This paper introduces the Chinese"Dove"——A practical application system of bird-mimetic air vehicles developed for more than a decade by the Institute of Flight Vehicle Innovation of Northwest Polytechnic ...This paper introduces the Chinese"Dove"——A practical application system of bird-mimetic air vehicles developed for more than a decade by the Institute of Flight Vehicle Innovation of Northwest Polytechnic University(NWPU)in China.Firstly,the main components,flight capability and flight verification of the Chinese"Dove"are presented.Then,the methods for the aerodynamic simulation and wind tunnel experiments are put forward.Secondly,the design of high-lift and high-thrust flexible flapping wings,a series of flapping mechanisms,gust-resistance layout and micro flight control/navigation system are presented.Some future studies on the application system of bionic micro air vehicles are given,including observation of natural flight creatures,aerodynamics in flight,mechanical and new material driving systems,structural mechanics,flight mechanics,and the information perception and intelligent decision-making control,which are related to research of flight bioinformatic perception and brain science.Finally,some application examples of complex flapping movements,active/passive deformation of bird wings,new low-energy motion-driven system,bionic intelligent decision-making and control/navigation are discussed.展开更多
The Three-toed Woodpecker subspecies Picoides tridactylus funebris is endemic to the Qinghai-Tibet plateau in China. No part of its life history was ever reported since its discovery in 1870. To close this gap, we obs...The Three-toed Woodpecker subspecies Picoides tridactylus funebris is endemic to the Qinghai-Tibet plateau in China. No part of its life history was ever reported since its discovery in 1870. To close this gap, we observed foraging behavior of a pair between April and August 2007. A total of 117 observations (28 for male and 89 for female) were obtained by following the birds within their home-ranges using radio-tracking. P. t. funebris preferred foraging on live spruces and snags bigger than available with an average diameter of breast height (DBH) of 32.7 ± 9.2 cm. The most frequent foraging technique was pecking (39.8% of foraging time) and peeling (13.2%). Moreover, sap-sucking was observed more often in P. t. funebris than in P. t. alpinus, suggesting that P. t. funebris was more dependent on the tree sap than the other subspecies. We found distinct niche partitioning between the sexes with respect to use of three out of four investigated parameters of the foraging substrates. These differences were likely related to sexual dimorphism pronounced by slightly larger bill of the male. We concluded that the subspecies P. t. funebris displayed foraging behavior which was very similar to that of other subspecies of the Three-toed Woodpecker.展开更多
Fuel accumulation, mainly as fatty acids, is one of the main characteristics of migratory, birds. Studying to what extent each population or species manages fuel load and how it varies along routes of migration or bet...Fuel accumulation, mainly as fatty acids, is one of the main characteristics of migratory, birds. Studying to what extent each population or species manages fuel load and how it varies along routes of migration or between seasons (autumn and spring migrations) is crucial to our understanding of bird migration strategies. Our aim here was to analyse whether migratory blackcaps Sylvia atrieapilla passing through northern Iberia differ in their mean fuel loads, rate of fuel accumulation and ' potential' flight ranges between migration seasons. Blackcaps were mist netted for 4 h-periods beginning at dawn from 16 September to 15 November 2003 - 2005, and from 1 March to 30 April 2004 - 2006 in a European Atlantic hedgerow at Loza, northern Iberia. Both fuel load and fuel deposition rate (this latter assessed with difference in body mass of within-season recaptured individuals) were higher in autumn than in spring. Possible hypotheses explaining these results could be seasonal-associated variations in food availability (likely lower during spring than during autumn), the fact that a fraction of the migrants captured in spring could breed close to the study area and different selective pressures for breeding and wintering展开更多
Animal populations,with a known history of introduction events,provide opportunities to study the dynamics of how rapid shi s in ecological context a ect behavioral(e.g.,responses to brood parasitism) and life-history...Animal populations,with a known history of introduction events,provide opportunities to study the dynamics of how rapid shi s in ecological context a ect behavioral(e.g.,responses to brood parasitism) and life-history(e.g.,clutch and egg parameters) traits.We studied the European Green nch(Carduelis chloris) introduced to New Zealand,regarding foreign-egg rejection behaviors and also compared their clutch characteristics with data from the source populations in the United Kingdom.Although previously this species had been considered an unsuitable host for the Common Cuckoo(Cuculus canorus),and not impacted by selection pressure associated with brood parasitism,we found that Green nches in our study population were able to eject experimental eggs at low frequencies.In contrast,nest desertion rates were similar in experimentally parasitized and control unmanipulated nests,implying that nest desertion is not an antiparasite adaptation in this species.Contrary to previous studies,we did not nd signi cant di erences in clutch and egg sizes between introduced and source populations.is study emphasizes(1) the importance of using control treatments in studies of host responses to experimental parasitism,(2) including apparently unsuitable hosts of brood parasites,and(3) meta-replicating prior studies to further the process of gaining and validating scienti c knowledge.展开更多
