile of immunogenic proteins was different and there were similarities between strains of the same species. Only one 68-kD protein was common to pigeon and budgerigar droppings, while proteins of 200, 175, 140, 100, and 35 kD were detected as specific in one bird species. These results provide insight to further characterize these proteins, and to design new serological tests specific to different bird species. These tests may help to refine strategies of antigenic exclusion and also to allow a patient compensation in case of BFL of occupational origin.

  8. 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...

  9. Effect of torsional stiffness and inertia on the dynamics of low aspect ratio flapping wings.

    Science.gov (United States)

    Xiao, Qing; Hu, Jianxin; Liu, Hao

    2014-03-01

    Micro air vehicle-motivated aerodynamics in biological flight has been an important subject in the past decade. Inspired by the novel flapping wing mechanisms in insects, birds and bats, we have carried out a numerical study systematically investigating a three-dimensional flapping rigid wing with passively actuated lateral and rotational motion. Distinguishing it from the limited existing studies, this work performs a systematic examination on the effects of wing aspect ratio (AR = 1.0 to infinity), inertia (density ratio σ = 4-32), torsional stiffness (frequency ratio F = 1.5-10 and infinity) and pivot point (from chord-center to leading edge) on the dynamics response of a low AR rectangular wing under an initial zero speed flow field condition. The simulation results show that the symmetry breakdown of the flapping wing results in a forward/backward motion with a rotational pitching. When the wing reaches its stable periodic state, the induced pitching frequency is identical to its forced flapping frequency. However, depending on various kinematic and dynamic system parameters, (i.e. flapping frequency, density ratio and pitching axis), the lateral induced velocity shows a number of different oscillating frequencies. Furthermore, compared with a one degree of freedom (DoF) wing in the lateral direction only, the propulsion performance of such a two DoF wing relies very much on the magnitude of torsional stiffness adding on the pivot point, as well as its pitching axis. In all cases examined here, thrust force and moment generated by a long span wing is larger than that of a short wing, which is remarkably linked to the strong reverse von Kármán vortex street formed in the wake of a wing.

  10. Limb disparity and wing shape in pterosaurs.

    Science.gov (United States)

    Dyke, G J; Nudds, R L; Rayner, J M V

    2006-07-01

    The limb proportions of the extinct flying pterosaurs were clearly distinct from their living counterparts, birds and bats. Within pterosaurs, however, we show that further differences in limb proportions exist between the two main groups: the clade of short-tailed Pterodactyloidea and the paraphyletic clades of long-tailed rhamphorhynchoids. The hindlimb to forelimb ratios of rhamphorhynchoid pterosaurs are similar to that seen in bats, whereas those of pterodactyloids are much higher. Such a clear difference in limb ratios indicates that the extent of the wing membrane in rhamphorhynchoids and pterodactyloids may also have differed; this is borne out by simple ternary analyses. Further, analyses also indicate that the limbs of Sordes pilosus, a well-preserved small taxon used as key evidence for inferring the extent and shape of the wing membrane in all pterosaurs, are not typical even of its closest relatives, other rhamphorhynchoids. Thus, a bat-like extensive hindlimb flight membrane, integrated with the feet and tail may be applicable only to a small subset of pterosaur diversity. The range of flight morphologies seen in these extinct reptiles may prove much broader than previously thought.

  11. Flapping before Flight: High Resolution, Three-Dimensional Skeletal Kinematics of Wings and Legs during Avian Development.

    Science.gov (United States)

    Heers, Ashley M; Baier, David B; Jackson, Brandon E; Dial, Kenneth P

    2016-01-01

    Some of the greatest transformations in vertebrate history involve developmental and evolutionary origins of avian flight. Flight is the most power-demanding mode of locomotion, and volant adult birds have many anatomical features that presumably help meet these demands. However, juvenile birds, like the first winged dinosaurs, lack many hallmarks of advanced flight capacity. Instead of large wings they have small "protowings", and instead of robust, interlocking forelimb skeletons their limbs are more gracile and their joints less constrained. Such traits are often thought to preclude extinct theropods from powered flight, yet young birds with similarly rudimentary anatomies flap-run up slopes and even briefly fly, thereby challenging longstanding ideas on skeletal and feather function in the theropod-avian lineage. Though skeletons and feathers are the common link between extinct and extant theropods and figure prominently in discussions on flight performance (extant birds) and flight origins (extinct theropods), skeletal inter-workings are hidden from view and their functional relationship with aerodynamically active wings is not known. For the first time, we use X-ray Reconstruction of Moving Morphology to visualize skeletal movement in developing birds, and explore how development of the avian flight apparatus corresponds with ontogenetic trajectories in skeletal kinematics, aerodynamic performance, and the locomotor transition from pre-flight flapping behaviors to full flight capacity. Our findings reveal that developing chukars (Alectoris chukar) with rudimentary flight apparatuses acquire an "avian" flight stroke early in ontogeny, initially by using their wings and legs cooperatively and, as they acquire flight capacity, counteracting ontogenetic increases in aerodynamic output with greater skeletal channelization. In conjunction with previous work, juvenile birds thereby demonstrate that the initial function of developing wings is to enhance leg

  12. Design optimization of deployable wings

    Science.gov (United States)

    Gaddam, Pradeep

    Morphing technology is an important aspect of UAV design, particularly in regards to deployable systems. The design of such system has an important impact on the vehicle's performance. The primary focus of the present research work was to determine the most optimum deployable wing design from 3 competing designs and develop one of the deployable wing designs to test in the research facility. A Matlab code was developed to optimize 3 deployable wing concepts inflatable, inflatable telescopic and rigid-folding wings based on a sequential optimization strategy. The constraints that were part of the code include the packaging constraints during its stowed state, fixed length of the deployed section and the minimum L/D constraint. This code resulted in determining the optimum weight of all the 3 designs, the most optimum weight design is the inflatable wing design. This is a result of the flexible skin material and also due to no rigid parts in the deployed wing section. Another goal of the research involved developing an inflatable telescopic wing. The prototype was tested in a wind tunnel, while the actual wing was tested in the altitude chamber to determine the deployment speed, input pressure, analyze and predict the deployment sequence and behavior of the wing at such high wind speeds and altitudes ranging from 60,000 ft to 90,000 ft. Results from these tests allowed us to conclude the deployment sequence of the telescopic wing followed from the root to the tip section. The results were used to analyze the deployment time of the wing. As expected the deployment time decreased with an increase in input pressure. The results also show us that as the altitude increases, the deployment speed of the wing also increased. This was demonstrated when the wing was tested at a maximum altitude pressure of 90,000ft, well above the design altitude of 60,000ft.

  13. 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...

  14. Winging Its Way

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This spring, the world again faces the prospect of a bird flu outbreak Hawks, tigers, dogs and cats. These animals are not directly related in the biological chain, but they are all threatened by the same disease-the H5N1 avian flu virus.

  15. Avian wing geometry and kinematics of a free-flying barn owl in flapping flight

    Science.gov (United States)

    Wolf, Thomas; Konrath, Robert

    2015-02-01

    This paper presents results of high-resolution three-dimensional wing shape measurements performed on free-flying barn owls in flapping flight. The applied measurement technique is introduced together with a moving camera set-up, allowing for an investigation of the free flapping flight of birds with high spatial and temporal resolution. Based on the three-dimensional surface data, a methodology for parameterizing the wing profile along with wing kinematics during flapping flight has been developed. This allowed a description of the spanwise varying kinematics and aerodynamic parameters (e.g. effective angles of attack, camber, thickness) of the wing in dependence on the flapping phase. The results are discussed in detail using the data of a single flight, whereas a comparison of some kinematic parameters obtained from different flights is given too.

  16. 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.

  17. 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....

  18. 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...

  19. Bioaccumulation of polonium {sup 210}Po in marine birds

    Energy Technology Data Exchange (ETDEWEB)

    Skwarzec, B. [University of Gdansk, Faculty of Chemistry, Chair of Analytical Chemistry, ul. Sobieskiego 18/19, 80-952 Gdansk (Poland)]. E-mail: bosk@chemik.chem.univ.gda.pl; Fabisiak, J. [Naval Academy, Smidowicza 61, 81-103 Gdynia (Poland)

    2007-07-01

    The aim of this work was to determine the {sup 210}Po content in marine birds which permanently or temporally live in the Polish part of the Baltic Sea. We chose 11 species of sea birds: three species permanently residing at southern Baltic Sea, four species of wintering birds and three species of migrating birds. The results show that the polonium is non-uniformly distributed in the marine birds. The highest activities of {sup 210}Po were observed in feathers, muscles and liver and the lowest in skin and skeleton. Species of birds that eat crustaceans, molluscs, fish and plants (long-tailed duck Clangula hyemalis, white-winged scoter Melanitta fusca) accumulated more polonium than species that eat mainly fish (great cormorant Phalacrocorax carbo, common guillemot Uria aalge) or plants (tufted duck Aythya fuligula). Moreover, about 63% of the {sup 210}Po that was located in feathers of razorbil (Alca torda) and long-tailed duck (C. hyemalis) was apparently adsorbed, suggesting an external source such as the air. It means that the adsorption of {sup 210}Po on the feather surface may be an important transfer from air to water.

  20. Use of thermography and fluorescein angiography in the management of a Chilean flamingo with avascular necrosis of the wing.

    Science.gov (United States)

    Hurley-Sanders, Jennifer L; Bowman, Karl F; Wolfe, Barbara A; Nutter, Felicia B; Sladky, Kurt K; Stoskopf, Michael K

    2012-12-01

    A Chilean flamingo (Phoenicopterus chilensis) was presented to the veterinary clinic at the North Carolina Zoological Park for evaluation of acute weakness of the right wing. Results of a physical examination revealed a lack of a palpable pulse in the radial artery, which suggested occlusion or obstruction of the vessel. Radiography, thermography, and fluorescein angiography confirmed right wing injury and vascular compromise. Based on the poor prognosis for return to function associated with irreversible vascular damage, the wing was amputated. After a period of observation and treatment, the bird was returned to public exhibit.

  1. 苏科版初中生物《鸟类》教学设计%The teaching design of junior biology"birds"

    Institute of Scientific and Technical Information of China (English)

    王芳

    2013-01-01

    By organizing the paper airplane game, help students gain insights in the game, construct the bird flight depends on the three elements, and using the experience of life, the relevant teaching tools and textbook knowledge will be abstracted three factors, solve the teaching focus, clear biological structure and adapted to the function. Children have a keen interest naturally, when the students present the elements of the flight of birds, what adverse factors bird life have, through the activities, exchange, sharing, to obtain certification or revise their idea, all the students’ thought has been deepening and development, form positive attitudes. Students think that birds flying because of the wings, install the wings can fly, forming the cognitive conflict and student experiences, and learn to conform to the schema, the denotation and connotation of birds.%通过合理组织纸飞机游戏,帮助学生在游戏中获得感悟,建构鸟类飞行取决于的三个要素,并利用生活经验、相关教具与课本知识将抽象概括的三个要素具体化,解决教学重点,明确生物结构与功能相适应的意识。孩子天生对自然有着浓厚的兴趣,当学生提出鸟类飞行的要素,鸟类的生存还有哪些不利因素等,通过活动、交流、分享、获得验证或修订自己想法的时候,全体学生的思维得到了深化与发展,形成积极的科学态度。学生认为鸟类飞行是由于翅膀,是学生已有图式,通过人安装翅膀能否飞行,与学生已有经验形成认知冲突,并通过本节课的学习来顺应图式,明确鸟类的内涵和外延。

  2. Automated measurement of Drosophila wings

    Directory of Open Access Journals (Sweden)

    Mezey Jason

    2003-12-01

    Full Text Available Abstract Background Many studies in evolutionary biology and genetics are limited by the rate at which phenotypic information can be acquired. The wings of Drosophila species are a favorable target for automated analysis because of the many interesting questions in evolution and development that can be addressed with them, and because of their simple structure. Results We have developed an automated image analysis system (WINGMACHINE that measures the positions of all the veins and the edges of the wing blade of Drosophilid flies. A video image is obtained with the aid of a simple suction device that immobilizes the wing of a live fly. Low-level processing is used to find the major intersections of the veins. High-level processing then optimizes the fit of an a priori B-spline model of wing shape. WINGMACHINE allows the measurement of 1 wing per minute, including handling, imaging, analysis, and data editing. The repeatabilities of 12 vein intersections averaged 86% in a sample of flies of the same species and sex. Comparison of 2400 wings of 25 Drosophilid species shows that wing shape is quite conservative within the group, but that almost all taxa are diagnosably different from one another. Wing shape retains some phylogenetic structure, although some species have shapes very different from closely related species. The WINGMACHINE system facilitates artificial selection experiments on complex aspects of wing shape. We selected on an index which is a function of 14 separate measurements of each wing. After 14 generations, we achieved a 15 S.D. difference between up and down-selected treatments. Conclusion WINGMACHINE enables rapid, highly repeatable measurements of wings in the family Drosophilidae. Our approach to image analysis may be applicable to a variety of biological objects that can be represented as a framework of connected lines.

  3. Distribution of the characteristics of barbs and barbules on barn owl wing feathers.

    Science.gov (United States)

    Weger, Matthias; Wagner, Hermann

    2017-03-03

    Owls are known for the development of a silent flight. One conspicuous specialization of owl wings that has been implied in noise reduction and that has been demonstrated to change the aerodynamic behavior of the wing is a soft dorsal wing surface. The soft surface is a result of changes in the shape of feather barbs and barbules in owls compared with other bird species. We hypothesized that as the aerodynamic characteristics of a wing change along its chordwise and spanwise direction, so may the shape of the barbs and barbules. Therefore, we examined in detail the shapes of the barbs and barbules in chordwise and spanwise directions. The results showed changes in the shapes of barbs and barbules at the anterior and distal parts of the wing, but not at more posterior parts. The increased density of hook radiates at the distalmost wing position could serve to stiffen that vane part that is subject to the highest forces. The change of pennulum length in the anterior part of the wing and the uniformity further back could mean that a soft surface may be especially important in regions where flow separation may occur.

  4. The barn owl wing: an inspiration for silent flight in the aviation industry?

    Science.gov (United States)

    Bachmann, Thomas; Mühlenbruch, Georg; Wagner, Hermann

    2011-04-01

    Barn owls are specialists in prey detection using acoustic information. The flight apparatus of this bird of prey is most efficiently adapted to the hunting behavior by reducing flight noise. An understanding of the underlying mechanisms owls make use of could help minimize the noise disturbances in airport or wind power plant neighborhood. Here, we characterize wings of barn owls in terms of an airfoil as a role model for studying silent flight. This characterization includes surface and edge specialization (serrations, fringes) evolved by the owl. Furthermore, we point towards possible adaptations of either noise suppression or air flow control that might be an inspiration for the construction of modern aircraft. Three-dimensional imaging techniques such as surface digitizing, computed tomography and confocal laser scanning microscopy were used to investigate the wings and feathers in high spatial resolution. We show that wings of barn owls are huge in relation to their body mass resulting in a very low wing loading which in turn enables a slow flight and an increased maneuverability. Profiles of the wing are highly cambered and anteriorly thickened, especially at the proximal wing, leading to high lift production during flight. However, wind tunnel experiments showed that the air flow tends to separate at such wing configurations, especially at low-speed flight. Barn owls compensated this problem by evolving surface and edge modifications that stabilize the air flow. A quantitative three-dimensionally characterization of some of these structures is presented.

  5. Aerodynamic Analysis of Flexible Flapping Wing Micro Aerial Vehicle Using Quasi-Steady Approach

    Science.gov (United States)

    Vijayakumar, Kolandapaiyan; Chandrasekhar, Uttam; Chandrashekhar, Nagaraj

    2016-10-01

    In recent times flexible flapping-wing aerodynamics has generated a great deal of interest and is the topic of contemporary research because of its potential application in micro aerial vehicles (MAVs). The prominent features of MAVs include low Reynolds Number, changing the camber of flapping wings, development of related mechanisms, study of the suitability airfoil shape selection and other parameters. Generally, low Reynolds Number is similar to that of an insect or a bird (103-105). The primary goal of this project work is to perform CFD analysis on flexible flapping wing MAVs in order to estimate the lift and drag by using engineering methods such as quasi-steady approach. From the wind tunnel data, 3-D deformation is obtained. For CFD analysis, two types of quasi-steady methods are considered. The first method is to slice the wing section chord-wise and span wise at multiple regions, frame by frame, and obtain the 2-D corrugated camber section for each frame. This 2-D corrugated camber is analysed using CFD techniques and all the individual 2-D corrugated camber results are summed up frame by frame, to obtain the total lift and drag for one wing beat. The second method is to consider the 3D wing in entirety and perform the CFD analysis to obtain the lift and drag for five wing beat.

  6. Two new ornithurine birds from the Early Cretaceous of western Liaoning, China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    We describe two new ornithurine birds from the Early Cretaceous Jiufotang Formation of western Liaoning, northeast China: Yanornis martini gen. et sp. nov. and Yixianornis grabaui gen. et sp. nov. They represent the best fossil record of ornithurine birds known from the Early Cretaceous. They are more advanced than the most primitive ornithurine Liaoningornis, and are more similar to the other two Chinese Early Cretaceous ornithurines Chaoyangia and Songlingornis. Compared with Confuciusornis, Liaoxiornis and Eoenantiornis from the same age, the two new birds show remarkable advanced characteristics and suggest the presence of powerful flight capability like modern birds. Compared with Yixianornis and Chaoyangia, Yanornis is larger, with a more elongated skull and relatively long wings. The new discoveries indicate that by the Early Cretaceous both enantiornithine and ornithurine birds had already radiated significantly. The flight structures of Yanornis and Yixianornis are hardly distinguishable from those of modern birds; however, both retain a few primitive traits such as teeth on the jaws, wing claws and pubic symphysis, which exclude them from being the most recent ancestor of all ex-tant birds.

  7. Abnormal behavior in caged birds kept as pets.

    Science.gov (United States)

    van Hoek, C S; ten Cate, C

    1998-01-01

    There are a limited number of studies dealing with abnormal behavior in caged birds kept as pets. However, these studies demonstrate the presence of abnormal behavior in both songbirds and parrots. Ethological studies on these birds, as well as studies on domestic and zoo birds, indicate that inappropriate rearing and housing conditions may lead to behavioral abnormalities. Together these data indicate that behavioral abnormalities occur among both wild-caught and domesticated pet birds. The severity and magnitude of these abnormalities is probably underestimated, and there is a need for systematic studies on the nature, origin, variability, species-specificity, and reversibility of behavioral problems in pet birds. Abnormal behavior in caged birds may to some extent be prevented and reduced by environmental enrichment. However, most enrichment studies are anecdotal and not based on a thorough analysis of the behavioral abnormalities, which may lead to measures resulting in a reduction of symptoms rather than the underlying causes. Although it is likely that several of these problems could be reduced by modifying rearing and housing conditions, the current insights into the causal mechanisms underlying abnormal behavior of domesticated and wild-caught pet birds are limited, as are the insights into the possibilities of preventing or curing abnormal behavior.

  8. A study on forces acting on a flapping wing

    OpenAIRE

    Cetiner O.; Fenercioglu I.; Vuruskan A.

    2013-01-01

    In order to study the forces acting on a flapping wing, an experimental investigation is performed in steady water flow. In this study, a SD7003 airfoil undergoes combined pitching and plunging motion which simulates the forward flight of small birds. The frequency of pitching motion is equal to the frequency of plunging motion and pitch leads the plunge by a phase angle of 90 degrees. The experiments are conducted at Reynolds numbers of 2500 ≤ Re ≤ 13700 and the vortex formation is recorded ...

  9. Stiffness of desiccating insect wings

    Energy Technology Data Exchange (ETDEWEB)

    Mengesha, T E; Vallance, R R [Department of Mechanical Engineering, The George Washington University, 738 Phillips Hall, 801 22nd St NW, Washington, DC 20052 (United States); Mittal, R, E-mail: vallance@gwu.edu [Department of Mechanical Engineering, Johns Hopkins University, 126 Latrobe Hall, 3400 N Charles Street, Baltimore, MD 21218 (United States)

    2011-03-15

    The stiffness of insect wings is typically determined through experimental measurements. Such experiments are performed on wings removed from insects. However, the wings are subject to desiccation which typically leads to an increase in their stiffness. Although this effect of desiccation is well known, a comprehensive study of the rate of change in stiffness of desiccating insect wings would be a significant aid in planning experiments as well as interpreting data from such experiments. This communication presents a comprehensive experimental analysis of the change in mass and stiffness of gradually desiccating forewings of Painted Lady butterflies (Vanessa cardui). Mass and stiffness of the forewings of five butterflies were simultaneously measured every 10 min over a 24 h period. The averaged results show that wing mass declined exponentially by 21.1% over this time period with a time constant of 9.8 h, while wing stiffness increased linearly by 46.2% at a rate of 23.4 {mu}N mm{sup -1} h{sup -1}. For the forewings of a single butterfly, the experiment was performed over a period of 1 week, and the results show that wing mass declined exponentially by 52.2% with a time constant of 30.2 h until it reached a steady-state level of 2.00 mg, while wing stiffness increased exponentially by 90.7% until it reached a steady-state level of 1.70 mN mm{sup -1}. (communication)

  10. [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.

  11. 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.

  12. Beetle wings are inflatable origami

    Science.gov (United States)

    Chen, Rui; Ren, Jing; Ge, Siqin; Hu, David

    2015-11-01

    Beetles keep their wings folded and protected under a hard shell. In times of danger, they must unfold them rapidly in order for them to fly to escape. Moreover, they must do so across a range of body mass, from 1 mg to 10 grams. How can they unfold their wings so quickly? We use high-speed videography to record wing unfolding times, which we relate to the geometry of the network of blood vessels in the wing. Larger beetles have longer unfolding times. Modeling of the flow of blood through the veins successfully accounts for the wing unfolding speed of large beetles. However, smaller beetles have anomalously short unfolding times, suggesting they have lower blood viscosity or higher driving pressure. The use of hydraulics to unfold complex objects may have implications in the design of micro-flying air vehicles.

  13. Blue-winged teals swim in shallow water

    Science.gov (United States)

    1999-01-01

    A pair of blue-winged teals glide through the waters of the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. Inhabiting marshes, shallow ponds and lakes from British Columbia, Quebec and Newfoundland to North Carolina, the Gulf Coast and southern California, the teal winters as far south as South America. The 92,000-acre refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

  14. From daily movements to population distributions: weather affects competitive ability in a guild of soaring birds.

    Science.gov (United States)

    Shepard, Emily L C; Lambertucci, Sergio A

    2013-11-06

    The ability of many animals to access and exploit food is dependent on the ability to move. In the case of scavenging birds, which use soaring flight to locate and exploit ephemeral resources, the cost and speed of movement vary with meteorological factors. These factors are likely to modify the nature of interspecific interactions, as well as individual movement capacity, although the former are less well understood. We used aeronautical models to examine how soaring performance varies with weather within a guild of scavenging birds and the consequences this has for access to a common resource. Birds could be divided broadly into those with low wing loading that are more competitive in conditions with weak updraughts and low winds (black vultures and caracaras), and those with high wing loading that are well adapted for soaring in strong updraughts and moderate to high winds (Andean condors). Spatial trends in meteorological factors seem to confine scavengers with high wing loading to the mountains where they out-compete other birds; a trend that is borne out in worldwide distributions of the largest species. However, model predictions and carcass observations suggest that the competitive ability of these and other birds varies with meteorological conditions in areas where distributions overlap. This challenges the view that scavenging guilds are structured by fixed patterns of dominance and suggests that competitive ability varies across spatial and temporal scales, which may ultimately be a mechanism promoting diversity among aerial scavengers.

  15. Unsteady aerodynamics and flow control for flapping wing flyers

    Science.gov (United States)

    Ho, Steven; Nassef, Hany; Pornsinsirirak, Nick; Tai, Yu-Chong; Ho, Chih-Ming

    2003-11-01

    The creation of micro air vehicles (MAVs) of the same general sizes and weight as natural fliers has spawned renewed interest in flapping wing flight. With a wingspan of approximately 15 cm and a flight speed of a few meters per second, MAVs experience the same low Reynolds number (10 4-10 5) flight conditions as their biological counterparts. In this flow regime, rigid fixed wings drop dramatically in aerodynamic performance while flexible flapping wings gain efficacy and are the preferred propulsion method for small natural fliers. Researchers have long realized that steady-state aerodynamics does not properly capture the physical phenomena or forces present in flapping flight at this scale. Hence, unsteady flow mechanisms must dominate this regime. Furthermore, due to the low flight speeds, any disturbance such as gusts or wind will dramatically change the aerodynamic conditions around the MAV. In response, a suitable feedback control system and actuation technology must be developed so that the wing can maintain its aerodynamic efficiency in this extremely dynamic situation; one where the unsteady separated flow field and wing structure are tightly coupled and interact nonlinearly. For instance, birds and bats control their flexible wings with muscle tissue to successfully deal with rapid changes in the flow environment. Drawing from their example, perhaps MAVs can use lightweight actuators in conjunction with adaptive feedback control to shape the wing and achieve active flow control. This article first reviews the scaling laws and unsteady flow regime constraining both biological and man-made fliers. Then a summary of vortex dominated unsteady aerodynamics follows. Next, aeroelastic coupling and its effect on lift and thrust are discussed. Afterwards, flow control strategies found in nature and devised by man to deal with separated flows are examined. Recent work is also presented in using microelectromechanical systems (MEMS) actuators and angular speed

  16. A fundamental avian wing-stroke provides a new perspective on the evolution of flight.

    Science.gov (United States)

    Dial, Kenneth P; Jackson, Brandon E; Segre, Paolo

    2008-02-21

    The evolution of avian flight remains one of biology's major controversies, with a long history of functional interpretations of fossil forms given as evidence for either an arboreal or cursorial origin of flight. Despite repeated emphasis on the 'wing-stroke' as a necessary avenue of investigation for addressing the evolution of flight, no empirical data exist on wing-stroke dynamics in an experimental evolutionary context. Here we present the first comparison of wing-stroke kinematics of the primary locomotor modes (descending flight and incline flap-running) that lead to level-flapping flight in juvenile ground birds throughout development. We offer results that are contrary both to popular perception and inferences from other studies. Starting shortly after hatching and continuing through adulthood, ground birds use a wing-stroke confined to a narrow range of less than 20 degrees , when referenced to gravity, that directs aerodynamic forces about 40 degrees above horizontal, permitting a 180 degrees range in the direction of travel. Based on our results, we put forth an ontogenetic-transitional wing hypothesis that posits that the incremental adaptive stages leading to the evolution of avian flight correspond behaviourally and morphologically to transitional stages observed in ontogenetic forms.

  17. Artificial evolution of the morphology and kinematics in a flapping-wing mini-UAV.

    Science.gov (United States)

    de Margerie, E; Mouret, J B; Doncieux, S; Meyer, J-A

    2007-12-01

    Birds demonstrate that flapping-wing flight (FWF) is a versatile flight mode, compatible with hovering, forward flight and gliding to save energy. This extended flight domain would be especially useful on mini-UAVs. However, design is challenging because aerodynamic efficiency is conditioned by complex movements of the wings, and because many interactions exist between morphological (wing area, aspect ratio) and kinematic parameters (flapping frequency, stroke amplitude, wing unfolding). Here we used artificial evolution to optimize these morpho-kinematic features on a simulated 1 kg UAV, equipped with wings articulated at the shoulder and wrist. Flight tests were conducted in a dedicated steady aerodynamics simulator. Parameters generating horizontal flight for minimal mechanical power were retained. Results showed that flight at medium speed (10-12 m s(-1)) can be obtained for reasonable mechanical power (20 W kg(-1)), while flight at higher speed (16-20 m s(-1)) implied increased power (30-50 W kg(-1)). Flight at low speed (6-8 m s(-1)) necessitated unrealistic power levels (70-500 W kg(-1)), probably because our simulator neglected unsteady aerodynamics. The underlying adaptation of morphology and kinematics to varying flight speed were compared to available biological data on the flight of birds.

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. Experimental Characterization of Wings for a Hawkmoth-Sized Micro Air Vehicle

    Science.gov (United States)

    2014-03-27

    that the rotation is controlled passively, which differs from birds and bats which can “actively control wing shape through muscular flexure and...Backer Plate 3. Fiber Board Backer Plate 4. Aluminum Backer Plate 5. Cloth Insulative Layer 34 Figure 3.15: Press Plate Layout. The Mylar® bonds with...August 2002. http://archive.darpa.mil/DARPATech2002/presentations/ tto pdf/speeches/WILSONSB.pdf. 129 [33] Wood , R. J. “Liftoff of a 60mg flapping-wing

  3. Assembly modes of dragonfly wings.

    Science.gov (United States)

    Zhao, Hong-Xiao; Yin, Ya-Jun; Zhong, Zheng

    2011-12-01

    The assembly modes of dragonfly wings are observed through FEG-ESEM. Different from airplane wings, dragonfly wings are found to be assembled through smooth transition mode and global package mode. First, at the vein/membrane conjunctive site, the membrane is divided into upper and lower portions from the center layer and transited smoothly to the vein. Then the two portions pack the vein around and form the outer surface of the vein. Second, at the vein/spike conjunctive site, the vein and spike are connected smoothly into a triplet. Last, at the vein/membrane/spike conjunctive site, the membrane (i.e., the outer layer of the vein) transits smoothly to the spike, packs it around, and forms its outer layer. In short, the membrane looks like a closed coat packing the wing as a whole. The smooth transition mode and the global package mode are universal assembly modes in dragonfly wings. They provide us the references for better understanding of the functions of dragonfly wings and the bionic manufactures of the wings of flights with mini sizes.

  4. Breeding bird assemblages associated with stages of forest succession in large river floodplains

    Science.gov (United States)

    Knutson, M.G.; McColl, L.E.; Suarez, S.A.

    2005-01-01

    Floodplain forests rival all other habitat types in bird density and diversity. However, major successional changes are predicted for floodplain forests along the Mississippi River in the coming decades; young forests may replace the existing mature silver maple (Acer saccharinum L.) forests in some areas. We wanted to assess how the breeding bird community might respond to these changes. We studied stands of young forests along the middle Mississippi River, comparing the breeding bird assemblages among three stages of forest succession: shrub/scrub, young cottonwood (Populus deltoides Marshall) and willow (Salix nigra Marshall) forests, and mature silver maple dominated forests. We recorded a total of 54 bird species; the most frequently observed species were the indigo bunting (Passerina cyanea), red-winged blackbird (Agelaius phoeniceus), and yellow-billed cuckoo (Coccyzus americanus). Bird species richness differed among the habitat types, with mature forests supporting the largest number of species and the most species of management concern. The shrub/scrub and mature forest bird assemblages were distinct and shared few species, but the young forests had no identifiable bird species assemblage, sharing species found in both of the other habitat types. The bird assemblages we observed in young forests may become more prevalent as aging floodplain forests are replaced with younger stages of forest succession. Under this scenario, we would expect a temporary local decrease in bird species richness and habitat for species of management concern.

  5. Changes in timing, duration, and symmetry of molt of Hawaiian forest birds.

    Science.gov (United States)

    Freed, Leonard A; Cann, Rebecca L

    2012-01-01

    Food limitation greatly affects bird breeding performance, but the effect of nutritive stress on molt has barely been investigated outside of laboratory settings. Here we show changes in molting patterns for an entire native Hawaiian bird community at 1650-1900 m elevation on the Island of Hawaii between 1989-1999 and 2000-2006, associated with severe food limitation throughout the year beginning in 2000. Young birds and adults of all species took longer to complete their molt, including months never or rarely used during the 1989-1999 decade. These included the cold winter months and even the early months of the following breeding season. In addition, more adults of most species initiated their molt one to two months earlier, during the breeding season. Suspended molt, indicated by birds temporarily not molting primary flight feathers during the months of peak primary molt, increased in prevalence. Food limitation reached the point where individuals of all species had asymmetric molt, with different primary flight feathers molted on each wing. These multiple changes in molt, unprecedented in birds, had survival consequences. Adult birds captured during January to March, 2000-2004, had lower survival in four of five species with little effect of extended molt. Extended molt may be adaptive for a nutrient stressed bird to survive warm temperatures but not cool winter temperatures that may obliterate the energy savings. The changing molt of Hawaiian birds has many implications for conservation and for understanding life history aspects of molt of tropical birds.

  6. Effect of litter substrates on the performance, carcass traits, and environmental comfort of red-winged tinamou (Rhynchotus rufescens)

    NARCIS (Netherlands)

    Carvalho Nunes, Joao; Carvalho, M.M.; Sugui, J.K.; Queiroz, F.A.; Santana, A.E.; Hata, M.E.; Aiura, A.L.O.; Oliveira, J.A.; Queiroz, De Sandra Aidar

    2016-01-01

    The study aimed at evaluating the effect of litter substrates on the performance, carcass traits, and environmental comfort of red-winged tinamou (Rhynchotus rufescens). In this experiment, 160 birds, with 100 and 300 days of age, were housed into 20 pens, and distributed according to a completel

  7. Structural Analysis of a Dragonfly Wing

    NARCIS (Netherlands)

    Jongerius, S.R.; Lentink, D.

    2010-01-01

    Dragonfly wings are highly corrugated, which increases the stiffness and strength of the wing significantly, and results in a lightweight structure with good aerodynamic performance. How insect wings carry aerodynamic and inertial loads, and how the resonant frequency of the flapping wings is tuned

  8. Experimental investigation of the effect of chordwise flexibility on the aerodynamics of flapping wings in hovering flight

    Science.gov (United States)

    Mazaheri, K.; Ebrahimi, A.

    2010-05-01

    Ornithopters or mechanical birds produce aerodynamic lift and thrust through the flapping motion of their wings. Here, we use an experimental apparatus to investigate the effects of a wing's twisting stiffness on the generated thrust force and the power required at different flapping frequencies. A flapping wing system and an experimental set-up were designed to measure the unsteady aerodynamic and inertial forces, power usage and angular speed of the flapping wing motion. A data acquisition system was set-up to record important data with the appropriate sampling frequency. The aerodynamic performance of the vehicle under hovering (i.e., no wind) conditions was investigated. The lift and thrust that were produced were measured for different flapping frequencies and for various wings with different chordwise flexibilities. The results show the manner in which the elastic deformation and inertial flapping forces affect the dynamical behavior of the wing. It is shown that the generalization of the actuator disk theory is, at most, only valid for rigid wings, and for flexible wings, the power P varies by a power of about 1.0 of the thrust T. This aerodynamic information can also be used as benchmark data for unsteady flow solvers.

