Siga este link para ver outros tipos de publicações sobre o tema: Bird damage.
Artigos de revistas sobre o tema "Bird damage"
Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos
Veja os 50 melhores artigos de revistas para estudos sobre o assunto "Bird damage".
Ao lado de cada fonte na lista de referências, há um botão "Adicionar à bibliografia". Clique e geraremos automaticamente a citação bibliográfica do trabalho escolhido no estilo de citação de que você precisa: APA, MLA, Harvard, Chicago, Vancouver, etc.
Você também pode baixar o texto completo da publicação científica em formato .pdf e ler o resumo do trabalho online se estiver presente nos metadados.
Veja os artigos de revistas das mais diversas áreas científicas e compile uma bibliografia correta.
1
Lindell, Catherine, Melissa Hannay e Benjamin Hawes. "Bird Management in Blueberries and Grapes". Agronomy 8, n.º 12 (7 de dezembro de 2018): 295. http://dx.doi.org/10.3390/agronomy8120295.
Texto completo da fonteResumo:
Bird damage to fruit is a long-standing challenge for growers that imposes significant costs because of yield losses and grower efforts to manage birds. We measured bird damage in ‘Bluecrop’ blueberry fields and Pinot noir vineyards in 2012–2014 in Michigan to investigate how year, grower, and forest cover influenced the proportions of bird damage. We tested whether inflatable tubemen (2013–2014) and a methyl anthranilate spray (2015) reduced bird damage in blueberries, and tested the deterrent effect of inflatable tubemen in grapes (2014). Years when crop yield was lower tended to have a higher damage percentage; for blueberries, bird damage was highest in 2012, and in grapes, damage was highest in 2012 and 2014. Neither blueberry fields nor vineyards with inflatable tubemen showed significantly reduced bird damage, although the blueberry fields showed a non-significant trend toward lower damage in the tubemen blocks. Blueberry field halves treated with the methyl anthranilate spray had equivalent bird damage to untreated halves. Our results correspond to previous work showing that percent bird damage varies by year, which was likely because bird consumption of fruit is relatively constant over time, while fruit yield varies. Fruit growers should expect a higher proportion of bird damage in low-fruit contexts, such as low-yield years, and prepare to invest more in bird management at those times. Investigating patterns of bird damage and testing deterrent strategies remain challenges. Bird activity is spatially and temporally variable, and birds’ mobility necessitates tests at large scales.
2
Honda, Takeshi. "Exploiting Scanning Behavior for Predators Can Reduce Rice Damage Caused by Birds". International Journal of Zoology 2015 (2015): 1–3. http://dx.doi.org/10.1155/2015/568494.
Texto completo da fonteResumo:
Rice is often damaged by birds, especially sparrows, in Asia. Bird nets are sometimes used as countermeasures; however this approach is expensive and labor intensive. For this reason, farmers generally eschew bird nets, even though no alternative countermeasures are available. This study focused on exploiting the bird behavior of scanning for predators to reduce crop damage. When birds forage for seeds on the ground they often stop pecking and briefly raise their heads, apparently to scan for predators. Low visibility habitats increase scanning behavior and increased scanning behavior reduces habitat quality from the bird’s perspective; therefore, this study tested the relationship between rice damage rate and visibility at the periphery of rice fields, where tree sparrows rest after feeding. Overall, low visibility reduced damage to rice. Because visibility was mainly affected by weeds, weed management techniques contribute to crop damage management. To reduce damage, weeding can be decreased; therefore, this technique is cost- and labor-efficient.
3
Coleman, J., e E. B. Spurr. "Farmer perceptions of bird damage and control in arable crops". New Zealand Plant Protection 54 (1 de agosto de 2001): 184–87. http://dx.doi.org/10.30843/nzpp.2001.54.3719.
Texto completo da fonteResumo:
One hundred arable farmers from across New Zealand were randomly selected and interviewed in summer 2000 to assess their perceptions of the nature and extent of bird damage to their crops the bird species involved the factors affecting the level of damage and the type and cost of any bird control undertaken Most farmers considered birds caused serious damage to their crops with wheat barley peas and some speciality seed crops such as brassicas borage and evening primrose most at risk Damage was rarely perceived to exceed 5 in cereals but was often higher in speciality crops It was most severe at seed maturation The birds responsible for most of the damage were house sparrows and greenfinches Most farmers undertook some form of bird control to protect their crops with shooting gas guns and avicides most commonly used The overall expenditure on bird control was far less than the value of the damage reported
4
Jun, Liu. "Dynamic Damage of Aircraft Wing Leading Edge Impacted by Birds". Applied Mechanics and Materials 385-386 (agosto de 2013): 292–95. http://dx.doi.org/10.4028/www.scientific.net/amm.385-386.292.
Texto completo da fonteResumo:
In order to verify the preliminary design of Aircraft Wing Leading Edge structures to bird impacting loads. The tests of bird impacting on Wing Leading Edge structure configurations were carried out using the relevant experimental facility. The impacting velocity was measured by laser velocity finder. The structure configuration was impacted by bird on three points and the whole process of dynamic deformation and damage on bird and Wing Leading Edge structure were recorded using high speed camera system. The test results showed that the leading edge slat was weak in anti-bird impacting and can not satisfy the airworthiness certification requirements. At the meantime the test results provid abundant experimental validation datas for the numerical simulation model applied in birds impacting.
5
Zafante, Matthew, e Steve Hampton. "LOST BIRD-YEARS: QUANTIFYING BIRD INJURIES IN NATURAL RESOURCE DAMAGE ASSESSMENTS FOR OIL SPILLS1". International Oil Spill Conference Proceedings 2005, n.º 1 (1 de maio de 2005): 1019–23. http://dx.doi.org/10.7901/2169-3358-2005-1-1019.
Texto completo da fonteResumo:
ABSTRACT Large oil spills routinely impact hundreds or even thousands of birds. In order to determine the compensation that responsible parties owe the public, trustee agencies typically examine the number of live and dead birds collected to estimate total bird mortality caused by the spill (Ford et al., 1987). In these natural resource damage assessments (NRDA), compensation is typically based upon the potential ecological benefits that flow from a restoration project. In the case of a bird kill, final compensation is based upon the cost of implementing a restoration project and not upon a dollar value per bird. The dominant paradigm for calculating compensatory restoration for bird injuries is Resource Equivalency Analysis (REA). This paper begins by providing a brief overview of REA when applied to birds. We then examine the REA implications of varying the level of mortality, baseline variability, and demographic variables in a simple population model that tracks both injured and baseline population levels. After finding no evidence that these factors necessarily produce short recovery times, we summarize two general approaches for calculating lost bird-years. We conclude that short recovery times (e.g., one-year) are unlikely for birds when using individual-based measures of injury. Further, we believe that recovery times may be much longer than currently calculated for situations where plausible “recovery mechanisms” cannot be defined.
6
Peisley, Rebecca K., Manu E. Saunders e Gary W. Luck. "Cost-benefit trade-offs of bird activity in apple orchards". PeerJ 4 (30 de junho de 2016): e2179. http://dx.doi.org/10.7717/peerj.2179.
Texto completo da fonteResumo:
Birds active in apple orchards in south–eastern Australia can contribute positively (e.g., control crop pests) or negatively (e.g., crop damage) to crop yields. Our study is the first to identify net outcomes of these activities, using six apple orchards, varying in management intensity, in south–eastern Australia as a study system. We also conducted a predation experiment using real and artificial codling moth (Cydia pomonella) larvae (a major pest in apple crops). We found that: (1) excluding birds from branches of apple trees resulted in an average of 12.8% more apples damaged by insects; (2) bird damage to apples was low (1.9% of apples); and (3) when trading off the potential benefits (biological control) with costs (bird damage to apples), birds provided an overall net benefit to orchard growers. We found that predation of real codling moth larvae was higher than for plasticine larvae, suggesting that plasticine prey models are not useful for inferring actual predation levels. Our study shows how complex ecological interactions between birds and invertebrates affect crop yield in apples, and provides practical strategies for improving the sustainability of orchard systems.