Interest in phenotypic flexibility has increased dramatically over the last decade, but flexibility during reproduction has received relatively little attention from avian scientists, despite its possible impact on fi...Interest in phenotypic flexibility has increased dramatically over the last decade, but flexibility during reproduction has received relatively little attention from avian scientists, despite its possible impact on fitness. Because most avian species maintain atrophied reproductive organs when not active, reproduction in birds requires major tissue remodeling in preparation for breeding. Females undergo rapid (days) recrudescence and regression of their reproductive organs at each breeding attempt, while males grow their organs ahead of time at a much slower rate (weeks) and may maintain them at maximal size throughout the breeding season. Reproduction is associated with significant metabolic costs. Egg production leads to a 22%-27% increase in resting metabolic rate (RMR) over non-reproductive values. This is partly due to the activity of the oviduct, an organ that may allow females to adjust reproductive investment by modulating egg size and quality. In males, gonadal recrudescence may lead to a 30% increase in RMR, but the data are inconsistent and general conclusions regarding energetic costs of reproduction in males will require more research. Recent studies on captive female zebra finches describe the impacts of these costs on daily energy budgets and highlight the strategies used by birds to maintain their investment in reproduction when energy is limited. Whenever possible, birds use behavioral flexibility as a first means of saving energy. Decreasing locomotor activity saves energy during challenges such as egg production or exposure to cold temperatures and is an efficient way to buffer variation in individual daily energy budgets. However, when behavioral flexibility is not possible, birds must rely on flexibility at the physiological level to meet energy demands. In zebra finches breeding in the cold, this results in a reduced pace of laying, likely due to down-regulation of both reproductive and non-reproductive function, allowing females to defend minimal egg size and maintain reproductive success. More research involving a range of species in captive and flee-living conditions is needed to determine how phenotypic flexibility during tissue remodeling and early reproductive investment translates to natural conditions and affects fitness [Current Zoology 56 (6): 767-792, 2010].展开更多
Birds and other animals are frequently killed by cars,causing the death of many million individuals per year.Why some species are killed more often than others has never been investigated.In this work hypothesized tha...Birds and other animals are frequently killed by cars,causing the death of many million individuals per year.Why some species are killed more often than others has never been investigated.In this work hypothesized that risk taking behavior may affect the probability of certain kinds of individuals being killed disproportionately often.Furthermore,behavior of individuals on roads,abundance,habitat preferences,breeding sociality,and health status may all potentially affect the risk of being killed on roads.We used information on the abundance of road kills and the abundance in the surrounding environment of 50 species of birds obtained during regular censuses in 2001 2006 in a rural site in Denmark to test these predictions.The frequency of road kills increased linearly with abundance,while the proportion of individuals sitting on the road or flying low across the road only explained little additional variation in frequency of road casualties.After having accounted for abundance,we found that species with a short flight distance and hence taking greater risks when approached by a potential cause of danger were killed disproportionately often.In addition,solitary species,species with a high prevalence of Plasmodium infection,and species with a large bursa of Fabricius for their body size had a high susceptibility to being killed by cars.These findings suggest that a range of different factors indicative of risk-taking behavior,visual acuity and health status cause certain bird species to be susceptible to casualties due to cars.展开更多