  9. Shape optimisation and performance analysis of flapping wings

    KAUST Repository

    Ghommem, Mehdi

    2012-09-04

    In this paper, shape optimisation of flapping wings in forward flight is considered. This analysis is performed by combining a local gradient-based optimizer with the unsteady vortex lattice method (UVLM). Although the UVLM applies only to incompressible, inviscid flows where the separation lines are known a priori, Persson et al. [1] showed through a detailed comparison between UVLM and higher-fidelity computational fluid dynamics methods for flapping flight that the UVLM schemes produce accurate results for attached flow cases and even remain trend-relevant in the presence of flow separation. As such, they recommended the use of an aerodynamic model based on UVLM to perform preliminary design studies of flapping wing vehicles Unlike standard computational fluid dynamics schemes, this method requires meshing of the wing surface only and not of the whole flow domain [2]. From the design or optimisation perspective taken in our work, it is fairly common (and sometimes entirely necessary, as a result of the excessive computational cost of the highest fidelity tools such as Navier-Stokes solvers) to rely upon such a moderate level of modelling fidelity to traverse the design space in an economical manner. The objective of the work, described in this paper, is to identify a set of optimised shapes that maximise the propulsive efficiency, defined as the ratio of the propulsive power over the aerodynamic power, under lift, thrust, and area constraints. The shape of the wings is modelled using B-splines, a technology used in the computer-aided design (CAD) field for decades. This basis can be used to smoothly discretize wing shapes with few degrees of freedom, referred to as control points. The locations of the control points constitute the design variables. The results suggest that changing the shape yields significant improvement in the performance of the flapping wings. The optimisation pushes the design to "bird-like" shapes with substantial increase in the time

  10. Conceptual design and optimization methodology for box wing aircraft

    OpenAIRE

    Jemitola, Paul Olugbeji

    2012-01-01

    A conceptual design optimization methodology was developed for a medium range box wing aircraft. A baseline conventional cantilever wing aircraft designed for the same mis- sion and payload was also optimized alongside a baseline box wing aircraft. An empirical formula for the mass estimation of the fore and aft wings of the box wing aircraft was derived by relating conventional cantilever wings to box wing aircraft wings. The results indicate that the fore and aft wings would ...

  11. Lift-optimal aspect ratio of a revolving wing at low Reynolds number

    Science.gov (United States)

    Jardin, Thierry; Colonius, Tim

    2016-11-01

    Lentink & Dickinson (2009) showed that rotational acceleration stabilized the leading-edge vortex on revolving, low-aspect-ratio wings, and hypothesized that a Rossby number of around 3, which is achieved during each half-stroke for a variety of hovering insects, seeds, and birds, represents a convergent high-lift solution across a range of scales in nature. Subsequent work has verified that, in particular, the Coriolis acceleration is responsible for LEV stabilization. Implicit in these results is that there exists an optimal aspect ratio for wings revolving about their root, because it is otherwise unclear why, apart from possible physiological reasons, the convergent solution would not occur for an even lower Rossby number. We perform direct numerical simulations of the flow past revolving wings where we vary the aspect ratio and Rossby numbers independently by displacing the wing root from the axis of rotation. We show that the optimal lift coefficient represents a compromise between competing trends where the coefficient of lift increases monotonically with aspect ratio, holding Rossby number constant, but decreases monotonically with Rossby number, when holding aspect ratio constant. For wings revolving about their root, this favors wings of aspect ratio between 3 and 4. The authors gratefully acknowledge support from Fondation ISAE-Supaero.

  12. A blue-winged teal swims in the waters of KSC

    Science.gov (United States)

    1999-01-01

    This male blue-winged teal is one of 23 species of migratory waterfowl that winter in the waters of the Merritt Island National Wildlife Refuge at Kennedy Space Center. The male is usually identified with pale blue shoulder patches and a white crescent in front of its eye. The blue-winged teal's normal range is from Canada to North Carolina, the Gulf Coast and southern California, preferring marshes, shallow ponds and lakes. It winters as far as northern South America. The refuge provides wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds. The 92,000-acre refuge is also habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles.

  13. 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...

  14. 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,...

  15. Webcams for bird detection and monitoring: a demonstration study.

    Science.gov (United States)

    Verstraeten, Willem W; Vermeulen, Bart; Stuckens, Jan; Lhermitte, Stefaan; Van der Zande, Dimitry; Van Ranst, Marc; Coppin, Pol

    2010-01-01

    Better insights into bird migration can be a tool for assessing the spread of avian borne infections or ecological/climatologic issues reflected in deviating migration patterns. This paper evaluates whether low budget permanent cameras such as webcams can offer a valuable contribution to the reporting of migratory birds. An experimental design was set up to study the detection capability using objects of different size, color and velocity. The results of the experiment revealed the minimum size, maximum velocity and contrast of the objects required for detection by a standard webcam. Furthermore, a modular processing scheme was proposed to track and follow migratory birds in webcam recordings. Techniques such as motion detection by background subtraction, stereo vision and lens distortion were combined to form the foundation of the bird tracking algorithm. Additional research to integrate webcam networks, however, is needed and future research should enforce the potential of the processing scheme by exploring and testing alternatives of each individual module or processing step.

  16. Wing and body kinematics of takeoff and landing flight in the pigeon (Columba livia).

    Science.gov (United States)

    Berg, Angela M; Biewener, Andrew A

    2010-05-01

    Takeoff and landing are critical phases in a flight. To better understand the functional importance of the kinematic adjustments birds use to execute these flight modes, we studied the wing and body movements of pigeons (Columba livia) during short-distance free-flights between two perches. The greatest accelerations were observed during the second wingbeat of takeoff. The wings were responsible for the majority of acceleration during takeoff and landing, with the legs contributing only one-quarter of the acceleration. Parameters relating to aerodynamic power output such as downstroke amplitude, wingbeat frequency and downstroke velocity were all greatest during takeoff flight and decreased with each successive takeoff wingbeat. This pattern indicates that downstroke velocity must be greater for accelerating flight to increase the amount of air accelerated by the wings. Pigeons used multiple mechanisms to adjust thrust and drag to accelerate during takeoff and decelerate during landing. Body angle, tail angle and wing plane angles all shifted from more horizontal orientations during takeoff to near-vertical orientations during landing, thereby reducing drag during takeoff and increasing drag during landing. The stroke plane was tilted steeply downward throughout takeoff (increasing from -60+/-5 deg. to -47+/-1 deg.), supporting our hypothesis that a downward-tilted stroke plane pushes more air rearward to accelerate the bird forward. Similarly, the stroke plane tilted upward during landing (increasing from -1+/-2 deg. to 17+/-7 deg.), implying that an upward-tilted stroke plane pushes more air forward to slow the bird down. Rotations of the stroke plane, wing planes and tail were all strongly correlated with rotation of the body angle, suggesting that pigeons are able to redirect aerodynamic force and shift between flight modes through modulation of body angle alone.

  17. WINGS Data Release

    DEFF Research Database (Denmark)

    Moretti, A.; Poggianti, B. M.; Fasano, G.;

    2014-01-01

    Context. To effectively investigate galaxy formation and evolution, it is of paramount importance to exploit homogeneous data for large samples of galaxies in different environments. Aims. The WIde-field Nearby Galaxy-cluster Survey (WINGS) project aim is to evaluate physical properties of galaxies......, and on the cluster redshift, reaching on average 90% at V ≲ 21.7. Near-infrared photometric catalogs for 26 (in K) and 19 (in J) clusters are part of the database and the number of sources is 962 344 in K and 628 813 in J. Here again the completeness depends on the data quality, but it is on average higher than 90......% for J ≲ 20.5 and K ≲ 19.4. The IR subsample with a Sersic fit comprises 71 687 objects. A morphological classification is available for 39 923 galaxies. We publish spectroscopic data, including 6132 redshifts, 5299 star formation histories, and 4381 equivalent widths. Finally, a calculation of local...

  18. Static aeroelastic analysis of composite wing

    Science.gov (United States)

    Lee, IN; Hong, Chang Sun; Miura, Hirokazu; Kim, Seung KO

    1990-01-01

    A static aeroelastic analysis capability that can predict aerodynamic loads for the deformed shape of the composite wing has been developed. The finite element method (FEM) was used for composite plate structural analysis, and the linear vortex lattice method (VLM) was used for steady aerodynamic analysis. The final deformed shape of the wing due to applied forces is determined by iterative manner using FEM and VLM. FEM and VLM analysis are related by a surface spline interpolation procedure. The wing with Gr/Ep composite material has been investigated to see the wing deformation effect. Aerodynamic load change due to wing flexibility has been investigated. Also, the effect of fiber orientation and sweep angle on the deformation pattern and aerodynamic coefficients are examined. For a certain fiber orientation, the deflection and aerodynamic loading of the composite wing is very much reduced. The swept forward wing has more significant effect of wing flexibility on aerodynamic coefficient than the swept back wing does.

  19. 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,

  20. Local elasticity and adhesion of nanostructures on Drosophila melanogaster wing membrane studied using atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Ryan, E-mail: rbwagner@purdue.edu [School of Mechanical Engineering, Purdue University, West Lafayette (United States); Brick Nanotechnology Center, Purdue University, West Lafayette (United States); Pittendrigh, Barry R. [Department of Entomology, University of Illinois, Champaign (United States); Raman, Arvind, E-mail: raman@purdue.edu [School of Mechanical Engineering, Purdue University, West Lafayette (United States); Brick Nanotechnology Center, Purdue University, West Lafayette (United States)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer We studied the wing membrane of Drosophila melanogaster with atomic force microscopy. Black-Right-Pointing-Pointer We report the structure, elasticity, and adhesion on the wing membrane in air and nitrogen environments. Black-Right-Pointing-Pointer Results provide insight into the nature of the wing membrane enabling the development of biomimetic surface and micro air vehicles. - Abstract: Insect wings have a naturally occurring, complex, functional, hierarchical microstructure and nanostructure, which enable a remarkably water-resistant and self-cleaning surface. Insect wings are used as a basis for engineering biomimetic materials; however, the material properties of these nanostructures such as local elastic modulus and adhesion are poorly understood. We studied the wings of the Canton-S strain of Drosophila melanogaster (hereafter referred to as Drosophila) with atomic force microscopy (AFM) to quantify the local material properties of Drosophila wing surface nanostructures. The wings are found to have a hierarchical structure of 10-20 {mu}m long, 0.5-1 {mu}m diameter hair, and at a much smaller scale, 100 nm diameter and 30-60 nm high bumps. The local properties of these nanoscale bumps were studied under ambient and dry conditions with force-volume AFM. The wing membrane was found to have a elastic modulus on the order of 1000 MPa and the work of adhesion between the probe and wing membrane surface was found to be on the order of 100 mJ/m{sup 2}, these properties are the same order of magnitude as common thermoplastic polymers such as polyethylene. The difference in work of adhesion between the nanoscale bump and membrane does not change significantly between ambient (relative humidity of 30%) or dry conditions. This suggests that the nanoscale bumps and the surrounding membrane are chemically similar and only work to increase hydrophobicity though surface roughening or the geometric lotus effect.

  1. Wing bone laminarity is not an adaptation for torsional resistance in bats

    Directory of Open Access Journals (Sweden)

    Andrew H. Lee

    2015-03-01

    Full Text Available Torsional loading is a common feature of skeletal biomechanics during vertebrate flight. The importance of resisting torsional loads is best illustrated by the convergence of wing bone structure (e.g., long with thin walls across extant bats and birds. Whether or not such a convergence occurs at the microstructural level is less clear. In volant birds, the humeri and ulnae often contain abundant laminar bony tissue in which primary circumferential vascular canals course concentrically about the long axis of the bone. These circumferential canals and the matrix surrounding them presumably function to resist the tissue-level shear stress caused by flight-induced torsion. Here, we assess whether or not laminar bone is a general adaptive feature in extant flying vertebrates using a histological analysis of bat bones. We sampled the humeri from six adult taxa representing a broad phylogenetic and body size range (6–1,000 g. Transverse thick sections were prepared from the midshaft of each humerus. Bone tissue was classified based on the predominant orientation of primary vascular canals. Our results show that humeri from bats across a wide phylogenetic and body size range do not contain any laminar bone. Instead, humeri are essentially avascular in bats below about 100 g and are poorly vascularized with occasional longitudinal to slightly radial canals in large bats. In contrast, humeri from birds across a comparable size range (40–1,000 g are highly vascularized with a wide range in bone laminarity. Phylogenetically-informed scaling analyses reveal that the difference in vascularity between birds and bats is best explained by higher somatic relative growth rates in birds. The presence of wing bone laminarity in birds and its absence in bats suggests that laminar bone is not a necessary biomechanical feature in flying vertebrates and may be apomorphic to birds.

  2. Morphogenesis in bat wings: linking development, evolution and ecology.

    Science.gov (United States)

    Adams, Rick A

    2008-01-01

    The evolution of powered flight in mammals required specific developmental shifts from an ancestral limb morphology to one adapted for flight. Through studies of comparative morphogenesis, investigators have quantified points and rates of divergence providing important insights into how wings evolved in mammals. Herein I compare growth,development and skeletogenesis of forelimbs between bats and the more ancestral state provided by the rat (Rattus norvegicus)and quantify growth trajectories that illustrate morphological divergence both developmentally and evolutionarily. In addition, I discuss how wing shape is controlled during morphogenesis by applying multivariate analyses of wing bones and wing membranes and discuss how flight dynamics are stabilized during flight ontogeny. Further, I discuss the development of flight in bats in relation to the ontogenetic niche and how juveniles effect populational foraging patterns. In addition, I provide a hypothetical ontogenetic landscape model that predicts how and when selection is most intense during juvenile morphogenesis and test this model with data from a population of the little brown bat, Myotis lucifugus.

  3. Aerodynamics of a bio-inspired flexible flapping-wing micro air vehicle.

    Science.gov (United States)

    Nakata, T; Liu, H; Tanaka, Y; Nishihashi, N; Wang, X; Sato, A

    2011-12-01

    MAVs (micro air vehicles) with a maximal dimension of 15 cm and nominal flight speeds of around 10 m s⁻¹, operate in a Reynolds number regime of 10⁵ or lower, in which most natural flyers including insects, bats and birds fly. Furthermore, due to their light weight and low flight speed, the MAVs' flight characteristics are substantially affected by environmental factors such as wind gust. Like natural flyers, the wing structures of MAVs are often flexible and tend to deform during flight. Consequently, the aero/fluid and structural dynamics of these flyers are closely linked to each other, making the entire flight vehicle difficult to analyze. We have recently developed a hummingbird-inspired, flapping flexible wing MAV with a weight of 2.4-3.0 g and a wingspan of 10-12 cm. In this study, we carry out an integrated study of the flexible wing aerodynamics of this flapping MAV by combining an in-house computational fluid dynamic (CFD) method and wind tunnel experiments. A CFD model that has a realistic wing planform and can mimic realistic flexible wing kinematics is established, which provides a quantitative prediction of unsteady aerodynamics of the four-winged MAV in terms of vortex and wake structures and their relationship with aerodynamic force generation. Wind tunnel experiments further confirm the effectiveness of the clap and fling mechanism employed in this bio-inspired MAV as well as the importance of the wing flexibility in designing small flapping-wing MAVs.

  4. A bizarre Jurassic maniraptoran theropod with preserved evidence of membranous wings.

    Science.gov (United States)

    Xu, Xing; Zheng, Xiaoting; Sullivan, Corwin; Wang, Xiaoli; Xing, Lida; Wang, Yan; Zhang, Xiaomei; O'Connor, Jingmai K; Zhang, Fucheng; Pan, Yanhong

    2015-05-01

    The wings of birds and their closest theropod relatives share a uniform fundamental architecture, with pinnate flight feathers as the key component. Here we report a new scansoriopterygid theropod, Yi qi gen. et sp. nov., based on a new specimen from the Middle-Upper Jurassic period Tiaojishan Formation of Hebei Province, China. Yi is nested phylogenetically among winged theropods but has large stiff filamentous feathers of an unusual type on both the forelimb and hindlimb. However, the filamentous feathers of Yi resemble pinnate feathers in bearing morphologically diverse melanosomes. Most surprisingly, Yi has a long rod-like bone extending from each wrist, and patches of membranous tissue preserved between the rod-like bones and the manual digits. Analogous features are unknown in any dinosaur but occur in various flying and gliding tetrapods, suggesting the intriguing possibility that Yi had membranous aerodynamic surfaces totally different from the archetypal feathered wings of birds and their closest relatives. Documentation of the unique forelimbs of Yi greatly increases the morphological disparity known to exist among dinosaurs, and highlights the extraordinary breadth and richness of the evolutionary experimentation that took place close to the origin of birds.

  5. Cholinesterase inhibition of birds inhabiting wheat fields treated with methyl parathion and toxaphene

    Science.gov (United States)

    Niethammer, K.R.; Baskett, T.S.

    1983-01-01

    Red-winged blackbirds (Agelaius phoeniceus) and dickcissels (Spiza americana) inhabiting wheat fields treated with 0.67 kg AI/ha methyl parathion and 1.35 kg AI/ha toxaphene showed brain cholinesterase (ChE) inhibition compared with birds inhabiting untreated fields. Maximum inhibition occurred about five days after insecticide application. ChE activities again approached normal 10 days after treatment. ChE inhibition for dickcissels and red-winged blackbirds differed significantly (p<0.05); maximum inhibition for the former species was 74%, and for the latter, 40%. These differences could not be explained by the diets of the two species, as they were similar.

  6. 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.

  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. 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)

  9. 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…

  10. 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)

  11. The DelFly design, aerodynamics, and artificial intelligence of a flapping wing robot

    CERN Document Server

    de Croon, G C H E; Remes, B D W; Ruijsink, R; De Wagter, C

    2016-01-01

    This book introduces the topics most relevant to autonomously flying flapping wing robots: flapping-wing design, aerodynamics, and artificial intelligence. Readers can explore these topics in the context of the "Delfly", a flapping wing robot designed at Delft University in The Netherlands. How are tiny fruit flies able to lift their weight, avoid obstacles and predators, and find food or shelter? The first step in emulating this is the creation of a micro flapping wing robot that flies by itself. The challenges are considerable: the design and aerodynamics of flapping wings are still active areas of scientific research, whilst artificial intelligence is subject to extreme limitations deriving from the few sensors and minimal processing onboard. This book conveys the essential insights that lie behind success such as the DelFly Micro and the DelFly Explorer. The DelFly Micro, with its 3.07 grams and 10 cm wing span, is still the smallest flapping wing MAV in the world carrying a camera, whilst the DelFly Expl...

  12. Aircraft wing structural detail design (wing, aileron, flaps, and subsystems)

    Science.gov (United States)

    Downs, Robert; Zable, Mike; Hughes, James; Heiser, Terry; Adrian, Kenneth

    1993-01-01

    The goal of this project was to design, in detail, the wing, flaps, and ailerons for a primary flight trainer. Integrated in this design are provisions for the fuel system, the electrical system, and the fuselage/cabin carry-through interface structure. This conceptual design displays the general arrangement of all major components in the wing structure, taking into consideration the requirements set forth by the appropriate sections of Federal Aviation Regulation Part 23 (FAR23) as well as those established in the statement of work.

  13. A computational study of the wing-wing and wing-body interactions of a model insect

    Institute of Scientific and Technical Information of China (English)

    Xin Yu; Mao Sun

    2009-01-01

    The aerodynamic interaction between the contralateral wings and between the body and wings of a model insect are studied, by using the method of numerically solving the Navier-Stokes equations over moving overset grids, under typical hovering and forward flight conditions. Both the interaction between the contralateral wings and the interaction between the body and wings are very weak, e.g. at hovering, changes in aerodynamic forces of a wing due to the present of the other wing are less than 3% and changes in aerodynamic forces of the wings due to presence of thebody are less than 2%. The reason for this is as following. During each down-or up-stroke, a wing produces a vortexring, which induces a relatively large jet-like flow inside the ring but very small flow outside the ring. The vortex tings of the left and right wings are on the two sides of the body. Thus one wing is outside vortex ring of the other wing and the body is outside the vortex rings of the left and right wings, resulting in the weak interactions.

  14. Insect Evolution: The Origin of Wings.

    Science.gov (United States)

    Ross, Andrew

    2017-02-06

    The debate on the evolution of wings in insects has reached a new level. The study of primitive fossil insect nymphs has revealed that wings developed from a combination of the dorsal part of the thorax and the body wall.

  15. Aerodynamic control with passively pitching wings

    Science.gov (United States)

    Gravish, Nick; Wood, Robert

    Flapping wings may pitch passively under aerodynamic and inertial loads. Such passive pitching is observed in flapping wing insect and robot flight. The effect of passive wing pitch on the control dynamics of flapping wing flight are unexplored. Here we demonstrate in simulation and experiment the critical role wing pitching plays in yaw control of a flapping wing robot. We study yaw torque generation by a flapping wing allowed to passively rotate in the pitch axis through a rotational spring. Yaw torque is generated through alternating fast and slow upstroke and and downstroke. Yaw torque sensitively depends on both the rotational spring force law and spring stiffness, and at a critical spring stiffness a bifurcation in the yaw torque control relationship occurs. Simulation and experiment reveal the dynamics of this bifurcation and demonstrate that anomalous yaw torque from passively pitching wings is the result of aerodynamic and inertial coupling between the pitching and stroke-plane dynamics.

  16. Structural colors from Morpho peleides butterfly wing scales

    KAUST Repository

    Ding, Yong

    2009-01-01

    A male Morpho peleides butterfly wing is decorated by two types of scales, cover and ground scales. We have studied the optical properties of each type of scales in conjunction with the structural information provided by cross-sectional transmission electron microscopy and computer simulation. The shining blue color is mainly from the Bragg reflection of the one-dimensional photonic structure, e.g., the shelf structure packed regularly in each ridges on cover scales. A thin-film-like interference effect from the base plate of the cover scale enhances such blue color and further gives extra reflection peaks in the infrared and ultraviolet regions. The analogy in the spectra acquired from the original wing and that from the cover scales suggests that the cover scales take a dominant role in its structural color. This study provides insight of using the biotemplates for fabricating smart photonic structures. © 2009 American Institute of Physics.

  17. Span morphing using the GNATSpar wing

    OpenAIRE

    2016-01-01

    Rigid wings usually fly at sub-optimal conditions generating unnecessary aerodynamic loses represented in flight time, fuel consumption, and unfavourable operational characteristics. High aspect ratio wings have good range and fuel efficiency, but lack manoeuvrability. On the other hand, low aspect ratio wings fly faster and are more manoeuvrable, but have poor aerodynamic performance. Span morphing technology allows integrating both features in a single wing design and allows continuously ad...

  18. Topology Optimization of an Aircraft Wing

    Science.gov (United States)

    2015-06-11

    constraint is met. Optimizations were performed on a general aviation experi- mental aircraft wing subject to pressure loading simulating maximum...compared to traditional means. Additionally, a fuel tank was integrated into the wing structure as a proof-of-concept for the potential benefits of AM...topology and sizing optimization of the wing integrated with the fuel tank , spars, and skin. This resulted in a total wing mass reduction of 10.8

  19. Structural Analysis of a Dragonfly Wing

    OpenAIRE

    Jongerius, S.R.; Lentink, D.

    2010-01-01

    Dragonfly wings are highly corrugated, which increases the stiffness and strength of the wing significantly, and results in a lightweight structure with good aerodynamic performance. How insect wings carry aerodynamic and inertial loads, and how the resonant frequency of the flapping wings is tuned for carrying these loads, is however not fully understood. To study this we made a three-dimensional scan of a dragonfly (Sympetrum vulgatum) fore- and hindwing with a micro-CT scanner. The scans c...

  20. Low Aspect-Ratio Wings for Wing-Ships

    DEFF Research Database (Denmark)

    Filippone, Antonino; Selig, M.

    1998-01-01

    Flying on ground poses technical and aerodynamical challenges. The requirements for compactness, efficiency, manouverability, off-design operation,open new areas of investigations in the fieldof aerodynamic analysis and design. A review ofthe characteristics of low-aspect ratio wings, in- and out...

  1. An integrated approach on free flight mechanisms in insects and birds.

    Science.gov (United States)

    Liu, Hao

    2005-11-01

    To provide an overall understanding of aerodynamic and dynamic mechanisms in flying insects and birds we have succeed in establishing a biology-inspired dynamic flight simulator, which is capable to mimic hovering, forward flight and quick-turn on a basis of modeling of realistic geometry and wing kinematics, and modeling of wing-body flight dynamics. Coupling of an in-house CFD solver and a newly developed flapping flight dynamic solver enables the free flight simulation with consideration of both wing-wing interaction and wing-body interaction, and hence a systematic and quantitative evaluation of aerodynamics and flight stability in realistic flying animals. We carried out a systematic computational study on the hovering-and forward-flight of a wing-body moth model and validated the numerical results by comparing with the force-and moment-measurements based on a robotic moth model. Our results indicate that the leading-edge vortex is a universal high-lift/thrust enhancement mechanism in animal flight; and both aerodynamic force and inertial force are important in lift/thrust generation and power requirement, in particular in flight maneuverability.

  2. 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

  3. 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...

  4. Nesting ecology and behavior of Broad-winged Hawks in moist karst forests of Puerto Rico

    Science.gov (United States)

    Hengstenberg, D.W.; Vilella, F.J.

    2005-01-01

    The Puerto Rican Broad-winged Hawk (Buteo platypterus brunnescens) is an endemic and endangered subspecies inhabiting upland montane forests of Puerto Rico. The reproductive ecology, behavior, and nesting habitat of the Broad-winged Hawk were studied in Ri??o Abajo Forest, Puerto Rico, from 2001-02. We observed 158 courtship displays by Broad-winged Hawks. Also, we recorded 25 territorial interactions between resident Broad-winged Hawks and intruding Red-tailed Hawks (Buteo jamaicensis jamaicensis). Broad-winged Hawks displaced intruding Red-tailed Hawks from occupied territories (P = 0.009). Mayfield nest survival was 0.67 across breeding seasons (0.81 in 2001, N = 6; 0.51 in 2002, N = 4), and pairs averaged 1.1 young per nest (years combined). The birds nested in mixed species timber plantations and mature secondary forest. Nests were placed in the upper reaches of large trees emerging from the canopy. Nest tree DBH, understory stem density, and distance to karst cliff wall correctly classified (77.8%) nest sites. ?? 2005 The Raptor Research Foundation, Inc.

  5. De novo transcriptome analysis of wing development-related signaling pathways in Locusta migratoria manilensis and Ostrinia furnacalis (Guenee.

    Directory of Open Access Journals (Sweden)

    Suning Liu

    Full Text Available BACKGROUND: Orthopteran migratory locust, Locusta migratoria, and lepidopteran Asian corn borer, Ostrinia furnacalis, are two types of insects undergoing incomplete and complete metamorphosis, respectively. Identification of candidate genes regulating wing development in these two insects would provide insights into the further study about the molecular mechanisms controlling metamorphosis development. We have sequenced the transcriptome of O. furnacalis larvae previously. Here we sequenced and characterized the transcriptome of L. migratoria wing discs with special emphasis on wing development-related signaling pathways. METHODOLOGY/PRINCIPAL FINDINGS: Illumina Hiseq2000 was used to sequence 8.38 Gb of the transcriptome from dissected nymphal wing discs. De novo assembly generated 91,907 unigenes with mean length of 610 nt. All unigenes were searched against five databases including Nt, Nr, Swiss-Prot, COG, and KEGG for annotations using blastn or blastx algorithm with an cut-off E-value of 10-5. A total of 23,359 (25.4% unigenes have homologs within at least one database. Based on sequence similarity to homologs known to regulate Drosophila melanogaster wing development, we identified 50 and 46 potential wing development-related unigenes from L. migratoria and O. furnacalis transcriptome, respectively. The identified unigenes encode putative orthologs for nearly all components of the Hedgehog (Hh, Decapentaplegic (Dpp, Notch (N, and Wingless (Wg signaling pathways, which are essential for growth and pattern formation during wing development. We investigated the expression profiles of the component genes involved in these signaling pathways in forewings and hind wings of L. migratoria and O. furnacalis. The results revealed the tested genes had different expression patterns in two insects. CONCLUSIONS/SIGNIFICANCE: This study provides the comprehensive sequence resource of the wing development-related signaling pathways of L. migratoria. The

  6. Bat flight with bad wings: is flight metabolism affected by damaged wings?

    Science.gov (United States)

    Voigt, Christian C

    2013-04-15

    Infection of North American bats with the keratin-digesting fungus Geomyces destructans often results in holes and ruptures of wing membranes, yet it is unknown whether flight performance and metabolism of bats are altered by such injuries. I conducted flight experiments in a circular flight arena with Myotis albescens and M. nigricans individuals with an intact or ruptured trailing edge of one of the plagiopatagial membranes. In both species, individuals with damaged wings were lighter, had a higher aspect ratio (squared wing span divided by wing area) and an increased wing loading (weight divided by wing area) than conspecifics with intact wings. Bats with an asymmetric reduction of the wing area flew at similar speeds to conspecifics with intact wings but performed fewer flight manoeuvres. Individuals with damaged wings showed lower metabolic rates during flight than conspecifics with intact wings, even when controlling for body mass differences; the difference in mass-specific metabolic rate may be attributable to the lower number of flight manoeuvres (U-turns) by bats with damaged wings compared with conspecifics with intact wings. Possibly, bats compensated for an asymmetric reduction in wing area by lowering their body mass and avoiding flight manoeuvres. In conclusion, it may be that bats suffer from moderate wing damage not directly, by experiencing increased metabolic rate, but indirectly, by a reduced manoeuvrability and foraging success. This could impede a bat's ability to gain sufficient body mass before hibernation.

  7. 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.

  8. Metabolic 'engines' of flight drive genome size reduction in birds.

    Science.gov (United States)

    Wright, Natalie A; Gregory, T Ryan; Witt, Christopher C

    2014-03-22

    The tendency for flying organisms to possess small genomes has been interpreted as evidence of natural selection acting on the physical size of the genome. Nonetheless, the flight-genome link and its mechanistic basis have yet to be well established by comparative studies within a volant clade. Is there a particular functional aspect of flight such as brisk metabolism, lift production or maneuverability that impinges on the physical genome? We measured genome sizes, wing dimensions and heart, flight muscle and body masses from a phylogenetically diverse set of bird species. In phylogenetically controlled analyses, we found that genome size was negatively correlated with relative flight muscle size and heart index (i.e. ratio of heart to body mass), but positively correlated with body mass and wing loading. The proportional masses of the flight muscles and heart were the most important parameters explaining variation in genome size in multivariate models. Hence, the metabolic intensity of powered flight appears to have driven genome size reduction in birds.

  9. [Winged scapula in lyme borreliosis].

    Science.gov (United States)

    Rausch, V; Königshausen, M; Gessmann, J; Schildhauer, T A; Seybold, D

    2016-06-01

    Here we present the case of a young patient with one-sided winged scapula and lyme borreliosis. This disease can be very delimitating in daily life. If non-operative treatment fails, dynamic or static stabilization of the scapula can be a therapeutic option.

  10. The Wings for Angels Project

    Science.gov (United States)

    McMillan, Liberty; McMillan, Ellen; Ayers, Ann

    2012-01-01

    How can the spirits of critically ill children be raised? Alexis Weisel (co-president of the Monarch High School National Art Honor Society, 2010-2011) had this question in mind when she initiated and developed the Wings for Angels Project after hearing about the Believe in Tomorrow (BIT) organization through her art teacher, Ellen McMillan. The…

  11. FLEXIBLE WING INDIVIDUAL DROP GLIDER

    Science.gov (United States)

    The feasibility of the paraglider concept as a means of descent for individual airborne troops is presented. Full-scale 22-foot inflatable wings and...in an effort to achieve system reliability. The feasibility of using the paraglider as a means of controlled delivery of airborne paratroopers was successfully demonstrated.

  12. Wings: Women Entrepreneurs Take Flight.

    Science.gov (United States)

    Baldwin, Fred D.

    1997-01-01

    Women's Initiative Networking Groups (WINGS) provides low- and moderate-income women in Appalachian Kentucky with training in business skills, contacts, and other resources they need to succeed as entrepreneurs. The women form informal networks to share business know-how and support for small business startup and operations. The program plans to…

  13. Bird-Wing” abdominal phalloplasty: A novel surgical technique for penile reconstruction

    OpenAIRE

    Minu Bajpai

    2013-01-01

    Aim: To describe a technique of phalloplasty that is devoid of donor site scarring and suitable for urethral inlay and penile prosthesis in subsequent stages in cases of aphallia. Materials and Methods: Four patients with various disorders of sex development with 46 XY and severe penile deficiency, including one with complete androgen insensitivity syndrome who was initially raised as female, have been operated using a "Bird Wing" lower abdominal skin crease incision. Results: The patients′ a...

  14. Aeroelastic flutter of feathers, flight and the evolution of non-vocal communication in birds.

    Science.gov (United States)

    Clark, Christopher J; Prum, Richard O

    2015-11-01

    Tonal, non-vocal sounds are widespread in both ordinary bird flight and communication displays. We hypothesized these sounds are attributable to an aerodynamic mechanism intrinsic to flight feathers: aeroelastic flutter. Individual wing and tail feathers from 35 taxa (from 13 families) that produce tonal flight sounds were tested in a wind tunnel. In the wind tunnel, all of these feathers could flutter and generate tonal sound, suggesting that the capacity to flutter is intrinsic to flight feathers. This result implies that the aerodynamic mechanism of aeroelastic flutter is potentially widespread in flight of birds. However, the sounds these feathers produced in the wind tunnel replicated the actual flight sounds of only 15 of the 35 taxa. Of the 20 negative results, we hypothesize that 10 are false negatives, as the acoustic form of the flight sound suggests flutter is a likely acoustic mechanism. For the 10 other taxa, we propose our negative wind tunnel results are correct, and these species do not make sounds via flutter. These sounds appear to constitute one or more mechanism(s) we call 'wing whirring', the physical acoustics of which remain unknown. Our results document that the production of non-vocal communication sounds by aeroelastic flutter of flight feathers is widespread in birds. Across all birds, most evolutionary origins of wing- and tail-generated communication sounds are attributable to three mechanisms: flutter, percussion and wing whirring. Other mechanisms of sound production, such as turbulence-induced whooshes, have evolved into communication sounds only rarely, despite their intrinsic ubiquity in ordinary flight.

  15. Avian cholera causes marine bird mortality in the Bering Sea of Alaska

    Science.gov (United States)

    Bodenstein, Barbara L.; Kimberlee Beckmen,; Gay Sheffield,; Kathy Kuletz,; Van Hemert, Caroline R.; Berlowski-Zier, Brenda M.; Shearn-Bochsler, Valerie I.