7
Yamaguchi, Yasuhiro, Hoshiko Yoshida, Masayuki Saito e Midori Saeki. "Bird damage to sunflower harvest". Japanese Journal of Ornithology 61, n.º 1 (2012): 124–29. http://dx.doi.org/10.3838/jjo.61.124.
Texto completo da fonte
8
Daugovish, Oleg, e Michi Yamomoto. "(112) Bird Control in Production Strawberries with Falconry". HortScience 41, n.º 4 (julho de 2006): 1047C—1047. http://dx.doi.org/10.21273/hortsci.41.4.1047c.
Texto completo da fonteResumo:
California leads national strawberry fruit production with annual value in Ventura County alone near $300 million. Bird damage to fruit routinely accounts for 3–5% losses and may exceed 50% in some fields. Conventional bird control tools have limited or no effect on fruit damage and may contribute to noise pollution. A four-site study at Oxnard, Calif., from Jan. to Apr. 2005 (highest value fresh market season) showed that release of Peregrine, Saker, or Barbary falcons in combination with helium balloon launching (site 4) in response to fruit damage reduced fruit damage from 80–90% to 15–20% after 1 week. When fruit damage increased again (>20%) a repeated 1-week daily program completely reduced fruit damage during the rest of the season. Falconry alone at site 2 (near man-made structures) for two consecutive days reduced fruit damage from 70–80% to 10–20%, however, at site 3, near giant reed, three weeks of daily releases did not eliminate the damage, but confined it to the strawberry beds adjacent to reed shelter (reducing overall damage from 100% to 25–50%). High frequency of release is likely unfeasible and destruction of shelter habitat may be justified. Falconry alone before damage occurrence (site 1) seemed to prevent fruit damage; however, lack of birds and fruit damage before, during, and after releases made it difficult to draw conclusions about the success of the preventive program. In April, no fruit damage occurred even during bird presence suggesting the change in their diet. The study showed that seed-eating birds were the main pests at Oxnard, Calif., and that trained falcons can disperse them, thus, reducing fruit damage. The success of falconry was site-specific and depended on proximity of suitable habitat and availability of food sources for pest birds.
9
Wang, Jinfeng, e Edwin E. Herricks. "Risk Assessment of Bird–Aircraft Strikes at Commercial Airports". Transportation Research Record: Journal of the Transportation Research Board 2266, n.º 1 (janeiro de 2012): 78–84. http://dx.doi.org/10.3141/2266-09.
Texto completo da fonteResumo:
Bird strikes are a continuing problem in aviation. Despite the number and severity of reported bird strikes, quantification of the effect of contributory factors has been limited because of the absence of data, especially data on bird activity around airfields. The purpose of this study is to provide initial insight into this important problem by combining a number of databases and information resources available at the Seattle–Tacoma International Airport in Washington, including airplane operations, bird strike reports, and the avian radar data on bird movements. Logistic regression and multinomial regression models were used to analyze, respectively, bird strike occurrence and severity. The results indicate that bird track density and airplane movement frequency significantly correlate with bird strike occurrence. High altitude and cloudy weather increase the probability of serious damage. Airplanes weighing less than 27,000 kg and those with turbofan engines and struck positions including tail and light move the propensity toward minor damage compared with no damage. Factors such as single-engine airplanes, medium and large birds, and strikes occurring at engines and wings increase the chance of both serious and minor damage. The findings of this study could provide support for potential changes in airport bird hazard management, airplane operations, and engineering designs of engines and airframes. The study highlights the importance of managing accurate bird strike reports and applying new statistical approaches as more data become available.
10
Curtis, Paul D., Ian A. Merwin, Marvin P. Pritts e David V. Peterson. "Chemical Repellents and Plastic Netting for Reducing Bird Damage to Sweet Cherries, Blueberries, and Grapes". HortScience 29, n.º 10 (outubro de 1994): 1151–55. http://dx.doi.org/10.21273/hortsci.29.10.1151.
Texto completo da fonteResumo:
We conducted 3 years of field tests comparing two chemicals [methyl anthranilate (MA, a natural compound used as a flavor additive) and Keyplex-350 (a proprietary micronutrient formulation)] that were reported to repel birds to exclusionary plastic netting and nontreated plots. Cumulative fruit damage from birds was monitored on sweet and tart cherry (Prunus avium L. and P. cerasus L.), blueberry (Vaccinium corymbosum L.), and wine grapes (Vitis vinifera × labrusca). Initial MA formulations caused injury to fruit and foliage. Two modified MA formulations with microencapsulation and photooxidation inhibitors provided significant reductions in bird damage and fruit splitting on sweet cherries in one of four experiments. A taste panel could not detect MA residues on sweet cherries at harvest. Bird damage was slightly reduced in MA-treated grapes, but damage to blueberries was similar in MA and control treatments. Keyplex did not deter birds from feeding on fruit and caused blemishes on and an unpleasant flavor in treated fruit. Many bird species were observed feeding on these fruit crops during successive years at the three experimental sites. Although these two chemicals have the potential to deter bird depredation, our work suggests that neither is consistently effective against all the frugivorous species in the northeastern United States. Chemical name used: 2-Aminobenzoic acid methyl ester [methyl anthranilate (MA)].
11
Markovic, Maja, e Ksenija Palic. "Natural enemies of fish as cause of economic losses in fish ponds". Veterinarski glasnik 60, n.º 5-6 (2006): 417–21. http://dx.doi.org/10.2298/vetgl0606417m.
Texto completo da fonteResumo:
The presence of natural enemies of fish can result in huge economic damage to fish ponds. Direct damages result from the fact that ichthyophagous bird species are capable of eating large quantities of fish in a short time interval, or can cause mechanical injuries to fish which later on become ideal places for the development of secondary infections. In the surviving fish, depending on the depth of the lesions, the healing process takes place either by regeneration or substitution. More serious, bigger damaged areas heal with a scar that can lead to the deforming of parts of the body, and consumers find such fish, which are generally used for human consumption, repellent. According to Schaperclaus, birds can cause even more than 60% losses in carp breeding ponds, in particular in objects where carp fry are maintained. Indirect damages occur when the bird organs are inhabited by larvae or other forms of parasites, which reach the water through feces, and later become fish pathogens through transitory hosts.
12
Luck, Gary W., Shannon Triplett e Peter G. Spooner. "Bird use of almond plantations: implications for conservation and production". Wildlife Research 40, n.º 6 (2013): 523. http://dx.doi.org/10.1071/wr13079.