The purpose of this study was to examine the behavioral impact of varying LED (light emitting diode) spectral emissions on avian species. A novel oculo-neuro-motor response to monochromatic LEDs has been identified....The purpose of this study was to examine the behavioral impact of varying LED (light emitting diode) spectral emissions on avian species. A novel oculo-neuro-motor response to monochromatic LEDs has been identified. LED colored light of sufficient intensity matched to the short-wavelength cones of avian species can efficiently diminish overall visual perception leading to an augmented behavioral response. The study method involved monitoring the change in behavioral response after exposure to high brightness monochromatic LED light to wild Osprey (Pandion haliaetus) foraging and nesting in their natural environment. Our results demonstrated a statistically significant change in foraging behaviors with wild Osprey (p = 0.005) and in nesting behavior as a result of exposure to high brightness monochromatic LED light. An augmented behavioral responses was observed which is believed to be analogous to human reaction to solar glare and glint. The neuroimaging mechanism of avian species is discussed. This novel augmented behavioral response provides a new technique of studying the neuroscience of temporal and spatial light stimulus. A non-lethal deterrence technique involving the augmented behavioral response could mitigate mortality and morbidity of avian-human conflict in areas such as airports, airplane bird strikes, and wind turbines.展开更多
Anas poecilorhyncha is one of improved variety of mallards, which was the protected bird species listed by International Union for Conservation of Nature (1UCN). Little is known until now about behavioral characteri...Anas poecilorhyncha is one of improved variety of mallards, which was the protected bird species listed by International Union for Conservation of Nature (1UCN). Little is known until now about behavioral characteristics of the mallard. The objective of this study was to compare the behavioral differentials between A. poecilorhyncha and domestic duck in order to make a strategy to manage A. poecilorhyncha under the condition of animal welfare. A total of 180 birds were distributed into six groups with 30 birds for each group. They were placed in a room of 3 m ~ 4 m and fed for one year old. Sansui ducks, a kind of native domestic duck (Sansui laying duck) were used for behavioral comparison. Two different rooms in the same building were applied, one room for A. poecilorhyncha and another one for Sansui ducks. All behaviors for A. poecilorhyncha and Sansui ducks were coded using the program The Observer XT 11.5 (Noldus Information Technology, Beijing). The duration of observation was from 8:00 am to 18:00 pm daily and lasted 5 d. The results showed that there were similar behavioral percentages between A. poecilorhyncha and domestic duck. Percentages of standing activity spent for A. poecilorhyncha and Sansui duck were 34.59% and 30.25%, respectively. Accordingly, the activities, such as wing plugging, preening and head stretching, were more than 5.51%. The other activities, including walking, drinking and tail wagging, occupied less proportions (〈 3%). While the specific behaviors, like aggression, alerting, wing dithering, clawing, nodding, pendulum clawing and crawling, took less than 1% of percentage. There were large differences between A. poecilorhyncha and domestic duck when comparing eight behavioral peaks. Lag sequential analysis was used to calculate frequency of transition between a pair of activities. Some parameters were very significant, like the frequency value from foraging converted to drinking in Sansui duck was 369-515, but 37-65 in A. poecilorhyncha. The best explaining could be given that Sansui duck was better domesticated than spot-billed duck. This study provides the basic data to study and develop spot-billed duck.展开更多
Gestures, particularly pointing, are regarded as important pre-speech acts. Intentional and referential pointing has been shown previously in humans and apes but not in songbirds, although some avian species show cogn...Gestures, particularly pointing, are regarded as important pre-speech acts. Intentional and referential pointing has been shown previously in humans and apes but not in songbirds, although some avian species show cognitive abilities rivaling those of apes, and their brain structures and functions show putative preconditions for referential gestural signaling (i.e. mirror neurons, links of vocal learning nuclei to discrete brain areas active during limb and body movements). The results reported are based on trials testing predator detection and responses to a taxidermic model of a wedge-tailed eagle by Australian magpies Gymnorhina tibicen. Magpies were subjected to three conditions of finding this model in their territory (open, sheltered and hidden). In the sheltered and bidden conditions, the discoverer simultaneously engaged in alarm calls and beak pointing, a behavior that has not been described previously. Other group members at once assembled and, after watching the first bird, adopted the same posture by pointing to the location of the intruder. The question is whether beak and body movements orienting towards important stimuli or events are instances of arousal, imitation or intentional communication. The latter presupposes that onlookers interpret the signal and respond by altering their own behavior appropriate to the original stimulus and not merely by imitating the first signaler. Evidence presented here indicates that the act of pointing may well be a complex cognitive behavior, i.e., an intentional and referential signal, showing that pointing is not limited to having hands and arms [Current Zoology 57 (4): 453-467, 2011].展开更多