    2015-01-01

    The first known avian cholera outbreak among wild birds in Alaska occurred during November 2013. Liver, intestinal, and splenic necrosis consistent with avian cholera was noted, and Pasteurella multocida serotype 1 was isolated from liver and lung or spleen in Crested Auklets (Aethia cristatella), Thick-billed Murres (Uria lomvia), Common Eider (Somateria mollissima), Northern Fulmars (Fulmarus glacialis), and Glaucous-winged Gulls (Larus glaucescens).

  16. Review Results on Wing-Body Interference

    OpenAIRE

    Frolov Vladimir

    2016-01-01

    The paper presents an overview of results for wing-body interference, obtained by the author for varied wing-body combinations. The lift-curve slopes of the wing-body combinations are considered. In this paper a discrete vortices method (DVM) and 2D potential model for cross-flow around fuselage are used. The circular and elliptical cross-sections of the fuselage and flat wings of various forms are considered. Calculations showed that the value of the lift-curve slopes of the wing-body combin...

  17. Linking foraging decisions to residential yard bird composition.

    Directory of Open Access Journals (Sweden)

    Susannah B Lerman

    Full Text Available Urban bird communities have higher densities but lower diversity compared with wildlands. However, recent studies show that residential urban yards with native plantings have higher native bird diversity compared with yards with exotic vegetation. Here we tested whether landscape designs also affect bird foraging behavior. We estimated foraging decisions by measuring the giving-up densities (GUD; amount of food resources remaining when the final forager quits foraging on an artificial food patch, i.e seed trays in residential yards in Phoenix, AZ, USA. We assessed how two yard designs (mesic: lush, exotic vegetation; xeric: drought-tolerant and native vegetation differed in foraging costs. Further, we developed a statistical model to calculate GUDs for every species visiting the seed tray. Birds foraging in mesic yards depleted seed trays to a lower level (i.e. had lower GUDs compared to birds foraging in xeric yards. After accounting for bird densities, the lower GUDs in mesic yards appeared largely driven by invasive and synanthropic species. Furthermore, behavioral responses of individual species were affected by yard design. Species visiting trays in both yard designs had lower GUDs in mesic yards. Differences in resource abundance (i.e., alternative resources more abundant and of higher quality in xeric yards contributed to our results, while predation costs associated with foraging did not. By enhancing the GUD, a common method for assessing the costs associated with foraging, our statistical model provided insights into how individual species and bird densities influenced the GUD. These differences we found in foraging behavior were indicative of differences in habitat quality, and thus our study lends additional support for native landscapes to help reverse the loss of urban bird diversity.

  18. Linking foraging decisions to residential yard bird composition.

    Science.gov (United States)

    Lerman, Susannah B; Warren, Paige S; Gan, Hilary; Shochat, Eyal

    2012-01-01

    Urban bird communities have higher densities but lower diversity compared with wildlands. However, recent studies show that residential urban yards with native plantings have higher native bird diversity compared with yards with exotic vegetation. Here we tested whether landscape designs also affect bird foraging behavior. We estimated foraging decisions by measuring the giving-up densities (GUD; amount of food resources remaining when the final forager quits foraging on an artificial food patch, i.e seed trays) in residential yards in Phoenix, AZ, USA. We assessed how two yard designs (mesic: lush, exotic vegetation; xeric: drought-tolerant and native vegetation) differed in foraging costs. Further, we developed a statistical model to calculate GUDs for every species visiting the seed tray. Birds foraging in mesic yards depleted seed trays to a lower level (i.e. had lower GUDs) compared to birds foraging in xeric yards. After accounting for bird densities, the lower GUDs in mesic yards appeared largely driven by invasive and synanthropic species. Furthermore, behavioral responses of individual species were affected by yard design. Species visiting trays in both yard designs had lower GUDs in mesic yards. Differences in resource abundance (i.e., alternative resources more abundant and of higher quality in xeric yards) contributed to our results, while predation costs associated with foraging did not. By enhancing the GUD, a common method for assessing the costs associated with foraging, our statistical model provided insights into how individual species and bird densities influenced the GUD. These differences we found in foraging behavior were indicative of differences in habitat quality, and thus our study lends additional support for native landscapes to help reverse the loss of urban bird diversity.

  19. Detection of aflatoxin-contaminated grain by three granivorous bird species.

    Science.gov (United States)

    Perez, M; Henke, S E; Fedynich, A M

    2001-04-01

    Supplemental feeding of game species and the use of backyard feeders to attract avian wildlife are common practices throughout the United States. However, these activities may expose wildlife to aflatoxins. We tested the hypothesis that wild birds would avoid consuming aflatoxin-contaminated feed. Individual northern bobwhites (Colinus virginianus), white-winged doves (Zenaida asiatica), and green jays (Cyanocorax yncas) were presented with feeders that had four compartments, which contained milo that was contaminated with aflatoxin levels of 0, 100, 500, and 1,000 microg/kg, respectively. Feed remaining was weighed at 6, 12, 18, 24, 36, 48, 60, and 72 hr after the initiation of the trial. White-winged doves and northern bobwhites did not avoid contaminated feed. However, green jays selected against aflatoxin-tainted grain. Because white-winged doves and northern bobwhites did not avoid contaminated feed, the risk of exposure to this potentially hazardous toxin exists for these species.

  20. The influence of load carrying on the energetics and kinematics of terrestrial locomotion in a diving bird

    OpenAIRE

    2013-01-01

    Summary The application of artificial loads to mammals and birds has been used to provide insight into the mechanics and energetic cost of terrestrial locomotion. However, only two species of bird have previously been used in loading experiments, the cursorial guinea fowl (Numida meleagris) and the locomotor-generalist barnacle goose (Branta leucopsis). Here, using respirometry and treadmill locomotion, we investigate the energetic cost of carrying trunk loads in a diving bird, the tufted ...

  1. Review Results on Wing-Body Interference

    Directory of Open Access Journals (Sweden)

    Frolov Vladimir

    2016-01-01

    Full Text Available The paper presents an overview of results for wing-body interference, obtained by the author for varied wing-body combinations. The lift-curve slopes of the wing-body combinations are considered. In this paper a discrete vortices method (DVM and 2D potential model for cross-flow around fuselage are used. The circular and elliptical cross-sections of the fuselage and flat wings of various forms are considered. Calculations showed that the value of the lift-curve slopes of the wing-body combinations may exceed the same value for an isolated wing. This result confirms an experimental data obtained by other authors earlier. Within a framework of the used mathematical models the investigations to optimize the wing-body combination were carried. The present results of the optimization problem for the wing-body combination allowed to select the optimal geometric characteristics for configuration to maximize the values of the lift-curve slopes of the wing-body combination. It was revealed that maximums of the lift-curve slopes for the optimal mid-wing configuration with elliptical cross-section body had a sufficiently large relative width of the body (more than 30% of the span wing.

  2. AST Composite Wing Program: Executive Summary

    Science.gov (United States)

    Karal, Michael

    2001-01-01

    The Boeing Company demonstrated the application of stitched/resin infused (S/RFI) composite materials on commercial transport aircraft primary wing structures under the Advanced Subsonic technology (AST) Composite Wing contract. This report describes a weight trade study utilizing a wing torque box design applicable to a 220-passenger commercial aircraft and was used to verify the weight savings a S/RFI structure would offer compared to an identical aluminum wing box design. This trade study was performed in the AST Composite Wing program, and the overall weight savings are reported. Previous program work involved the design of a S/RFI-base-line wing box structural test component and its associated testing hardware. This detail structural design effort which is known as the "semi-span" in this report, was completed under a previous NASA contract. The full-scale wing design was based on a configuration for a MD-90-40X airplane, and the objective of this structural test component was to demonstrate the maturity of the S/RFI technology through the evaluation of a full-scale wing box/fuselage section structural test. However, scope reductions of the AST Composite Wing Program pre-vented the fabrication and evaluation of this wing box structure. Results obtained from the weight trade study, the full-scale test component design effort, fabrication, design development testing, and full-scale testing of the semi-span wing box are reported.

  3. Topology of Vortex-Wing Interaction

    Science.gov (United States)

    McKenna, Chris; Rockwell, Donald

    2016-11-01

    Aircraft flying together in an echelon or V formation experience aerodynamic advantages. Impingement of the tip vortex from the leader (upstream) wing on the follower wing can yield an increase of lift to drag ratio. This enhancement is known to depend on the location of vortex impingement on the follower wing. Particle image velocimetry is employed to determine streamline topology in successive crossflow planes, which characterize the streamwise evolution of the vortex structure along the chord of the follower wing and into its wake. Different modes of vortex-follower wing interaction are created by varying both the spanwise and vertical locations of the leader wing. These modes are defined by differences in the number and locations of critical points of the flow topology, and involve bifurcation, attenuation, and mutual induction. The bifurcation and attenuation modes decrease the strength of the tip vortex from the follower wing. In contrast, the mutual induction mode increases the strength of the follower tip vortex. AFOSR.

  4. Piezoelectrically actuated insect scale flapping wing

    Science.gov (United States)

    Mukherjee, Sujoy; Ganguli, Ranjan

    2010-04-01

    An energy method is used in order to derive the non-linear equations of motion of a smart flapping wing. Flapping wing is actuated from the root by a PZT unimorph in the piezofan configuration. Dynamic characteristics of the wing, having the same size as dragonfly Aeshna Multicolor, are analyzed using numerical simulations. It is shown that flapping angle variations of the smart flapping wing are similar to the actual dragonfly wing for a specific feasible voltage. An unsteady aerodynamic model based on modified strip theory is used to obtain the aerodynamic forces. It is found that the smart wing generates sufficient lift to support its own weight and carry a small payload. It is therefore a potential candidate for flapping wing of micro air vehicles.

  5. Periodic and Chaotic Flapping of Insectile Wings

    CERN Document Server

    Huang, Yangyang

    2015-01-01

    Insects use flight muscles attached at the base of the wings to produce impressive wing flapping frequencies. The maximum power output of these flight muscles is insufficient to maintain such wing oscillations unless there is good elastic storage of energy in the insect flight system. Here, we explore the intrinsic self-oscillatory behavior of an insectile wing model, consisting of two rigid wings connected at their base by an elastic torsional spring. We study the wings behavior as a function of the total energy and spring stiffness. Three types of behavior are identified: end-over-end rotation, chaotic motion, and periodic flapping. Interestingly, the region of periodic flapping decreases as energy increases but is favored as stiffness increases. These findings are consistent with the fact that insect wings and flight muscles are stiff. They further imply that, by adjusting their muscle stiffness to the desired energy level, insects can maintain periodic flapping mechanically for a range of operating condit...

  6. The birds of Sehlabathebe National Park, Lesotho

    Directory of Open Access Journals (Sweden)

    G. Kopij

    2002-12-01

    Full Text Available A total of 117 bird species has been recorded in Sehlabathebe National Park, south-east Lesotho, consisting of 29 vagrants, 18 visitors and 70 breeding and probable breeding residents. For each species status was determined and abundance roughly estimated. Quantitative studies on breeding bird communities were carried out by means of the line transect method on four transects with the total length ca 30 km in the park and on two transects with the total length of ca 20 km outside the park. In the park, dominant species were represented by the Stonechat Saxicola torquata, Ayres’ Cisticola Cisticola ayresii, Yellow-rumped Widow Euplectes capensis and Wailing Cisticola Cisticola lais. Outside the park dominants were represented by Cape Weaver Ploceus capensis, Cape Sparrow Passer melanurus, Cape Canary Serinus canicollis, Common Quail Coturnix coturnix, Stonechat, Cape Bunting Emberiza capensis and Drakensberg Siskin Pseudochloroptila symonsi. Characteristic, high-altitude species in the park included Drakensberg Siskin, Mountain Pipit Anthus hoeschi, Orange-breasted Rockjumper Chaetops auriantius, Banded Martin Riparia cincta and Sentinel Rock Thrush Monticola explorator. Species such as the Laughing Dove Streptopelia senegalensis, Sicklewinged Chat Cercomela sinuata, Mountain Chat Oenanthe monticola, Thick-billed Lark Galerida magnirostris, Red-winged Starling Onychognathus morio, Alpine Swift Apus melba Cape Sparrow, Grey-headed Sparrow Passer diffusus, Red Bishop Euplectes orix and Golden Bishop Euplectes afer were absent or occurred in very low densities in the park, although they are widespread and common in the Maluti/Drakensberg grasslands (including areas neighbouring to the park. The lack of trees and shrubs for nesting, the lack of cultivated fields as feeding places and competition with related species both for food and nesting sites, may partly play a role in this regard.

  7. A study on forces acting on a flapping wing

    Directory of Open Access Journals (Sweden)

    Cetiner O.

    2013-04-01

    Full Text Available In order to study the forces acting on a flapping wing, an experimental investigation is performed in steady water flow. In this study, a SD7003 airfoil undergoes combined pitching and plunging motion which simulates the forward flight of small birds. The frequency of pitching motion is equal to the frequency of plunging motion and pitch leads the plunge by a phase angle of 90 degrees. The experiments are conducted at Reynolds numbers of 2500 ≤ Re ≤ 13700 and the vortex formation is recorded using the digital particle image velocimetry (DPIV technique. A prediction of thrust force and efficiency is calculated from the average wake deficit of DPIV data, the near-wake vorticity patterns and time dependent velocity vectors are determined to comment on the thrust and drag indication. Direct force measurements are attempted using a Force/Torque sensor which is capable of measuring forces and moments in three axial directions.

  8. 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,...

  9. 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,...

  10. 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...

  11. 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...

  12. 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...

  13. 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。

  14. Effects of multiple vein microjoints on the mechanical behaviour of dragonfly wings: numerical modelling.

    Science.gov (United States)

    Rajabi, H; Ghoroubi, N; Darvizeh, A; Appel, E; Gorb, S N

    2016-03-01

    Dragonfly wings are known as biological composites with high morphological complexity. They mainly consist of a network of rigid veins and flexible membranes, and enable insects to perform various flight manoeuvres. Although several studies have been done on the aerodynamic performance of Odonata wings and the mechanisms involved in their deformations, little is known about the influence of vein joints on the passive deformability of the wings in flight. In this article, we present the first three-dimensional finite-element models of five different vein joint combinations observed in Odonata wings. The results from the analysis of the models subjected to uniform pressures on their dorsal and ventral surfaces indicate the influence of spike-associated vein joints on the dorsoventral asymmetry of wing deformation. Our study also supports the idea that a single vein joint may result in different angular deformations when it is surrounded by different joint types. The developed numerical models also enabled us to simulate the camber formation and stress distribution in the models. The computational data further provide deeper insights into the functional role of resilin patches and spikes in vein joint structures. This study might help to more realistically model the complex structure of insect wings in order to design more efficient bioinspired micro-air vehicles in future.

  15. Expression of Genes Involved in Drosophila Wing Morphogenesis and Vein Patterning Are Altered by Spaceflight

    Science.gov (United States)

    Parsons-Wingerter, Patricia A.; Hosamani, Ravikumar; Bhattacharya, Sharmila

    2015-01-01

    Imaginal wing discs of Drosophila melanogaster (fruit fly) defined during embryogenesis ultimately result in mature wings of stereotyped (specific) venation patterning. Major regulators of wing disc development are the epidermal growth factor receptor (EGF), Notch, Hedgehog (Hh), Wingless (Wg), and Dpp signaling pathways. Highly stereotyped vascular patterning is also characteristic of tissues in other organisms flown in space such as the mouse retina and leaves of Arabidopsis thaliana. Genetic and other adaptations of vascular patterning to space environmental factors have not yet been systematically quantified, despite widespread recognition of their critical importance for terrestrial and microgravity applications. Here we report changes in gene expression with space flight related to Drosophila wing morphogenesis and vein patterning. In addition, genetically modified phenotypes of increasingly abnormal ectopic wing venation in the Drosophila wing1 were analyzed by NASA's VESsel GENeration Analysis (VESGEN) software2. Our goal is to further develop insightful vascular mappings associated with bioinformatic dimensions of genetic or other molecular phenotypes for correlation with genetic and other molecular profiling relevant to NASA's GeneLab and other Space Biology exploration initiatives.

  16. Bionic design and experimental research on blade of small axial fan based on characteristics of wings of typical birds%基于典型鸟类翅膀特征的小型轴流风机叶片仿生设计与试验

    Institute of Scientific and Technical Information of China (English)

    廖庚华; 胡钦超; 杨莹; 韩志武; 任露泉; 刘庆平

    2012-01-01

    The surface characteristics of the wings sparrow hawk and long-eared owl were extracted and used to optimize the blade of small axial fan to improve aerodynamic performance of the fan.The best fan was selected from eight bionic axial fans using CFD method.Computer simulation analysis and aerodynamic experiments show that the flow-static pressure curve of the bionic blade fan is remarkable better than that of prototype fan.The maximum mass flow rate of the bionic fan is 6.1% higher than that of prototype fan and the maximum static pressure is 7% higher,respectively.Experiments also show that the V-section is better than arc-section of the blade.The study provides a preliminary basis for optimizing the parameters of the blade of bionic fan.%基于提取的雀鹰、长耳鸮翅膀的表面特征对小型轴流风机的叶片进行仿生优化,以求提高风机的气动性能。设计出8种仿生风机模型,通过CFD计算选出最优的仿生风机模型进行性能试验验证,并与原型风机进行了对比。对比试验流量-静压曲线发现,仿生风机气动性能明显好于原型风机,最大质量流量提高了6.1%,最大静压提高了7.0%,并发现V型截面好于圆弧型截面。本研究为叶片仿生参数的进一步优化提供了前期基础。

  17. Translational damping on high-frequency flapping wings

    Science.gov (United States)

    Parks, Perry A.

    Flapping fliers such as insects and birds depend on passive translational and rotational damping to terminate quick maneuvers and to provide a source of partial stability in an otherwise unstable dynamic system. Additionally, passive translational and rotational damping reduce the amount of active kinematic changes that must be made to terminate maneuvers and maintain stability. The study of flapping-induced damping phenomena also improves the understanding of micro air vehicle (MAV) dynamics needed for the synthesis of effective flight control strategies. Aerodynamic processes which create passive translational and rotational damping as a direct result of symmetric flapping with no active changes in wing kinematics have been previously studied and were termed flapping counter-force (FCF) and flapping counter-torque (FCT), respectively. In this first study of FCF measurement in air, FCF generation is measured using a pendulum system designed to isolate and measure the relationship of translational flapping-induced damping with wingbeat frequency for a 2.86 gram mechanical flapper equipped with real cicada wings. Analysis reveals that FCF generation and wingbeat frequency are directly proportional, as expected from previous work. The quasi-steady FCF model using Blade-Element-Theory is used as an estimate for translational flapping-induced damping. In most cases, the model proves to be accurate in predicting the relationship between flapping-induced damping and wingbeat frequency. "Forward-backward" motion proves to have the strongest flapping-induced damping while "up-down" motion has the weakest.

  18. 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

  19. 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.

  20. Effects of wing locations on wing rock induced by forebody vortices

    Directory of Open Access Journals (Sweden)

    Ma Baofeng

    2016-10-01

    Full Text Available Previous studies have shown that asymmetric vortex wakes over slender bodies exhibit a multi-vortex structure with an alternate arrangement along a body axis at high angle of attack. In this investigation, the effects of wing locations along a body axis on wing rock induced by forebody vortices was studied experimentally at a subcritical Reynolds number based on a body diameter. An artificial perturbation was added onto the nose tip to fix the orientations of forebody vortices. Particle image velocimetry was used to identify flow patterns of forebody vortices in static situations, and time histories of wing rock were obtained using a free-to-roll rig. The results show that the wing locations can affect significantly the motion patterns of wing rock owing to the variation of multi-vortex patterns of forebody vortices. As the wing locations make the forebody vortices a two-vortex pattern, the wing body exhibits regularly divergence and fixed-point motion with azimuthal variations of the tip perturbation. If a three-vortex pattern exists over the wing, however, the wing-rock patterns depend on the impact of the highest vortex and newborn vortex. As the three vortices together influence the wing flow, wing-rock patterns exhibit regularly fixed-points and limit-cycled oscillations. With the wing moving backwards, the newborn vortex becomes stronger, and wing-rock patterns become fixed-points, chaotic oscillations, and limit-cycled oscillations. With further backward movement of wings, the vortices are far away from the upper surface of wings, and the motions exhibit divergence, limit-cycled oscillations and fixed-points. For the rearmost location of the wing, the wing body exhibits stochastic oscillations and fixed-points.

  1. 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 ...

  2. 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 ...

  3. Effects of tannins on fruit selection in three southern African frugivorous birds.

    Science.gov (United States)

    Zungu, Manqoba M; Downs, Colleen T

    2015-02-01

    Tannins are common secondary compounds in plant material and are known for their ability to bind to protein which reduces nitrogen availability in the diet. In fruits, these compounds are responsible for their astringency which is thought to result in reduced food intake. In this study, the repellent effects of tannins were examined in three species of frugivorous birds: red-winged starlings Onychognathus morio, speckled mousebirds Colius striatus and Cape white-eyes Zosterops virens. Birds were fed artificial fruit diets containing varying levels of tannins in paired choice tests with the amount of food eaten by birds used to determine preference. Red-winged starlings were attracted to the control diet, indifferent to the medium tannin diet and deterred by the high tannin diet whereas speckled mousebirds and Cape white-eyes were not deterred at all concentrations. The discrepancy in the results was attributed to differences in taste sensitivity, tolerance levels and detoxification mechanisms of secondary compounds between species. Because fruit selection and ultimately fruit removal rates affect plant community composition, the disparity in the results suggests that frugivorous birds do not contribute equally to plant community dynamics. However, plant secondary compounds in fruits are diverse and their effects are similarly diverse and there is potential that different groups of secondary compounds generate disparate effects. Similar studies on other types of secondary compounds may thus contribute towards a broader understanding of the role of secondary compounds in mediating fruit-frugivore interactions.

  4. Numerical Simulation of Bird Flight Using Both CFD and Computational Flight Dynamics

    Science.gov (United States)

    Ueno, Yosuke; Nakamura, Yoshiaki

    A numerical simulation method taking into account both aerodynamics and flight dynamics has been developed to simulate the flight of a low speed flying object, where it undergoes unsteady deformation. This method can also be applied to simulate the unsteady motion of small vehicles such as micro air vehicles (MAV). In the present study, we take up a bird and demonstrate its flight in the air. In particular the effect of fluid forces on the bird's flying motion is examined in detail, based on CFD×CFD: Computational Fluid Dynamics (CFD) and Computational Flight Dynamics. It is found from simulated results that this bird can generate lift and thrust enough to fly by flapping its wing. In addition, it can make a level flight by adjusting its oscillation frequency. Thus, the present method is promising to study the aerodynamics and flight dynamics of a moving object with its shape morphing.

  5. Experimental Study on the Wing Formation of a Paraglider Canopy Cell (Inflatable Wing)

    Science.gov (United States)

    Yamamori, Keitaro; Umemura, Akira; Hishida, Manabu

    This study focuses on the formation mechanism of para-foil canopy. Three types of model wing, which represent each cell of para-foil canopy (a rigid wing with air intake, an inflatable wing and a cassette model) were prepared to explore the effects of air intake on inflatable wing formation in wind tunnel experiments. The flow fields both outside and inside of the wings were investigated, together with the process that the flexible wing inflates to form a wing. It was found that the robust nature of canopy is derived from the concaving deformation of the leading edge at small angles of attack, and the enhanced outward suction pressure acting on the leading edge, which are caused by the flexibility of the wing as well as the pressure of air intake in sacrifice of increased drag coefficient.

  6. Rotor/Wing Interactions in Hover

    Science.gov (United States)

    Young, Larry A.; Derby, Michael R.

    2002-01-01

    Hover predictions of tiltrotor aircraft are hampered by the lack of accurate and computationally efficient models for rotor/wing interactional aerodynamics. This paper summarizes the development of an approximate, potential flow solution for the rotor-on-rotor and wing-on-rotor interactions. This analysis is based on actuator disk and vortex theory and the method of images. The analysis is applicable for out-of-ground-effect predictions. The analysis is particularly suited for aircraft preliminary design studies. Flow field predictions from this simple analytical model are validated against experimental data from previous studies. The paper concludes with an analytical assessment of the influence of rotor-on-rotor and wing-on-rotor interactions. This assessment examines the effect of rotor-to-wing offset distance, wing sweep, wing span, and flaperon incidence angle on tiltrotor inflow and performance.

  7. Molecular ecological insights into neotropical bird-tick interactions

    NARCIS (Netherlands)

    Miller, Matthew J.; Esser, Helen J.; Loaiza, Jose R.; Herre, Edward Allen; Aguilar, Celestino; Quintero, Diomedes; Alvarez, Eric; Bermingham, Eldredge

    2016-01-01

    In the tropics, ticks parasitize many classes of vertebrate hosts. However, because many tropical tick species are only identifiable in the adult stage, and these adults usually parasitize mammals, most attention on the ecology of tick-host interactions has focused on mammalian hosts. In contrast, i

  8. RNAi screening of developmental toolkit genes: a search for novel wing genes in the red flour beetle, Tribolium castaneum.

    Science.gov (United States)

    Linz, David M; Tomoyasu, Yoshinori

    2015-01-01

    The amazing array of diversity among insect wings offers a powerful opportunity to study the mechanisms guiding morphological evolution. Studies in Drosophila (the fruit fly) have identified dozens of genes important for wing development. These genes are often called candidate genes, serving as an ideal starting point to study wing development in other insects. However, we also need to explore beyond the candidate genes to gain a more comprehensive view of insect wing evolution. As a first step away from the traditional candidate genes, we utilized Tribolium (the red flour beetle) as a model and assessed the potential involvement of a group of developmental toolkit genes (embryonic patterning genes) in beetle wing development. We hypothesized that the highly pleiotropic nature of these developmental genes would increase the likelihood of finding novel wing genes in Tribolium. Through the RNA interference screening, we found that Tc-cactus has a less characterized (but potentially evolutionarily conserved) role in wing development. We also found that the odd-skipped family genes are essential for the formation of the thoracic pleural plates, including the recently discovered wing serial homologs in Tribolium. In addition, we obtained several novel insights into the function of these developmental genes, such as the involvement of mille-pattes and Tc-odd-paired in metamorphosis. Despite these findings, no gene we examined was found to have novel wing-related roles unique in Tribolium. These results suggest a relatively conserved nature of developmental toolkit genes and highlight the limited degree to which these genes are co-opted during insect wing evolution.

  9. Morphing fixed wing MAV modeling using VAM

    OpenAIRE

    2012-01-01

    The design and implementation of a morphing Micro Air Vehicle (MAV) wing using a smart composite is attempted in this research work. Control surfaces actuated by traditional servos are difficult to instrument and fabricate on thin composite-wings of MAVs. Piezoelectric Fiber Reinforced Composites (PFRCs) are the chosen smart structural materials in the current work for incorporation onto fixed-wing MAVs to simultaneously perform the dual functions of structural load-bearing and actuatio...

  10. Cross Service Fixed-Wing Cost Estimation

    Science.gov (United States)

    2016-05-17

    costs. The end product of this project will be a method for any service to estimate fixed-wing costs for sorties to use in mission cost estimation for...TRAC-M-TR-16-021 May 2016 Cross Service Fixed-Wing Cost Estimation TRADOC Analysis Center 700 Dyer Road Monterey, California 93943-0692 This study... Service Fixed-Wing Cost Estimation MAJ Jarrod S. Shingleton TRADOC Analysis Center 700 Dyer Road Monterey, California 93943-0692 DISTRIBUTION STATEMENT

  11. A helicopter that flaps its wings: the Ornicopter flaps its wings like a bird to get into the air

    NARCIS (Netherlands)

    Mols, B.

    2003-01-01

    No other type of aircraft is as manoeuvrable as a helicopter. Reverse in full flight, rotate in the air, hover at a standstill, the helicopter can do it all. The police, fire services, medical services, military and civil aviation all use the helicopter for the freedom of flight it offers. However,

  12. Detailed description of the Ócsa Bird Ringing Station, Hungary

    Directory of Open Access Journals (Sweden)

    Csörgő Tibor

    2016-12-01

    Full Text Available The present paper acts as an introduction to a series that will describe the exploratory analyses of migration phenology and morphometrics of the most common passerine species at the Ócsa Bird Ringing Station. This station is situated in the Ócsa Landscape Protection Area that belongs to the Duna–Ipoly National Park, Hungary. The area is somewhat cooler and more humid than the surrounding agricultural fields and tree plantations, covered by a mosaic of diverse hygrophilous vegetation patches. Bird trapping is mostly based on Japanese mist-net lines crossing different plant communities. During the period of 1984–2015, a total of 422,862 birds were trapped and ringed here, while 202,739 local, 1,235 within country, and 443 foreign recaptures were also recorded. Each bird is characterized by the following data: location and time of capture, species, age, sex, scores of fat, pectoral muscle, wing tip abrasion, and moult, length of wing, 3rd primary, and tail, and body mass. After subjected to a rigorous quality check, digital data are deposited in the archive of the Hungarian Bird Ringing Centre, and the EURING data base. From time to time, other research projects also utilized the accessibility of wild birds captured here, thus collection of blood samples, ecto- and endoparasites was carried out at the station. The relatively long time span, large number of species and individuals, and the readily available environmental (weather, vegetation, etc. data makes the avian data collected here a suitable base for studies of various disciplines like capture methodology, habitat preferences, breeding, migration, and wintering, effects of weather and climate change, and epidemiology of viruses and parasites.

  13. High performance forward swept wing aircraft

    Science.gov (United States)

    Koenig, David G. (Inventor); Aoyagi, Kiyoshi (Inventor); Dudley, Michael R. (Inventor); Schmidt, Susan B. (Inventor)

    1988-01-01

    A high performance aircraft capable of subsonic, transonic and supersonic speeds employs a forward swept wing planform and at least one first and second solution ejector located on the inboard section of the wing. A high degree of flow control on the inboard sections of the wing is achieved along with improved maneuverability and control of pitch, roll and yaw. Lift loss is delayed to higher angles of attack than in conventional aircraft. In one embodiment the ejectors may be advantageously positioned spanwise on the wing while the ductwork is kept to a minimum.

  14. Veins improve fracture toughness of insect wings.

    Directory of Open Access Journals (Sweden)

    Jan-Henning Dirks

    Full Text Available During the lifetime of a flying insect, its wings are subjected to mechanical forces and deformations for millions of cycles. Defects in the micrometre thin membranes or veins may reduce the insect's flight performance. How do insects prevent crack related material failure in their wings and what role does the characteristic vein pattern play? Fracture toughness is a parameter, which characterises a material's resistance to crack propagation. Our results show that, compared to other body parts, the hind wing membrane of the migratory locust S. gregaria itself is not exceptionally tough (1.04±0.25 MPa√m. However, the cross veins increase the wing's toughness by 50% by acting as barriers to crack propagation. Using fracture mechanics, we show that the morphological spacing of most wing veins matches the critical crack length of the material (1132 µm. This finding directly demonstrates how the biomechanical properties and the morphology of locust wings are functionally correlated in locusts, providing a mechanically 'optimal' solution with high toughness and low weight. The vein pattern found in insect wings thus might inspire the design of more durable and lightweight artificial 'venous' wings for micro-air-vehicles. Using the vein spacing as indicator, our approach might also provide a basis to estimate the wing properties of endangered or extinct insect species.

  15. Analysis of bat wings for morphing

    Science.gov (United States)

    Leylek, Emily A.; Manzo, Justin E.; Garcia, Ephrahim

    2008-03-01

    The morphing of wings from three different bat species is studied using an extension of the Weissinger method. To understand how camber affects performance factors such as lift and lift to drag ratio, XFOIL is used to study thin (3% thickness to chord ratio) airfoils at a low Reynolds number of 100,000. The maximum camber of 9% yielded the largest lift coefficient, and a mid-range camber of 7% yielded the largest lift to drag ratio. Correlations between bat wing morphology and flight characteristics are covered, and the three bat wing planforms chosen represent various combinations of morphological components and different flight modes. The wings are studied using the extended Weissinger method in an "unmorphed" configuration using a thin, symmetric airfoil across the span of the wing through angles of attack of 0°-15°. The wings are then run in the Weissinger method at angles of attack of -2° to 12° in a "morphed" configuration modeled after bat wings seen in flight, where the camber of the airfoils comprising the wings is varied along the span and a twist distribution along the span is introduced. The morphed wing configurations increase the lift coefficient over 1000% from the unmorphed configuration and increase the lift to drag ratio over 175%. The results of the three different species correlate well with their flight in nature.

  16. Subtractive Structural Modification of Morpho Butterfly Wings.

    Science.gov (United States)

    Shen, Qingchen; He, Jiaqing; Ni, Mengtian; Song, Chengyi; Zhou, Lingye; Hu, Hang; Zhang, Ruoxi; Luo, Zhen; Wang, Ge; Tao, Peng; Deng, Tao; Shang, Wen

    2015-11-11

    Different from studies of butterfly wings through additive modification, this work for the first time studies the property change of butterfly wings through subtractive modification using oxygen plasma etching. The controlled modification of butterfly wings through such subtractive process results in gradual change of the optical properties, and helps the further understanding of structural optimization through natural evolution. The brilliant color of Morpho butterfly wings is originated from the hierarchical nanostructure on the wing scales. Such nanoarchitecture has attracted a lot of research effort, including the study of its optical properties, its potential use in sensing and infrared imaging, and also the use of such structure as template for the fabrication of high-performance photocatalytic materials. The controlled subtractive processes provide a new path to modify such nanoarchitecture and its optical property. Distinct from previous studies on the optical property of the Morpho wing structure, this study provides additional experimental evidence for the origination of the optical property of the natural butterfly wing scales. The study also offers a facile approach to generate new 3D nanostructures using butterfly wings as the templates and may lead to simpler structure models for large-scale man-made structures than those offered by original butterfly wings.

  17. Bird on a (live) wire

    Energy Technology Data Exchange (ETDEWEB)

    Farr, M.

    2003-09-30

    Bird mortality as a result of contact with power lines is discussed. U. S. statistics are cited, according to which 174 million birds annually die as a result of contact with power lines, specifically when birds touch two phases of current at the same time. Raptors are particularly vulnerable to power-line electrocution due to their habit of perching on the highest vantage point available as they survey the ground for prey. Hydro lines located in agricultural areas, with bodies of water on one side and fields on the other, also obstruct flight of waterfowl as dusk and dawn when visibility is low. Various solutions designed to minimize the danger to birds are discussed. Among these are: changing the configuration of wires and cross arms to make them more visible to birds in flight and less tempting as perches, and adding simple wire markers such as flags, balloons, and coloured luminescent clips that flap and twirl in the wind. There is no evidence of any coordinated effort to deal with this problem in Ontario. However, a report is being prepared for submission to Environment Canada outlining risks to birds associated with the growing number of wind turbine power generators (negligible compared with power lines and communications towers), and offering suggestions on remedial measures. The Fatal Light Awareness Program (FLAP) also plans to lobby the Canadian Wildlife Service to discuss the possibility of coordinating efforts to monitor, educate about and ultimately reduce this form of bird mortality.