Texto completo da fonteResumo:
Context Farmland crops may suffer damage from native animals, but also provide a critical resource during times of food scarcity. We know little about bird use of almond crops. Aims To examine factors influencing temporal and spatial variation in the use of almond crops in north-western Victoria by bird species, including the threatened regent parrot (Polytelis anthopeplus), and to record levels of crop damage. Methods We measured bird occurrence in 15 transects during the almond-growing season of 2009/10, and 32 transects during 2010/11. Crop-damage assessments were conducted in 2010/11. Spatio-temporal variation in bird occurrence was related to seasonal factors, landscape variables and bird-control activities. Key results Significantly more regent parrots and small parrots (e.g. Platycercus elegans and Psephotus haematonotus) were recorded in almond plantations in 2009/10 than in 2010/11. Rainfall and wheat production was much higher in 2010/11, and we hypothesise that the availability of alternative foods reduced parrot dependence on almonds. Regent parrot occurrence did not differ across months within a season, but more small parrots were recorded during almond nut maturity. Regent parrots appeared to prefer locations where almond crops abutted native vegetation, but only during 2009/10, a dry year with likely limited food availability. Small parrots occurred more often in crops close to riverine vegetation and distant from farm offices. Nut damage was generally low, with only 7 of 32 transects sustaining >4% total damage, but damage assessments were conducted during a season of high rainfall, with likely greater availability of alternative food. Percentage damage was significantly correlated with the number of regent and small parrots. Shooting activity did not deter birds from using almond crops. Conclusions Parrots appear to rely more on almond crops for food when environmental conditions limit other food resources. A key strategy for managing bird impacts on almonds while supporting species conservation is to provide decoy crops of preferred native plants. Implications Rapid loss of almond plantations may lead to population declines in the threatened regent parrot if the availability of alternative food is not simultaneously increased. The role of production land uses in supporting native birds needs to be recognised by conservation management agencies.
13
Sausse, Christophe, e Myriam Lévy. "Bird damage to sunflower: international situation and prospects". OCL 28 (2021): 34. http://dx.doi.org/10.1051/ocl/2021020.
Texto completo da fonteResumo:
Bird damage to sunflowers (Helianthus annuus) degrades the profitability of this crop and calls into question its place in rotations. Our international literature review shows that sunflower is one of the crops most vulnerable to bird attacks. However, these predatory pests are not specialized: if the sunflower is affected in one region, then the other crops sharing the same cycle could also be affected to varying degrees. All production areas are affected by flowerhead damage at maturity. Damage at emergence has recently become more visible in France, Italy and Switzerland, probably as a result of global changes and evolving farming practices. Birds are highly mobile pests with complex behaviour. The problem needs to be tackled in a hierarchical framework that takes into account field, landscape, and regional scales, along with processes at different timescales from rapid field selection to long term demographic trends. Moreover, the distribution of damage is asymmetrical: few fields are affected, but with a high severity. At this time, there is no single effective method for preventing damage, and coordination at the landscape scale should be initiated to find potential solutions. Finally, there is a gap between theoretical and applied knowledge, even though initiatives in North America have helped to move research forward. These difficulties imply an integrated approach combining partially effective methods, the association of several stakeholders, and the coordination of several policies (agricultural, environmental, and recreational hunting or wildlife management). Additionally, data collection appears essential to acquire knowledge about economic damage and efficacy of control programmes. Digital technology can be useful for such purposes. Finally, this review advocates international networking to consolidate a research community on this topic and on the wider issue of bird damage to crops.
14
Bhusal, Santosh, Kapil Khanal, Shivam Goel, Manoj Karkee e Matthew Edmund Taylor. "Bird Deterrence in a Vineyard Using an Unmanned Aerial System (UAS)". Transactions of the ASABE 62, n.º 2 (2019): 561–69. http://dx.doi.org/10.13031/trans.12923.
Texto completo da fonteResumo:
Abstract. Washington State growers lose more than $80 million annually to bird damage in fruit crops such as cherries, grapes, Honeycrisp apples, and blueberries. Conventional bird deterrence techniques, such as netting, auditory devices, visual devices, chemical application, falconry, and shooting, are either costly, ineffective, or harmful to birds. At the same time, unmanned aerial systems (UAS) have become popular in military, civilian, and agricultural applications due to decreasing cost, good maneuverability, and their ability to perform multiple types of missions. This article presents an approach using UAS to deter birds and minimize their damage to wine grapes. A quadcopter UAS was flown for three days in September 2016 over a section (30 m × 30 m) of a vineyard to deter birds. The test section of the vineyard was next to a canyon with many trees that provided shelter for a large number of birds. The experimental design included different deterrence methods against birds, including auditory deterrence, visual deterrence, and varying UAS flight patterns. The test section of the vineyard was under continuous video surveillance from 7:00 to 9:00 a.m. using four GoPro cameras for five continuous days, including three days when the UAS was flown. A Gaussian mixture model-based motion detection algorithm was used to detect birds in the videos, a Kalman filter was then used for tracking the detected birds, and bird activities (incoming and outgoing birds) were counted based on the movement of birds across the plot boundary. Two accuracy measures (precision and recall) were calculated to analyze the performance of the automated bird detection and counting system. The results showed that the proposed system achieved a precision of 84% and recall of 87% in counting incoming and outgoing birds. The automated bird counting system was then used to evaluate the performance of the UAS-based bird deterrence system. The results showed that bird activity was more than 300% higher on days with no UAS flights compared to days when the UAS was flown with on-board bird deterrence measures. UAS flights covering the entire experimental plot with auditory deterrence had a better effect than flights with visual deterrence. The results showed the potential for developing an automated bird deterrence system for vineyards and other crops. Extended studies with multi-year, multi-field, and multi-platform experiments are essential to further validate the results. Keywords: Bird deterrence, Fruit crops, Machine vision, Unmanned aerial systems, Vineyards.
15
Shnayder, Elena P., Elvira G. Nikolenko e Igor V. Karyakin. "Electrocutions of Bids on Power Lines in the Khakassia Republic, Russia, in 2020". Raptors Conservation, n.º 41 (2020): 26–63. http://dx.doi.org/10.19074/1814-8654-2020-41-26-63.
Texto completo da fonteResumo:
The article represents results of inspection of power lines for bird casualty in the Minusinsk Hollow, Khakassia, Russia in 2020. Previous inspection was done in the region in 2011 thus our work reveals changes in bird casualty over the last 10 years. The bird mortality on power lines of medium voltage remains remarkably high – mean value for the breeding season is 8.21 ind. per 1 km of line. The most dangerous lines are the ones on concrete poles with pin insulators located in open habitats away from human settlements. Lines of this type attract vast abundance of birds with high species diversity including high percentage of birds of prey and owls. Short lines protruding in the open terrain and parts of lines running through hilly landscapes are of extreme danger. Electrocuted birds are mostly represented by Corvids (66%). Raptors made 28% from the total, represented mostly by the common species such as Kestrel (Falco tinnunculus) – 17.7% and Black Kite (Milvus migrans) – 6.5%, that is character for the forest-steppe zone of Russia. Total damage done to nature by 111.5 km of surveyed power lines was accounted for 18 100 000 Rub (about €204 000 or $243 770). The overall damage which could be caused by the power network of Khakassia was estimated as 64 171 440 Rub per year (that is equal to €723 310 or $864 246). This involves death of more than 3 252 birds per year in one small republic. The damage caused by one electricity pole calculated by the actual results of inspection was 10 485.6 Rub, that is at least 10 time higher that the cost of a set of bird-protection devices for a pole. At the end of the article, we gave our recommendations for minimizing the damage.
16
Van Bael, Sunshine A., Peter Bichier e Russell Greenberg. "Bird predation on insects reduces damage to the foliage of cocoa trees (Theobroma cacao) in western Panama". Journal of Tropical Ecology 23, n.º 6 (29 de outubro de 2007): 715–19. http://dx.doi.org/10.1017/s0266467407004440.
Texto completo da fonteResumo:
In the Neotropics, crops that are grown in agroforestry systems with shade trees support high levels of bird diversity compared with crops grown without shade (Estrada & Coates-Estrada 2005, Faria et al. 2006). Several experiments in shaded coffee farms have explored how insectivorous birds reduce herbivore numbers and their damage to plants and have simultaneously approached ecological questions that are applied (e.g. biological control) and basic (e.g. tri-trophic interactions) (Borkhataria et al. 2006, Greenberg et al., Perfecto et al. 2004). Here we used exclosures to test whether birds lower the densities of herbivorous insects and reduce insect damage to cocoa (Theobroma cacao L., Sterculiaceae) foliage in shaded farms of western Panama. Although bird predation has been shown to reduce insect damage to crops in other systems (Mols & Visser 2002), we provide the first test for shade-grown cocoa.