Natural killer (NK) cell is a key component of innate immunity and plays an important role in host defense against virus infection by directly destroying infected cells. Influenza is a respiratory disease transmitte...Natural killer (NK) cell is a key component of innate immunity and plays an important role in host defense against virus infection by directly destroying infected cells. Influenza is a respiratory disease transmitted in the early phase of virus infection. Evasion of host innate immunity including NK cells is critical for the virus to expand and establish a successful acute infection. Previously, we showed that human influenza HIN1 virus infects NK cells and induces cell apoptosis, as well as inhibits NK cell activity. In this study, we further demonstrated that avian influenza virus also directly targeted NK cells as an immunoevasion strategy. The avian virus infected human NK cells and induced cell apoptosis. In addition, avian influenza virion and HA protein inhibited NK cell cytotoxicity. This novel strategy has obvious advantages for avian influenza virus, allowing the virus sufficient time to expand and subsequent spread before the onset of the specific immune response. Our findings provide an important clue for the immunopathogenesis of avian influenza, and also suggest that direct targeting NK cells may be a common strategy used by both human and avian influenza viruses to evade NK cell immunity.展开更多
The distance from an approaching threat at which animals initiate flight - flight-initiation distance (FID) -- is a sensitive metric of variation in risk, but the effects on FID associated with the risk of possessin...The distance from an approaching threat at which animals initiate flight - flight-initiation distance (FID) -- is a sensitive metric of variation in risk, but the effects on FID associated with the risk of possessing highly detectable external coloration are unknown. We tested whether variation in the degree of plumage vividness in birds explained variation in flight-initiation distance. After controlling for body mass, the distance at which the experimental approach began, and phylogenetic relatedness, plumage vividness was not a predictor of FID. Contrary to the expectation that vividness affects risk, and therefore risk assess- ment, these results suggest that birds do not compensate for greater visual conspicuousness by fleeing sooner from approaching threats [Current Zoology 61 (4): 773-780, 2015].展开更多
Human infections with influenza H7 subtypes, such as H7Ng, have raised concerns worldwide. Here, we report a human infection with a novel influenza A(HTN4) virus. A 68 years-old woman with cardiovascular and cholecy...Human infections with influenza H7 subtypes, such as H7Ng, have raised concerns worldwide. Here, we report a human infection with a novel influenza A(HTN4) virus. A 68 years-old woman with cardiovascular and cholecystic comorbidities developed rapidly progressed pneumonia with influenza-like-illness as initial symptom, recovered after 23 days-hospitalization including 8 days in ICLI. Laboratory indicators for liver and blood coagulation dysfunction were observed. Oseltamivir phosphate, glucocorticoids and antibiotics were jointly implemented, with nasal catheterization of oxygen inhalation for this patient. We obtained the medical records and collected serial respiratory and blood specimens from her. We col- lected throat, cloacal and/or feces samples of poultry and wild birds from the patient's backyard, neigh- borhood, local live poultry markets (LPMs) and the nearest lake. All close contacts of the patient were followed up and sampled with throat swabs and sera. Influenza viruses and other respiratory pathogens were tested by real-time RT-PCR, viral culturing and/or sequencing for human respiratory and bird sam- ples. Micro-neutralizing assay was performed for sera. A novel reassortant wild bird-origin H7N4 virus is identified from the patient and her backyard poultry (chickens and ducks) by sequencing, which is dis- tinct from previously-reported avian H7N4 and H7N9 viruses. At least four folds increase of neutralizing antibodies to H7N4 was detected in her convalescent sera. No samples from close contacts, wild birds or other poultry were tested positive for H7N4 by real-time RT-PCR.展开更多
Recently-developed capabilities for tracking the movements of individual birds over the course of a year or longer has provided increasing evidence for consistent individual differences in migration schedules and dest...Recently-developed capabilities for tracking the movements of individual birds over the course of a year or longer has provided increasing evidence for consistent individual differences in migration schedules and destinations. This raises questions about the relative importance of individual consistency versus flexibility in the evolution of migration strategies, and has implications for the ability of populations to respond to climatic change. Using geolocators, we tracked the migrations of Scopoli's shearwaters Calonectris diomedea breeding in Linosa (Italy) across three years, and analysed timing and spatial aspects of their movements. Birds showed remarkable variation in their main wintering destination along the western coast of Africa. We found significant individual consistency in the total distance traveled, time spent in transit, and time that individuals spent in the win- tering areas. We found extensive sex differences in scheduling, duration, distances and destinations of migratory journeys. We also found sex differences in the degree of individual consistency in aspects of migration behaviour. Despite strong evidence for individual consistency, which indicates that migration journeys from the same bird tended to be more similar than those of dif- ferent birds, there remained substantial intra-individual variation between years. Indeed, we also found clear annual differences in departure dates, return dates, wintering period, the total distance traveled and re^rn routes from wintering grounds back to the colony. These findings show that this population flexibly shifts migration schedules as well as routes between years in response to direct or indirect effects of heterogeneity in the environment, while maintaining consistent individual migration strategies [Current Zoology 60 (5): 631-641, 2014].展开更多