  18. Bristol Bay, Alaska Subarea 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 shorebirds, waterfowl, raptors, diving birds, and seabirds in the Bristol Bay Subarea. The Subarea...

  19. Three-dimensional, high-resolution skeletal kinematics of the avian wing and shoulder during ascending flapping flight and uphill flap-running.

    Directory of Open Access Journals (Sweden)

    David B Baier

    Full Text Available Past studies have shown that birds use their wings not only for flight, but also when ascending steep inclines. Uphill flap-running or wing-assisted incline running (WAIR is used by both flight-incapable fledglings and flight-capable adults to retreat to an elevated refuge. Despite the broadly varying direction of travel during WAIR, level, and descending flight, recent studies have found that the basic wing path remains relatively invariant with reference to gravity. If so, joints undergo disparate motions to maintain a consistent wing path during those specific flapping modes. The underlying skeletal motions, however, are masked by feathers and skin. To improve our understanding of the form-functional relationship of the skeletal apparatus and joint morphology with a corresponding locomotor behavior, we used XROMM (X-ray Reconstruction of Moving Morphology to quantify 3-D skeletal kinematics in chukars (Alectoris chukar during WAIR (ascending with legs and wings and ascending flight (AF, ascending with wings only along comparable trajectories. Evidence here from the wing joints demonstrates that the glenohumeral joint controls the vast majority of wing movements. More distal joints are primarily involved in modifying wing shape. All bones are in relatively similar orientations at the top of upstroke during both behaviors, but then diverge through downstroke. Total excursion of the wing is much smaller during WAIR and the tip of the manus follows a more vertical path. The WAIR stroke appears "truncated" relative to ascending flight, primarily stemming from ca. 50% reduction in humeral depression. Additionally, the elbow and wrist exhibit reduced ranges of angular excursions during WAIR. The glenohumeral joint moves in a pattern congruent with being constrained by the acrocoracohumeral ligament. Finally, we found pronounced lateral bending of the furcula during the wingbeat cycle during ascending flight only, though the phasic pattern in chukars

  20. Invasive alien birds in Denmark

    DEFF Research Database (Denmark)

    Nyegaard, Timme; Heldbjerg, Henning; Fox, Anthony David

    Avian Introduced Alien Species (IAS) constitute a threat to the integrity of native biodiversity, the economy and human health, so here we briefly review some of the problems posed by such species around the world in relation to bird species in Denmark. A new European Union Regulation on Invasive...... the importance of mechanisms such as DOFs (Danish Ornithological Society, BirdLife Denmark) Atlas project, Common Bird Monitoring (breeding and wintering species) and DOFbasen to contribute data on the current geographical and numerical distribution of the few serious alien avian species already present...

  1. Birds of the Mongol Empire

    Directory of Open Access Journals (Sweden)

    Eugene N. Anderson

    2016-09-01

    Full Text Available The Mongol Empire, the largest contiguous empire the world has ever known, had, among other things, a goodly number of falconers, poultry raisers, birdcatchers, cooks, and other experts on various aspects of birding. We have records of this, largely in the Yinshan Zhengyao, the court nutrition manual of the Mongol empire in China (the Yuan Dynasty. It discusses in some detail 22 bird taxa, from swans to chickens. The Huihui Yaofang, a medical encyclopedia, lists ten taxa used medicinally. Marco Polo also made notes on Mongol bird use. There are a few other records. This allows us to draw conclusions about Mongol ornithology, which apparently was sophisticated and detailed.

  2. Angels, Demons, Birds and Dinosaurs

    DEFF Research Database (Denmark)

    Ries, Christopher Jacob

    2010-01-01

    of birds, setting the international agenda for research in bird evolution for the next 40 years. In Denmark, however, Heilmann's highly original work was generally ignored or even ridiculed by zoologists. This article demonstrates how Heilmann's artistic abilities played an important role in securing him...... international renown as a palaeontologist, while at the same time his lack of scientific credentials led to his complete isolation from the Danish zoological establishment. And it suggests that Heilmann's unyielding efforts to solve the riddle of bird evolution in the borderland between art and science...

  3. Invasive alien birds in Denmark

    DEFF Research Database (Denmark)

    Fox, Anthony David; Heldbjerg, Henning; Nyegaard, Timme

    2015-01-01

    Avian Introduced Alien Species (IAS) constitute a threat to the integrity of native biodiversity, the economy and human health, so here we briefly review some of the problems posed by such species around the world in relation to such bird species in Denmark. A new European Union Regulation...... show the importance of mechanisms such as DOF’s (Dansk Ornitologisk Forening, BirdLife Denmark) Atlas project, Common Bird Census (breeding and wintering species) and DOFbasen to contribute data on the current geographical and numerical distribution of the few serious alien avian species already...

  4. Hezarfen wings: a lower lateral cartilage-based cartilage suspension technique for the adjustment of nasal tip rotation and projection and the correction of supratip deformity.

    Science.gov (United States)

    Yeşiloğlu, Nebil; Sarici, Murat; Temiz, Gökhan; Yildiz, Kemalettin; Mersa, Berkan; Filinte, Gaye Taylan

    2014-05-01

    Nasal tip surgery is one of the most important parts of rhinoplasty to achieve an attractive nose. There are numerous techniques focusing on the correction of nasal tip rotation and projection. In this article, a new cartilage support derived from the cephalic border of lower lateral cartilages is used for the adjustment of tip rotation and projection, whereas improving supratip fullness is presented. Bilaterally harvested cartilage extensions are resembled as bird's wings and dedicated to the wings that were created by the world's first scientist who flew from one continent to another: Hezarfen Ahmed Çelebi. Thirty-two patients who underwent open-approach rhinoplasty operation including the abovementioned method were evaluated retrospectively. After performing conventional steps of open approach rhinoplasty, a wing is created by making a cephalic incision parallel to the lateral crural axis leaving the medial attachment intact and then undermined. Then, the cartilage is turned over the midline bilaterally as it acts like a curb by pulling or releasing the wings to adjust to the desired tip rotation and projection and sutured to the repaired upper lateral cartilage roof. Other 2 types of using these wings were asymmetric suturing one of the wings to help in the redirection of deviated nasal tip (n = 12) and suturing each other at midline to support the overlying skin like a tent with supratip deficiency (n = 7). The authors presented here both esthetic and functional outcomes of Hezarfen wings' method that was used for both nasal tip adjustments and supratip support.

  5. Genotyping of Cryptosporidium spp. from free-living wild birds from Brazil.

    Science.gov (United States)

    Sevá, Anaiá da Paixão; Funada, Mikaela Renata; Richtzenhain, Leonardo; Guimarães, Marta Brito; Souza, Sheila de Oliveira; Allegretti, Luciana; Sinhorini, Juliana Anaya; Duarte, Vanessa Vertematti; Soares, Rodrigo Martins

    2011-01-10

    In wild and domestic birds, cryptosporidiosis is often associated with infections by Cryptosporidium galli, Cryptosporidium baileyi and Cryptosporidium meleagridis. In addition to these species, a number of avian Cryptosporidium species yet to be fully characterized are commonly found among exotic and wild avian isolates. The present study aimed to detect and identify samples of Cryptosporidium spp. from free-living wild birds, in order to contribute to the knowledge of the variability of this parasite in the free-living population of Brazil. Stool samples were collected from 242 birds, with the following proportions of individuals: 50 Emberizidae (20.7%), 112 Psittacidae (46.3%), 44 Cardinalidae (18.2%), 12 Turdidae (5.0%), eight Ramphastidae (3.3%), seven Icteridae (2.9%), three Estrilididae (1.2%), two Contigidae (0.8%), two Thraupidae (0.8%) and two Fringilidae (0.8%). Among the 242 fecal samples from wild birds, 16 (6.6%) were positive for the presence of oocysts of Cryptosporidium. Molecular characterization of the 16 samples of Cryptosporidium, were performed with phylogenetic reconstructions employing 292 positions of 18S rDNA. None of the samples of birds was characterized as C. meleagridis. C. galli was identified in one rufous-bellied thrush (Turdus rufiventris), five green-winged saltators (Saltator similis), one slate-coloured seedeater (Sporophila schistacea), one goldfinch (Carduelis carduelis) and three saffron finches (Sicalis flaveola). One goldfinch isolate, one buffy-fronted seedeater (Sporophila frontalis), one red-cowled cardinal (Paroaria dominicana) and one other saffron finch (S. flaveola) were identified as C. baileyi. Avian genotype II was found in an isolate from a white-eyed parakeet (Aratinga leucophthalma). Clinical symptoms of cryptosporidiosis in birds have already been described and the number of wild birds which were shedding parasites was high. Therefore, further epidemiological research and disease surveillance of birds in the

  6. 21 CFR 1240.65 - Psittacine birds.

    Science.gov (United States)

    2010-04-01

    ... DISEASES Specific Administrative Decisions Regarding Interstate Shipments § 1240.65 Psittacine birds. (a) The term psittacine birds shall include all birds commonly known as parrots, Amazons, Mexican double... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Psittacine birds. 1240.65 Section 1240.65 Food...

  7. Analytical modeling and experimental evaluation of a passively morphing ornithopter wing

    Science.gov (United States)

    Wissa, Aimy A.

    Ornithopters or flapping wing Unmanned Aerial Vehicles (UAVs) have potential applications in both civil and military sectors. Amongst all categories of UAVs, ornithopters have a unique ability to fly in low Reynolds number flight regimes and have the agility and maneuverability of rotary wing aircraft. In nature, birds achieve such performance by exploiting various wing kinematics known as gaits. The objective of this work was to improve the steady level flight wing performance of an ornithopter by implementing the Continuous Vortex Gait (CVG) using a novel passive compliant spine. The CVG is a set of bio-inspired kinematics that natural flyers use to produce lift and thrust during steady level flight. A significant contribution of this work was the recognition that the CVG is an avian gait that could be achieved using a passive morphing mechanism. In contrast to rigid-link mechanisms and active approaches, reported by other researchers in the open literature, passive morphing mechanisms require no additional energy expenditure, while introducing minimal weight addition and complexity. During the execution of the CVG, the avian wing wrist is the primary joint responsible for the wing shape changes. Thus a compliant mechanism, called a compliant spine, was fabricated, and integrated in the ornithopter's wing leading edge spar where an avian wrist would normally exist, namely at 37% of the wing half span. Each compliant spine was designed to be flexible in bending during the wing upstroke and stiff in bending during the wing downstroke. Inserting a variable stiffness compliant mechanism in the leading edge (LE) spar of the ornithopter could affect its structural stability. An analytical model was developed to determine the structural stability of the ornithopter LE spar. The model was validated using experimental measurements. The LE spar equations of motion were then reformulated into Mathieu's equation and the LE spar was proven to be structurally stable with a

  8. The Realization and Study of Optical Wings

    Science.gov (United States)

    Artusio-Glimpse, Alexandra Brae

    Consider the airfoil: a carefully designed structure capable of stable lift in a uniform air flow. It so happens that air pressure and radiation (light) pressure are similar phenomena because each transfer momentum to flow-disturbing objects. This, then, begs the question: does an optical analogue to the airfoil exist? Though an exceedingly small effect, scientists harness radiation pressure in a wide gamut of applications from micromanipulation of single biological particles to the propulsion of large spacecrafts called solar sails. We introduce a cambered, refractive rod that is subjected to optical forces analogous to those seen in aerodynamics, and I call this analogue the optical wing. Flight characteristics of optical wings are determined by wing shape and material in a uniform radiation field. Theory predicts the lift force and axial torque are functions of the wing's angle of attack with stable and unstable orientations. These structures can operate as intensity-dependent, parametrically driven oscillators. In two-dimensions, the wings exhibit bistability when analyzed in an accelerating frame. In three-dimensions, the motion of axially symmetric spinning hemispherical wings is analogous to a spinning top. Experiments on semi-buoyant wings in water found semicylindrically shaped, refractive microparticles traversed a laser beam and rotated to an illumination-dependent stable orientation. Preliminary tests aid in the development of a calibrated force measurement experiment to directly evaluate the optical forces and torque on these samples. A foundational study of the optical wing, this work contributes to future advancements of flight-by-light.

  9. North American Breeding Bird Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This protocol framework provides guidance for conducting surveys of North American bird populations at multiple stations within two or more regions. The BBS is a...

  10. Barrier Infrared Detector (BIRD) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — JPL will design, fabricate, and fully characterize a 640x512 format HOT-BIRD FPA with increased quantum efficiency and extended spectral coverage. Unlike the small...

  11. 75 FR 53774 - Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations...

    Science.gov (United States)

    2010-09-01

    ... Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain...-1231-9BPP-L2] RIN 1018-AX06 Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain..., Interior. ACTION: Final rule. SUMMARY: This rule prescribes special early-season migratory bird...

  12. 77 FR 29515 - Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for...

    Science.gov (United States)

    2012-05-17

    ... Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for the 2012-13... RIN 1018-AX97 Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting... in an earlier document to establish annual hunting regulations for certain migratory game birds...

  13. 77 FR 23093 - Migratory Bird Hunting; Proposed 2012-13 Migratory Game Bird Hunting Regulations (Preliminary...

    Science.gov (United States)

    2012-04-17

    ... Bird Hunting; Proposed 2012-13 Migratory Game Bird Hunting Regulations (Preliminary) With Requests for Indian Tribal Proposals and Requests for 2014 Spring and Summer Migratory Bird Subsistence Harvest... Migratory Bird Hunting; Proposed 2012-13 Migratory Game Bird Hunting Regulations (Preliminary) With...

  14. 76 FR 32224 - Migratory Birds; Take of Migratory Birds by the Armed Forces

    Science.gov (United States)

    2011-06-03

    ... Fish and Wildlife Service Migratory Birds; Take of Migratory Birds by the Armed Forces AGENCY: Fish and... birds during approved military readiness activities without violating the Migratory Bird Treaty Act... the Armed Forces to incidentally take migratory birds. The Authorization Act also stated that...

  15. 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

  16. Trypanosomes of some Fennoscandian birds

    Directory of Open Access Journals (Sweden)

    Gordon F. Bennett

    1994-12-01

    Full Text Available Linear measurements and derived indices of trypanosomes from species of Fennoscandian birds were compared to those reported form Trypanosoma avium, T. everetti, T. ontarioensis and T. paddae. The trypanosomes encountered in the Fennoscandian birds were identified as T. avium from Tengmalm's owl Aegolius funereus and the pied flycatcher Ficedula hypoleuca, T. everetti from the great tit Parus major and collared flycatcher F. albicollis and T. ontarioensis from the collared flycatcher; T. paddae was not seen.

  17. Orientation and navigation in birds

    Directory of Open Access Journals (Sweden)

    H. Bouwman

    1998-07-01

    Full Text Available How birds orientate and navigate over long distances, remains one of the subjects of ornithology eliciting much interest. Birds use combinations of different sources of information to find direction and position. Some of these are the geomagnetic field, celestial bodies, mosaic and gradient maps, sound, smell, idiotetic information and others. Different species use different combinations of sources. This ability is partially inherent and partially learned.

  18. Nanoindentation Mechanical Properties and Structural Biomimetic Models of Three Species of Insects Wings

    Institute of Scientific and Technical Information of China (English)

    TONG Jin; CHANG Zhiyong; YANG Xiao; ZHANG Jin; LIU Xianping; CHETWYND Derek G; CHEN Donghui; SUN Jiyu

    2015-01-01

    Mimicking insect flights were used to design and develop new engineering materials. Although extensive research was done to study various aspects of lfying insects. Because the detailed mechanics and underlying principles involved in insect lfights remain largely unknown. A systematic study was carried on insect lfights by using a combination of several advanced techniques to develop new models for the simulation and analysis of the wing membrane and veins of three types of insect wings, namely dragonfly (Pantala lfavescensFabricius), honeybee (Apis cerana cerana Fabricius) and lfy (Sarcophaga carnaria Linnaeus). In order to gain insights into the lfight mechanics of insects, reverse engineering methods were used to establish three-dimensional geometrical models of the membranous wings, so we can make a comparative analysis. Then nano-mechanical test of the three insect wing membranes was performed to provide experimental parameter values for mechanical models in terms of nano-hardness and elastic modulus. Finally, a computational model was established by using the ifnite element analysis (ANSYS) to analyze and compare the wings under a variety of simpliifed load regimes that are concentrated force, uniform line-load and a torque. This work opened up the possibility towards developing an engineering basis for the biomimetic design of thin solid iflms and 2D advanced engineering composite materials.

  19. Winglets on low aspect ratio wings

    Science.gov (United States)

    Kuhlman, John M.; Liaw, Paul

    1987-01-01

    The drag reduction potentially available from the use of winglets at the tips of low aspect ratio (1.75-2.67) wings with pronounced (45-60 deg) leading edge sweep is assessed numerically for the case of a cruise design point at Mach of 0.8 and a lift coefficient of 0.3. Both wing-winglet and wing-alone design geometries are derived from a linear-theory, minimum induced drag design methodology. Relative performance is evaluated with a nonlinear extended small disturbance potential flow analysis code. Predicted lift coefficient/pressure drag coefficient increases at equal lift for the wing-winglet configurations over the wing-alone planform are of the order of 14.6-15.8, when boundary layer interaction is included.

  20. Blue-winged teals in the Merritt Island National Wildlife Refuge

    Science.gov (United States)

    1999-01-01

    Two male blue-winged teals are joined by a female in the waters of the Merritt Island National Wildlife Refuge, which shares a boundary with Kennedy Space Center. The teals inhabit marshes, shallow ponds and lakes from British Columbia, Quebec and Newfoundland to North Carolina, the Gulf Coast and southern California, wintering as far south as South America. The 92,000- acre wildlife refuge is a habitat for more than 310 species of birds, 25 mammals, 117 fishes and 65 amphibians and reptiles. The marshes and open water of the refuge also provide wintering areas for 23 species of migratory waterfowl, as well as a year-round home for great blue herons, great egrets, wood storks, cormorants, brown pelicans and other species of marsh and shore birds.

  1. Conceptual design for a laminar-flying-wing aircraft

    Science.gov (United States)

    Saeed, T. I.

    The laminar-flying-wing aircraft appears to be an attractive long-term prospect for reducing the environmental impact of commercial aviation. In assessing its potential, a relatively straightforward initial step is the conceptual design of a version with restricted sweep angle. Such a design is the topic of this thesis. Subject to constraints, this research aims to; provide insight into the parameters affecting practical laminar-flow-control suction power requirements; identify a viable basic design specification; and, on the basis of this, an assessment of the fuel efficiency through a detailed conceptual design study. It is shown that there is a minimum power requirement independent of the suction system design, associated with the stagnation pressure loss in the boundary layer. This requirement increases with aerofoil section thickness, but depends only weakly on Mach number and (for a thick, lightly-loaded laminar flying wing) lift coefficient. Deviation from the optimal suction distribution, due to a practical chamber-based architecture, is found to have very little effect on the overall suction coefficient. In the spanwise direction, through suitable choice of chamber depth, the pressure drop due to frictional and inertial effects may be rendered negligible. Finally, it is found that the pressure drop from the aerofoil surface to the pump collector ducts determines the power penalty. To identify the viable basic design specification, a high-level exploration of the laminar flying wing design space is performed. The characteristics of the design are assessed as a function of three parameters: thickness-to-chord ratio, wingspan, and unit Reynolds number. A feasible specification, with 20% thickness-to-chord, 80 m span and a unit Reynolds number of 8 x 106 m-1, is identified; it corresponds to a 187 tonne aircraft which cruises at Mach 0.67 and altitude 22,500 ft, with lift coefficient 0.14. On the basis of this specification, a detailed conceptual design is

  2. Brain size, head size and behaviour of a passerine bird.

    Science.gov (United States)

    Møller, A P

    2010-03-01

    A recent increase in comparative studies of the ecological and evolutionary consequences of brain size in birds and primates in particular have suggested that cognitive abilities constitute a central link. Surprisingly, there are hardly any intraspecific studies investigating how individuals differing in brain size behave, how such individuals are distributed and how brain size is related to life history and fitness components. Brain mass of the barn swallow Hirundo rustica was strongly predicted by external head volume, explaining 99.5% of the variance, allowing for repeatable estimates of head volume as a reflection of brain size. Repeatability of head volume within and between years was high, suggesting that measurement errors were small. In a 2 years study of 501 individual adult barn swallows, I showed that head volume differed between sexes and age classes, with yearlings having smaller and more variable heads than older individuals, and females having smaller and more variable heads than males. Large head volume was not a consequence of large body size, which was a poor predictor of head volume. Birds with large heads arrived early from spring migration, independent of sex and age, indicating that migratory performance may have an important cognitive component. Head volume significantly predicted capture date and recapture probability, suggesting that head volume is related to learning ability, although morphological traits such as wing length, aspect ratio and wing area were unimportant predictors. Intensity of defence of offspring increased with head volume in females, but not in males. Barn swallows with large heads aggregated in large colonies, suggesting that individuals with large heads were more common in socially complex environments. These results suggest that brain size is currently under natural and sexual selection, and that micro-evolutionary processes affecting brain size can be studied under field conditions.

  3. Blood parasites, body condition, and wing length in two subspecies of yellow wagtail (Motacilla flava) during migration.

    Science.gov (United States)

    Shurulinkov, Peter; Chakarov, Nayden; Daskalova, Girgina

    2012-05-01

    Blood parasites of migrating yellow wagtails of two subspecies--Motacilla flava feldegg and Motacilla flava flava-were studied on a sample of 473 birds caught in spring and autumn periods in Bulgaria. We controlled eight "migration waves" (flocks captured in different evenings) of yellow wagtails for four parameters--average body mass, average fat level, average wing length, and average prevalence of different hematozoan species. Gametocytes or meronts of a total of six species of hematozoa belonging to three genera were identified-Haemoproteus motacillae, Haemoproteus anthi, Plasmodium relictum, Plasmodium subpraecox, Plasmodium cathemerium, and Tryponosoma avium. Mixed infections were detected in 31 cases, of which 14 were of H. anthi/H. motacillae type. Parasite species composition was similar in the two studied subspecies of M. flava. We did not find any significant differences in the overall infection prevalence or number of infecting parasites between M. f. flava and M. f. feldegg. Parasite prevalence and the number of co-infecting parasites in spring were much higher than in fall. Season had a strong influence on the prevalence of H. anthi and H. motacillae, and for both, there was a marginally significant interaction between subspecies and season, but not a season-independent influence of subspecies. Males of M. f. feldegg had a significantly higher overall blood parasite prevalence and prevalence of H. anthi than females. Sex-related differences in the prevalence of other parasites were not significant. Migration waves of yellow wagtails differed in overall infection status and in H. motacillae prevalence, but not for H. anthi prevalence. We also found significant differences in fat score, weight, and wing length between the studied migration waves of the yellow wagtails. Fat scores of birds infected with different hematozoa were lower compared with those of the non-infected birds. This only marginally was true for body weight and was not the case for wing

  4. Evidence for the exchange of blood parasites between North America and the Neotropics in blue-winged teal (Anas discors)

    Science.gov (United States)

    Ramey, Andy M.; Reed, John; Walther, Patrick; Link, Paul; Schmutz, Joel A.; Douglas, David; Stallknecht, David E.; Soos, Catherine

    2016-01-01

    Blue-winged teal (Anas discors) are abundant, small-bodied dabbling ducks that breed throughout the prairies of the northcentral USA and central Canada and that winter in the southern USA and northern Neotropics. Given the migratory tendencies of this species, it is plausible that blue-winged teal may disperse avian pathogens, such as parasites causing avian malaria, between spatially distant areas. To test the hypothesis that blue-winged teal play a role in the exchange of blood parasites between North America and areas further south, we collected information on migratory tendencies of this species and sampled birds at spatially distant areas during breeding and non-breeding periods to diagnose and genetically characterize parasitic infections. Using a combination of band recovery data, satellite telemetry, molecular diagnostics, and genetic analyses, we found evidence for (1) migratory connectivity of blue-winged teal between our sampling locations in the Canadian prairies and along the US Gulf Coast with areas throughout the northern Neotropics, (2) parasite acquisition at both breeding and non-breeding areas, (3) infection of blue-winged teal sampled in Canada and the USA withPlasmodium parasite lineages associated with the Neotropics, and (4) infection of blue-winged teal with parasites that were genetically related to those previously reported in waterfowl in both North America and South America. Collectively, our results suggest that blue-winged teal likely play a role in the dispersal of blood parasites between the Neotropics and North America, and therefore, the targeting of this species in surveillance programs for the early detection of Neotropical-origin avian pathogens in the USA may be informative.

  5. Habitat variation and wing coloration affect wing shape evolution in dragonflies.

    Science.gov (United States)

    Outomuro, D; Dijkstra, K-D B; Johansson, F

    2013-09-01

    Habitats are spatially and temporally variable, and organisms must be able to track these changes. One potential mechanism for this is dispersal by flight. Therefore, we would expect flying animals to show adaptations in wing shape related to habitat variation. In this work, we explored variation in wing shape in relation to preferred water body (flowing water or standing water with tolerance for temporary conditions) and landscape (forested to open) using 32 species of dragonflies of the genus Trithemis (80% of the known species). We included a potential source of variation linked to sexual selection: the extent of wing coloration on hindwings. We used geometric morphometric methods for studying wing shape. We also explored the phenotypic correlation of wing shape between the sexes. We found that wing shape showed a phylogenetic structure and therefore also ran phylogenetic independent contrasts. After correcting for the phylogenetic effects, we found (i) no significant effect of water body on wing shape; (ii) male forewings and female hindwings differed with regard to landscape, being progressively broader from forested to open habitats; (iii) hindwings showed a wider base in wings with more coloration, especially in males; and (iv) evidence for phenotypic correlation of wing shape between the sexes across species. Hence, our results suggest that natural and sexual selection are acting partially independently on fore- and hindwings and with differences between the sexes, despite evidence for phenotypic correlation of wing shape between males and females.

  6. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Hudson River: 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, passerine birds, and gulls and terns in the...

  7. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Northern 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, passerines, pelagic birds, raptors, shorebirds, wading birds, and...

  8. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Northwest Arctic, Alaska: 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, and gulls/terns in Northwest...

  9. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Florida Panhandle: 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...

  10. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Mississippi: 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...

  11. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: North Carolina: 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...

  12. Lab-on-a-bird: biophysical monitoring of flying birds.

    Science.gov (United States)

    Gumus, Abdurrahman; Lee, Seoho; Ahsan, Syed S; Karlsson, Kolbeinn; Gabrielson, Richard; Guglielmo, Christopher G; Winkler, David W; Erickson, David

    2015-01-01

    The metabolism of birds is finely tuned to their activities and environments, and thus research on avian systems can play an important role in understanding organismal responses to environmental changes. At present, however, the physiological monitoring of bird metabolism is limited by the inability to take real-time measurements of key metabolites during flight. In this study, we present an implantable biosensor system that can be used for continuous monitoring of uric acid levels of birds during various activities including flight. The system consists of a needle-type enzymatic biosensor for the amperometric detection of uric acid in interstitial fluids. A lightweight two-electrode potentiostat system drives the biosensor, reads the corresponding output current and wirelessly transfers the data or records to flash memory. We show how the device can be used to monitor, in real time, the effects of short-term flight and rest cycles on the uric acid levels of pigeons. In addition, we demonstrate that our device has the ability to measure uric acid level increase in homing pigeons while they fly freely. Successful application of the sensor in migratory birds could open up a new way of studying birds in flight which would lead to a better understanding of the ecology and biology of avian movements.

  13. Consumer Insights

    Institute of Scientific and Technical Information of China (English)

    JANKOT

    2004-01-01

    Fang Jun, the head of consumer and market insights of Unilever Shanghai, has summarized his early life as a market in two sentences: rush about to study market changes;act all day to observe consumer behavior. And now?"Tell stories, conduct interviews and piece together different data; calculate numbers,build models and write reports."

  14. 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.

  15. Acute oral toxicities of wildland fire control chemicals to birds

    Science.gov (United States)

    Vyas, N.B.; Spann, J.W.; Hill, E.F.

    2009-01-01

    Wildland fire control chemicals are released into the environment by aerial and ground applications to manage rangeland, grassland, and forest fires. Acute oral 24 h median lethal dosages (LD50) for three fire retardants (Fire-Trol GTS-R?, Phos-Chek D-75F?, and Fire-Trol LCG-R?) and two Class A fire suppressant foams (Silv-Ex? and Phos-Chek WD881?) were estimated for northern bobwhites, Colinus virginianus, American kestrels, Falco sparverius, and red-winged blackbirds, Agelaius phoeniceus. The LD50s of all chemicals for the bobwhites and red-winged blackbirds and for kestrels dosed with Phos-Chek WD881? and Silv-Ex? were above the predetermined 2000 mg chemical/kg body mass regulatory limit criteria for acute oral toxicity. The LD50s were not quantifiable for kestrels dosed with Fire-Trol GTS-R?, Phos-Chek D-75F?, and Fire-Trol LCG-R? because of the number of birds which regurgitated the dosage. These chemicals appear to be of comparatively low order of acute oral toxicity to the avian species tested.

  16. Modeling and Mapping Golden-winged Warbler Abundance to Improve Regional Conservation Strategies

    Directory of Open Access Journals (Sweden)

    Wayne E. Thogmartin

    2010-12-01

    Full Text Available Conservation planning requires identifying pertinent habitat factors and locating geographic locations where land management may improve habitat conditions for high priority species. I derived habitat models and mapped predicted abundance for the Golden-winged Warbler (Vermivora chrysoptera, a species of high conservation concern, using bird counts, environmental variables, and hierarchical models applied at multiple spatial scales. My aim was to understand habitat associations at multiple spatial scales and create a predictive abundance map for purposes of conservation planning for the Golden-winged Warbler. My models indicated a substantial influence of landscape conditions, including strong positive associations with total forest composition within the landscape. However, many of the associations I observed were counter to reported associations at finer spatial extents; for instance, I found Golden-winged Warblers negatively associated with several measures of edge habitat. No single spatial scale dominated, indicating that this species is responding to factors at multiple spatial scales. I found Golden-winged Warbler abundance was negatively related with Blue-winged Warbler (Vermivora cyanoptera abundance. I also observed a north-south spatial trend suggestive of a regional climate effect that was not previously noted for this species. The map of predicted abundance indicated a large area of concentrated abundance in west-central Wisconsin, with smaller areas of high abundance along the northern periphery of the Prairie Hardwood Transition. This map of predicted abundance compared favorably with independent evaluation data sets and can thus be used to inform regional planning efforts devoted to conserving this species.

  17. Blood protozoa of imported birds.

    Science.gov (United States)

    Manwell, R D; Rossi, G S

    1975-02-01

    Large numbers of birds, until recently, were brought into the United States each year. Countries of origin were varied, and included those of Australasia, Africa, South America, and the Caribbean islands, as well as other places. With them of course come their parasites, some of which may be potential pathogens to domestic avifauna. In part for this reason, a survey was undertaken of blood parasites of birds from pet shops and importers. So far a total of 1234 birds belonging to 186 species has been examined. Several new species and subspecies of avian Plasmodium have been found in the course of this study, including P. octamerium Manwell, 1968 in a Pintail Whydah, Vidua macoura, from Africa; P paranucleophilum Manwell & Sessler, 1971 in a South American tanager, Tachyphonus sp; and P. nucleophilum toucani Manwell & Sessler 1971 in a Swainson's Toucan, Ramphastos s. swainsonii. Plasmodium huffi Muniz, Soares & Battista is undoubtedly a synonym pro parte for the last. Plasmodium tenue Laveran & Maruliaz, long thought to be a synonym of Plasmodium vaughani Novy & MacNeal, was rediscovered and found to be a valid species. Plasmodium nucleophilum, infrequently seen in the New World, occurred in many Asian and African birds, and especially in starlings. Infections with other species of Plasmodium were common. Haemoproteus was the commonest blood parasite; Leucocytozoon was very rare as was Atoxoplasma (Lankesterella). The 2 families of birds best represented were the Fringillidae and the Psittacidae, but no blood parasites were seen in the latter. It is clear that imported birds are often infected with blood protozoa, some of which are unknown from native birds.

  18. Interval Finite Element Analysis of Wing Flutter

    Institute of Scientific and Technical Information of China (English)

    Wang Xiaojun; Qiu Zhiping

    2008-01-01

    The influences of uncertainties in structural parameters on the flutter speed of wing are studied. On the basis of the deterministic flutter analysis model of wing, the uncertainties in structural parameters are considered and described by interval numbers. By virtue of first-order Taylor series expansion, the lower and upper bound curves of the transient decay rate coefficient versus wind velocity are given. So the interval estimation of the flutter critical wind speed of wing can be obtained, which is more reasonable than the point esti- mation obtained by the deterministic flutter analysis and provides the basis for the further non-probabilistic interval reliability analysis of wing flutter. The flow chart for interval finite element model of flutter analysis of wing is given. The proposed interval finite element model and the stochastic finite element model for wing flutter analysis are compared by the examples of a three degrees of freedorn airfoil and fuselage and a 15° swepthack wing, and the results have shown the effectiveness and feasibility of the presented model. The prominent advantage of the proposed interval finite element model is that only the bounds of uncertain parameters axe required, and the probabilistic distribution densities or other statistical characteristics are not needed.

  19. Comparative use of riparian corridors and oases by migrating birds in southeast Arizona

    Science.gov (United States)

    Skagen, S.K.; Melcher, C.P.; Howe, W.H.; Knopf, F.L.

    1998-01-01

    The relative importance of cottonwood-willow riparian corridors and isolated oases to land birds migrating across southeastern Arizona was evaluated during four spring migrations, 1989 to 1994, based on patterns of species richness, relative abundance, density, and body condition of birds. We surveyed birds in 13 study sites ranging in size and connectivity from small isolated patches to extensive riparian forest, sampled vegetation and insects, and captured birds in mistnets. The continuous band of riparian vegetation along the San Pedro River does not appear to be functioning as a corridor for many migrating species, although it may for a few, namely Yellow-breasted Chats (Icteria virens), Summer Tanagers (Piranga rubra), and Northern Rough-winged Swallows (Steldigopteryx serripennis), which account for fewer than 10% of the individuals migrating through the area. Small, isolated oases hosted more avian species than the corridor sites, and the relative abundances of most migrating birds did not differ between sites relative to size-connectivity. There were few differences in between-year variability in the relative abundances of migrating birds between corridor and oasis sites. Between-year variability decreased with overall abundance of species and was greater for species with breeding ranges that centered north of 50??N latitude. Body condition of birds did not differ relative to the size-connectivity of the capture site, but individuals of species with more northerly breeding ranges had more body fat than species that breed nearby. Peak migration densities of several bird species far exceeded breeding densities reported for the San Pedro River, suggesting that large components of these species were en route migrants. Peak densities of Yellow Warblers (Dendroica petechia) reached 48.0 birds/ha, of Wilson's Warblers (Wilsonia pusilla) 33.7 birds/ha, and of Yellow-rumped Warblers (D. coronata) 30.1 birds/ha. Riparian vegetation is limited in extent in the

  20. Combined particle-image velocimetry and force analysis of the three-dimensional fluid-structure interaction of a natural owl wing.