17
Saakian, Alexander. "Theoretical aspects of calculating the main design parameters of an electric bird repeller". АгроЭкоИнфо 5, n.º 47 (22 de setembro de 2021): 8. http://dx.doi.org/10.51419/20215508.
Texto completo da fonteResumo:
The problem of scaring birds, which has turned into a problem of protecting economic objects from biological damage caused by birds, was born in ancient times and remains relevant to this day. Elevators, fishing and animal husbandry facilities, and other agricultural structures have become the favorite habitats of synanthropic birds. The first ones cause irreparable economic damage to agriculture, destroying, in particular, crops in fields and gardens. One of the solutions to this problem, which became the goal of this work, is to increase the efficiency of protecting agricultural facilities from synanthropic birds with the help of electric bird repellents. To carry out this research work, an experimental stand was designed and constructed in the laboratory of the State Agrarian University of the Northern Trans-Urals, which received a positive decision for a patent. With its help, an analytical dependence of the magnitude of the scaring pulse on the mass of the bird was obtained; a method for calculating the minimum and maximum distances of the scaring range for the blue pigeon was developed. Keywords: SYNANTHROPIC BIRDS, AGRICULTURAL STRUCTURES, ELECTRIC BIRD REPELLER, DESIGN PARAMETERS PULSE, ELECTRIC CURRENT, EFFICIENCY
18
Honda, Takeshi, Jun-ichi Tsuboi e Hiroshi Kuwata. "Seeing Is Feeding for the Frugivorous Bird Brown-Eared Bulbul (Microscelis amaurotis)". International Journal of Zoology 2015 (2015): 1–5. http://dx.doi.org/10.1155/2015/869820.
Texto completo da fonteResumo:
We examined feeding behavior by visually blocking fruit to establish a new theory of bird damage management for agricultural practices. Partly or fully invisible clusters of grapes were fixed on a perch. The birds selectively pecked the clearly visible part of the half-visible bag at a pecking count rate of 0.94–1.00 (95% CI). Half-visible bags allowed the birds to look inside like a skirt and detect the initially hidden portions of grapes, which were covered with opaque white bags. However, very few birds pecked at the white bags that were partially covering the grapes. That is, very few birds attempted to eat covered but easily detectable fruits. Only five birds gravitated toward the grapes in the completely covered nontranslucent bags, but they never pecked at them. Our results show that visual blocking could be a promising new technique to prevent bird damage.
19
Metz, Isabel, Thorsten Mühlhausen, Joost Ellerbroek, Dirk Kügler, Hans van Gasteren, Jan Kraemer e Jacco Hoekstra. "Simulation Model to Calculate Bird-Aircraft Collisions and Near Misses in the Airport Vicinity". Aerospace 5, n.º 4 (25 de outubro de 2018): 112. http://dx.doi.org/10.3390/aerospace5040112.
Texto completo da fonteResumo:
Annually, thousands of birds collide with aircraft. The impact usually has lethal consequences for the bird, the involved aircraft can experience severe damage. The highest bird strike risk occurs at low altitudes. Therefore, aircraft within the airport area as well as the adjacent approach and departure corridors are especially vulnerable to collisions with birds. To analyse risk-reducing measures in these areas, a fast-time bird strike simulation environment was developed. An open-source Air Traffic Management simulator was enhanced with a model to represent bird movements and to recognize bird strikes. To confirm the reproducibility of the outcome, Monte Carlo simulations were performed. They included bird movement data from one year and air traffic flight plans for various air traffic volumes. The number of strikes and near misses showed an expected variance within the individual replications. The results indicate that the predictability of the number of strikes and near misses increases with rising number of birds, and rising air traffic intensity. Thus, by considering simulation scenarios including bird movement information from all seasons and a sufficient air traffic volume, the described set-up leads to stable results.
20
Michel, Nicole L., Thomas W. Sherry e Walter P. Carson. "The omnivorous collared peccary negates an insectivore-generated trophic cascade in Costa Rican wet tropical forest understorey". Journal of Tropical Ecology 30, n.º 1 (11 de novembro de 2013): 1–11. http://dx.doi.org/10.1017/s0266467413000709.
Texto completo da fonteResumo:
Abstract:Insectivorous birds and bats often protect plants through density- and trait-mediated cascades, but the degree to which insectivores reduce herbivorous arthropods and leaf damage varies among systems. Top-down interaction strength may be influenced by the biotic and abiotic context, including the presence of vegetation-disturbing animals. We tested two hypotheses: (1) insectivorous birds and bats initiate trophic cascades in tropical rain-forest understorey; and (2) the native, omnivorous collared peccary (Pecari tajacu) negates these cascades via non-trophic effects. We studied the top-down effects of birds and bats on understorey plants in north-eastern Costa Rica using 60 netted exclosures within and outside existing peccary exclosures. Excluding birds and bats increased total arthropod densities by half, both with and without peccaries. Bird/bat exclosures increased Diptera density by 28% and leaf damage by 24% without peccaries, consistent with a trophic cascade. However, bird/bat exclosures decreased Diptera density by 32% and leaf damage by 34% with peccaries, a negation of the trophic cascade. Excluding peccaries increased leaf damage by 43% on plants without birds and bats. This is the first study, to our knowledge, to demonstrate that the non-trophic activity of an omnivorous ungulate can reverse a trophic cascade.
21
Peisley, Rebecca K., Manu E. Saunders e Gary W. Luck. "Providing perches for predatory and aggressive birds appears to reduce the negative impact of frugivorous birds in vineyards". Wildlife Research 44, n.º 4 (2017): 334. http://dx.doi.org/10.1071/wr17028.
Texto completo da fonteResumo:
Context Birds active in vineyards in south-eastern Australia can reduce or enhance crop yields via their foraging activities (e.g. by consuming grapes or by preying on grape-eating species). Aims We examined the effectiveness of artificial perches in encouraging predatory birds into vineyards to scare frugivorous birds and consequently reduce the damage they cause to grapes. Methods We monitored 12 artificial perches for 4 months during the growing season, spread over six vineyards in north-eastern Victoria, and compared bird damage to grapes at these sites with control sites without perches. Key results We found that raptors did not use the artificial perches. However, the large and aggressive Australian magpie (Cracticus tibicen) commonly used perches and we recorded 38513 perch visits by this species. Grapevines around perch sites suffered >50% less grape damage (4.13% damage per bunch) than control sites (8.57% damage per bunch). Conclusions Our results suggest that providing artificial perches in vineyards can play a role in reducing frugivore damage to grapes. However, the effectiveness of perches can vary under different environmental conditions and certain perch types are not suitable for all predatory or aggressive birds. Implications Future research should focus on the potential role of large-bodied and competitively aggressive species such as the Australian magpie in altering the activity of smaller frugivorous birds in vineyards, and also on the optimum height and location of artificial perches within vineyards to increase visitation by other predatory or aggressive bird species.
22
Luck, Gary W. "The net return from animal activity in agro-ecosystems: trading off benefits from ecosystem services against costs from crop damage". F1000Research 2 (12 de novembro de 2013): 239. http://dx.doi.org/10.12688/f1000research.2-239.v1.