The level of genetic variation among individuals may affect performance by reducing the ability of prey to detect and escape from predators if lack of genetic variation reduces flight ability directly or indirectly th...The level of genetic variation among individuals may affect performance by reducing the ability of prey to detect and escape from predators if lack of genetic variation reduces flight ability directly or indirectly through reduced parasite resistance. We investigated vulnerability of common avian prey species to predation by the sparrowhawk Accipiter nisus and the goshawk A. gentilis in relation to an index of genetic similarity among adults of potential prey species. We estimated a prey vulnerability in- dex that reflects the abundance of prey relative to the expected abundance according to local population density, and related this index to band sharing coefficients based on analyses of minisatellites for adults in local breeding populations. The prey vulnera- bility index was positively correlated with the band sharing coefficient in both predators, even when controlling for potentially confounding variables. These findings indicate that prey species with high band sharing coefficients, and hence low levels of genetic variation, are more readily caught by avian predators. Therefore, predation may constitute a major cost of low levels of genetic variation in extant populations of prey [Current Zoology 61(1): 1-9, 2015].展开更多
The majority of our knowledge of avian energetics is based on studies of birds from temperate and high latitudes. Using the largest existing sample of wild-caught Old World tropical species, we showed that birds from ...The majority of our knowledge of avian energetics is based on studies of birds from temperate and high latitudes. Using the largest existing sample of wild-caught Old World tropical species, we showed that birds from Southern Vietnam had lower basal metabolic rate (BMR) than temperate species. The strongest dissimilarity between tropical and temperate species was the low scaling exponent in the allometric relation between BMR and body mass in tropical birds (the regression slope was 0.573). The passerine migrants to temperate and high latitudes had higher BMR than tropical sedentary passerines. Body mass alone accounted for 93% of the variation in BMR (body mass ranged from 5 to 252 g). Contrary to some other studies, we did not find evidence besides the above mentioned that phylogeny, taxonomy, behavior, or ecology have a significant influence on BMR variation among tropical birds.展开更多
We have developed a simple method to synthesize 6-seleno-2′-deoxyguanosine(SedG)by selectively replacing the 6-oxygen atom with selenium.This selenium-atom-specific modification(SAM)alters the optical properties of t...We have developed a simple method to synthesize 6-seleno-2′-deoxyguanosine(SedG)by selectively replacing the 6-oxygen atom with selenium.This selenium-atom-specific modification(SAM)alters the optical properties of the naturally occurring2′-deoxyguanosine(dG).Unlike the native dG,the UVabsorption ofSedG is significantly influenced by the pH of the aqueous solution.Moreover,SedG is fluorescent at the physiological pH and exhibits pH-dependent fluorescence in aqueous solutions.Furthermore,SedG has noticeable fluorescence in non-aqueous solutions,indicating its sensitivity to environmental changes.This is the first time a fluorescent nucleoside by single-atom alteration has been observed.Fluorescent nucleosides modified by a single atom have great potential as molecular probes with minimal perturbations to investigate nucleoside interactions with proteins,such as membrane-transporter proteins.展开更多
基金supported by the National Key Research and Development Program of China(No.2017YFB1300102)the National Natural Science Foundation of China(No.U1613227)。
文摘This paper introduces the Chinese"Dove"——A practical application system of bird-mimetic air vehicles developed for more than a decade by the Institute of Flight Vehicle Innovation of Northwest Polytechnic University(NWPU)in China.Firstly,the main components,flight capability and flight verification of the Chinese"Dove"are presented.Then,the methods for the aerodynamic simulation and wind tunnel experiments are put forward.Secondly,the design of high-lift and high-thrust flexible flapping wings,a series of flapping mechanisms,gust-resistance layout and micro flight control/navigation system are presented.Some future studies on the application system of bionic micro air vehicles are given,including observation of natural flight creatures,aerodynamics in flight,mechanical and new material driving systems,structural mechanics,flight mechanics,and the information perception and intelligent decision-making control,which are related to research of flight bioinformatic perception and brain science.Finally,some application examples of complex flapping movements,active/passive deformation of bird wings,new low-energy motion-driven system,bionic intelligent decision-making and control/navigation are discussed.