    Science.gov (United States)

    Winzen, A; Roidl, B; Schröder, W

    2016-04-01

    Low-speed aerodynamics has gained increasing interest due to its relevance for the design process of small flying air vehicles. These small aircraft operate at similar aerodynamic conditions as, e.g. birds which therefore can serve as role models of how to overcome the well-known problems of low Reynolds number flight. The flight of the barn owl is characterized by a very low flight velocity in conjunction with a low noise emission and a high level of maneuverability at stable flight conditions. To investigate the complex three-dimensional flow field and the corresponding local structural deformation in combination with their influence on the resulting aerodynamic forces, time-resolved stereoscopic particle-image velocimetry and force and moment measurements are performed on a prepared natural barn owl wing. Several spanwise positions are measured via PIV in a range of angles of attack [Formula: see text] 6° and Reynolds numbers 40 000 [Formula: see text] 120 000 based on the chord length. Additionally, the resulting forces and moments are recorded for -10° ≤ α ≤ 15° at the same Reynolds numbers. Depending on the spanwise position, the angle of attack, and the Reynolds number, the flow field on the wing's pressure side is characterized by either a region of flow separation, causing large-scale vortical structures which lead to a time-dependent deflection of the flexible wing structure or wing regions showing no instantaneous deflection but a reduction of the time-averaged mean wing curvature. Based on the force measurements the three-dimensional fluid-structure interaction is assumed to considerably impact the aerodynamic forces acting on the wing leading to a strong mechanical loading of the interface between the wing and body. These time-depending loads which result from the flexibility of the wing should be taken into consideration for the design of future small flying air vehicles using flexible wing structures.

  1. Induce Drag Reduction of an Airplane Wing

    Directory of Open Access Journals (Sweden)

    Md. Fazle Rabbi

    2015-06-01

    Full Text Available This work describes the aerodynamic characteristics for aircraft wing model with and without slotted winglet. When an aircraft moves forward with a high speed then a small circulatory motion of air is created at the wingtip due to the pressure difference between the upper and lower surface of the wing is called vortices. This circulatory fluid tends to leak from lower to upper surface of wing which causes downward motion is called “downwash” and generates a component of the local lift force in the direction of the free stream called induced drag. Downwash causes reduction of lift and contribute induced drag to the total drag. Drag reduction for aerial vehicles has a range of positive ramifications: reduced fuel consumption, larger operational range, greater endurance and higher achievable speeds. An experimental study is conducted to examine the potentiality of slotted winglet for the reduction of induced drag, and for the improvement of lift coefficient without increasing the span of aircraft wing. The model composed of a swept wing built from NACA 0012 airfoil. The test conducted in subsonic wind tunnel of 1m×1m rectangular test section at flow speed 25m/s placing the wing without winglet, wing with winglet at 30° inclination, wing with winglet at 60° inclination, and wing with winglet at 70° inclination at angle of attack ranging from 0 to 16 degree. The test result shows 20- 25% reduction in drag coefficient and 10-20% increase in lift coefficient by using slotted winglet.

  2. Influence of wing loading on the trade-off between pursuit-diving and flight in common guillemots and razorbills.

    Science.gov (United States)

    Thaxter, C B; Wanless, S; Daunt, F; Harris, M P; Benvenuti, S; Watanuki, Y; Grémillet, D; Hamer, K C

    2010-04-01

    Species of bird that use their wings for underwater propulsion are thought to face evolutionary trade-offs between flight and diving, leading to the prediction that species with different wing areas relative to body mass (i.e. different wing loadings) also differ in the relative importance of flight and diving activity during foraging trips. We tested this hypothesis for two similarly sized species of Alcidae (common guillemots and razorbills) by using bird-borne devices to examine three-dimensional foraging behaviour at a single colony. Guillemots have 30% higher wing loading than razorbills and, in keeping with this difference, razorbills spent twice as long in flight as a proportion of trip duration whereas guillemots spent twice as long in diving activity. Razorbills made a large number of short, relatively shallow dives and spent little time in the bottom phase of the dive whereas guillemots made fewer dives but frequently attained depths suggesting that they were near the seabed (ca. 35-70 m). The bottom phase of dives by guillemots was relatively long, indicating that they spent considerable time searching for and pursuing prey. Guillemots also spent a greater proportion of each dive bout underwater and had faster rates of descent, indicating that they were more adept at maximising time for pursuit and capture of prey. These differences in foraging behaviour may partly reflect guillemots feeding their chicks single large prey obtained near the bottom and razorbills feeding their chicks multiple prey from the water column. Nonetheless, our data support the notion that interspecific differences in wing loadings of auks reflect an evolutionary trade-off between aerial and underwater locomotion.

  3. Birds and polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Albers, P.H.

    2006-01-01

    Polycyclic aromatic hydrocarbons (PAH) are present throughout the global environment and are produced naturally and by activities of humans. Effects of PAH on birds have been determined by studies employing egg injection, egg immersion, egg shell application, single and multiple oral doses, subcutaneous injection, and chemical analysis of field-collected eggs and tissue. The four-to six-ring aromatic compounds are the most toxic to embryos, young birds, and adult birds. For embryos, effects include death, developmental abnormalities, and a variety of cellular and biochemical responses. For adult and young birds, effects include reduced egg production and hatching, increased clutch or brood abandonment, reduced growth, increased organweights, and a variety of biochemical responses. Trophic level accumulation is unlikely. Environmental exposure to PAH in areas of high human population or habitats affected by recent petroleum spills might be sufficient to adversely affect reproduction. Evidence of long-term effects of elevated concentrations of environmental PAH on bird populations is very limited and the mechanisms of effect are unclear.

  4. CineVersum BlackWing Four

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    从BlackWing One到现在最新推出的BlackWing Four,一直以来C1ndVersum所带来的投影机都受到了不少投影机爱好者的关注,其帅气的外形搭配独特的欧美系画面风格,让人印象深刻。BlackWingFour是Cine Versum最为强悍的家庭影院投影机之一,

  5. Static aeroelastic analysis for generic configuration wing

    Science.gov (United States)

    Lee, IN; Miura, Hirokazu; Chargin, Mladen K.

    1991-01-01

    A static aeroelastic analysis capability that calculates flexible air loads for generic configuration wings was developed. It was made possible by integrating a finite element structural analysis code (MSC/NASTRAN) and a panel code of aerodynamic analysis based on linear potential flow theory. The framework already built in MSC/NASTRAN was used, and the aerodynamic influence coefficient matrix was computed externally and inserted in the NASTRAN by means of a DMAP program. It was shown that deformation and flexible air loads of an oblique wing configuration including asymmetric wings can be calculated reliably by this code both in subsonic and supersonic speeds.

  6. AFM Study of Structure Influence on Butterfly Wings Coloration

    Directory of Open Access Journals (Sweden)

    Dinara Sultanovna Dallaeva

    2012-01-01

    Full Text Available This study describes the structural coloration of the butterfly Vanessa Atalanta wings and shows how the atomic force microscopy (AFM can be applied to the study of wings morphology and wings surface behavior under the temperature. The role of the wings morphology in colors was investigated. Different colors of wings have different topology and can be identified by them. AFM in semi-contact mode was used to study the wings surface. The wing surface area, which is close to the butterfly body, has shiny brown color and the peak of surface roughness is about 600 nm. The changing of morphology at different temperatures is shown.

  7. Biomimetic Drag Reduction Study on Herringbone Riblets of Bird Feather

    Institute of Scientific and Technical Information of China (English)

    Huawei Chen; Fugang Rao; Xiaopeng Shang; Deyuan Zhang; Ichiro Hagiwara

    2013-01-01

    Birds have gradually formed various excellent structures such as streamlined shape and hollow shaft of feather to improve their flying performance by millions of years of natural selection.As typical property of bird feather,herringbone riblets align along the shaft of each feather,which is caused by perfect link of barbs,especially for the primary and secondary feathers of wings.Such herringbone riblets of feather are assumed to have great impact on drag reduction.In this paper,microstructures of secondary feathers of adult pigeons are investigated by SEM,and their structural parameters are statistically obtained.Based on quantitative analysis of feather structure,novel biomimetic herringbone riblets with narrow smooth edge are proposed to reduce surface drag.In comparison with traditional microgroove riblets and other drag reduction structures,the drag reduction rate of the proposed biomimetic herringbone riblets is experimentally clarified up to 16%,much higher than others.Moreover,the drag reduction mechanism of herringbone riblets are also confirmed and exploited by CFD.

  8. Modular color evolution facilitated by a complex nanostructure in birds.

    Science.gov (United States)

    Eliason, Chad M; Maia, Rafael; Shawkey, Matthew D

    2015-02-01

    The way in which a complex trait varies, and thus evolves, is critically affected by the independence, or modularity, of its subunits. How modular designs facilitate phenotypic diversification is well studied in nonornamental (e.g., cichlid jaws), but not ornamental traits. Diverse feather colors in birds are produced by light absorption by pigments and/or light scattering by nanostructures. Such structural colors are deterministically related to the nanostructures that produce them and are therefore excellent systems to study modularity and diversity of ornamental traits. Elucidating if and how these nanostructures facilitate color diversity relies on understanding how nanostructural traits covary, and how these traits map to color. Both of these remain unknown in an evolutionary context. Most dabbling ducks (Anatidae) have a conspicuous wing patch with iridescent color caused by a two-dimensional photonic crystal of small (100-200 nm) melanosomes. Here, we ask how this complex nanostructure affects modularity of color attributes. Using a combination of electron microscopy, spectrophotometry, and comparative methods, we show that nanostructural complexity causes functional decoupling and enables independent evolution of different color traits. These results demonstrate that color diversity is facilitated by how nanostructures function and may explain why some birds are more color-diverse than others.

  9. Seventeenth breeding-bird census. 34. Diked wet meadow

    Science.gov (United States)

    Robbins, C.S.; Boyer, G.F.

    2000-01-01

    Several characteristics of plumage, including color and molt schedule, are influenced by hormonal signals, and hence may be modified by endocrine active contaminants. If so, the functions of plumage (e.g. communication for mating or territorial defense), may be compromised by exposure to such compounds. Polychlorinated biphenyls (PCBs) are ubiquitous and persistent environmental toxins that can disrupt endocrine function in laboratory animals. Captive American kestrels (Falco sparverius) were fed PCBs (Aroclor 1242) at 6 and 60 ppm, thyroxine at 10 ppm, estradiol at 1.4 ppm, and a thyroid hormone blocker (propylthiouracil: PTU) at 2000 ppm, mixed in their normal diet. Plumage characteristics measured included: the width of the black subterminal band on the tail, brightness (a composite index of hue and saturation), reflectance from 230 - 800 nm (measured on a reflectance spectrophotometer), the pattern of feather loss and regrowth on the tail and wing, and the timing of onset and the duration of molt. PCB-treated birds did not differ from controls, but birds treated with thyroxine were significantly different from those dosed with estradiol or PTU in the width of subterminal tail bands, reflectance, and duration of molt. Thus, although hormone treatments did modify some of the plumage characteristics we measured, PCB treatments at these exposure levels did not.

  10. THE BIRD PATICA IN BULGARIAN

    Directory of Open Access Journals (Sweden)

    M. N. Belova

    2015-01-01

    Full Text Available The paper observes some words for waterfowls (aquatic birds occurring exclusively in South Slavic languages: пат, патка, пате, патица 'duck, goose' and some of their derivatives. The root in these words is generally attributed to common Slavic pъt'bird', but the origin of the vowel timbre (a instead of ъ is unclear. Furthermore, this root could also be found in Eastern and rarely Western Slavic names for another bird 'куропатка' ('Perdix'.  Here all of the attempts for explaining the root vowel are summarized; also I propose a new convergence with the turkish root pat-/pač-, which could have had strong influence on the root vowel in a number of derivatives in Bulgarian, Macedonian, Serbian and Croatian.

  11. Invasive alien birds in Denmark

    DEFF Research Database (Denmark)

    Fox, Anthony David; Heldbjerg, Henning; Nyegaard, Timme

    2015-01-01

    Avian Introduced Alien Species (IAS) constitute a threat to the integrity of native biodiversity, the economy and human health, so here we briefly review some of the problems posed by such species around the world in relation to such bird species in Denmark. A new European Union Regulation...... on Invasive Alien Species implemented in January 2015 establishes a framework for actions to combat alien species, which requires Member States to prevent the spread of alien species, provide early warning and rapid responses to their presence and management of established alien species where they occur. We...... show the importance of mechanisms such as DOF’s (Dansk Ornitologisk Forening, BirdLife Denmark) Atlas project, Common Bird Census (breeding and wintering species) and DOFbasen to contribute data on the current geographical and numerical distribution of the few serious alien avian species already...

  12. Parametric weight evaluation of joined wings by structural optimization

    Science.gov (United States)

    Miura, Hirokazu; Shyu, Albert T.; Wolkovitch, Julian

    1988-01-01

    Joined-wing aircraft employ tandem wings having positive and negative sweep and dihedral, arranged to form diamond shapes in both plan and front views. An optimization method was applied to study the effects of joined-wing geometry parameters on structural weight. The lightest wings were obtained by increasing dihedral and taper ratio, decreasing sweep and span, increasing fraction of airfoil chord occupied by structural box, and locating the joint inboard of the front wing tip.

  13. Fruit fly scale robots can hover longer with flapping wings than with spinning wings.

    Science.gov (United States)

    Hawkes, Elliot W; Lentink, David

    2016-10-01

    Hovering flies generate exceptionally high lift, because their wings generate a stable leading edge vortex. Micro flying robots with a similar wing design can generate similar high lift by either flapping or spinning their wings. While it requires less power to spin a wing, the overall efficiency depends also on the actuator system driving the wing. Here, we present the first holistic analysis to calculate how long a fly-inspired micro robot can hover with flapping versus spinning wings across scales. We integrate aerodynamic data with data-driven scaling laws for actuator, electronics and mechanism performance from fruit fly to hummingbird scales. Our analysis finds that spinning wings driven by rotary actuators are superior for robots with wingspans similar to hummingbirds, yet flapping wings driven by oscillatory actuators are superior at fruit fly scale. This crossover is driven by the reduction in performance of rotary compared with oscillatory actuators at smaller scale. Our calculations emphasize that a systems-level analysis is essential for trading-off flapping versus spinning wings for micro flying robots.

  14. DrawWing, a program for numerical description of insect wings

    Directory of Open Access Journals (Sweden)

    Adam Tofilski

    2004-05-01

    Full Text Available There is usually a pattern of veins on an insect wing. This pattern is species-specific and is used taxonomically. For example, the coordinates of some characteristic points on the wing are used to compare vein patterns. The characteristic points are often vein junctions or vein ends. A tool is presented that enables automatic identification of vein junctions. An image of an insect wing is used to determine the wing outline and veins. The vein skeleton is obtained using a thinning algorithm. Bezier splines are fitted to both the wing outline and the vein skeleton. The splines are saved in an encapsulated postscript file. Another output file in text format contains the coordinates of vein junctions. Both the program and its source code are available under GNU General Public License at [www.cyf-kr.edu.pl/~rotofils/drawwing.html]. The program presented in this paper automatically provides a numerical description of an insect wing. It converts an image of an insect wing to a list of coordinates of vein junctions, and a wing diagram that can be used as an illustration. Coordinates of the vein junctions extracted by the program from wing images were used successfully to discriminate between males of Dolichovespula sylvestris and Dolichovespula saxonica.

  15. Fuglene. Audubon: Birds of America

    DEFF Research Database (Denmark)

    Schlichtkrull, Torsten

    2010-01-01

    The Royal Library owns one of the most exceptional works in book history, an original edition of John James Audubon Birds of America. This edition, in a format called “double elephant folio” was published from 1827 to 1838. On basis of existing literature, this article briefly describes the work...... the Royal Library and the University Library, joined the library cooperation of the 1800’s on an equal standing with the other two libraries. The Classen’s Library and the library’s founder, industrialist JF Classen are described briefly in this article. Due to two library mergers the Birds of America...

  16. Chemical compass for bird navigation

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Hore, Peter J.; Ritz, Thorsten

    2014-01-01

    Migratory birds travel spectacular distances each year, navigating and orienting by a variety of means, most of which are poorly understood. Among them is a remarkable ability to perceive the intensity and direction of the Earth's magnetic field. Biologically credible mechanisms for the detection...... increased interest following the proposal in 2000 that free radical chemistry could occur in the bird's retina initiated by photoexcitation of cryptochrome, a specialized photoreceptor protein. In the present paper we review the important physical and chemical constraints on a possible radical...

  17. Molecular determinants of bat wing development.

    Science.gov (United States)

    Sears, K E

    2008-01-01

    The specialization of the forelimb into a wing allowed bats to become the only mammals to achieve powered flight. Recent studies in developmental biology have begun to elucidate the molecular mechanisms behind elements of this important morphological transformation. Specifically, researchers have identified molecular changes contributing to: the formation of the bat wing membrane, the elongation of skeletal elements of the bat wing and the reduction of the bat ulna. The general picture emerging from this research is that small changes in the expression of genes critical to many aspects of development have driven large changes in bat wing morphology. Thus, bats can be added to the growing list of groups in which expression changes in key developmental genes have been linked to the evolution of morphological innovations (e.g. early bilaterians, cetaceans, insects).

  18. Trajectory Optimization Design for Morphing Wing Missile

    Institute of Scientific and Technical Information of China (English)

    Ruisheng Sun; Chao Ming; Chuanjie Sun

    2015-01-01

    This paper presents a new particle swarm optimization ( PSO) algorithm to optimize the trajectory of morphing⁃wing missile so as to achieve the enlargement of the maximum range. Equations of motion for the two⁃dimensional dynamics are derived by treating the missile as an ideal controllable mass point. An investigation of aerodynamic characteristics of morphing⁃wing missile with varying geometries is performed. After deducing the optimizing trajectory model for maximizing range, a type of discrete method is put forward for taking optimization control problem into nonlinear dynamic programming problem. The optimal trajectory is solved by using PSO algorithm and penalty function method. The simulation results suggest that morphing⁃wing missile has the larger range than the fixed⁃shape missile when launched at supersonic speed, while morphing⁃wing missile has no obvious range increment than the fixed⁃shape missile at subsonic speed.

  19. Left-Wing Extremism: The Current Threat

    Energy Technology Data Exchange (ETDEWEB)

    Karl A. Seger

    2001-04-30

    Left-wing extremism is ''alive and well'' both in the US and internationally. Although the current domestic terrorist threat within the U. S. is focused on right-wing extremists, left-wing extremists are also active and have several objectives. Leftist extremists also pose an espionage threat to U.S. interests. While the threat to the U.S. government from leftist extremists has decreased in the past decade, it has not disappeared. There are individuals and organizations within the U.S. who maintain the same ideology that resulted in the growth of left-wing terrorism in this country in the 1970s and 1980s. Some of the leaders from that era are still communicating from Cuba with their followers in the U.S., and new leaders and groups are emerging.

  20. Mallard age and sex determination from wings

    Science.gov (United States)

    Carney, S.M.; Geis, A.D.

    1960-01-01

    This paper describes characters on the wing plumage of the mallard that indicate age and sex. A key outlines a logical order in which to check age and sex characters on wings. This method was tested and found to be more than 95 percent reliable, although it was found that considerable practice and training with known-age specimens was required to achieve this level of accuracy....The implications of this technique and the sampling procedure it permits are discussed. Wing collections could provide information on production, and, if coupled with a banding program could permit seasonal population estimates to be calculated. In addition, representative samples of wings would provide data to check the reliability of several other waterfowl surveys.

  1. Coriolis effects enhance lift on revolving wings.

    Science.gov (United States)

    Jardin, T; David, L

    2015-03-01

    At high angles of attack, an aircraft wing stalls. This dreaded event is characterized by the development of a leading edge vortex on the upper surface of the wing, followed by its shedding which causes a drastic drop in the aerodynamic lift. At similar angles of attack, the leading edge vortex on an insect wing or an autorotating seed membrane remains robustly attached, ensuring high sustained lift. What are the mechanisms responsible for both leading edge vortex attachment and high lift generation on revolving wings? We review the three main hypotheses that attempt to explain this specificity and, using direct numerical simulations of the Navier-Stokes equations, we show that the latter originates in Coriolis effects.

  2. Analysis of the Wing Tsun Punching Methods

    Directory of Open Access Journals (Sweden)

    Jeff Webb

    2012-07-01

    Full Text Available The three punching techniques of Wing Tsun, while few in number, represent an effective approach to striking with the closed fist. At first glance, the rather short stroke of each punch would seem disproportionate to the amount of power it generates. Therefore, this article will discuss the structure and body mechanics of each punch, in addition to the various training methods employed for developing power. Two of the Wing Tsun punches, namely the lifting punch and the hooking punch, are often confused with similar punches found in Western boxing. The key differences between the Wing Tsun and boxing punches, both in form and function, will be discussed. Finally, the strategy for applying the Wing Tsun punches will serve as the greatest factor in differentiating them from the punches of other martial arts styles.

  3. Birds of a feather: Neanderthal exploitation of raptors and corvids.

    Directory of Open Access Journals (Sweden)

    Clive Finlayson

    Full Text Available The hypothesis that Neanderthals exploited birds for the use of their feathers or claws as personal ornaments in symbolic behaviour is revolutionary as it assigns unprecedented cognitive abilities to these hominins. This inference, however, is based on modest faunal samples and thus may not represent a regular or systematic behaviour. Here we address this issue by looking for evidence of such behaviour across a large temporal and geographical framework. Our analyses try to answer four main questions: 1 does a Neanderthal to raptor-corvid connection exist at a large scale, thus avoiding associations that might be regarded as local in space or time?; 2 did Middle (associated with Neanderthals and Upper Palaeolithic (associated with modern humans sites contain a greater range of these species than Late Pleistocene paleontological sites?; 3 is there a taphonomic association between Neanderthals and corvids-raptors at Middle Palaeolithic sites on Gibraltar, specifically Gorham's, Vanguard and Ibex Caves? and; 4 was the extraction of wing feathers a local phenomenon exclusive to the Neanderthals at these sites or was it a geographically wider phenomenon?. We compiled a database of 1699 Pleistocene Palearctic sites based on fossil bird sites. We also compiled a taphonomical database from the Middle Palaeolithic assemblages of Gibraltar. We establish a clear, previously unknown and widespread, association between Neanderthals, raptors and corvids. We show that the association involved the direct intervention of Neanderthals on the bones of these birds, which we interpret as evidence of extraction of large flight feathers. The large number of bones, the variety of species processed and the different temporal periods when the behaviour is observed, indicate that this was a systematic, geographically and temporally broad, activity that the Neanderthals undertook. Our results, providing clear evidence that Neanderthal cognitive capacities were comparable to

  4. Birds of a feather: Neanderthal exploitation of raptors and corvids.

    Science.gov (United States)

    Finlayson, Clive; Brown, Kimberly; Blasco, Ruth; Rosell, Jordi; Negro, Juan José; Bortolotti, Gary R; Finlayson, Geraldine; Sánchez Marco, Antonio; Giles Pacheco, Francisco; Rodríguez Vidal, Joaquín; Carrión, José S; Fa, Darren A; Rodríguez Llanes, José M

    2012-01-01

    The hypothesis that Neanderthals exploited birds for the use of their feathers or claws as personal ornaments in symbolic behaviour is revolutionary as it assigns unprecedented cognitive abilities to these hominins. This inference, however, is based on modest faunal samples and thus may not represent a regular or systematic behaviour. Here we address this issue by looking for evidence of such behaviour across a large temporal and geographical framework. Our analyses try to answer four main questions: 1) does a Neanderthal to raptor-corvid connection exist at a large scale, thus avoiding associations that might be regarded as local in space or time?; 2) did Middle (associated with Neanderthals) and Upper Palaeolithic (associated with modern humans) sites contain a greater range of these species than Late Pleistocene paleontological sites?; 3) is there a taphonomic association between Neanderthals and corvids-raptors at Middle Palaeolithic sites on Gibraltar, specifically Gorham's, Vanguard and Ibex Caves? and; 4) was the extraction of wing feathers a local phenomenon exclusive to the Neanderthals at these sites or was it a geographically wider phenomenon?. We compiled a database of 1699 Pleistocene Palearctic sites based on fossil bird sites. We also compiled a taphonomical database from the Middle Palaeolithic assemblages of Gibraltar. We establish a clear, previously unknown and widespread, association between Neanderthals, raptors and corvids. We show that the association involved the direct intervention of Neanderthals on the bones of these birds, which we interpret as evidence of extraction of large flight feathers. The large number of bones, the variety of species processed and the different temporal periods when the behaviour is observed, indicate that this was a systematic, geographically and temporally broad, activity that the Neanderthals undertook. Our results, providing clear evidence that Neanderthal cognitive capacities were comparable to those of

  5. Investigating the Transonic Flutter Boundary of the Benchmark Supercritical Wing

    Science.gov (United States)

    Heeg, Jennifer; Chwalowski, Pawel

    2017-01-01

    This paper builds on the computational aeroelastic results published previously and generated in support of the second Aeroelastic Prediction Workshop for the NASA Benchmark Supercritical Wing configuration. The computational results are obtained using FUN3D, an unstructured grid Reynolds-Averaged Navier-Stokes solver developed at the NASA Langley Research Center. The analysis results focus on understanding the dip in the transonic flutter boundary at a single Mach number (0.74), exploring an angle of attack range of ??1 to 8 and dynamic pressures from wind off to beyond flutter onset. The rigid analysis results are examined for insights into the behavior of the aeroelastic system. Both static and dynamic aeroelastic simulation results are also examined.

  6. Bird community responses to the edge between suburbs and reserves.

    Science.gov (United States)

    Ikin, Karen; Barton, Philip S; Knight, Emma; Lindenmayer, David B; Fischer, Joern; Manning, Adrian D

    2014-02-01

    New insights into community-level responses at the urban fringe, and the mechanisms underlying them, are needed. In our study, we investigated the compositional distinctiveness and variability of a breeding bird community at both sides of established edges between suburban residential areas and woodland reserves in Canberra, Australia. Our goals were to determine if: (1) community-level responses were direct (differed with distance from the edge, independent of vegetation) or indirect (differed in response to edge-related changes in vegetation), and (2) if guild-level responses provided the mechanism underpinning community-level responses. We found that suburbs and reserves supported significantly distinct bird communities. The suburban bird community, characterised by urban-adapted native and exotic species, had a weak direct edge response, with decreasing compositional variability with distance from the edge. In comparison, the reserve bird community, characterised by woodland-dependent species, was related to local tree and shrub cover. This was not an indirect response, however, as tree and shrub cover was not related to edge distance. We found that the relative richness of nesting, foraging and body size guilds also displayed similar edge responses, indicating that they underpinned the observed community-level responses. Our study illustrates how community-level responses provide valuable insights into how communities respond to differences in resources between two contrasting habitats. Further, the effects of the suburban matrix penetrate into reserves for greater distances than previously thought. Suburbs and adjacent reserves, however, provided important habitat resources for many native species and the conservation of these areas should not be discounted from continued management strategies.

  7. Constitutive innate immunity is a component of the pace-of-life syndrome in tropical birds

    NARCIS (Netherlands)

    Tieleman, BI; Williams, JB; Ricklefs, RE; Klasing, KC; Williams, Joseph B.; Ricklefs, Robert E.; Klasing, Kirk C.

    2005-01-01

    We studied the relationship between one component of immune function and basal metabolic rate (BMR), an indicator of the 'pace-of-life syndrome', among 12 tropical bird species and among individuals of the tropical house wren (Troglodytes aedon), to gain insights into functional connections between

  8. Wetting Characteristics of Insect Wing Surfaces

    Institute of Scientific and Technical Information of China (English)

    Doyoung Byun; Jongin Hong; Saputra; Jin Hwan Ko; Young Jong Lee; Hoon Cheol Park; Bong-Kyu Byun; Jennifer R. Lukes

    2009-01-01

    Biological tiny structures have been observed on many kinds of surfaces such as lotus leaves, which have an effect on the coloration of Morpho butterflies and enhance the hydrophobicity of natural surfaces. We investigated the micro-scale and nano-scale structures on the wing surfaces of insects and found that the hierarchical multiple roughness structures help in enhancing the hydrophobicity. After examining 10 orders and 24 species of flying Pterygotan insects, we found that micro-scale and nano-scale structures typically exist on both the upper and lower wing surfaces of flying insects. The tiny structures such as denticle or setae on the insect wings enhance the hydrophobicity, thereby enabling the wings to be cleaned more easily. And the hydrophobic insect wings undergo a transition from Cassie to Wenzel states at pitch/size ratio of about 20. In order to examine the wetting characteristics on a rough surface, a biomimetic surface with micro-scale pillars is fabricated on a silicon wafer,which exhibits the same behavior as the insect wing, with the Cassie-Wenzel transition occurring consistently around a pitch/width value of 20.

  9. Lift augmentation for highly swept wing aircraft

    Science.gov (United States)

    Rao, Dhanvada M. (Inventor)

    1993-01-01

    A pair of spaced slots, disposed on each side of an aircraft centerline and spaced well inboard of the wing leading edges, are provided in the wing upper surfaces and directed tangentially spanwise toward thin sharp leading wing edges of a highly swept, delta wing aircraft. The slots are individually connected through separate plenum chambers to separate compressed air tanks and serve, collectively, as a system for providing aircraft lift augmentation. A compressed air supply is tapped from the aircraft turbojet power plant. Suitable valves, under the control of the aircraft pilot, serve to selective provide jet blowing from the individual slots to provide spanwise sheets of jet air closely adjacent to the upper surfaces and across the aircraft wing span to thereby create artificial vortices whose suction generate additional lift on the aircraft. When desired, or found necessary, unequal or one-side wing blowing is employed to generate rolling moments for augmented lateral control. Trailing flaps are provided that may be deflected differentially, individually, or in unison, as needed for assistance in take-off or landing of the aircraft.

  10. Do 'Early Birds' Get the Healthier Worm?

    Science.gov (United States)

    ... medlineplus.gov/news/fullstory_163902.html Do 'Early Birds' Get the Healthier Worm? Late-to-bed types ... 2017 FRIDAY, March 3, 2017 (HealthDay News) -- Early birds may have a leg up over night owls ...

  11. Birds observed at Shemya Island, Aleutian Islands

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers Shemya Island bird surveys. The reports outline migrant bird activity during August 31 to October 3, 1977. The purpose of the study was to survey...

  12. Cape Romain National Wildlife Refuge Bird List

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This bird list includes 293 species of birds which have been recorded on the refuge, principally on Bulls Island, and is based on observations by refuge personnel...

  13. Understanding relations between breeding bird species and extreme weather

    Science.gov (United States)

    Allstadt, A.; Bateman, B.; Pidgeon, A. M.; Radeloff, V.; Vavrus, S. J.; Keuler, N.; Clayton, M.; Albright, T.; Thogmartin, W.; Heglund, P.

    2013-12-01

    Extreme weather events are increasing in frequency due to climate change. Extreme weather events like periods of drought or cold snaps may impose hardship on many animal and plant populations. However, little is known about biotic response to extreme events. For example, some species experience population size changes in association with extreme weather, and some do not. However the mechanisms responsible for observed declines in avian abundance following heat waves and drought are not clear. Our goal was to characterize the population changes of North American bird species in relation to temperature and precipitation extremes using North American Breeding Bird Survey (BBS) data. We derived standardized measures of extreme precipitation and air temperature based on phase 2 NASA Land Data Assimilation System (NLDAS-2), an hourly 1/8 degree resolution land surface forcing dataset, and modeled population responses, during the breeding season, of 363 bird species. Of those species in which a change was observed, many demonstrated decreases in total population size, suggesting either mortality or reproductive failure (or both) are the causative mechanisms of this decline. A greater proportion of population changes were associated with extreme conditions in the same year than in the previous year. Some species exhibited population decreases in areas of extreme weather and increases in areas with environmental conditions more favorable to breeding while overall abundance remained relatively constant, which might indicate movement. The patterns of bird population changes in relation to extreme weather events provide insight for planners as they consider modifications to our national protected area network that will limit threats posed by climate change to bird populations.

  14. Flow interactions lead to orderly formations of flapping wings in forward flight

    Science.gov (United States)

    Ramananarivo, Sophie; Fang, Fang; Oza, Anand; Zhang, Jun; Ristroph, Leif

    2016-11-01

    Classic models of fish schools and flying formations of birds are built on the hypothesis that the preferred locations of an individual are determined by the flow left by its upstream neighbor. Lighthill posited that arrangements may in fact emerge passively from hydro- or aerodynamic interactions, drawing an analogy to the formation of crystals by intermolecular forces. Here, we carry out physical experiments aimed at testing the Lighthill conjecture and find that self-propelled flapping wings spontaneously assume one of multiple arrangements due to flow interactions. Wings in a tandem pair select the same forward speed, which tends to be faster than a single wing, while maintaining a separation distance that is an integer multiple of the wavelength traced out by each body. When perturbed, these locomotors robustly return to the same arrangement, and direct hydrodynamic force measurements reveal springlike restoring forces that maintain group cohesion. We also use these data to construct an interaction potential, showing how the observed positions of the follower correspond to stable wells in an energy landscape. Flow visualization and vortex-based theoretical models reveal coherent interactions in which the follower surfs on the periodic wake left by the leader. These results indicate that, for the high-Reynolds-number flows characteristic of schools and flocks, collective locomotion at enhanced speed and in orderly formations can emerge from flow interactions alone. If true for larger groups, then the view of collectives as ordered states of matter may prove to be a useful analogy.