Texto completo da fonteResumo:
Animals provide benefits to agriculture through the provision of ecosystem services, but also inflict costs such as damaging crops. These benefits and costs are mostly examined independently, rather than comparing the trade-offs of animal activity in the same system and quantifying the net return from beneficial minus detrimental activities. Here, I examine the net return associated with the activity of seed-eating birds in almond orchards by quantifying the economic costs and benefits of bird consumption of almonds. Pre-harvest, the consumption of harvestable almonds by birds cost growers AUD$57.50 ha-1 when averaged across the entire plantation. Post-harvest, the same bird species provide an ecosystem service by removing mummified nuts from trees that growers otherwise need to remove to reduce threats from fungal infection or insect pest infestations. The value of this ecosystem service ranged from AUD$82.50 ha-1–$332.50 ha-1 based on the replacement costs of mechanical or manual removal of mummified nuts, respectively. Hence, bird consumption of almonds yielded a positive net return of AUD$25–$275 ha-1 averaged across the entire plantation. However, bird activity varied spatially resulting in positive net returns occurring primarily at the edges of crops where activity was higher, compared to negative net returns in crop interiors. Moreover, partial mummy nut removal by birds meant that bird activity may only reduce costs to growers rather than replace these costs completely. Similar cost-benefit trade-offs exist across nature, and quantifying net returns can better inform land management decisions such as when to control pests or promote ecosystem service provision.
23
Luck, Gary W. "The net return from animal activity in agro-ecosystems: trading off benefits from ecosystem services against costs from crop damage". F1000Research 2 (30 de abril de 2014): 239. http://dx.doi.org/10.12688/f1000research.2-239.v2.
Texto completo da fonteResumo:
Animals provide benefits to agriculture through the provision of ecosystem services, but also inflict costs such as damaging crops. These benefits and costs are mostly examined independently, rather than comparing the trade-offs of animal activity in the same system and quantifying the net return from beneficial minus detrimental activities. Here, I examine the net return associated with the activity of seed-eating birds in almond orchards by quantifying the economic costs and benefits of bird consumption of almonds. Pre-harvest, the consumption of harvestable almonds by birds cost growers AUD$57.50 ha-1 when averaged across the entire plantation. Post-harvest, the same bird species provide an ecosystem service by removing mummified nuts from trees that growers otherwise need to remove to reduce threats from fungal infection or insect pest infestations. The value of this ecosystem service ranged from AUD$82.50 ha-1–$332.50 ha-1 based on the replacement costs of mechanical or manual removal of mummified nuts, respectively. Hence, bird consumption of almonds yielded a positive net return of AUD$25–$275 ha-1 averaged across the entire plantation. However, bird activity varied spatially resulting in positive net returns occurring primarily at the edges of crops where activity was higher, compared to negative net returns in crop interiors. Moreover, partial mummy nut removal by birds meant that bird activity may only reduce costs to growers rather than replace these costs completely. Similar cost-benefit trade-offs exist across nature, and quantifying net returns can better inform land management decisions such as when to control pests or promote ecosystem service provision.
24
Sun, Youchao, Yuemei Zhang, Yadong Zhou, Haitao Zhang, Haijun Zeng e Kun Yang. "Evaluating Impact Damage of Flat Composite Plate for Surrogate Bird-Strike Testing of Aeroengine Fan Blade". Journal of Composites Science 5, n.º 7 (30 de junho de 2021): 171. http://dx.doi.org/10.3390/jcs5070171.
Texto completo da fonteResumo:
Bird-strike failure of fan blades is one of the basic challenges for the safety of aircraft engines. Simplified flat blade-like plates are always used for damage mechanism study of composite laminates. One undesirable issue is the failure at the root of clamped flat plates under high-velocity impact. For this purpose, two different strategies were exploited to obtain desirable impact damage distributions, namely the impact location and the boundary condition. Numerical models of the simplified flat blade-like plate and the bird projectile were constructed by using finite element method (FEM) and smoothed particle hydrodynamics (SPH) approaches. The impact damage distributions were comparatively investigated in detail. The numerical results show that changing the boundary condition is the most effective way to obtain preferable impact damages for further failure analysis of real fan blades. Present results will be useful to the future surrogate experimental design of simplified bird-strike testing.
25
Kale, Manoj Ashokrao, Nandkishor Dudhe, Raju Kasambe e Prosun Bhattacharya. "Crop Depredation by Birds in Deccan Plateau, India". International Journal of Biodiversity 2014 (3 de setembro de 2014): 1–8. http://dx.doi.org/10.1155/2014/947683.
Texto completo da fonteResumo:
Extent of crop depredation in agricultural fields of groundnut, pearl millet, peas, sorghum and sunflower was assessed in Pune, Akola and Amravati, the three productive districts of Maharashtra, India. The study included interviews with the farmers, identification of the bird species responsible for the crop depredation and actual field assessment of damage. The problem of crop depredation is severe for the crops mostly during harvesting season. Most farmers were not satisfied with the conventional bird repelling techniques. A maximum depredation was observed by Sorghum crops by house sparrows Passer domesticus, baya weavers Ploceus philippinus, and rose-ringed parakeets Psittacula krameri, accounting to 52% of the total damage. Blue rock pigeons Columba livia damaged 42% of the peas crop (chick peas and pigeon peas), while house sparrows and baya weaver damaged the groundnut crop by 26% in the sampling plots. House sparrow Passer domesticus and baya weaver Ploceus philippinus damaged the groundnut crop in the sampling plots just after the sowing period. The sustainable solution for reducing crop depredation is a need for the farmers and also such techniques will help avoid direct or indirect effects of use of lethal bird control techniques on bird species.
26
Metz, Isabel C., Joost Ellerbroek, Thorsten Mühlhausen, Dirk Kügler e Jacco M. Hoekstra. "The Bird Strike Challenge". Aerospace 7, n.º 3 (13 de março de 2020): 26. http://dx.doi.org/10.3390/aerospace7030026.
Texto completo da fonteResumo:
Collisions between birds and aircraft pose a severe threat to aviation and avian safety. To understand and prevent these bird strikes, knowledge about the factors leading to these bird strikes is vital. However, even though it is a global issue, data availability strongly varies and is difficult to put into a global picture. This paper aims to close this gap by providing an in-depth review of studies and statistics to obtain a concise overview of the bird strike problem in commercial aviation on an international level. The paper illustrates the factors contributing to the occurrence and the potential consequences in terms of effect on flight and damage. This is followed by a presentation of the risk-reducing measures currently in place as well as their limitations. The paper closes with an insight into current research investigating novel methods to prevent bird strikes.
27
Sun, Guang, Dongsheng Wang, Shuyong Gao, Wenliang Cui, Jing Yan, Yu Wang e Jian Wang. "Research on New Artificial-Guided Bird Prevention Device Based on Bird Damage Characteristics". IOP Conference Series: Earth and Environmental Science 267 (8 de junho de 2019): 032096. http://dx.doi.org/10.1088/1755-1315/267/3/032096.
Texto completo da fonte
28
Metz, Isabel C., Joost Ellerbroek, Thorsten Mühlhausen, Dirk Kügler e Jacco M. Hoekstra. "Analysis of Risk-Based Operational Bird Strike Prevention". Aerospace 8, n.º 2 (28 de janeiro de 2021): 32. http://dx.doi.org/10.3390/aerospace8020032.