基金supported by National Natural Sciences Foundation of China (30620130110)the Chinese Academy of Sciences
文摘The Three-toed Woodpecker subspecies Picoides tridactylus funebris is endemic to the Qinghai-Tibet plateau in China. No part of its life history was ever reported since its discovery in 1870. To close this gap, we observed foraging behavior of a pair between April and August 2007. A total of 117 observations (28 for male and 89 for female) were obtained by following the birds within their home-ranges using radio-tracking. P. t. funebris preferred foraging on live spruces and snags bigger than available with an average diameter of breast height (DBH) of 32.7 ± 9.2 cm. The most frequent foraging technique was pecking (39.8% of foraging time) and peeling (13.2%). Moreover, sap-sucking was observed more often in P. t. funebris than in P. t. alpinus, suggesting that P. t. funebris was more dependent on the tree sap than the other subspecies. We found distinct niche partitioning between the sexes with respect to use of three out of four investigated parameters of the foraging substrates. These differences were likely related to sexual dimorphism pronounced by slightly larger bill of the male. We concluded that the subspecies P. t. funebris displayed foraging behavior which was very similar to that of other subspecies of the Three-toed Woodpecker.
基金supported by a postgraduate fellowship from the Basque Governmentsupported by project CGL2007-61395(Ministry of Education and Science,Government of Spain)
文摘Fuel accumulation, mainly as fatty acids, is one of the main characteristics of migratory, birds. Studying to what extent each population or species manages fuel load and how it varies along routes of migration or between seasons (autumn and spring migrations) is crucial to our understanding of bird migration strategies. Our aim here was to analyse whether migratory blackcaps Sylvia atrieapilla passing through northern Iberia differ in their mean fuel loads, rate of fuel accumulation and ' potential' flight ranges between migration seasons. Blackcaps were mist netted for 4 h-periods beginning at dawn from 16 September to 15 November 2003 - 2005, and from 1 March to 30 April 2004 - 2006 in a European Atlantic hedgerow at Loza, northern Iberia. Both fuel load and fuel deposition rate (this latter assessed with difference in body mass of within-season recaptured individuals) were higher in autumn than in spring. Possible hypotheses explaining these results could be seasonal-associated variations in food availability (likely lower during spring than during autumn), the fact that a fraction of the migrants captured in spring could breed close to the study area and different selective pressures for breeding and wintering
基金supported by Human Frontier Science Program awards (RGY69/07 to TG,PC,and MEH and RGY86/12 to TG and MEH)
文摘Animal populations,with a known history of introduction events,provide opportunities to study the dynamics of how rapid shi s in ecological context a ect behavioral(e.g.,responses to brood parasitism) and life-history(e.g.,clutch and egg parameters) traits.We studied the European Green nch(Carduelis chloris) introduced to New Zealand,regarding foreign-egg rejection behaviors and also compared their clutch characteristics with data from the source populations in the United Kingdom.Although previously this species had been considered an unsuitable host for the Common Cuckoo(Cuculus canorus),and not impacted by selection pressure associated with brood parasitism,we found that Green nches in our study population were able to eject experimental eggs at low frequencies.In contrast,nest desertion rates were similar in experimentally parasitized and control unmanipulated nests,implying that nest desertion is not an antiparasite adaptation in this species.Contrary to previous studies,we did not nd signi cant di erences in clutch and egg sizes between introduced and source populations.is study emphasizes(1) the importance of using control treatments in studies of host responses to experimental parasitism,(2) including apparently unsuitable hosts of brood parasites,and(3) meta-replicating prior studies to further the process of gaining and validating scienti c knowledge.