  15. Numerical study of the trailing vortex of a wing with wing-tip blowing

    Science.gov (United States)

    Lim, Hock-Bin

    1994-01-01

    Trailing vortices generated by lifting surfaces such as helicopter rotor blades, ship propellers, fixed wings, and canard control surfaces are known to be the source of noise, vibration, cavitation, degradation of performance, and other hazardous problems. Controlling these vortices is, therefore, of practical interest. The formation and behavior of the trailing vortices are studied in the present research. In addition, wing-tip blowing concepts employing axial blowing and spanwise blowing are studied to determine their effectiveness in controlling these vortices and their effects on the performance of the wing. The 3D, unsteady, thin-layer compressible Navier-Stokes equations are solved using a time-accurate, implicit, finite difference scheme that employs LU-ADI factorization. The wing-tip blowing is simulated using the actuator plane concept, thereby, not requiring resolution of the jet slot geometry. Furthermore, the solution blanking feature of the chimera scheme is used to simplify the parametric study procedure for the wing-tip blowing. Computed results are shown to compare favorably with experimental measurements. It is found that axial wing-tip blowing, although delaying the rolling-up of the trailing vortices and the near-field behavior of the flowfield, does not dissipate the circulation strength of the trailing vortex farther downstream. Spanwise wing-tip blowing has the effect of displacing the trailing vortices outboard and upward. The increased 'wing-span' due to the spanwise wing-tip blowing has the effect of lift augmentation on the wing and the strengthening of the trailing vortices. Secondary trailing vortices are created at high spanwise wing-tip blowing intensities.

  16. Bat predation on nocturnally migrating birds

    OpenAIRE

    Ibáñez, Carlos; Juste, Javier; García-Mudarra, Juan L.; Agirre-Mendi, Pablo T.

    2001-01-01

    Bat predation on birds is a very rare phenomenon in nature. Most documented reports of bird-eating bats refer to tropical bats that occasionally capture resting birds. Millions of small birds concen- trate and cross over the world’s temperate regions during migra- tion, mainly at night, but no nocturnal predators are known to benefit from this enormous food resource. An analysis of 14,000 fecal pellets of the greater noctule bat (Nyctalus lasiopterus) reveals that this species captures a...

  17. 76 FR 48693 - Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian...

    Science.gov (United States)

    2011-08-08

    ... August 8, 2011 Part V Department of the Interior Fish and Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian Reservations and Ceded... RIN 1018-AX34 Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain...

  18. 76 FR 54051 - Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations

    Science.gov (United States)

    2011-08-30

    ... Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations; Final Rule #0;#0... OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX34 Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations AGENCY: Fish and Wildlife Service,...

  19. 77 FR 53117 - Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations

    Science.gov (United States)

    2012-08-30

    ... Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations; Final Rule #0;#0...; ] DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX97 Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations AGENCY: Fish and Wildlife...

  20. 75 FR 47681 - Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian...

    Science.gov (United States)

    2010-08-06

    ... Interior Fish and Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Proposed Migratory Bird Hunting... INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX06 Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian Reservations and Ceded Lands for the 2010-11...

  1. 78 FR 52657 - Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations

    Science.gov (United States)

    2013-08-23

    ... Bird Hunting; Final Frameworks for Early Season Migratory Bird Hunting Regulations; Final Rule #0;#0... OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AY87 Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations AGENCY: Fish and Wildlife Service,...

  2. Birds and Bird Habitat: What Are the Risks from Industrial Wind Turbine Exposure?

    Science.gov (United States)

    Sprague, Terry; Harrington, M. Elizabeth; Krogh, Carmen M. E.

    2011-01-01

    Bird kill rate and disruption of habitat has been reported when industrial wind turbines are introduced into migratory bird paths or other environments. While the literature could be more complete regarding the documentation of negative effects on birds and bird habitats during the planning, construction, and operation of wind power projects,…

  3. The Bird Box Survey Project

    Science.gov (United States)

    Willis, Patrick

    2014-01-01

    When high school students are asked what's the best part of science class, many will say it's the field trips. Students enjoy engaging in authentic, community-based science outside the classroom. To capitalize on this, Patrick Willis created the Bird Box Survey Project for his introductory field biology class. The project takes students…

  4. The Breeding Bird Survey, 1966

    Science.gov (United States)

    Robbins, C.S.; Van Velzen, W.T.

    1967-01-01

    A Breeding Bird Survey of a large section on North America was conducted during June 1966. Cooperators ran a total of 585 Survey routes in 26 eastern States and 4 Canadian Provinces. Future coverage of established routes will enable changes in the abundance of North American breeding birds to be measured. Routes are selected at random on the basis of one-degree blocks of latitude and longitude. Each 241/2-mile route, with 3-minute stops spaced one-half mile apart, is driven by automobile. All birds heard or seen at the stops are recorded on special forms and the data are then transferred to machine punch cards. The average number of birds per route is tabulated by State, along with the total number of each species and the percent of routes and stops upon which they were recorded. Maps are presented showing the range and abundance of selected species. Also, a year-to-year comparison is made of populations of selected species on Maryland routes in 1965 and 1966.

  5. Physiological adaptation in desert birds

    NARCIS (Netherlands)

    Williams, JB; Tieleman, BI; Williams, Joseph B.

    2005-01-01

    We call into question the idea that birds have not evolved unique physiological adaptations to desert environments. The rate at which desert larks metabolize energy is lower than in mesic species within the same family, and this lower rate of living translates into a lower overall energy requirement

  6. Notes on some Sumatran birds

    NARCIS (Netherlands)

    Junge, G.C.A.

    1948-01-01

    During the war I was able to identify some collections of birds from Sumatra, present in the Leiden Museum. These collections were brought together by E. Jacobson and W. C. van Heurn in the Padang Highlands in 1013; by W. Groeneveldt in the same area in 1914 and 1915; bij L. P. Cosquino de Bussy and

  7. Managing a Bird Flu Pandemic

    Science.gov (United States)

    Stover, Del

    2006-01-01

    Concern about a possible bird flu pandemic has grown in the medical community with the spread of the avian flu virus around the globe. Health officials say there is no immediate threat but add that an influenza pandemic occurs every 30 to 40 years, and prudence demands planning now. That planning will increasingly involve local school officials,…

  8. Plastic ingestion in marine-associated bird species from the eastern North Pacific.

    Science.gov (United States)

    Avery-Gomm, S; Provencher, J F; Morgan, K H; Bertram, D F

    2013-07-15

    In addition to monitoring trends in plastic pollution, multi-species surveys are needed to fully understand the pervasiveness of plastic ingestion. We examined the stomach contents of 20 bird species collected from the coastal waters of the eastern North Pacific, a region known to have high levels of plastic pollution. We observed no evidence of plastic ingestion in Rhinoceros Auklet, Marbled Murrelet, Ancient Murrelet or Pigeon Guillemot, and low levels in Common Murre (2.7% incidence rate). Small sample sizes limit our ability to draw conclusions about population level trends for the remaining fifteen species, though evidence of plastic ingestion was found in Glaucous-Winged Gull and Sooty Shearwater. Documenting levels of plastic ingestion in a wide array of species is necessary to gain a comprehensive understanding about the impacts of plastic pollution. We propose that those working with bird carcasses follow standard protocols to assess the levels of plastic ingestion whenever possible.

  9. Genome sequence of a novel H14N7 subtype influenza A virus isolated from a blue-winged teal (Anas discors) harvested in Texas, USA

    Science.gov (United States)

    Ramey, Andy M.; Reeves, Andrew; Poulson, Rebecca L.; Carter, Deborah L.; Davis-Fields, Nicholas; Stallknecht, David E.

    2016-01-01

    We report here the complete genome sequence of a novel H14N7 subtype influenza A virus (IAV) isolated from a blue-winged teal (Anas discors) harvested in Texas, USA. The genomic characteristics of this IAV strain with a previously undetected subtype combination suggest recent viral evolution within the New World wild-bird IAV reservoir.                   

  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. 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.

  12. Velogenic Newcastle disease in imported caged birds.

    Science.gov (United States)

    Clavijo, A; Robinson, Y; Booth, T; Munroe, F

    2000-05-01

    Velogenic Newcastle disease was diagnosed in pet birds intended for importation into Canada. Virological and histopathological examination confirmed the presence of the disease. The group of birds was denied entry into Canada. Similar birds illegally imported are a potential source of velogenic Newcastle disease virus and are a threat to domestic poultry.

  13. Velogenic Newcastle disease in imported caged birds.

    OpenAIRE

    Clavijo, A.; Robinson, Y; Booth, T.; Munroe, F

    2000-01-01

    Velogenic Newcastle disease was diagnosed in pet birds intended for importation into Canada. Virological and histopathological examination confirmed the presence of the disease. The group of birds was denied entry into Canada. Similar birds illegally imported are a potential source of velogenic Newcastle disease virus and are a threat to domestic poultry.

  14. I LIKE LISTENING TO BIRDS SINGING

    Institute of Scientific and Technical Information of China (English)

    刘向勤; 廖明娟

    2002-01-01

    Every early morning, birds' happy singing wakes me up. I get dressed quickly and have a wash and brush up, then watch birds and listen to them singing happily in the trees. The singing of different kinds of birds sounds like a piece of beautiful symphonic music. Birds’singing makes me relaxed and happy and it also recalls me something of the Past.

  15. The Physics of Bird Flight: An Experiment

    Science.gov (United States)

    Mihail, Michael D.; George, Thomas F.; Feldman, Bernard J.

    2008-01-01

    This article describes an experiment that measures the forces acting on a flying bird during takeoff. The experiment uses a minimum of equipment and only an elementary knowledge of kinematics and Newton's second law. The experiment involves first digitally videotaping a bird during takeoff, analyzing the video to determine the bird's position as a…

  16. DNA barcoding of Dutch birds

    Directory of Open Access Journals (Sweden)

    Mansour Aliabadian

    2013-12-01

    Full Text Available The mitochondrial cytochrome c-oxidase subunit I (COI can serve as a fast and accurate marker for the identification of animal species, and has been applied in a number of studies on birds. We here sequenced the COI gene for 387 individuals of 147 species of birds from the Netherlands, with 83 species being represented by >2 sequences. The Netherlands occupies a small geographic area and 95% of all samples were collected within a 50 km radius from one another. The intraspecific divergences averaged 0.29% among this assemblage, but most values were lower; the interspecific divergences averaged 9.54%. In all, 95% of species were represented by a unique barcode, with 6 species of gulls and skua (Larus and Stercorariusat least one shared barcode. This is best explained by these species representing recent radiations with ongoing hybridization. In contrast, one species, the Lesser Whitethroat Sylvia curruca showed deep divergences, averaging 5.76% and up to 8.68% between individuals. These possibly represent two distinct taxa, S. curruca and S. blythi, both clearly separated in a haplotype network analysis. Our study adds to a growing body of DNA barcodes that have become available for birds, and shows that a DNA barcoding approach enables to identify known Dutch bird species with a very high resolution. In addition some species were flagged up for further detailed taxonomic investigation, illustrating that even in ornithologically well-known areas such as the Netherlands, more is to be learned about the birds that are present.

  17. Schemed Power-augmented Flow for Wing-in-ground Effect Craft in Cruise

    Institute of Scientific and Technical Information of China (English)

    YANG Wei; YANG Zhigang

    2011-01-01

    To provide detailed insight into schemed power-angmented flow for wing-in-ground effect (WIG) craft in view of the concept of cruising with power assistance, this paper presents a numerical study.The engine installed before the wing for power-augmented flow is replaced by a simplified engine model in the simulations, and is considered to be equipped with a thrust vector nozzle.Flow features with different deflected nozzle angles are studied.Comparisons are made on aerodynamics to evaluate performance of power-augmented ram (PAR) modes in cruise.Considerable schemes of power-augmented flow in cruise are described.The air blown from the PAR engine accelerates the flow around wing and a high-speed attached flow near the trailing edge is recorded for certain deflected nozzle angles.This effect takes place and therefore the separation is prevented not only at the trailing edge but also on the whole upper side.The realization of suction varies with PAR modes.It is also found that scheme of blowing air under the wing for PAR engine is aerodynamically not efficient in cruise.The power-augmented flow is extremely complicated.The numerical results give clear depiction of the flow.Optimal scheme of power-augmented flow with respect to the craft in cruise depends on the specific engines and the flight regimes.

  18. 3-D flow and scour near a submerged wing dike: ADCP measurements on the Missouri River

    Science.gov (United States)

    Jamieson, E.C.; Rennie, C.D.; Jacobson, R.B.; Townsend, R.D.

    2011-01-01

    Detailed mapping of bathymetry and three-dimensional water velocities using a boat-mounted single-beam sonar and acoustic Doppler current profiler (ADCP) was carried out in the vicinity of two submerged wing dikes located in the Lower Missouri River near Columbia, Missouri. During high spring flows the wing dikes become submerged, creating a unique combination of vertical flow separation and overtopping (plunging) flow conditions, causing large-scale three-dimensional turbulent flow structures to form. On three different days and for a range of discharges, sampling transects at 5 and 20 m spacing were completed, covering the area adjacent to and upstream and downstream from two different wing dikes. The objectives of this research are to evaluate whether an ADCP can identify and measure large-scale flow features such as recirculating flow and vortex shedding that develop in the vicinity of a submerged wing dike; and whether or not moving-boat (single-transect) data are sufficient for resolving complex three-dimensional flow fields. Results indicate that spatial averaging from multiple nearby single transects may be more representative of an inherently complex (temporally and spatially variable) three-dimensional flow field than repeated single transects. Results also indicate a correspondence between the location of calculated vortex cores (resolved from the interpolated three-dimensional flow field) and the nearby scour holes, providing new insight into the connections between vertically oriented coherent structures and local scour, with the unique perspective of flow and morphology in a large river.

  19. Conservation of forest birds: evidence of a shifting baseline in community structure.

    Directory of Open Access Journals (Sweden)

    Chadwick D Rittenhouse

    Full Text Available BACKGROUND: Quantifying changes in forest bird diversity is an essential task for developing effective conservation actions. When subtle changes in diversity accumulate over time, annual comparisons may offer an incomplete perspective of changes in diversity. In this case, progressive change, the comparison of changes in diversity from a baseline condition, may offer greater insight because changes in diversity are assessed over longer periods of times. Our objectives were to determine how forest bird diversity has changed over time and whether those changes were associated with forest disturbance. METHODOLOGY/PRINCIPAL FINDINGS: We used North American Breeding Bird Survey data, a time series of Landsat images classified with respect to land cover change, and mixed-effects models to associate changes in forest bird community structure with forest disturbance, latitude, and longitude in the conterminous United States for the years 1985 to 2006. We document a significant divergence from the baseline structure for all birds of similar migratory habit and nest location, and all forest birds as a group from 1985 to 2006. Unexpectedly, decreases in progressive similarity resulted from small changes in richness (<1 species per route for the 22-year study period and modest losses in abundance (-28.7 - -10.2 individuals per route that varied by migratory habit and nest location. Forest disturbance increased progressive similarity for Neotropical migrants, permanent residents, ground nesting, and cavity nesting species. We also documented highest progressive similarity in the eastern United States. CONCLUSIONS/SIGNIFICANCE: Contemporary forest bird community structure is changing rapidly over a relatively short period of time (e.g., approximately 22 years. Forest disturbance and forest regeneration are primary factors associated with contemporary forest bird community structure, longitude and latitude are secondary factors, and forest loss is a tertiary

  20. The birds-consumers of the fruits and disseminators of Phellodendron Rupr. seeds in the south of Russian Far East

    Directory of Open Access Journals (Sweden)

    V. A. Nechaev

    2016-02-01

    Full Text Available Based on the results of the long-term investigation, carried out in the Russian Far East (Primorye and Khabarovsk Territories, Amur and Sakhalin regions, and published data about bird ecology, the actual material about the birds feeding seeds and berries of the Amur cork-tree, Phellodendron amurense Rupr. and Sakhalin cork-tree, Ph. sachalinensis (Fr. Schmidt Sarg., is given in the article. It has been found 43 carpophagous bird species from 15 families and 5 orders. The cork-tree berries, small roundish juicy fruits with little stones, are eaten by the birds of 40 species from 13 families; basically by Grey-headed Woodpecker – Picus canus, Azure-winged Magpies – Cyanopica cyanus, Bohemian and Japanaese Waxwings – Bombycilla garrulus and B. japonica, Thrushes: Pale Thrush – Turdus pallidus, Eyebrowed Thrush – Turdus obscurus, Grey-backed Thrush – T. hortulorum, Naumann’s Thrush – T. naumanni, and Dusky Thrush – T. eunomus, Eurasian Nuthatch – Sitta europaea, Pallas’s Rose Finch – Carpodacus roseus. The secondary birds – 16 species. On the Sakhalin isl. the Sakhalin cork-tree, Ph. sachalinensis berries are eaten by the birds of 33 species from 12 families, on the South Kuriles (Kunashir isl. – by the birds of 28 species from 11 families. On Sakhalin the berries are eaten basically by the Waxwings (2 species, Dusky and Brown-headed – Turdus chrysolaus – Thrushes, Eurasian Nuthatch, Pallas’s Rose Finch; and secondary birds – 12 species. There are 5 species of the primary birds and 8 species of the secondary birds on the Kunashir isl. A participation of the birds in the dissemination of the cork-tree, Phellodendron Rupr., during seasonal migrations in winter and autumn has been considered. The active birds in the seed distribution are Grey-headed Woodpecker, Azure-winged Magpies, Waxwings, Thrushes and others; while they are eating the berries, the seeds are not damaged in the gastrointestinal tract and pushed

  1. Design and Performance of Insect-Scale Flapping-Wing Vehicles

    Science.gov (United States)

    Whitney, John Peter

    Micro-air vehicles (MAVs)---small versions of full-scale aircraft---are the product of a continued path of miniaturization which extends across many fields of engineering. Increasingly, MAVs approach the scale of small birds, and most recently, their sizes have dipped into the realm of hummingbirds and flying insects. However, these non-traditional biologically-inspired designs are without well-established design methods, and manufacturing complex devices at these tiny scales is not feasible using conventional manufacturing methods. This thesis presents a comprehensive investigation of new MAV design and manufacturing methods, as applicable to insect-scale hovering flight. New design methods combine an energy-based accounting of propulsion and aerodynamics with a one degree-of-freedom dynamic flapping model. Important results include analytical expressions for maximum flight endurance and range, and predictions for maximum feasible wing size and body mass. To meet manufacturing constraints, the use of passive wing dynamics to simplify vehicle design and control was investigated; supporting tests included the first synchronized measurements of real-time forces and three-dimensional kinematics generated by insect-scale flapping wings. These experimental methods were then expanded to study optimal wing shapes and high-efficiency flapping kinematics. To support the development of high-fidelity test devices and fully-functional flight hardware, a new class of manufacturing methods was developed, combining elements of rigid-flex printed circuit board fabrication with "pop-up book" folding mechanisms. In addition to their current and future support of insect-scale MAV development, these new manufacturing techniques are likely to prove an essential element to future advances in micro-optomechanics, micro-surgery, and many other fields.

  2. Mapping global diversity patterns for migratory birds.

    Science.gov (United States)

    Somveille, Marius; Manica, Andrea; Butchart, Stuart H M; Rodrigues, Ana S L

    2013-01-01

    Nearly one in five bird species has separate breeding and overwintering distributions, and the regular migrations of these species cause a substantial seasonal redistribution of avian diversity across the world. However, despite its ecological importance, bird migration has been largely ignored in studies of global avian biodiversity, with few studies having addressed it from a macroecological perspective. Here, we analyse a dataset on the global distribution of the world's birds in order to examine global spatial patterns in the diversity of migratory species, including: the seasonal variation in overall species diversity due to migration; the contribution of migratory birds to local bird diversity; and the distribution of narrow-range and threatened migratory birds. Our analyses reveal a striking asymmetry between the Northern and Southern hemispheres, evident in all of the patterns investigated. The highest migratory bird diversity was found in the Northern Hemisphere, with high inter-continental turnover in species composition between breeding and non-breeding seasons, and extensive regions (at high latitudes) where migratory birds constitute the majority of the local avifauna. Threatened migratory birds are concentrated mainly in Central and Southern Asia, whereas narrow-range migratory species are mainly found in Central America, the Himalayas and Patagonia. Overall, global patterns in the diversity of migratory birds indicate that bird migration is mainly a Northern Hemisphere phenomenon. The asymmetry between the Northern and Southern hemispheres could not have easily been predicted from the combined results of regional scale studies, highlighting the importance of a global perspective.

  3. Urban Bird Feeding: Connecting People with Nature.

    Directory of Open Access Journals (Sweden)

    Daniel T C Cox

    Full Text Available At a time of unprecedented biodiversity loss, researchers are increasingly recognizing the broad range of benefits provided to humankind by nature. However, as people live more urbanized lifestyles there is a progressive disengagement with the natural world that diminishes these benefits and discourages positive environmental behaviour. The provision of food for garden birds is an increasing global phenomenon, and provides a readily accessible way for people to counter this trend. Yet despite its popularity, quite why people feed birds remains poorly understood. We explore three loosely defined motivations behind bird feeding: that it provides psychological benefits, is due to a concern about bird welfare, and/or is due to a more general orientation towards nature. We quantitatively surveyed households from urban towns in southern England to explore attitudes and actions towards garden bird feeding. Each household scored three Likert statements relating to each of the three motivations. We found that people who fed birds regularly felt more relaxed and connected to nature when they watched garden birds, and perceived that bird feeding is beneficial for bird welfare while investing time in minimising associated risks. Finally, feeding birds may be an expression of a wider orientation towards nature. Overall, we found that the feelings of being relaxed and connected to nature were the strongest drivers. As urban expansion continues both to threaten species conservation and to change peoples' relationship with the natural world, feeding birds may provide an important tool for engaging people with nature to the benefit of both people and conservation.

  4. Mapping global diversity patterns for migratory birds.

    Directory of Open Access Journals (Sweden)

    Marius Somveille

    Full Text Available Nearly one in five bird species has separate breeding and overwintering distributions, and the regular migrations of these species cause a substantial seasonal redistribution of avian diversity across the world. However, despite its ecological importance, bird migration has been largely ignored in studies of global avian biodiversity, with few studies having addressed it from a macroecological perspective. Here, we analyse a dataset on the global distribution of the world's birds in order to examine global spatial patterns in the diversity of migratory species, including: the seasonal variation in overall species diversity due to migration; the contribution of migratory birds to local bird diversity; and the distribution of narrow-range and threatened migratory birds. Our analyses reveal a striking asymmetry between the Northern and Southern hemispheres, evident in all of the patterns investigated. The highest migratory bird diversity was found in the Northern Hemisphere, with high inter-continental turnover in species composition between breeding and non-breeding seasons, and extensive regions (at high latitudes where migratory birds constitute the majority of the local avifauna. Threatened migratory birds are concentrated mainly in Central and Southern Asia, whereas narrow-range migratory species are mainly found in Central America, the Himalayas and Patagonia. Overall, global patterns in the diversity of migratory birds indicate that bird migration is mainly a Northern Hemisphere phenomenon. The asymmetry between the Northern and Southern hemispheres could not have easily been predicted from the combined results of regional scale studies, highlighting the importance of a global perspective.

  5. Flow field of flexible flapping wings

    Science.gov (United States)

    Sallstrom, Erik

    The agility and maneuverability of natural fliers would be desirable to incorporate into engineered micro air vehicles (MAVs). However, there is still much for engineers to learn about flapping flight in order to understand how such vehicles can be built for efficient flying. The goal of this study is to develop a methodology for capturing high quality flow field data around flexible flapping wings in a hover environment and to interpret it to gain a better understanding of how aerodynamic forces are generated. The flow field data was captured using particle image velocimetry (PIV) and required that measurements be taken around a repeatable flapping motion to obtain phase-averaged data that could be studied throughout the flapping cycle. Therefore, the study includes the development of flapping devices with a simple repeatable single degree of freedom flapping motion. The acquired flow field data has been examined qualitatively and quantitatively to investigate the mechanisms behind force production in hovering flight and to relate it to observations in previous research. Specifically, the flow fields have been investigated around a rigid wing and several carbon fiber reinforced flexible membrane wings. Throughout the whole study the wings were actuated with either a sinusoidal or a semi-linear flapping motion. The semi-linear flapping motion holds the commanded angular velocity nearly constant through half of each half-stroke while the sinusoidal motion is always either accelerating or decelerating. The flow fields were investigated by examining vorticity and vortex structures, using the Q criterion as the definition for the latter, in two and three dimensions. The measurements were combined with wing deflection measurements to demonstrate some of the key links in how the fluid-structure interactions generated aerodynamic forces. The flow fields were also used to calculate the forces generated by the flapping wings using momentum balance methods which yielded

  6. 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.

  7. Antifatigue properties of dragonfly Pantala flavescens wings.

    Science.gov (United States)

    Li, Xiu-Juan; Zhang, Zhi-Hui; Liang, Yun-Hong; Ren, Lu-Quan; Jie, Meng; Yang, Zhi-Gang

    2014-05-01

    The wing of a dragonfly is thin and light, but can bear high frequent alternating stress and present excellent antifatigue properties. The surface morphology and microstructure of the wings of dragonfly Pantala flavescens were observed using SEM in this study. Based on the biological analysis method, the configuration, morphology, and structure of the vein were studied, and the antifatigue properties of the wings were investigated. The analytical results indicated that the longitudinal veins, cross veins, and membrane of dragonfly wing form a optimized network morphology and spacially truss-like structure which can restrain the formation and propagation of the fatigue cracks. The veins with multilayer structure present high strength, flexibility, and toughness, which are beneficial to bear alternating load during the flight of dragonfly. Through tensile-tensile fatigue failure tests, the results were verified and indicate that the wings of dragonfly P. flavescens have excellent antifatigue properties which are the results of the biological coupling and synergistic effect of morphological and structural factors.

  8. Magnetoreception and baroreception in birds.

    Science.gov (United States)

    O'Neill, Paul

    2013-01-01

    The world as we know it is defined by our senses, although as humans we are equipped to receive and interpret only a fraction of the potential sensory information available. Birds have evolved with different sensory priorities to our own; they can use the Earth's magnetic field as a navigational aid, and are sensitive to slight changes in barometric pressure. These abilities help explain the impressive ability of many bird species to orientate, navigate, and maintain steady altitude during flight over long distances, even in the absence of clear visual cues. This review will explore the history of research into these "avian" senses, highlighting their likely mechanisms of action, underlying neuronal circuitry and evolutionary origins.

  9. 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.

  10. Critical Care of Pet Birds.

    Science.gov (United States)

    Jenkins, Jeffrey Rowe

    2016-05-01

    Successful care of the critical pet bird patient is dependent on preparation and planning and begins with the veterinarian and hospital staff. An understanding of avian physiology and pathophysiology is key. Physical preparation of the hospital or clinic includes proper equipment and understanding of the procedures necessary to provide therapeutic and supportive care to the avian patient. An overview of patient intake and assessment, intensive care environment, and fluid therapy is included.

  11. Aeroelastic Analysis of Modern Complex Wings

    Science.gov (United States)

    Kapania, Rakesh K.; Bhardwaj, Manoj K.; Reichenbach, Eric; Guruswamy, Guru P.

    1996-01-01

    A process is presented by which aeroelastic analysis is performed by using an advanced computational fluid dynamics (CFD) code coupled with an advanced computational structural dynamics (CSD) code. The process is demonstrated on an F/A-18 Stabilator using NASTD (an in-house McDonnell Douglas Aerospace East CFD code) coupled with NASTRAN. The process is also demonstrated on an aeroelastic research wing (ARW-2) using ENSAERO (an in-house NASA Ames Research Center CFD code) coupled with a finite element wing-box structures code. Good results have been obtained for the F/A-18 Stabilator while results for the ARW-2 supercritical wing are still being obtained.

  12. Transonic flow theory of airfoils and wings

    Energy Technology Data Exchange (ETDEWEB)

    Garabedian, P R

    1976-01-01

    Supercritical wing technology is expected to have a significant influence on the next generation of commercial aircraft. Computational fluid dynamics is playing a central role in the development of new supercritical wing sections. One of the principal tools is a fast and reliable code that simulates two-dimensional wind tunnel data for transonic flow at high Reynolds numbers. This is used widely by industry to assess drag creep and drag rise. Codes for the design of shockless airfoils by the hodograph method have not been so well received because they usually require a lot of trial and error. However, a more advanced mathematical approach makes it possible to assign the pressure as a function of the arc length and then obtain a shockless airfoil that nearly achieves the given distribution of pressure. This tool should enable engineers to design families of transonic airfoils more easily both for airplane wings and for compressor blades in cascade.

  13. Gradual assembly of avian body plan culminated in rapid rates of evolution across the dinosaur-bird transition.

    Science.gov (United States)

    Brusatte, Stephen L; Lloyd, Graeme T; Wang, Steve C; Norell, Mark A

    2014-10-20

    The evolution of birds from theropod dinosaurs was one of the great evolutionary transitions in the history of life. The macroevolutionary tempo and mode of this transition is poorly studied, which is surprising because it may offer key insight into major questions in evolutionary biology, particularly whether the origins of evolutionary novelties or new ecological opportunities are associated with unusually elevated "bursts" of evolution. We present a comprehensive phylogeny placing birds within the context of theropod evolution and quantify rates of morphological evolution and changes in overall morphological disparity across the dinosaur-bird transition. Birds evolved significantly faster than other theropods, but they are indistinguishable from their closest relatives in morphospace. Our results demonstrate that the rise of birds was a complex process: birds are a continuum of millions of years of theropod evolution, and there was no great jump between nonbirds and birds in morphospace, but once the avian body plan was gradually assembled, birds experienced an early burst of rapid anatomical evolution. This suggests that high rates of morphological evolution after the development of a novel body plan may be a common feature of macroevolution, as first hypothesized by G.G. Simpson more than 60 years ago.

  14. Active Aeroelastic Tailoring of High-Aspect-Ratio Composite Wings

    Science.gov (United States)

    2005-09-01

    34 - 26000 , ......... . . . ...... . . .... .. .......................... ... - - ----------- 21000 ... ........... ~0 50 LOAD... ISO 5: B s mission....f Figure 5: Basic mission profile 7 Figure 6: Baseline single-wing and joined-wing vehicles 3.1 Baseline vehicles Three sets

  15. Dispersal of invasive Phytolacca americana seeds by birds in an urban garden in China.

    Science.gov (United States)

    Li, Ning; Yang, Wen; Fang, Shubo; Li, Xinhai; Liu, Zhanchen; Leng, Xin; An, Shuqing

    2017-01-01

    Although seed dispersal is a key process determining the regeneration and spread of invasive plant populations, few studies have explicitly addressed the link between dispersal vector behavior and seedling recruitment to gain insight into the invasion process within an urban garden context. We evaluated the role of bird vectors in the dispersal of pokeweed (Phytolacca americana), a North American herb that is invasive in urban gardens in China. Fruiting P. americana attracted both generalist and specialist bird species that fed on and dispersed its seeds. The generalist species Pycnonotus sinensis and Urocissa erythrorhyncha were the most frequent dispersers. Seedling numbers of P. americana were strongly associated with the perching behavior of frugivorous birds. If newly recruited bird species use seedling-safe perching sites, the P. americana will regenerate faster, which would enhance its invasive potential. Based on our observations, we conclude that the 2 main bird vectors, P. sinensis and U. erythrorhyncha, provide potential effective dispersal agents for P. americana. Our results highlight the role of native birds in seed dispersal of invasive plants in urban gardens.

  16. Humeral remodeling and soft tissue injury of the wings caused by backpack harnesses for radio transmitters in New Zealand Takahē (Porphyrio hochstetteri).

    Science.gov (United States)

    Michael, Sarah; Gartrell, Brett; Hunter, Stuart

    2013-07-01

    Backpack harnesses are commonly used to attach radio and satellite transmitters to a wide range of bird species for research and conservation management. They are an integral part of the conservation management of the New Zealand Takahē (Porphyrio hochstetteri), an endangered flightless rail. Radio transmitters mounted on backpack harnesses enable the birds to be tracked in their remaining native range of remote, mountainous Fiordland, New Zealand. We evaluated 26 Takahē retrospectively at necropsy by gross examination, radiography, and computed tomography to assess damage from the backpack harness. Ten birds that had never worn a harness had no evidence of wing injury. Of the 16 birds that had worn a harness, 10 (63%) had superficial soft tissue injury to skin or patagium or more severe injury, such as remodeling of the distal humerus at the harness cord-wing interface, or pathologic fractures. Such injuries are hypothesized to be associated with discomfort, increased risk of infection or fracture, and therefore reduced fitness. These findings have implications for all avian species deployed with backpack harnesses.

  17. Frequency Response of an Aircraft Wing with Discrete Source Damage Using Equivalent Plate Analysis

    Science.gov (United States)

    Krishnamurthy, T.; Eldred, Lloyd B.

    2007-01-01

    An equivalent plate procedure is developed to provide a computationally efficient means of matching the stiffness and frequencies of flight vehicle wing structures for prescribed loading conditions. Several new approaches are proposed and studied to match the stiffness and first five natural frequencies of the two reference models with and without damage. One approach divides the candidate reference plate into multiple zones in which stiffness and mass can be varied using a variety of materials including aluminum, graphite-epoxy, and foam-core graphite-epoxy sandwiches. Another approach places point masses along the edge of the stiffness-matched plate to tune the natural frequencies. Both approaches are successful at matching the stiffness and natural frequencies of the reference plates and provide useful insight into determination of crucial features in equivalent plate models of aircraft wing structures.

  18. Nonlinear, unsteady aerodynamic loads on rectangular and delta wings

    Science.gov (United States)

    Atta, E. H.; Kandil, O. A.; Mook, D. T.; Nayfeh, A. H.

    1977-01-01

    Nonlinear unsteady aerodynamic loads on rectangular and delta wings in an incompressible flow are calculated by using an unsteady vortex-lattice model. Examples include flows past fixed wings in unsteady uniform streams and flows past wings undergoing unsteady motions. The unsteadiness may be due to gusty winds or pitching oscillations. The present technique establishes a reliable approach which can be utilized in the analysis of problems associated with the dynamics and aeroelasticity of wings within a wide range of angles of attack.

  19. Spanwise transition section for blended wing-body aircraft

    Science.gov (United States)

    Hawley, Arthur V. (Inventor)

    1999-01-01

    A blended wing-body aircraft includes a central body, a wing, and a transition section which interconnects the body and the wing on each side of the aircraft. The two transition sections are identical, and each has a variable chord length and thickness which varies in proportion to the chord length. This enables the transition section to connect the thin wing to the thicker body. Each transition section has a negative sweep angle.