Texto completo da fonteResumo:
Bird strike prevention in civil aviation has traditionally focused on the airport perimeter. Since the risk of especially damaging bird strikes outside the airport boundaries is rising, this paper investigates the safety potential of operational bird strike prevention involving pilots and controllers. In such a concept, controllers would be equipped with a bird strike advisory system, allowing them to delay departures which are most vulnerable to the consequences of bird strikes in case of high bird strike risk. An initial study has shown the strong potential of the concept to prevent bird strikes in case of perfect bird movement prediction. This paper takes the research to the next level by taking into account the limited predictability of bird tracks. As such, the collision avoidance algorithm is extended to a bird strike risk algorithm. The risk of bird strikes is calculated for birds expected to cross the extended runway center line and to cause aircraft damage upon impact. By specifically targeting these birds and excluding birds lingering on the runway which are taken care of by the local wildlife control, capacity reductions should be limited, and the implementation remain feasible. The extrapolation of bird tracks is performed by simple linear regression based on the bird positions known at the intended take-off times. To calculate the probability of collision, uncertainties resulting from variability in bird velocity and track are included. The study demonstrates the necessity to limit alerts to potentially damaging strikes with birds crossing the extended runway center line to keep the imposed delays tolerable for airports operating at their capacity limits. It is shown that predicting bird movements based on simple linear regression without considering individual bird behavior is insufficient to achieve a safety-effect. Hence, in-depth studies of multi-year bird data to develop bird behavior models and reliable predictions are recommended for future research. This is expected to facilitate the implementation of a bird strike advisory system satisfying both safety and capacity aspects.
29
Dias, Gláucia M., Sara J. Queiroz, Juliana Sanches e Antonio Fernando C. Tombolato. "Mechanical damage on Bird-of-Paradise (Strelitzia reginae) postharvest". Revista Brasileira de Horticultura Ornamental 19, n.º 2 (16 de agosto de 2013): 93. http://dx.doi.org/10.14295/rbho.v19i2.653.
Texto completo da fonteResumo:
<p>The marketing of strelitzia (<em>Strelitzia reginae</em>) has been increasing due to its beauty, exotic colors and high post-harvest longevity. It has potential to increase also in international exports, however this has been limited by the scarcity of information on the flower post-harvest management and packaging. Therefore, this study aimed to further the technology of strelitzia postharvest to maintain high quality of the product and to select a packaging system suitable for export, ensuring high quality to the final consumer. The damages of the stem and the petal color on the buds of Strelitzia reginae were evaluated and it was observed that the stalks harvested with closed buds had extended longevity, while the flower stalks harvested with the first opened button had the highest flower opening rate. As for mechanical damage, the sleeve net protection most affected the visual appearance of the flowers. The cardboard box packaging showed the lowest percentage of damage in the stems.</p>
30
Price, Megan, e Alan Lill. "Does pedestrian traffic affect the composition of ?bush bird? assemblages?" Pacific Conservation Biology 14, n.º 1 (2008): 54. http://dx.doi.org/10.1071/pc080054.
Texto completo da fonteResumo:
Outdoor recreational activities (e.g., bushwalking and bird-watching) can increase participants? environmental awareness, but can also cause environmental damage and impact negatively on wildlife if conducted irresponsibly and/or in large numbers. A field experiment with a before-after-control-impact design conducted in Wyperfeld National Park, Victoria determined whether simulated bushwalking by researchers over a 4-week period had an immediate impact on the composition of breeding bird assemblages on ten 1-ha mallee plots. Birds were surveyed with point counts preand post-intrusion. Species richness, diversity and composition of bird assemblages were unaffected by the pedestrian traffic regime imposed. Results suggest that normal pedestrian traffic in spring and summer may not influence ?bush bird? assemblage composition very markedly in the short-term in Victorian parks. However, the birds could have responded to intrusion, but less dramatically than by leaving the plots. That bushwalking and allied activities may have other adverse effects on the behaviour and physiology of Australian ?bush birds? still needs to be investigated.
31
Tan, D., ZR Lu e JK Liu. "A two-step method for damage identification in beam structures based on influence line difference and acceleration data". Advances in Mechanical Engineering 10, n.º 7 (julho de 2018): 168781401878740. http://dx.doi.org/10.1177/1687814018787404.
Texto completo da fonteResumo:
This article presents a two-step approach for structural damage identification in beam structure. Damages are located using the influence line difference before and after damage, the calculation of damage severity is accomplished by acceleration data and bird mating optimizer algorithm. Local damages are simulated as the reduction of both the elemental Young’s modulus and mass of the beam. The technique for damage localization based on displacement influence line difference and its derivatives for beam structure has been outlined. An objective function that comprises dynamic acceleration is utilized in bird mating optimizer. All data are originated from only a few measurement points. Two numerical examples, namely, a simply supported beam and a four-span continuous beam, are investigated in this article. Identification results from different objective functions are compared with results from objective function conventional modal assurance criterion, which shows the superiority of the proposed function. In addition, results of dynamic responses under different types of excitation are presented. The effect of measurement noise level on damage identification results is studied. Studies in the article indicate that the proposed method is efficient and robust for identifying damages in beam structures.
32
Bhama, Prabhat K., Allen D. Hillel, Albert L. Merati e David Perkel. "Model for Examining Recovery of Phonation after Nerve Damage". Otolaryngology–Head and Neck Surgery 139, n.º 2_suppl (agosto de 2008): P97. http://dx.doi.org/10.1016/j.otohns.2008.05.512.
Texto completo da fonteResumo:
Problem Recurrent laryngeal nerve injury remains a dominant clinical issue in laryngology. To date, no animal model of laryngeal reinnervation has offered an outcome measure that can reflect the degree of recovery based on vocal function. We present an avian model system for studying recovery of learned vocalizations following nerve injury. Methods Digital recordings of bird song were made from 11 adult male zebra finches; 9 underwent bilateral crushing of the nerve supplying the vocal organ, and two birds underwent sham surgery. Song from all birds was then recorded regularly and analyzed based on temporal and spectral characteristics using computer software. Indices were calculated to indicate the degree of similarity between pre-operative and post-operative song. Results Nerve crush caused audible differences in song quality and significant drops (p<0.05) in measured spectral and, to a lesser degree, temporal indices. Spectral indices recovered significantly (mean=43.0%; SD=40.7; p<0.02), and there was an insignificant trend towards recovery of temporal index (mean=28.0%; SD=41.4; p=0.0771). In 5/9(56%) birds, there was a greater than 50% recovery of spectral indices within a four week period. Two birds exhibited substantially less recovery of spectral indices, and two had a persistent decline in spectral indices. Recovery of temporal index was highly variable as well, ranging from persistent further declines of 45.1% to recovery of 87.0%. Neither sham bird exhibited significant (p>0.05) differences in song following nerve crush. Conclusion The songbird model system allows functional analysis of learned vocalization following surgical damage to vocal nerves. Significance The zebra finch provides an animal model for the study of phonatory function following neurolaryngeal injury. Support This project was supported by NIH grant T32DC000018.
33
Avery, Michael L. "Application of Mimicry Theory to Bird Damage Control". Journal of Wildlife Management 49, n.º 4 (outubro de 1985): 1116. http://dx.doi.org/10.2307/3801404.
Texto completo da fonte
34
Fox, N. C., V. P. Saxton, M. C. T. Trought e J. D. Holland. "Falcons for grapes a solution for bird damage". New Zealand Plant Protection 59 (1 de agosto de 2006): 378. http://dx.doi.org/10.30843/nzpp.2006.59.4587.
Texto completo da fonte
35
Kumar Jha, Akhilesh, S. Sathyamoorthy e Viswa Prakash. "Bird strike damage and analysis of UAV’s airframe". Procedia Structural Integrity 14 (2019): 416–28. http://dx.doi.org/10.1016/j.prostr.2019.05.051.
Texto completo da fonte
36
Tasaka, S., M. Kanazawa, C. Kawai, K. Soejima, K. Yamaguchi, A. Takata, C. Torikata e J. Hata. "Fatal Diffuse Alveolar Damage from Bird Fanciers’ Lung". Respiration 64, n.º 4 (1997): 307–9. http://dx.doi.org/10.1159/000196694.