基金funded by the National Science and Engineering Research Council of Canada (NSERC) through a discovery granta postdoctoral fellowship a Nouveaux chercheurs grant from the Fonds Québécois de Recherche sur la Nature et les Technologies (FQRNT)
文摘Interest in phenotypic flexibility has increased dramatically over the last decade, but flexibility during reproduction has received relatively little attention from avian scientists, despite its possible impact on fitness. Because most avian species maintain atrophied reproductive organs when not active, reproduction in birds requires major tissue remodeling in preparation for breeding. Females undergo rapid (days) recrudescence and regression of their reproductive organs at each breeding attempt, while males grow their organs ahead of time at a much slower rate (weeks) and may maintain them at maximal size throughout the breeding season. Reproduction is associated with significant metabolic costs. Egg production leads to a 22%-27% increase in resting metabolic rate (RMR) over non-reproductive values. This is partly due to the activity of the oviduct, an organ that may allow females to adjust reproductive investment by modulating egg size and quality. In males, gonadal recrudescence may lead to a 30% increase in RMR, but the data are inconsistent and general conclusions regarding energetic costs of reproduction in males will require more research. Recent studies on captive female zebra finches describe the impacts of these costs on daily energy budgets and highlight the strategies used by birds to maintain their investment in reproduction when energy is limited. Whenever possible, birds use behavioral flexibility as a first means of saving energy. Decreasing locomotor activity saves energy during challenges such as egg production or exposure to cold temperatures and is an efficient way to buffer variation in individual daily energy budgets. However, when behavioral flexibility is not possible, birds must rely on flexibility at the physiological level to meet energy demands. In zebra finches breeding in the cold, this results in a reduced pace of laying, likely due to down-regulation of both reproductive and non-reproductive function, allowing females to defend minimal egg size and maintain reproductive success. More research involving a range of species in captive and flee-living conditions is needed to determine how phenotypic flexibility during tissue remodeling and early reproductive investment translates to natural conditions and affects fitness [Current Zoology 56 (6): 767-792, 2010].
文摘Birds and other animals are frequently killed by cars,causing the death of many million individuals per year.Why some species are killed more often than others has never been investigated.In this work hypothesized that risk taking behavior may affect the probability of certain kinds of individuals being killed disproportionately often.Furthermore,behavior of individuals on roads,abundance,habitat preferences,breeding sociality,and health status may all potentially affect the risk of being killed on roads.We used information on the abundance of road kills and the abundance in the surrounding environment of 50 species of birds obtained during regular censuses in 2001 2006 in a rural site in Denmark to test these predictions.The frequency of road kills increased linearly with abundance,while the proportion of individuals sitting on the road or flying low across the road only explained little additional variation in frequency of road casualties.After having accounted for abundance,we found that species with a short flight distance and hence taking greater risks when approached by a potential cause of danger were killed disproportionately often.In addition,solitary species,species with a high prevalence of Plasmodium infection,and species with a large bursa of Fabricius for their body size had a high susceptibility to being killed by cars.These findings suggest that a range of different factors indicative of risk-taking behavior,visual acuity and health status cause certain bird species to be susceptible to casualties due to cars.
基金This work was supported by grant No. IIP-1350562 from the National Science Foundation. NH Audubon Society provided assistance in tabulating the field results. Support at the test sites was provided by US Cellular, and NH Fish and Game Department--Milford Fish Hatchery.