  20. Design and aerodynamic characteristics of a span morphing wing

    Science.gov (United States)

    Yu, Yuemin; Liu, Yanju; Leng, Jinsong

    2009-03-01

    Flight vehicles are often designed to function around a primary operating point such as an efficient cruise or a high maneuverability mode. Performance and efficiency deteriorate rapidly as the airplane moves towards other portions of the flight envelope. One solution to this quandary is to radically change the shape of the aircraft. This yields both improved efficiency and a larger flight envelope. This global shape change is an example of morphing aircraft . One concept of morphing is the span morphing wing in which the wingspan is varied to accommodate multiple flight regimes. This type of design allows for at least two discreet modes of the aircraft. The original configuration, in which the extensible portion of the wing is fully retracted, yields a high speed dash mode. Fully extending the wing provides the aircraft with a low speed mode tailored for fine tracking and loiter tasks. This paper discusses the design of a span morphing wing that permits a change in the aspect ratio while simultaneously supporting structural wing loads. The wing cross section is maintained by NACA 4412 rib sections . The span morphing wing was investigated in different configurations. The wing area and the aspect ratio of the span morphing wing increase as the wings pan increases. Computational aerodynamics are used to estimate the performance and dynamic characteristics of each wing shape of this span morphing wing as its wingspan is changed. Results show that in order to obtain the same lift, the conventional wing requires a larger angle of attach(AOA) than that of the span morphing wing.The lift of the span morphing wing increases as the wing span ,Mach number and AOA increases.

  1. Decoupler pylon: wing/store flutter suppressor

    Science.gov (United States)

    Reed, W. H., III (Inventor)

    1982-01-01

    A device for suspending a store from a support such as an aircraft wing and more specifically for increasing the flutter speed of an aircraft flying with attached store and reducing the sensitivity of flutter to changes in the pitch inertia and center of gravity location of the store is described. It comprises softspring where the store pitch mode is decoupled from support modes and a low frequency active control mechanism which maintains store alignment. A pneumatic suspension system both isolates the store in pitch and, under conditions of changing mean load, aligns the store with the wing to which it is attached.

  2. 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.

  3. Titanium honeycomb structure. [for supersonic aircraft wing structure

    Science.gov (United States)

    Davis, R. A.; Elrod, S. D.; Lovell, D. T.

    1972-01-01

    A brazed titanium honeycomb sandwich system for supersonic transport wing cover panels provides the most efficient structure spanwise, chordwise, and loadwise. Flutter testing shows that high wing stiffness is most efficient in a sandwich structure. This structure also provides good thermal insulation if liquid fuel is carried in direct contact with the wing structure in integral fuel tanks.

  4. Influence of grazing and available moisture on breeding densities of grassland birds in the central platte river valley, Nebraska

    Science.gov (United States)

    Kim, D.H.; Newton, W.E.; Lingle, G.R.; Chavez-Ramirez, F.

    2008-01-01

    We investigated the relationship between grassland breeding bird densities and both grazing and available moisture in the central Platte River Valley. Nebraska between 1980 and 1996. We also compared species richness and community similarity of breeding birds in sedge (Carex spp.) meadows and mesic grasslands. Densities of two species had a significant relationship with grazing and six of seven focal species had a significant relationship with available moisture. Bobolink (Dolichonyx oryzivorus) and Brown-headed Cowbird (Molothrus ater) densities were lower in grazed plots compared to ungrazed plots, whereas Red-winged Blackbird (Agelaius phoeniceus) densities were greater in sedge-meadow plots compared to mesic grassland plots. Bobolink, Dickcissel (Spiza americana). and Brown-headed Cowbird were negatively associated with available moisture with breeding densities peaking during the driest conditions. Our results suggest that wet conditions increase species richness for the community through addition of wetland-dependant and wetland-associated birds, but decrease densities of ground-nesting grassland birds in wet-meadow habitats, whereas dry conditions reduce species richness but increase the density of the avian assemblage. We propose that wet-meadow habitats serve as local refugia for grassland-nesting birds during local or regional droughts.

  5. Geographical Barriers and Dispersal Propensity Interact to Limit Range Expansions of Himalayan Birds.

    Science.gov (United States)

    White, Alexander E

    2016-07-01

    Range expansions are limited by two key factors. These are (1) dispersal, which includes a species' intrinsic mobility, geographical barriers, and their interaction; and (2) the ability of a species to persist beyond its current range. I evaluate the role of these in affecting bird species distributions across the Himalayas, under a hypothesis that many species have recently expanded their range out of an eastern Pleistocene refuge. I measured wing shape as a proxy for dispersal ability and topographic complexity across the Himalayas as a proxy for dispersal barriers. As a factor affecting the potential for persistence in novel locations, I compared similarity of a species' climatic envelope in the east, the hypothesized historical refuge, and the west, the location of recent colonization. Climatic similarity, wing shape, and the interaction of topographic complexity with wing shape all contribute significantly to the range extent of a given species. The result highlights the important interaction between morphological and landscape factors in affecting successful range expansions. The two dispersal-related parameters together explain two times the variance explained by climate, but I present additional evidence that other factors besides climate-notably biotic interactions-affect the ability of a species to persist beyond its range.

  6. Computational wing optimization and comparisons with experiment for a semi-span wing model

    Science.gov (United States)

    Waggoner, E. G.; Haney, H. P.; Ballhaus, W. F.

    1978-01-01

    A computational wing optimization procedure was developed and verified by an experimental investigation of a semi-span variable camber wing model in the NASA Ames Research Center 14 foot transonic wind tunnel. The Bailey-Ballhaus transonic potential flow analysis and Woodward-Carmichael linear theory codes were linked to Vanderplaats constrained minimization routine to optimize model configurations at several subsonic and transonic design points. The 35 deg swept wing is characterized by multi-segmented leading and trailing edge flaps whose hinge lines are swept relative to the leading and trailing edges of the wing. By varying deflection angles of the flap segments, camber and twist distribution can be optimized for different design conditions. Results indicate that numerical optimization can be both an effective and efficient design tool. The optimized configurations had as good or better lift to drag ratios at the design points as the best designs previously tested during an extensive parametric study.

  7. Aerodynamic Interactions Between Contralateral Wings and Between Wings and Body of a Model Insect at Hovering and Small Speed Motions

    Institute of Scientific and Technical Information of China (English)

    LIANG Bin; SUN Mao

    2011-01-01

    In this paper,we study the aerodynamic interactions between the contralateral wings and between the body and wings of a model insect,when the insect is hovering and has various translational and rotational motions,using the method numerically solving the Navier-Stokes equations over moving overset grids.The aerodynamic interactional effects are identified by comparing the results of a complete model insect,the corresponding wing pair,single wing and body without the wings.Horizontal,vertical and lateral translations and roll,pitch and yaw rotations at small speeds are considered.The results indicate that for the motions considered,both the interaction between the contralateral wings and the interaction between the body and wings are weak.The changes in the forces and moments of a wing due to the contralateral wing interaction,of the wings due to the presence of the body,and of the body due to the presence of the wings are generally less than 4.5%.Results show that aerodynamic forces of wings and body can be measured or computed separately in the analysis of flight stability and control of hovering insects.

  8. Should Australia Export its Native Birds?

    OpenAIRE

    Kingwell, Ross S.

    1994-01-01

    Commercial export from Australia of native birds, wild or captive bred, is prohibited. This paper firstly describes the current legislation and regulations that restrict the export of native birds and discusses why governments have adopted such a regulatory approach to bird species preservation. Secondly, the paper reviews the debate concerning the export ban, pointing out strengths and weaknesses in arguments and indicating the important role of CITES. Lastly, the paper outlines a new case f...

  9. A checklist of birds of Kerala, India

    Directory of Open Access Journals (Sweden)

    Praveen J

    2015-11-01

    Full Text Available A checklist of birds of Kerala State is presented in this paper.  Accepted English names, scientific binomen, prevalent vernacular names in Malayalam, IUCN conservation status, endemism, Wildlife (Protection Act schedules, and the appendices in the CITES, pertaining to the birds of Kerala are also given.  The State of Kerala has 500 species of birds, 17 of which are endemic to Western Ghats, and 24 species fall under the various threatened categories of IUCN. 

  10. Effects of Grassland Bird Management on Nongame Bird Community Structure and Productivity

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The report includes data on bird/habitat relations, breeding biology, and effects of succession and current management practices on grassland bird communities in the...

  11. Aleutian Islands Coastal Resources Inventory and Environmental Sensitivity Maps: 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 the Aleutian Islands, Alaska....

  12. Grassland bird surveys in support of the Michigan Breeding Bird Atlas II: Final report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Grassland birds, as a group, have suffered the most severe population declines of any other North American birds (Herkert 1995, Herkert et al. 1996). Compared to...

  13. Hybrid Wing Body Configuration Scaling Study

    Science.gov (United States)

    Nickol, Craig L.

    2012-01-01

    The Hybrid Wing Body (HWB) configuration is a subsonic transport aircraft concept with the potential to simultaneously reduce fuel burn, noise and emissions compared to conventional concepts. Initial studies focused on very large applications with capacities for up to 800 passengers. More recent studies have focused on the large, twin-aisle class with passenger capacities in the 300-450 range. Efficiently scaling this concept down to the single aisle or smaller size is challenging due to geometric constraints, potentially reducing the desirability of this concept for applications in the 100-200 passenger capacity range or less. In order to quantify this scaling challenge, five advanced conventional (tube-and-wing layout) concepts were developed, along with equivalent (payload/range/technology) HWB concepts, and their fuel burn performance compared. The comparison showed that the HWB concepts have fuel burn advantages over advanced tube-and-wing concepts in the larger payload/range classes (roughly 767-sized and larger). Although noise performance was not quantified in this study, the HWB concept has distinct noise advantages over the conventional tube-and-wing configuration due to the inherent noise shielding features of the HWB. NASA s Environmentally Responsible Aviation (ERA) project will continue to investigate advanced configurations, such as the HWB, due to their potential to simultaneously reduce fuel burn, noise and emissions.

  14. Aerodynamics of a rigid curved kite wing

    CERN Document Server

    Maneia, Gianmauro; Tordella, Daniela; Iovieno, Michele

    2013-01-01

    A preliminary numerical study on the aerodynamics of a kite wing for high altitude wind power generators is proposed. Tethered kites are a key element of an innovative wind energy technology, which aims to capture energy from the wind at higher altitudes than conventional wind towers. We present the results obtained from three-dimensional finite volume numerical simulations of the steady air flow past a three-dimensional curved rectangular kite wing (aspect ratio equal to 3.2, Reynolds number equal to 3x10^6). Two angles of incidence -- a standard incidence for the flight of a tethered airfoil (6{\\deg}) and an incidence close to the stall (18{\\deg}) -- were considered. The simulations were performed by solving the Reynolds Averaged Navier-Stokes flow model using the industrial STAR-CCM+ code. The overall aerodynamic characteristics of the kite wing were determined and compared to the aerodynamic characteristics of the flat rectangular non twisted wing with an identical aspect ratio and section (Clark Y profil...

  15. Can Wing Tip Vortices Be Accurately Simulated?

    Science.gov (United States)

    2011-07-01

    additional tail buffeting.2 In commercial applications, winglets have been installed on passenger aircraft to minimize vortex formation and reduce lift...air. In military applications, wing tip In commercial applications, winglets have been installed on passenger aircraft to minimize increases with downstream distances.

  16. Conceptual Study of Rotary-Wing Microrobotics

    Science.gov (United States)

    2008-03-27

    xx  I.  Introduction ...Edge TPV Thermo-Photovoltaic CONCEPTUAL STUDY OF ROTARY-WING MICROROBOTICS I. Introduction Flying micro-robots offer unimaginable military...Tweezers 1989 1 cm3 inch robot 1991 Magnetostrictive mover in pipe 1992 Insect-based robot 1993 Ciliary-motion conveyor 1994 Pipe inspection robot

  17. Applications of a transonic wing design method

    Science.gov (United States)

    Campbell, Richard L.; Smith, Leigh A.

    1989-01-01

    A method for designing wings and airfoils at transonic speeds using a predictor/corrector approach was developed. The procedure iterates between an aerodynamic code, which predicts the flow about a given geometry, and the design module, which compares the calculated and target pressure distributions and modifies the geometry using an algorithm that relates differences in pressure to a change in surface curvature. The modular nature of the design method makes it relatively simple to couple it to any analysis method. The iterative approach allows the design process and aerodynamic analysis to converge in parallel, significantly reducing the time required to reach a final design. Viscous and static aeroelastic effects can also be accounted for during the design or as a post-design correction. Results from several pilot design codes indicated that the method accurately reproduced pressure distributions as well as the coordinates of a given airfoil or wing by modifying an initial contour. The codes were applied to supercritical as well as conventional airfoils, forward- and aft-swept transport wings, and moderate-to-highly swept fighter wings. The design method was found to be robust and efficient, even for cases having fairly strong shocks.

  18. Fiber-optically sensorized composite wing

    Science.gov (United States)

    Costa, Joannes M.; Black, Richard J.; Moslehi, Behzad; Oblea, Levy; Patel, Rona; Sotoudeh, Vahid; Abouzeida, Essam; Quinones, Vladimir; Gowayed, Yasser; Soobramaney, Paul; Flowers, George

    2014-04-01

    Electromagnetic interference (EMI) immune and light-weight, fiber-optic sensor based Structural Health Monitoring (SHM) will find increasing application in aerospace structures ranging from aircraft wings to jet engine vanes. Intelligent Fiber Optic Systems Corporation (IFOS) has been developing multi-functional fiber Bragg grating (FBG) sensor systems including parallel processing FBG interrogators combined with advanced signal processing for SHM, structural state sensing and load monitoring applications. This paper reports work with Auburn University on embedding and testing FBG sensor arrays in a quarter scale model of a T38 composite wing. The wing was designed and manufactured using fabric reinforced polymer matrix composites. FBG sensors were embedded under the top layer of the composite. Their positions were chosen based on strain maps determined by finite element analysis. Static and dynamic testing confirmed expected response from the FBGs. The demonstrated technology has the potential to be further developed into an autonomous onboard system to perform load monitoring, SHM and Non-Destructive Evaluation (NDE) of composite aerospace structures (wings and rotorcraft blades). This platform technology could also be applied to flight testing of morphing and aero-elastic control surfaces.

  19. Ecological Sustainability of Birds in Boreal Forests

    Directory of Open Access Journals (Sweden)

    Gerald Niemi

    1998-12-01

    Full Text Available We review characteristics of birds in boreal forests in the context of their ecological sustainability under both natural and anthropogenic disturbances. We identify the underlying ecological factors associated with boreal bird populations and their variability, review the interactions between boreal bird populations and disturbance, and describe some tools on how boreal bird populations may be conserved in the future. The boreal system has historically been an area with extensive disturbance such as fire, insect outbreaks, and wind. In addition, the boreal system is vulnerable to global climate change as well as increasing pressure on forest and water resources. Current knowledge indicates that birds play an important role in boreal forests, and sustaining these populations affords many benefits to the health of boreal forests. Many issues must be approached with caution, including the lack of knowledge on our ability to mimic natural disturbance regimes with management, our lack of understanding on fragmentation due to logging activity, which is different from permanent conversion to other land uses such as agriculture or residential area, and our lack of knowledge on what controls variability in boreal bird populations or the linkage between bird population fluctuations and productivity. The essential role that birds can provide is to clarify important ecological concerns and variables that not only will help to sustain bird populations, but also will contribute to the long-term health of the boreal forest for all species, including humans.

  20. Bird sexing by Fourier transform infrared spectroscopy

    Science.gov (United States)

    Steiner, Gerald; Bartels, Thomas; Krautwald-Junghanns, Maria-Elisabeth; Koch, Edmund

    2010-02-01

    Birds are traditionally classified as male or female based on their anatomy and plumage color as judged by the human eye. Knowledge of a bird's gender is important for the veterinary practitioner, the owner and the breeder. The accurate gender determination is essential for proper pairing of birds, and knowing the gender of a bird will allow the veterinarian to rule in or out gender-specific diseases. Several biochemical methods of gender determination have been developed for avian species where otherwise the gender of the birds cannot be determined by their physical appearances or characteristics. In this contribution, we demonstrate that FT-IR spectroscopy is a suitable tool for a quick and objective determination of the bird's gender. The method is based on differences in chromosome size. Male birds have two Z chromosomes and female birds have a W-chromosome and a Z-chromosome. Each Z-chromosome has approx. 75.000.000 bps whereas the W-chromosome has approx. 260.00 bps. This difference can be detected by FT-IR spectroscopy. Spectra were recorded from germ cells obtained from the feather pulp of chicks as well as from the germinal disk of fertilized but non-bred eggs. Significant changes between cells of male and female birds occur in the region of phosphate vibrations around 1080 and 1120 cm-1.

  1. Capturing birds with mist nets: A review

    Science.gov (United States)

    Keyes, B.E.; Grue, C.E.

    1982-01-01

    Herein we have tried to provide a comprehensive review of mist-netting techniques suitable for both novice and experienced netters. General mist-netting procedures and modifications developed by netters for particular bird species and habitats are included. Factors which influence capture success, including site selection, net specifications and placement, weather, and time of day, are discussed. Guidelines are presented for the care of netted birds and the use of mist-net data in the study of bird communities. The advantages of the use of mist nets over other methods of capturing birds are also discussed.

  2. Birds and bird habitats: guidelines for wind power projects

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-10-15

    Established in 2009, the Green Energy Act aims to increase the use of renewable energy sources including wind, water, solar and bioenergy in Ontario. The development of these resources is a major component of the province's plan, which aims to mitigate the contribution to climate change and to involve the Ontario's economy in the improvement of the quality of the environment. The Green Energy Act also considers as important the implementation of a coordinated provincial approval process, suggesting the integration of all Ministry requirements into a unique process during the evaluation of newly proposed renewable energy projects. The Ministry of the Environment's Renewable Energy Approval Regulation details the requirements for wind power projects involving significant natural features. Birds are an important part of Ontario's biodiversity and, according to the Ministry of Natural Resources, their habitats are considered as significant wildlife habitat (SWH). The Renewable Energy Approval Regulation and this guideline are meant to provide elements and guidance in order to protect bird SWH during the selection of a location of wind power facilities. . 27 refs., 1 tab., 2 figs.

  3. Mercury concentrations in eggs of red-winged blackbirds and tree swallows breeding in Voyageurs National Park, Minnesota

    Science.gov (United States)

    Robin W. Tyser,; Kristofer R. Rolfhus,; James G. Wiener,; Steve K. Windels,; Custer, Thomas W.; Dummer, Paul

    2016-01-01

    Most investigations of the environmental effects of mercury (Hg) have focused on aquatic food webs that include piscivorous fish or wildlife. However, recent investigations have shown that other species, including passerine songbirds, may also be at risk from exposure to methylmercury (MeHg). We quantified Hg concentrations in eggs of two species of songbirds, red-winged blackbirds (Agelaius phoeniceus) and tree swallows (Tachycineta bicolor), nesting in Voyageurs National Park, Minnesota, USA. Geometric mean concentrations of total Hg (THg) were lower in red-winged blackbird eggs [218 and 107 ng/g dry weight (dw) for 2012 and 2013, respectively] than in tree swallow eggs (228 and 300 ng/g dw for 2012 and 2013, respectively), presumably reflecting differences in the trophic positions of these two species. Concentrations of MeHg averaged 98.4 % of THg in red-winged blackbird eggs. Levels of THg observed in this study were well below critical toxicological benchmarks commonly applied to eggs of avian species, suggesting these breeding populations were not adversely affected by exposure to MeHg. In red-winged blackbirds, concentrations of THg in eggs collected in 2012 were twice those in eggs collected in 2013. Hg levels in eggs of both species increased with date of clutch initiation. In red-winged blackbirds, for example, temporal patterns showed that a 3-week delay in clutch initiation increased egg THg by 60 %. These observations indicate that in ovo exposure of wetland birds to MeHg can vary significantly within nesting season as well as between years.

  4. Orientation in birds. Olfactory navigation.

    Science.gov (United States)

    Papi, F

    1991-01-01

    Research work on the olfactory navigation of birds, which has only recently attracted attention, has shown that many wild species rely on an osmotactic mechanism to find food sources, even at a considerable distance. The homing pigeon, the only bird to have been thoroughly investigated with respect to olfactory navigation, has been found to rely on local odours for homeward orientation, and to integrate olfactory cues perceived during passive transportation with those picked up at the release site. It is possible to design experiments in which birds are given false olfactory information, and predictions about the effects of this can be made and tested. Pigeons are able to home from unfamiliar sites because they acquire an olfactory map extending beyond the area they have flown over. The olfactory map is built up by associating wind-borne odours with the direction from which they come; this was shown by experiments which aimed to prevent, limit or alter this association. One aim of the research work has been to test whether pigeons flying over unfamiliar areas also rely or can learn to rely on non-olfactory cues, depending on their local availability, and/or on the methods of rearing and training applied to them. Various evaluations have been made of the results; the most recent experiments, however, confirm that pigeons do derive directional information from atmospheric odours. A neurobiological approach is also in progress; its results show that some telencephalic areas are involved in orientation and olfactory navigation. The lack of any knowledge about the distribution and chemical nature of the odorants which allow pigeons to navigate hinders progress in this area of research.

  5. Genetics of colouration in birds.

    Science.gov (United States)

    Roulin, Alexandre; Ducrest, Anne-Lyse

    2013-01-01

    Establishing the links between phenotype and genotype is of great importance for resolving key questions about the evolution, maintenance and adaptive function of phenotypic variation. Bird colouration is one of the most studied systems to investigate the role of natural and sexual selection in the evolution of phenotypic diversity. Given the recent advances in molecular tools that allow discovering genetic polymorphisms and measuring gene and protein expression levels, it is timely to review the literature on the genetics of bird colouration. The present study shows that melanin-based colour phenotypes are often associated with mutations at melanogenic genes. Differences in melanin-based colouration are caused by switches of eumelanin to pheomelanin production or by changes in feather keratin structure, melanoblast migration and differentiation, as well as melanosome structure. Similar associations with other types of colourations are difficult to establish, because our knowledge about the molecular genetics of carotenoid-based and structural colouration is quasi inexistent. This discrepancy stems from the fact that only melanin-based colouration shows pronounced heritability estimates, i.e. the resemblance between related individuals is usually mainly explained by genetic factors. In contrast, the expression of carotenoid-based colouration is phenotypically plastic with a high sensitivity to variation in environmental conditions. It therefore appears that melanin-based colour traits are prime systems to understand the genetic basis of phenotypic variation. In this context, birds have a great potential to bring us to new frontiers where many exciting discoveries will be made on the genetics of phenotypic traits, such as colouration. In this context, a major goal of our review is to suggest a number of exciting future avenues.

  6. Aircraft energy efficiency laminar flow control wing design study

    Science.gov (United States)

    Bonner, T. F., Jr.; Pride, J. D., Jr.; Fernald, W. W.

    1977-01-01

    An engineering design study was performed in which laminar flow control (LFC) was integrated into the wing of a commercial passenger transport aircraft. A baseline aircraft configuration was selected and the wing geometry was defined. The LFC system, with suction slots, ducting, and suction pumps was integrated with the wing structure. The use of standard aluminum technology and advanced superplastic formed diffusion bonded titanium technology was evaluated. The results of the design study show that the LFC system can be integrated with the wing structure to provide a structurally and aerodynamically efficient wing for a commercial transport aircraft.

  7. Aerodynamics on a transport aircraft type wing-body model

    Science.gov (United States)

    Schmitt, V.

    1982-01-01

    The DFLR-F4 wing-body combination is studied. The 1/38 model is formed by a 9.5 aspect ratio transonic wing and an Airbus A 310 fuselage. The F4 wing geometrical characteristics are described and the main experimental results obtained in the S2MA wind tunnel are discussed. Both wing-fuselage interferences and viscous effects, which are important on the wing due to a high rear loading, are investigated by performing 3D calculations. An attempt is made to find their limitations.

  8. Investigation and design of a C-Wing passenger aircraft

    OpenAIRE

    Karan BIKKANNAVAR; Scholz, Dieter

    2016-01-01

    A novel nonplanar wing concept called C-Wing is studied and implemented on a commercial aircraft to reduce induced drag which has a significant effect on fuel consumption. A preliminary sizing method which employs an optimization algorithm is utilized. The Airbus A320 aircraft is used as a reference aircraft to evaluate design parameters and to investigate the C-Wing design potential beyond current wing tip designs. An increase in aspect ratio due to wing area reduction at 36m span results in...

  9. Junius B. Bird (1907- 1982)

    OpenAIRE

    Morris, Craig

    2014-01-01

    El 2 de abril de 1982 la arqueología andina perdió a uno de sus más distinguidos y queridos arqueólogos. Junius Bouton Bird falleció en la ciudad de Nueva York a la edad de 74 años, luego de una breve batalla con el cáncer. Era Conservador Emérito de Arqueología de Sud América en el Museo Americano de Historia Natural, su residencia científica durante la mayor parte de sus 50 años de vida profesional.

  10. 75 FR 29917 - Migratory Bird Permits; Changes in the Regulations Governing Migratory Bird Rehabilitation

    Science.gov (United States)

    2010-05-28

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AX09 Migratory Bird Permits; Changes in the Regulations Governing Migratory Bird Rehabilitation AGENCY: Fish and Wildlife Service, Interior. ACTION: Final... on October 27, 2003, to create regulations governing migratory bird rehabilitation in the...

  11. 78 FR 35844 - Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for...

    Science.gov (United States)

    2013-06-14

    ... Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AY87 Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for the 2013-14 Hunting Season; Notice of Meetings AGENCY... regulations for certain migratory game birds for the 2013-14 hunting season. This supplement to the...

  12. 76 FR 36508 - Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for...

    Science.gov (United States)

    2011-06-22

    ... Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX34 Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for the 2011-12 Hunting Season; Notice of Meetings AGENCY... regulations for certain migratory game birds for the 2011-12 hunting season. This supplement to the...

  13. 77 FR 42919 - Migratory Bird Hunting; Proposed Frameworks for Early-Season Migratory Bird Hunting Regulations...

    Science.gov (United States)

    2012-07-20

    ... July 20, 2012 Part V Department of the Interior Fish and Wildlife Service 50 CFR Part 20 Migratory Bird Hunting; Proposed Frameworks for Early-Season Migratory Bird Hunting Regulations; Notice of Meetings...; ] DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AX97 Migratory Bird...

  14. 78 FR 67183 - Proposed Information Collection; Migratory Bird Harvest Information Program and Migratory Bird...

    Science.gov (United States)

    2013-11-08

    ... Fish and Wildlife Service Proposed Information Collection; Migratory Bird Harvest Information Program and Migratory Bird Surveys AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice; request for... Bird Treaty Act (16 U.S.C. 703-711) and the Fish and Wildlife Act of 1956 (16 U.S.C. 742d)...

  15. 78 FR 27927 - Migratory Bird Permits; Depredation Order for Migratory Birds in California

    Science.gov (United States)

    2013-05-13

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AY65 Migratory Bird Permits; Depredation Order for Migratory Birds in California AGENCY: Fish and Wildlife Service, Interior. ACTION: Proposed rule. SUMMARY: We propose to revise the regulations that allow control of depredating birds in some counties...

  16. 78 FR 65578 - Migratory Bird Permits; Depredation Order for Migratory Birds in California

    Science.gov (United States)

    2013-11-01

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AY65 Migratory Bird Permits; Depredation Order for Migratory Birds in California AGENCY: Fish and Wildlife Service, Interior. ACTION: Final rule. SUMMARY: We revise the regulations that allow control of depredating birds in California. We specify the counties...

  17. Avian Assemblages at Bird Baths: A Comparison of Urban and Rural Bird Baths in Australia.

    Science.gov (United States)

    Cleary, Gráinne P; Parsons, Holly; Davis, Adrian; Coleman, Bill R; Jones, Darryl N; Miller, Kelly K; Weston, Michael A

    2016-01-01

    Private gardens provide habitat and resources for many birds living in human-dominated landscapes. While wild bird feeding is recognised as one of the most popular forms of human-wildlife interaction, almost nothing is known about the use of bird baths. This citizen science initiative explores avian assemblages at bird baths in private gardens in south-eastern Australia and how this differs with respect to levels of urbanisation and bioregion. Overall, 992 citizen scientists collected data over two, four-week survey periods during winter 2014 and summer 2015 (43% participated in both years). Avian assemblages at urban and rural bird baths differed between bioregions with aggressive nectar-eating species influenced the avian assemblages visiting urban bird baths in South Eastern Queensland, NSW North Coast and Sydney Basin while introduced birds contributed to differences in South Western Slopes, Southern Volcanic Plains and Victorian Midlands. Small honeyeaters and other small native birds occurred less often at urban bird baths compared to rural bird baths. Our results suggest that differences between urban versus rural areas, as well as bioregion, significantly influence the composition of avian assemblages visiting bird baths in private gardens. We also demonstrate that citizen science monitoring of fixed survey sites such as bird baths is a useful tool in understanding large-scale patterns in avian assemblages which requires a vast amount of data to be collected across broad areas.

  18. Large capacity oblique all-wing transport aircraft

    Science.gov (United States)

    Galloway, Thomas L.; Phillips, James A.; Kennelly, Robert A., Jr.; Waters, Mark H.

    1996-01-01

    Dr. R. T. Jones first developed the theory for oblique wing aircraft in 1952, and in subsequent years numerous analytical and experimental projects conducted at NASA Ames and elsewhere have established that the Jones' oblique wing theory is correct. Until the late 1980's all proposed oblique wing configurations were wing/body aircraft with the wing mounted on a pivot. With the emerging requirement for commercial transports with very large payloads, 450-800 passengers, Jones proposed a supersonic oblique flying wing in 1988. For such an aircraft all payload, fuel, and systems are carried within the wing, and the wing is designed with a variable sweep to maintain a fixed subsonic normal Mach number. Engines and vertical tails are mounted on pivots supported from the primary structure of the wing. The oblique flying wing transport has come to be known as the Oblique All-Wing (OAW) transport. This presentation gives the highlights of the OAW project that was to study the total concept of the OAW as a commercial transport.

  19. Multiple cues for winged morph production in an aphid metacommunity.

    Directory of Open Access Journals (Sweden)

    Mohsen Mehrparvar

    Full Text Available Environmental factors can lead individuals down different developmental pathways giving rise to distinct phenotypes (phenotypic plasticity. The production of winged or unwinged morphs in aphids is an example of two alternative developmental pathways. Dispersal is paramount in aphids that often have a metapopulation structure, where local subpopulations frequently go extinct, such as the specialized aphids on tansy (Tanacetum vulgare. We conducted various experiments to further understand the cues involved in the production of winged dispersal morphs by the two dominant species of the tansy aphid metacommunity, Metopeurum fuscoviride and Macrosiphoniella tanacetaria. We found that the ant-tended M. fuscoviride produced winged individuals predominantly at the beginning of the season while the untended M. tanacetaria produced winged individuals throughout the season. Winged mothers of both species produced winged offspring, although in both species winged offspring were mainly produced by unwinged females. Crowding and the presence of predators, effects already known to influence wing production in other aphid species, increased the percentage of winged offspring in M. tanacetaria, but not in M. fuscoviride. We find there are also other factors (i.e. temporal effects inducing the production of winged offspring for natural aphid populations. Our results show that the responses of each aphid species are due to multiple wing induction cues.

  20. Preliminary study of effects of winglets on wing flutter

    Science.gov (United States)

    Doggett, R. V., Jr.; Farmer, M. G.

    1976-01-01

    Some experimental flutter results are presented over a Mach number range from about 0.70 to 0.95 for a simple, swept, tapered, flat-plate wing model having a planform representative of subsonic transport airplanes and for the same wing model equipped with two different upper surface winglets. Both winglets had the same planform and area (about 2 percent of the basic-wing area); however, one weighed about 0.3 percent of the basic-wing weight, and the other weighed about 1.8 percent of the wing weight. The addition of the lighter winglet reduced the wing-flutter dynamic pressure by about 3 percent; the heavier winglet reduced the wing-flutter dynamic pressure by about 12 percent. The experimental flutter results are compared at a Mach number of 0.80 with analytical flutter results obtained by using doublet-lattice and lifting-surface (kernel-function) unsteady aerodynamic theories.

  1. Effects of the mosquito larvicide GB-1111 on red-winged blackbird embryos.

    Science.gov (United States)

    Albers, P H; Hoffman, D J; Buscemi, D M; Melancon, M J

    2003-01-01

    Golden Bear Oil (GB-1111; legal trade name for GB-1313) is a petroleum distillate that is used in the United States and other countries as a larvicide for mosquito suppression. As part of a multi-species evaluation of the potential effects of GB-1111 on birds, red-winged blackbird eggs were collected, artificially incubated, and treated with one of five amounts of GB-1111 varying from 0 to 10 times the expected exposure from a spray application of the maximum recommended amount (X=47 l/ha, 5 gal/ac). The application of 10 X caused a significant reduction in hatching success. A dose-related reduction of hepatic microsomal monooxygenase activity (EROD) was detected. Among body weights, skeletal measurements, and age at death, only crownrump length was different among experimental groups. Overall, the potential hazard to embryos of a representative wetland passerine appears minimal until the application rate exceeds 3 X.

  2. A review of compliant transmission mechanisms for bio-inspired flapping-wing micro air vehicles.

    Science.gov (United States)

    Zhang, C; Rossi, C

    2017-02-15

    Flapping-wing micro air vehicles (FWMAVs) are a class of unmanned aircraft that imitate flight characteristics of natural organisms such as birds, bats, and insects, in order to achieve maximum flight efficiency and manoeuvrability. Designing proper mechanisms for flapping transmission is an extremely important aspect for FWMAVs. Compliant transmission mechanisms have been considered as an alternative to rigid transmission systems due to their lower the number of parts, thereby reducing the total weight, lower energy loss thanks to little or practically no friction among parts, and at the same time, being able to store and release mechanical power during the flapping cycle. In this paper, the state-of-the-art research in this field is dealt upon, highlighting open challenges and research topics. An optimization method for designing compliant transmission mechanisms inspired by the thoraxes of insects is also introduced.

  3. Lead Poisoning in Wild Birds

    Science.gov (United States)

    Lahner, Lesanna L.; Franson, J. Christian

    2009-01-01

    Lead in its various forms has been used for thousands of years, originally in cooking utensils and glazes and more recently in many industrial and commercial applications. However, lead is a potent, potentially deadly toxin that damages many organs in the body and can affect all animals, including humans. By the mid 1990s, lead had been removed from many products in the United States, such as paint and fuel, but it is still commonly used in ammunition for hunting upland game birds, small mammals, and large game animals, as well as in fishing tackle. Wild birds, such as mourning doves, bald eagles, California condors, and loons, can die from the ingestion of one lead shot, bullet fragment, or sinker. According to a recent study on loon mortality, nearly half of adult loons found sick or dead during the breeding season in New England were diagnosed with confirmed or suspected lead poisoning from ingestion of lead fishing weights. Recent regulations in some states have restricted the use of lead ammunition on certain upland game hunting areas, as well as lead fishing tackle in areas frequented by common loons and trumpeter swans. A variety of alternatives to lead are available for use in hunting, shooting sports, and fishing activities.