Texto completo da fonte
37
Zhou, Yadong, Youchao Sun e Tianlin Huang. "SPH-FEM Design of Laminated Plies under Bird-Strike Impact". Aerospace 6, n.º 10 (7 de outubro de 2019): 112. http://dx.doi.org/10.3390/aerospace6100112.
Texto completo da fonteResumo:
Composite laminates can potentially reduce the weight of aircrafts; however, they are subjected to bird strike hazards in civil aviation. To handle their nonlinear dynamic behaviour, in this study, the impact damage of composite laminates were numerically evaluated and designed by means of smoothed particle hydrodynamics (SPH) and the finite element method (FEM) to simulate the interaction between bird projectiles and the laminates. Attention was mainly focused on the different damage modes in various laminates’ plies induced by bird impact on a square laminated plate. A continuum damage mechanics approach was exploited to simulate damage initiation and evolution in composite laminates. Damage maps were computed with respect to different ply angles, i.e., 0°, 45° and −45°. The damage distributions were comparatively investigated, and then the ply design was considered for crashworthiness improvement. The results aim to serve as a design guideline for future prototype-scale bird strike studies of complex laminated structures.
38
DINANTI, ROLISKA VIRGO, NURUL LAKSMI WINARNI e JATNA SUPRIATNA. "Vertical stratification of bird community in Cikepuh Wildlife Reserve, West Java, Indonesia". Biodiversitas Journal of Biological Diversity 19, n.º 1 (1 de janeiro de 2018): 134–39. http://dx.doi.org/10.13057/biodiv/d190120.
Texto completo da fonteResumo:
Dinanti RV, Winarni NL, Supriatna J. 2018. Vertical stratification of bird community in Cikepuh Wildlife Reserve, West Java, Indonesia. Biodiversitas 19: 134-139. The complexity of heterogeneous strata can be used to determine the distribution of resources in bird communities. However, deforestation causes damage and may disturb the bird community in the forest. Cikepuh Wildlife Reserve in West Java, Indonesia is an example of degraded forest due to deforestation. Illegal logging in the area leads to approximately 7000 hectares of forest conversion into a plantation area. This study was conducted to test the hypothesis of the differences in the diversity of birds in each stratum of vegetation and the differences in the diversity of birds in forest and plantation. The study was conducted in March 2016. Point count method was used for bird surveys. The calculation of Shannon-Wiener diversity index showed that forest had a higher diversity of birds (Hʹ = 3.09) than plantation (Hʹ = 2.78). Based on the rank abundance graph, each vegetation stratum had a different type of curve. The middle canopy layer had the highest bird abundance while the emergent and understory layers had the lowest abundance.
39
Goriup, Paul D. "Acidic air Pollution and birds in Europe". Oryx 23, n.º 2 (abril de 1989): 82–86. http://dx.doi.org/10.1017/s0030605300022742.
Texto completo da fonteResumo:
Evidence from a survey conducted by the European Continental Section of the International Council for Bird Preservation (ICBP-ECS) suggests that birds have not served as such good early warning indicators of ecological damage from acid precipitation as they have for damage from organochlorine pesticide use. Only a few highly specialized species have been badly affected, and then long after the impact was observed in other organisms. Some birds have even benefited from the superabundance of dead and decaying standing timber.
40
Saniga, M. "Quantitative and qualitative damage caused by mammals and birds to the planting and natural seeding". Journal of Forest Science 49, No. 1 (16 de janeiro de 2012): 37–43. http://dx.doi.org/10.17221/4676-jfs.
Texto completo da fonteResumo:
In the years 1999–2000, I studied damage to transplants in the planting and wildlings in the natural seeding at the locality Zamrlô in the Starohorské vrchy Mts. (750–1,000 m a.s.l., NE exposure, forest type Abieto-Fagetum). Damage to the woody plants by the mammals and birds in the planting was much higher (14%) than in the natural seeding (7%). All woody plant species were also more damaged in the planting (spruce 16%, larch 9%, fir 24%, beech 10%, and sycamore 10%) than in the natural seeding (spruce 7%, larch 6%, fir 10%, beech 7%, and sycamore 9%). There were found 8 mammals that damaged woody plants both in the planting and natural seeding (Apodemus sp., Capreolus capreolus L., Cervus elaphus L., Clethrionomys glareolus SCHREB., Lepus europaeus L., Microtus agrestis L., Microtus arvalis PALL., Sciurus vulgaris L.). Only one bird species was found to damage woody plants in the planting and natural seeding (Tetrao urogallus L.).
41
Imregun, M., e M. Vahdati. "Aeroelasticity analysis of a bird-damaged fan assembly using a large numerical model". Aeronautical Journal 103, n.º 1030 (dezembro de 1999): 569–78. http://dx.doi.org/10.1017/s0001924000064204.
Texto completo da fonteResumo:
Abstract Bird strike is a major consideration when designing fans for civil aero engines. Current methods rely on impact tests and structural optimisation but it is highly desirable to have predictive numerical models to assess the aerodynamic and aeroelastic stability of bird-damaged fan assemblies. A detailed feasibility study towards such a prediction capability, consisting of a CFD solver coupled to a finite element representation of the structure, is reported in this paper. A whole-assembly model was used for both the fluid and the structural domains, an approach necessitated by the loss of cyclic symmetry due to one or more blades undergoing plastic deformation under the effect of the bird impact. It was assumed that two consecutive blades had suffered unequal amount of bird damage, the so-called heavy and medium-damaged blades.
42
Li, Junjie, Yunfeng Lou, Gaoyuan Yu, Tong Li e Xianlong Jin. "Effect of Bird Yaw/Pitch Angles on Soft Impact Damage of a Fan Assembly". Complexity 2021 (16 de janeiro de 2021): 1–13. http://dx.doi.org/10.1155/2021/8879874.
Texto completo da fonteResumo:
This paper presents a numerical investigation of bird attitude angles affecting the soft-impact damage of a full fan assembly. Firstly, considering the geometry of a mallard, a real bird model is established by the Smoothed Particle Hydrodynamics (SPH) method and calibrated with available test data. Then, complying with airworthiness requirements, simulations of a full-bladed fan assembly subjected to a real bird were conducted to determine the critical ingestion parameters (CIP). Furthermore, a real bird with different attitude angles aimed at a full fan assembly was simulated. Results show that attitude angles of the bird produce a significant impact on the effect of the bird strike on rotating blades and would increase the possibility of blade failures, especially for the yaw angle of -45° and the pitch angle of −60°. It is invaluable for commercial airlines and engine manufactures to provide safe flight and landing by adopting the real bird model with critical yaw and pitch angles in the design for resistance to bird ingestion.
43
PESCADOR, M., e S. J. PERIS. "Effects of great bustards (Otis tarda) on cultivated areas in west-central Spain". Journal of Agricultural Science 130, n.º 1 (fevereiro de 1998): 9–15. http://dx.doi.org/10.1017/s0021859697005066.
Texto completo da fonteResumo:
Great bustard (Otis tarda) populations in Spain are located mostly in cultivated areas during winter. The birds concentrate in large flocks and feed on cultivated plants. This paper reports two types of bustard-caused damage which occur in cereal, lucerne and vetch crops in west-central Spain, as a result of grazing and other bird activities such as display. Field work was carried out between 1994 and 1995. Damage to cereal crops was caused during germination and early seedling growth or to young plants, although plants were able to recover from this by regrowth and the overall yield was not reduced. Vetch crops were damaged in localized areas, but these recovered and were useful for forage enrichment or as grain. However, the damage to lucerne plots, although local, was extensive, resulting in yield losses of 23–31% with respect to the total production.