  4. 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.

  5. 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.

  6. Effect of wing mass in free flight by a butterfly-like 3D flapping wing-body model

    Science.gov (United States)

    Suzuki, Kosuke; Okada, Iori; Yoshino, Masato

    2016-11-01

    The effect of wing mass in free flight of a flapping wing is investigated by numerical simulations based on an immersed boundary-lattice Boltzmann method. We consider a butterfly-like 3D flapping wing-model consisting of two square wings with uniform mass density connected by a rod-shaped body. We simulate free flights of the wing-body model with various mass ratios of the wing to the whole of the model. As a result, it is found that the lift and thrust forces decrease as the mass ratio increases, since the body with a large mass ratio experiences large vertical and horizontal oscillations in one period and consequently the wing tip speed relatively decreases. In addition, we find the critical mass ratio between upward flight and downward flight for various Reynolds numbers. This work was supported by JSPS KAKENHI Grant Number JP16K18012.

  7. The importance of leading edge vortices under simplified flapping flight conditions at the size scale of birds.

    Science.gov (United States)

    Hubel, Tatjana Y; Tropea, Cameron

    2010-06-01

    Over the last decade, interest in animal flight has grown, in part due to the possible use of flapping propulsion for micro air vehicles. The importance of unsteady lift-enhancing mechanisms in insect flight has been recognized, but unsteady effects were generally thought to be absent for the flapping flight of larger animals. Only recently has the existence of LEVs (leading edge vortices) in small vertebrates such as swifts, small bats and hummingbirds been confirmed. To study the relevance of unsteady effects at the scale of large birds [reduced frequency k between 0.05 and 0.3, k=(pifc)/U(infinity); f is wingbeat frequency, U(infinity) is free-stream velocity, and c is the average wing chord], and the consequences of the lack of kinematic and morphological refinements, we have designed a simplified goose-sized flapping model for wind tunnel testing. The 2-D flow patterns along the wing span were quantitatively visualized using particle image velocimetry (PIV), and a three-component balance was used to measure the forces generated by the wings. The flow visualization on the wing showed the appearance of LEVs, which is typically associated with a delayed stall effect, and the transition into flow separation. Also, the influence of the delayed stall and flow separation was clearly visible in measurements of instantaneous net force over the wingbeat cycle. Here, we show that, even at reduced frequencies as low as those of large bird flight, unsteady effects are present and non-negligible and have to be addressed by kinematic and morphological adaptations.

  8. 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

  9. 14 CFR 33.76 - Bird ingestion.

    Science.gov (United States)

    2010-01-01

    ... STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.76 Bird ingestion. (a... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bird ingestion. 33.76 Section 33.76... takeoff thrust or power. (2) The engine inlet throat area as used in this section to determine the...

  10. Fernbank Forest Birds in the Summer.

    Science.gov (United States)

    Schmalz, Georgann

    1991-01-01

    Provided is a listing of the common nesting birds and the neotropical migrant birds with nesting records in the approximate 65 acres of Fernbank Forest which is a preserve of mature urban hardwoods and pines within 10 miles of downtown Atlanta and a relic of what was once a large, uninterrupted tract of the Piedmont forest. (JJK)

  11. 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.

  12. Ability of Slovakian Pupils to Identify Birds

    Science.gov (United States)

    Prokop, Pavol; Rodak, Rastislav

    2009-01-01

    A pupil's ability to identify common organisms is necessary for acquiring further knowledge of biology. We investigated how pupils were able to identify 25 bird species following their song, growth habits, or both features presented simultaneously. Just about 19% of birds were successfully identified by song, about 39% by growth habit, and 45% of…

  13. Two Good Places for Bird Lovers

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    In the middle and lower reaches of the YangtzRiver,Poyang Lake and Dongting Lake are the towbiggest freshwater lakes in China and are also two ofthe most famous bird reserves in the country.Themagnificent scene of the large number of migrantbirds that fly over every winter is attracting more andmore bird lovers.

  14. Pheromones in birds: myth or reality?

    NARCIS (Netherlands)

    Caro, S.P.; Balthazart, J.

    2010-01-01

    Birds are anosmic or at best microsmatic… This misbelief persisted until very recently and has strongly influenced the outcome of communication studies in birds, with olfaction remaining neglected as compared to acoustic and visual channels. However, there is now clear empirical evidence showing tha

  15. 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

  16. Flapping wing micro-aerial-vehicle: Kinematics, membranes, and flapping mechanisms of ornithopter and insect flight

    Directory of Open Access Journals (Sweden)

    Mohd Firdaus Bin Abas

    2016-10-01

    Full Text Available The application of biomimetics in the development of unmanned-aerial-vehicles (UAV has advanced to an exceptionally small scale of nano-aerial-vehicles (NAV, which has surpassed its immediate predecessor of micro-aerial-vehicles (MAV, leaving a vast range of development possibilities that MAVs have to offer. Because of the prompt advancement into the NAV research development, the true potential and challenges presented by MAV development were never solved, understood, and truly uncovered, especially under the influence of transition and low Reynolds number flow characteristics. This paper reviews a part of previous MAV research developments which are deemed important of notification; kinematics, membranes, and flapping mechanisms ranges from small birds to big insects, which resides within the transition and low Reynolds number regimes. This paper also reviews the possibility of applying a piezoelectric transmission used to produce NAV flapping wing motion and mounted on a MAV, replacing the conventional motorized flapping wing transmission. Findings suggest that limited work has been done for MAVs matching these criteria. The preferred research approach has seen bias towards numerical analysis as compared to experimental analysis.

  17. Effects of the mosquito larvicide GB-1111 on red-winged blackbird embryos

    Energy Technology Data Exchange (ETDEWEB)

    Albers, P.H.; Hoffman, D.J.; Buscemi, D.M.; Melancon, M.J

    2003-10-01

    Mosquito larvicide GB-1111 poses a minimal risk to red-winged blackbird embryos when applied according to product label guidance. - Golden Bear Oil (GB-1111; legal trade name for GB-1313) is a petroleum distillate that is used in the United States and other countries as a larvicide for mosquito suppression. As part of a multi-species evaluation of the potential effects of GB-1111 on birds, red-winged blackbird eggs were collected, artificially incubated, and treated with one of five amounts of GB-1111 varying from 0 to 10 times the expected exposure from a spray application of the maximum recommended amount (X=47 l/ha, 5 gal/ac). The application of 10 X caused a significant reduction in hatching success. A dose-related reduction of hepatic microsomal monooxygenase activity (EROD) was detected. Among body weights, skeletal measurements, and age at death, only crownrump length was different among experimental groups. Overall, the potential hazard to embryos of a representative wetland passerine appears minimal until the application rate exceeds 3 X.

  18. Flapping wing micro-aerial-vehicle:Kinematics, membranes, and flapping mechanisms of ornithopter and insect flight

    Institute of Scientific and Technical Information of China (English)

    Mohd Firdaus Bin Abas; Azmin Shakrine Bin Mohd Rafie; Hamid Bin Yusoff; Kamarul Arifin Bin Ahmad

    2016-01-01

    The application of biomimetics in the development of unmanned-aerial-vehicles (UAV) has advanced to an exceptionally small scale of nano-aerial-vehicles (NAV), which has surpassed its immediate predecessor of micro-aerial-vehicles (MAV), leaving a vast range of development possi-bilities that MAVs have to offer. Because of the prompt advancement into the NAV research devel-opment, the true potential and challenges presented by MAV development were never solved, understood, and truly uncovered, especially under the influence of transition and low Reynolds number flow characteristics. This paper reviews a part of previous MAV research developments which are deemed important of notification; kinematics, membranes, and flapping mechanisms ranges from small birds to big insects, which resides within the transition and low Reynolds number regimes. This paper also reviews the possibility of applying a piezoelectric transmission used to pro-duce NAV flapping wing motion and mounted on a MAV, replacing the conventional motorized flapping wing transmission. Findings suggest that limited work has been done for MAVs matching these criteria. The preferred research approach has seen bias towards numerical analysis as com-pared to experimental analysis.

  19. The functional basis of wing patterning in Heliconius butterflies: the molecules behind mimicry.

    Science.gov (United States)

    Kronforst, Marcus R; Papa, Riccardo

    2015-05-01

    Wing-pattern mimicry in butterflies has provided an important example of adaptation since Charles Darwin and Alfred Russell Wallace proposed evolution by natural selection >150 years ago. The neotropical butterfly genus Heliconius played a central role in the development of mimicry theory and has since been studied extensively in the context of ecology and population biology, behavior, and mimicry genetics. Heliconius species are notable for their diverse color patterns, and previous crossing experiments revealed that much of this variation is controlled by a small number of large-effect, Mendelian switch loci. Recent comparative analyses have shown that the same switch loci control wing-pattern diversity throughout the genus, and a number of these have now been positionally cloned. Using a combination of comparative genetic mapping, association tests, and gene expression analyses, variation in red wing patterning throughout Heliconius has been traced back to the action of the transcription factor optix. Similarly, the signaling ligand WntA has been shown to control variation in melanin patterning across Heliconius and other butterflies. Our understanding of the molecular basis of Heliconius mimicry is now providing important insights into a variety of additional evolutionary phenomena, including the origin of supergenes, the interplay between constraint and evolvability, the genetic basis of convergence, the potential for introgression to facilitate adaptation, the mechanisms of hybrid speciation in animals, and the process of ecological speciation.

  20. The Functional Basis of Wing Patterning in Heliconius Butterflies: The Molecules Behind Mimicry

    Science.gov (United States)

    Kronforst, Marcus R.; Papa, Riccardo

    2015-01-01

    Wing-pattern mimicry in butterflies has provided an important example of adaptation since Charles Darwin and Alfred Russell Wallace proposed evolution by natural selection >150 years ago. The neotropical butterfly genus Heliconius played a central role in the development of mimicry theory and has since been studied extensively in the context of ecology and population biology, behavior, and mimicry genetics. Heliconius species are notable for their diverse color patterns, and previous crossing experiments revealed that much of this variation is controlled by a small number of large-effect, Mendelian switch loci. Recent comparative analyses have shown that the same switch loci control wing-pattern diversity throughout the genus, and a number of these have now been positionally cloned. Using a combination of comparative genetic mapping, association tests, and gene expression analyses, variation in red wing patterning throughout Heliconius has been traced back to the action of the transcription factor optix. Similarly, the signaling ligand WntA has been shown to control variation in melanin patterning across Heliconius and other butterflies. Our understanding of the molecular basis of Heliconius mimicry is now providing important insights into a variety of additional evolutionary phenomena, including the origin of supergenes, the interplay between constraint and evolvability, the genetic basis of convergence, the potential for introgression to facilitate adaptation, the mechanisms of hybrid speciation in animals, and the process of ecological speciation. PMID:25953905

  1. Effects of Dragonfly Wing Structure on the Dynamic Performances

    Institute of Scientific and Technical Information of China (English)

    Huaihui Ren; Xishu Wang; Xudong Li; Yinglong Chen

    2013-01-01

    The configurations of dragonfly wings,including the corrugations of the chordwise cross-section,the microstructure of the longitudinal veins and membrane,were comprehensively investigated using the Environmental Scanning Electron Microscopy (ESEM).Based on the experimental results reported previously,the multi-scale and multi-dimensional models with different structural features of dragonfly wing were created,and the biological dynamic behaviors of wing models were discussed through the Finite Element Method (FEM).The results demonstrate that the effects of different structural features on dynamic behaviors of dragonfly wing such as natural frequency/modal,bending/torsional deformation,reaction force/torque are very significant.The corrugations of dragonfly wing along the chordwise can observably improve the flapping frequency because of the greater structural stiffness of wings.In updated model,the novel sandwich microstructure of the longitudinal veins remarkably improves the torsional deformation of dragonfly wing while it has a little effect on the flapping frequency and bending deformation.These integrated structural features can adjust the deformation of wing oneself,therefore the flow field around the wings can be controlled adaptively.The fact is that the flights of dragonfly wing with sandwich microstructure of longitudinal veins are more efficient and intelligent.

  2. Role of wild bird and rodents in the epidemiology of subclinical salmonellosis in finishing pigs.

    Science.gov (United States)

    Andrés-Barranco, Sara; Vico, Juan P; Garrido, Victoria; Samper, Sofía; Herrera-León, Silvia; de Frutos, Cristina; Mainar-Jaime, Raúl C

    2014-09-01

    Wild birds and rodents may play an important role in the dynamics of subclinical pig salmonellosis, either as the introducers of the bacteria into the farm or as receptors of an infection already established in the farm. We tried to gain further insight into the epidemiology of this infection by studying the phenotypic (i.e., serotype and antimicrobial resistance patterns) and molecular characteristics of Salmonella strains isolated from samples collected from pigs and wildlife captured in the vicinity of pig farms. Salmonella-positive pig fecal samples were identified in 56.1% of the 41 farms investigated. Birds shedding Salmonella spp. were detected in 21.4% of the farms despite the low numbers of birds captured in many farms. Most Salmonella isolates from birds (74%) did not show any antimicrobial resistance (AR) pattern and belonged to phage types rarely seen in the pig population (U310, DT56, DT137, DT164), supporting the likely avian source of infection for most birds. The proportion of farms showing Salmonella-infected rodents was higher (46.2%), with Salmonella isolates showing a high homology with those likely originated from pigs. Salmonella-positive environmental samples were found in >50% of the farms, and the characteristics of these Salmonella strains supported the idea of pigs as a major source of Salmonella contamination of the farm environment. Dissemination of Salmonella in pig farms from areas of high Salmonella prevalence appeared to depend to some extent upon rodents and wild birds present in the farm, but the role of rodents in its maintenance seemed to be somewhat more relevant than that of birds. In conclusion, activities aimed at reducing the contact of these wild species with pigs will probably assist in the control of pig salmonellosis. Strict hygienic measures should be considered in areas of high prevalence of infection to lower the high load of environmental contamination.

  3. Ancient origins and multiple appearances of carotenoid-pigmented feathers in birds.

    Science.gov (United States)

    Thomas, Daniel B; McGraw, Kevin J; Butler, Michael W; Carrano, Matthew T; Madden, Odile; James, Helen F

    2014-08-07

    The broad palette of feather colours displayed by birds serves diverse biological functions, including communication and camouflage. Fossil feathers provide evidence that some avian colours, like black and brown melanins, have existed for at least 160 million years (Myr), but no traces of bright carotenoid pigments in ancient feathers have been reported. Insight into the evolutionary history of plumage carotenoids may instead be gained from living species. We visually surveyed modern birds for carotenoid-consistent plumage colours (present in 2956 of 9993 species). We then used high-performance liquid chromatography and Raman spectroscopy to chemically assess the family-level distribution of plumage carotenoids, confirming their presence in 95 of 236 extant bird families (only 36 family-level occurrences had been confirmed previously). Using our data for all modern birds, we modelled the evolutionary history of carotenoid-consistent plumage colours on recent supertrees. Results support multiple independent origins of carotenoid plumage pigmentation in 13 orders, including six orders without previous reports of plumage carotenoids. Based on time calibrations from the supertree, the number of avian families displaying plumage carotenoids increased throughout the Cenozoic, and most plumage carotenoid originations occurred after the Miocene Epoch (23 Myr). The earliest origination of plumage carotenoids was reconstructed within Passeriformes, during the Palaeocene Epoch (66-56 Myr), and not at the base of crown-lineage birds.

  4. Factors affecting the duration of nestling period and fledging order in Tengmalm's owl (Aegolius funereus): effect of wing length and hatching sequence.

    Science.gov (United States)

    Kouba, Marek; Bartoš, Luděk; Korpimäki, Erkki; Zárybnická, Markéta

    2015-01-01

    In altricial birds, the nestling period is an important part of the breeding phase because the juveniles may spend quite a long time in the nest, with associated high energy costs for the parents. The length of the nestling period can be variable and its duration may be influenced by both biotic and abiotic factors; however, studies of this have mostly been undertaken on passerine birds. We studied individual duration of nestling period of 98 Tengmalm's owl chicks (Aegolius funereus) at 27 nests during five breeding seasons using a camera and chip system and radio-telemetry. We found the nestlings stayed in the nest box for 27 - 38 days from hatching (mean ± SD, 32.4 ± 2.2 days). The individual duration of nestling period was negatively related to wing length, but no formally significant effect was found for body weight, sex, prey availability and/or weather conditions. The fledging sequence of individual nestlings was primarily related to hatching order; no relationship with wing length and/or other factors was found in this case. We suggest the length of wing is the most important measure of body condition and individual quality in Tengmalm's owl young determining the duration of the nestling period. Other differences from passerines (e.g., the lack of effect of weather or prey availability on nestling period) are considered likely to be due to different life-history traits, in particular different food habits and nesting sites and greater risk of nest predation among passerines.

  5. Characterization of the atypical karyotype of the black-winged kite Elanus caeruleus (Falconiformes: Accipitridae) by means of classical and molecular cytogenetic techniques.

    Science.gov (United States)

    Bed'Hom, Bertrand; Coullin, Philippe; Guillier-Gencik, Zuzana; Moulin, Sibyle; Bernheim, Alain; Volobouev, Vitaly

    2003-01-01

    The karyotype of the black-winged kite (Elanus caeruleus), a small diurnal raptor living in Africa, Asia and southern Europe, was studied with classical (G-, C-, R-banding, and Ag-NOR staining) and molecular cytogenetic methods, including primed in-situ labelling (PRINS) and fluorescence in-situ hybridization (FISH) with telomeric (TTAGGG) and centromeric DNA repeats. The study revealed that the genome size, measured by flow cytometry (3.1 pg), is in the normal avian range. However, the black-winged kite karyotype is particularly unusual among birds in having a moderate diploid number of 68 chromosomes, and containing only one pair of dot-shaped microchromosomes. Moreover, the macrochromosomes are medium-sized, with the Z and W gonosomes being clearly the largest in the set. C-banding shows that constitutive heterochromatin is located at the centromeric regions of all chromosomes, and that two pairs of small acrocentrics and the pair of microchromosomes are almost entirely heterochromatic and G-band negative. The distribution pattern of a centromeric repeated DNA sequence, as demonstrated by PRINS, follows that of C-heterochromatin. The localization of telomeric sequences by FISH and PRINS reveals many strong telomeric signals but no extratelomeric signal was observed. The atypical organization of the karyotype of the black-winged kite is considered in the context of the modes of karyotypic evolution in birds.

  6. Charge Capacity of Piezoelectric Membrane Wings

    Science.gov (United States)

    Grybas, Matthew; Hubner, J. Paul

    2015-11-01

    Micro air vehicles (MAVs) have small wings often fabricated with flexible frames and membranes. These membranes flex and vibrate. Piezoelectric films have the ability to convert induced stress or strain into electrical energy. Thus, it is of interest to investigate if piezoelectric films can be used as a structural member of an MAV wing and generate both lift and energy through passive vibrations. Both a shaker test and a wind tunnel test have been conducted to characterize and assess energy production and aerodynamic characteristics including lift, drag and efficiency. The piezoelectric film has been successful as a lifting surface and produces a measurable charge. This work was supported by NSF REU Site Award 1358991.

  7. The Crest Wing Wave Energy Device

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Antonishen, Michael Patrick

    This report presents the results of a continuation of an experimental study of the wave energy converting abilities of the Crest Wing wave energy converter (WEC), in the following referred to as ‘Phase 2'. The Crest Wing is a WEC that uses its movement in matching the shape of an oncoming wave...... to generate power. Model tests have been performed using scale models (length scale 1:30), provided by WaveEnergyFyn, in regular and irregular wave states that can be found in Assessment of Wave Energy Devices. Best Practice as used in Denmark (Frigaard et al., 2008). The tests were carried out at Dept....... of Civil Engineering, Aalborg University (AAU) in the 3D deep water wave tank. The displacement and force applied to a power take off system, provided by WaveEnergyFyn, were measured and used to calculate mechanical power available to the power take off....

  8. Interceptive management of winged maxillary central incisors

    Directory of Open Access Journals (Sweden)

    Mamta Dali

    2013-01-01

    Full Text Available Introduction: Winged maxillary incisors are a well-recognized clinical finding, which can result in psychological trauma to children at growing age. Interceptive treatment is usually carried out in mixed dentition period in order to reduce the severity of a developing malocclusion in future. Case Report: This paper reports a case of 6-years-old female patient with winged maxillary central incisor being treated with derotation technique using the beggs brackets along with nance palatal arch space maintainer. Discussion: The major advantages in carrying out this treatment with fixed brackets are the ease with which the force magnitude and vector can be controlled much more precisely than with a removable appliance, minimal discomfort to the patient and reduces the need for patient co-operation.

  9. WOODEN DOOR WINGS OF ADIYAMAN GREAT MOSQUE

    Directory of Open Access Journals (Sweden)

    Muhammet ARSLAN

    2010-06-01

    Full Text Available Woodworking which is in the most important Turk art branches have been used especially in Anatolia land readily. Wooden material that is seen on architectural units such as mimbar, ambo, wings of door and window, lectern has an important particularly with its ornamental figures. Wooden composition on the north and east doors of Adıyaman Great Mosque was built by Dulkadir Principality but regulated again in the last period of Ottoman Empire, is a theme which is exemined detailedly in Turk art. In this article, it is tried to determined ornamentel and tecnical characteristics of wooden door wings of Adıyaman Great Mosque belongs to early XX. century and the place of them in Turk art.

  10. Surveillance of avian influenza viruses in migratory birds in Egypt, 2003-09.

    Science.gov (United States)

    Soliman, Atef; Saad, Magdi; Elassal, Emad; Amir, Ehab; Plathonoff, Chantal; Bahgat, Verina; El-Badry, Maha; Ahmed, Lu'ay S; Fouda, Mostafa; Gamaleldin, Mohammed; Mohamed, Nahed Abd-Elal; Salyer, Stephanie; Cornelius, Claire; Barthel, Robert

    2012-07-01

    Migratory (particularly aquatic) birds are the major natural reservoirs for type A influenza viruses. However, their role in transmitting highly pathogenic avian influenza (HPAI) viruses is unclear. Egypt is a "funnel" zone of wild bird migration pathways from Central Asia and Europe to Eastern and Central Africa ending in South Africa. We sought to detect and isolate avian influenza viruses in migratory birds in Egypt. During September 2003-February 2009, the US Naval Medical Research Unit Number 3, Cairo, Egypt, in collaboration with the Egyptian Ministry of Environment, obtained cloacal swabs from 7,894 migratory birds captured or shot by hunters in different geographic areas in Egypt. Samples were processed by real-time reverse transcriptase PCR for detection of the influenza A matrix gene. Positive samples were processed for virus isolation in specific-pathogen-free embryonated eggs and isolates were subtyped by PCR and partial sequencing. Ninety-five species of birds were collected. Predominant species were Green-Winged Teal (Anas carolinensis; 32.0%, n=2,528), Northern Shoveler (Anas clypeata; 21.4%, n=1,686), and Northern Pintail (Anas acuta; 11.1%, n=877). Of the 7,894 samples, 745 (9.4%) were positive for the influenza A matrix gene (mainly from the above predominant species). Thirteen of the 745 (1.7%) were H5-positive by PCR (11 were low-pathogenic avian influenza and two were HPAI H5N1). The prevalences of influenza A was among regions were 10-15%, except in Middle Egypt (4%). Thirty-nine influenza isolates were obtained from PCR-positive samples. Seventeen subtypes of avian influenza viruses (including H5N1 and H7N7) were classified from 39 isolates using PCR and partial sequencing. Only one HPAI H5N1 was isolated in February 2006, from a wild resident Great Egret (Ardea alba). No major die-offs or sick migratory birds were detected during the study. We identified avian influenza virus subtypes not previously reported in Egypt. The HPAI H5N1 isolated

  11. Autonomous Deicing System For Airplane Wing

    Science.gov (United States)

    Hickman, G. A.; Gerardi, J. J.

    1993-01-01

    Prototype autonomous deicing system for airplane includes network of electronic and electromechanical modules at various locations in wings and connected to central data-processing unit. Small, integrated solid-state device, using long coils installed under leading edge, exciting small vibrations to detect ice and larger vibrations to knock ice off. In extension of concept, outputs of vibration sensors and other sensors used to detect rivet-line fractures, fatigue cracks, and other potentially dangerous defects.

  12. X-38 on B-52 Wing Pylon

    Science.gov (United States)

    1997-01-01

    A unique, close-up view of the X-38 (Crew Return Vehicle) under the wing of NASA's B-52 mothership prior to launch of the lifting-body research vehicle. The photo was taken from the observation window of the B-52 bomber as it banked in flight. The X-38 Crew Return Vehicle (CRV) research project is designed to develop the technology for a prototype emergency crew return vehicle or lifeboat for the International Space Station.

  13. CFD Analysis of UAV Flying Wing

    Directory of Open Access Journals (Sweden)

    Vasile PRISACARIU

    2016-09-01

    Full Text Available Numerical methods for solving equations describing the evolution of 3D fluid experienced a significant development closely related to the progress of information systems. Today, especially in the field of fluid mechanics, numerical simulations allow the study of gas-thermodynamic confirmed by experimental techniques in wind tunnel conditions and actual flight tests for modeling complex aircraft. The article shows a case of numerical analysis of the lifting surface on the UAV type flying wing.

  14. Palaearctic-African Bird Migration

    DEFF Research Database (Denmark)

    Iwajomo, Soladoye Babatola

    investigated the relationship between the timing of autumn migration and climatic variations at local and spatial scale. The first three papers focused on speciesspecific analysis. In them I described the age-specific patterns in biometrics, phenology and migration strategies as well as trends...... of birds from Europe to Africa and opens up the possibility of studying intra-African migration. I have used long-term, standardized autumn ringing data from southeast Sweden to investigate patterns in biometrics, phenology and population trends as inferred from annual trapping totals. In addition, I...... also molt their flight feathers at this location and intraspecific interactions are non-aggressive. The second manuscript investigates whether variations in the timing of migration of wader species at a stopover site in southeast Sweden is influence by local or regional climatic variables...

  15. Correlating Flight Behavior and Radar Measurements for Species Based Classification of Bird Radar Echoes for Wind Energy Site Assessment

    Science.gov (United States)

    Werth, S. P.; Frasier, S. J.

    2015-12-01

    Wind energy is one of the fastest-growing segments of the world energy market, offering a clean and abundant source of electricity. However, wind energy facilities can have detrimental effects on wildlife, especially birds and bats. Monitoring systems based on marine navigation radar are often used to quantify migration near potential wind sites, but the ability to reliably distinguish between bats and different varieties of birds has not been practically achieved. This classification capability would enable wind site selection that protects more vulnerable species, such as bats and raptors. Flight behavior, such as wing beat frequency, changes in speed, or changes in orientation, are known to vary by species [1]. The ability to extract these properties from radar data could ultimately enable a species based classification scheme. In this work, we analyze the relationship between radar measurements and bird flight behavior in echoes from avifauna. During the 2014 fall migration season, the UMass dual polarized weather radar was used to collect low elevation observations of migrating birds as they traversed through a fixed antenna beam. The radar was run during the night time, in clear-air conditions. Data was coherently integrated, and detections of biological targets exceeding an SNR threshold were extracted. Detections without some dominant frequency content (i.e. clear periodicity, potentially the wing beat frequency) were removed from the sample in order to isolate observations suspected to contain a single species or bird. For the remaining detections, measurements including the polarimetric products and the Doppler spectrum were extracted at each time step over the duration of the observation. The periodic and time changing nature of some of these different measurements was found to have a strong correlation with flight behavior (i.e. flapping vs. gliding behavior). Assumptions about flight behavior and orientation were corroborated through scattering

  16. Swim speeds and stroke patterns in wing-propelled divers: a comparison among alcids and a penguin.

    Science.gov (United States)

    Watanuki, Yutaka; Wanless, Sarah; Harris, Mike; Lovvorn, James R; Miyazaki, Masamine; Tanaka, Hideji; Sato, Katsufumi

    2006-04-01

    In diving birds, the volume and resulting buoyancy of air spaces changes with dive depth, and hydrodynamic drag varies with swim speed. These factors are important in the dive patterns and locomotion of alcids that use their wings both for aerial flight and underwater swimming and of penguins that use their wings only for swimming. Using small data-loggers on free-ranging birds diving to 20-30 m depth, we measured depth at 1 Hz and surge and heave accelerations at 32-64 Hz of four species of alcids (0.6-1.0 kg mass) and the smallest penguin species (1.2 kg). Low- and high-frequency components of the fluctuation of acceleration yielded estimates of body angles and stroke frequencies, respectively. Swim speed was estimated from body angle and rate of depth change. Brünnich's (Uria lomvia) and common (Uria aalge) guillemots descended almost vertically, whereas descent of razorbills (Alca torda), rhinoceros auklets (Cerorhinca monocerata) and little penguins (Eudyptula minor) was more oblique. For all species, swim speed during descent was within a relatively narrow range. Above depths of 20-30 m, where they were all positively buoyant, all species ascended without wing stroking. During descent, little penguins made forward accelerations on both the upstroke and downstroke regardless of dive depth. By contrast, descending alcids produced forward accelerations on both upstroke and downstroke at depths of <10 m but mainly on the downstroke at greater depths; this change seemed to correspond to the decrease of buoyancy with increasing depth. The magnitude of surge (forward) acceleration during downstrokes was smaller, and that during upstrokes greater, in little penguins than in alcids. This pattern presumably reflected the proportionally greater mass of upstroke muscles in penguins compared with alcids and may allow little penguins to swim at less variable instantaneous speeds.

  17. Functional analysis of genes differentially expressed in the Drosophila wing disc: role of transcripts enriched in the wing region.

    Science.gov (United States)

    Jacobsen, Thomas L; Cain, Donna; Paul, Litty; Justiniano, Steven; Alli, Anwar; Mullins, Jeremi S; Wang, Chun Ping; Butchar, Jon P; Simcox, Amanda

    2006-12-01

    Differential gene expression is the major mechanism underlying the development of specific body regions. Here we assessed the role of genes differentially expressed in the Drosophila wing imaginal disc, which gives rise to two distinct adult structures: the body wall and the wing. Reverse genetics was used to test the function of uncharacterized genes first identified in a microarray screen as having high levels of expression in the presumptive wing. Such genes could participate in elaborating the specific morphological characteristics of the wing. The activity of the genes was modulated using misexpression and RNAi-mediated silencing. Misexpression of eight of nine genes tested caused phenotypes. Of 12 genes tested, 10 showed effective silencing with RNAi transgenes, but only 3 of these had resulting phenotypes. The wing phenotypes resulting from RNAi suggest that CG8780 is involved in patterning the veins in the proximal region of the wing blade and that CG17278 and CG30069 are required for adhesion of wing surfaces. Venation and apposition of the wing surfaces are processes specific to wing development providing a correlation between the expression and function of these genes. The results show that a combination of expression profiling and tissue-specific gene silencing has the potential to identify new genes involved in wing development and hence to contribute to our understanding of this process. However, there are both technical and biological limitations to this approach, including the efficacy of RNAi and the role that gene redundancy may play in masking phenotypes.

  18. The effects of corrugation and wing planform on the aerodynamic force production of sweeping model insect wings

    Institute of Scientific and Technical Information of China (English)

    Guoyu Luo; Mao Sun

    2005-01-01

    The effects of corrugation and wing planform (shape and aspect ratio) on the aerodynamic force production of model insect wings in sweeping (rotating after an initial start) motion at Reynolds number 200 and 3500 at angle of attack 40° are investigated, using the method of computational fluid dynamics. A representative wing corrugation is considered. Wing-shape and aspect ratio (AR) of ten representative insect wings are considered; they are the wings of fruit fly, cranefly, dronefly, hoverfly, ladybird, bumblebee, honeybee, lacewing (forewing), hawkmoth and dragonfly (forewing), respectively (AR of these wings varies greatly,from 2.84 to 5.45). The following facts are shown.(1) The corrugated and flat-plate wings produce approximately the same aerodynamic forces. This is because for a sweeping wing at large angle of attack, the length scale of the corrugation is much smaller than the size of the separated flow region or the size of the leading edge vortex (LEV). (2) The variation in wing shape can have considerable effects on the aerodynamic force; but it has only minor effects on the force coefficients when the velocity at r2 (the radius of the second moment of wing area) is used as the reference velocity; i.e.the force coefficients are almost unaffected by the variation in wing shape. (3) The effects of AR are remarkably small:when AR increases from 2.8 to 5.5, the force coefficients vary only slightly; flowfield results show that when AR is relatively large, the part of the LEV on the outer part of the wings sheds during the sweeping motion. As AR is increased, on one hand,the force coefficients will be increased due to the reduction of 3-dimensional flow effects; on the other hand, they will be decreased due to the shedding of pan of the LEV; these two effects approximately cancel each other, resulting in only minor change of the force coefficients.

  19. Analysis and Flexible Structural Modeling for Oscillating Wing Utilizing Aeroelasticity

    Institute of Scientific and Technical Information of China (English)

    Shao Ke; Wu Zhigang; Yang Chao

    2008-01-01

    Making use of modal characteristics of the natural vibration of flexible structure to design the oscillating wing aircraft is proposed.A series of equations concerning the oscillating wing of flexible structures are derived. The kinetic equation for aerodynamic force coupled with elastic movement is set up, and relevant formulae are derived. The unsteady aerodynamic one in that formulae is revised. The design principle, design process and range of application of such oscillating wing analytical method are elaborated. A flexible structural oscillating wing model is set up, and relevant time response analysis and frequency response analysis are conducted. The analytical results indicate that adopting the new-type driving way for the oscillating wing will not have flutter problems and will be able to produce propulsive force. Furthermore, it will consume much less power than the fixed wing for generating the same lift.

  20. Video measurements of instantaneous forces of flapping wing vehicles

    Science.gov (United States)

    Jennings, Alan; Mayhew, Michael; Black, Jonathan

    2015-12-01

    Flapping wings for small aerial vehicles have revolutionary potential for maneuverability and endurance. Ornithopters fail to achieve the performance of their biological equivalents, despite extensive research on how animals fly. Flapping wings produce peak forces due to the stroke reversal of the wing. This research demonstrates in-flight measurements of an ornithopter through the use of image processing, specifically measuring instantaneous forces. Results show that the oscillation about the flight path is significant, being about 20% of the mean velocity and up to 10 g's. Results match forces with deformations of the wing to contrast the timing and wing shape of the upstroke and the downstroke. Holding the vehicle fixed (e.g. wind tunnel testing or simulations) structural resonance is affected along with peak forces, also affecting lift. Non-contact, in-flight measurements are proposed as the best method for matching the flight conditions of flapping wing vehicles.