44
Anderson, A., C. A. Lindell, W. F. Siemer e S. A. Shwiff. "The Welfare Impacts of Bird Damage and Its Control in California Wine Grape Production". Journal of Wine Economics 9, n.º 2 (3 de junho de 2014): 153–70. http://dx.doi.org/10.1017/jwe.2014.16.
Texto completo da fonteResumo:
AbstractWe developed a partial equilibrium model to examine the welfare impacts of bird damage and its control in California wine grape production. The model incorporates the impacts of pest damage and its control and allows the impacts to vary regionally. Importantly, the model requires minimal information to apply; only elasticities, current market price and production data, and information on the cost and effectiveness of the pest control methods are needed. We rely on data from a recent survey of California growers and use the model to estimate changes in wine grape prices, production levels, and consumer and producer surplus that result from both bird damage and its control in three grape-growing regions of California. Results suggest that eliminating the threat of bird damage and control costs results in an increase in producer and consumer surplus of 1.3% and 3%, respectively. Furthermore, eliminating current bird control and allowing any resulting damage would decrease producer and consumer surplus by 6.6% and 11.5%, respectively. (JEL Classifications: Q11, Q18, Q57)
45
Langston, Lee S. "New Bird Ingestion Tests?" Mechanical Engineering 140, n.º 05 (1 de maio de 2018): 52–53. http://dx.doi.org/10.1115/1.2018-may-4.
Texto completo da fonteResumo:
This article discusses the significance of bird ingestion in jet engines. Bird strikes occur at various aircraft locations, however, usually inflict most damage to the engines. Airplane damage and effect on flight from bird strikes are closely correlated to kinetic energy, derived from the mass (determined by the bird species) and the velocity of collision squared. The US statistics described in the article show that bird ingestion in commercial jet engines is significant and even more so, when combined with records from the rest of the flight world. Current statistics show that incidents of commercial aircraft jet engine bird ingestion are increasing, and are a continuing challenge over the next decade. Recently, European Aviation Safety Agency, working with other authorities, is proposing additional original equipment manufacturer bird ingestion testing requirements for an engine operating under climb conditions, following the ingestion of a medium sized bird into the engine core. It is also emphasized in the article that there is a need of a new systems approach to adequately mitigate the risks of aircraft and bird occupying the same air space at the same time.
46
Mamashukurov, A. "Place and Role of Some Mass Bird Species in Biological Damage in the Fergana Valley of Uzbekistan". Bulletin of Science and Practice 7, n.º 9 (15 de setembro de 2021): 32–41. http://dx.doi.org/10.33619/2414-2948/70/03.
Texto completo da fonteResumo:
The article provides data on the place and role of some common bird species in the Fergana Valley in biological damage. The reasons for the occurrence of biological damage in birds are discussed, the nature and degree of biological damage caused by white storks, green bee-eaters, myna, Indian and field sparrows on fish farms, power grid enterprises, viticulture and grain crops (wheat and rice) are discussed. Building their huge nests on the poles of high-voltage power lines during the year, white storks make short circuits, which lead to an interruption in the power supply. In the post-nesting period, large flocks of white storks arrive at fish farms. One bird eats an average of 600–800 g of fish per day. During spring and autumn migrations, green bee-eaters gathering at beekeeping farms, one pair per day destroys about 350–400 worker bees. Mynas, after the chicks leave the nests, together with fledglings, flies into the vineyards and, on average, damage 18.5% of the grape harvest. Field and Indian sparrows consume an average of 16.95% of the crop during the milky-wax ripeness of wheat. In rice fields during autumn migrations, the harm from sparrows is 2.1–13.4%. The article also provides data on some of the repellents used in preventing and reducing bio-damage caused by birds, discusses their effectiveness.
47
Liu, Lulu, Gang Luo, Wei Chen, Zhenhua Zhao e Xiong Huang. "Dynamic Behavior and Damage Mechanism of 3D Braided Composite Fan Blade under Bird Impact". International Journal of Aerospace Engineering 2018 (17 de dezembro de 2018): 1–16. http://dx.doi.org/10.1155/2018/5906078.
Texto completo da fonteResumo:
The three-dimensional braided composites, with intertwined fiber bundles in the through-thickness direction, have advantages of high interlaminar shear strength, fracture toughness, and excellent impact resistance, making them a promising material for applications in the field of aeroengine fan blades. As the bird impact behavior of the fan blade directly affects the safety of the aeroengines, it is of great significance to study the dynamic response and damage mechanism of 3D braided composites under bird strike load. In this paper, the bird impact tests on the 3D four-step braided composite targets were carried out using the gas gun system. The effects of impact velocity, impact location, and braiding angle on the bird impact behavior were studied. It is concluded that the damage and failure become more severe with the increasing impact velocity. The whole impact event could be divided into 3 stages, i.e., local deformation stage, postflow impact stage, and bending deflection stage. The braided composite presents flexible characteristics and could bear extraordinary deformation during the bird impact. One distinguishing feature of bird impact damage is the destruction of the clamping root due to bending load caused by cantilever construction. The internal damage form at the impact area was mainly the separation of the fiber bundles from the matrix while the breakage of the fiber bundles and the crushing of the matrix play the primary role at the root part. The target plate impacted at the 70% height had the largest bending angle and most serious damage, followed by those impacted at the 90% and 50% heights. Both the appearance damage and internal damage extent are smallest for 45° braiding composites.
48
Sari, Indah Fitri, Nuning Nurcahyani, M. Kanedi e Tugiyono Tugiyono. "Bird Species Diversity in Liwa Botanical Garden, West Lampung". Jurnal Ilmiah Biologi Eksperimen dan Keanekaragaman Hayati 7, n.º 1 (1 de abril de 2020): 1–6. http://dx.doi.org/10.23960/jbekh.v7i1.5.
Texto completo da fonteResumo:
The diversity of bird species can reflect the high biodiversity of an area. it means that birds can be used as a bio-indicator of environmental quality. Determining the quality and level ofenvironmental damage can be seen from the diversity of bird species in the region. Environmental quality will be better if the diversity of bird species in the region is diverse.Birds have an important role in protecting the ecosystem in the Liwa Botanical Garden. The presence of birds in the Liwa Botanical Garden has not been well identified. Therefore thisresearch needs to be done. This research was conducted on 12 October 2019 to 20 October 2019 in the Liwa Botanical Garden, West Lampung. Data collection of bird species isconducted in the morning at 06.30.00-08.30 West Indonesia Time and afternoon at 16.30-18.00 West Indonesia Time, with a combination of the count point and the transect method then all encounters with birds are recorded and identified directly at the study site. After the birds are identified, data is processed to find out Shannon's level index and diversity index. The species diversity index uses the Shannon and Weiner formula. The level of diversity is determined based on the species diversity index. The results showed that there were 15 bird species with a total of 466 individuals with a moderate diversity index and an evenness index indicating a distressed community.
49
Steinegger, Donald H., Danilo A. Agüero, Ron J. Johnson e Kent M. Eskridge. "Monofilament Lines Fail to Protect Grapes from Bird Damage". HortScience 26, n.º 7 (julho de 1991): 924. http://dx.doi.org/10.21273/hortsci.26.7.924.
Texto completo da fonte
50
ICHINOKIYAMA, Hiromichi, e Masami TAKEUCHI. "Protection of Citrus from Bird Damage by a Dog". Japanese Journal of Farm Work Research 43, n.º 1 (2008): 1–6. http://dx.doi.org/10.4035/jsfwr.43.1.
Texto completo da fonte