文摘The purpose of this study was to examine the behavioral impact of varying LED (light emitting diode) spectral emissions on avian species. A novel oculo-neuro-motor response to monochromatic LEDs has been identified. LED colored light of sufficient intensity matched to the short-wavelength cones of avian species can efficiently diminish overall visual perception leading to an augmented behavioral response. The study method involved monitoring the change in behavioral response after exposure to high brightness monochromatic LED light to wild Osprey (Pandion haliaetus) foraging and nesting in their natural environment. Our results demonstrated a statistically significant change in foraging behaviors with wild Osprey (p = 0.005) and in nesting behavior as a result of exposure to high brightness monochromatic LED light. An augmented behavioral responses was observed which is believed to be analogous to human reaction to solar glare and glint. The neuroimaging mechanism of avian species is discussed. This novel augmented behavioral response provides a new technique of studying the neuroscience of temporal and spatial light stimulus. A non-lethal deterrence technique involving the augmented behavioral response could mitigate mortality and morbidity of avian-human conflict in areas such as airports, airplane bird strikes, and wind turbines.
文摘Anas poecilorhyncha is one of improved variety of mallards, which was the protected bird species listed by International Union for Conservation of Nature (1UCN). Little is known until now about behavioral characteristics of the mallard. The objective of this study was to compare the behavioral differentials between A. poecilorhyncha and domestic duck in order to make a strategy to manage A. poecilorhyncha under the condition of animal welfare. A total of 180 birds were distributed into six groups with 30 birds for each group. They were placed in a room of 3 m ~ 4 m and fed for one year old. Sansui ducks, a kind of native domestic duck (Sansui laying duck) were used for behavioral comparison. Two different rooms in the same building were applied, one room for A. poecilorhyncha and another one for Sansui ducks. All behaviors for A. poecilorhyncha and Sansui ducks were coded using the program The Observer XT 11.5 (Noldus Information Technology, Beijing). The duration of observation was from 8:00 am to 18:00 pm daily and lasted 5 d. The results showed that there were similar behavioral percentages between A. poecilorhyncha and domestic duck. Percentages of standing activity spent for A. poecilorhyncha and Sansui duck were 34.59% and 30.25%, respectively. Accordingly, the activities, such as wing plugging, preening and head stretching, were more than 5.51%. The other activities, including walking, drinking and tail wagging, occupied less proportions (〈 3%). While the specific behaviors, like aggression, alerting, wing dithering, clawing, nodding, pendulum clawing and crawling, took less than 1% of percentage. There were large differences between A. poecilorhyncha and domestic duck when comparing eight behavioral peaks. Lag sequential analysis was used to calculate frequency of transition between a pair of activities. Some parameters were very significant, like the frequency value from foraging converted to drinking in Sansui duck was 369-515, but 37-65 in A. poecilorhyncha. The best explaining could be given that Sansui duck was better domesticated than spot-billed duck. This study provides the basic data to study and develop spot-billed duck.
文摘Gestures, particularly pointing, are regarded as important pre-speech acts. Intentional and referential pointing has been shown previously in humans and apes but not in songbirds, although some avian species show cognitive abilities rivaling those of apes, and their brain structures and functions show putative preconditions for referential gestural signaling (i.e. mirror neurons, links of vocal learning nuclei to discrete brain areas active during limb and body movements). The results reported are based on trials testing predator detection and responses to a taxidermic model of a wedge-tailed eagle by Australian magpies Gymnorhina tibicen. Magpies were subjected to three conditions of finding this model in their territory (open, sheltered and hidden). In the sheltered and bidden conditions, the discoverer simultaneously engaged in alarm calls and beak pointing, a behavior that has not been described previously. Other group members at once assembled and, after watching the first bird, adopted the same posture by pointing to the location of the intruder. The question is whether beak and body movements orienting towards important stimuli or events are instances of arousal, imitation or intentional communication. The latter presupposes that onlookers interpret the signal and respond by altering their own behavior appropriate to the original stimulus and not merely by imitating the first signaler. Evidence presented here indicates that the act of pointing may well be a complex cognitive behavior, i.e., an intentional and referential signal, showing that pointing is not limited to having hands and arms [Current Zoology 57 (4): 453-467, 2011].
基金supported in part by Theme-based Research Scheme (Project No. T11-705/14N)the General Research Fund (HKU 780113M,17121214 and 17115015)+1 种基金Research Grants Council of the Hong Kong SARShenzhen Science and Technology Innovation Committee (JCYJ20140411175241066),China
文摘Natural killer (NK) cell is a key component of innate immunity and plays an important role in host defense against virus infection by directly destroying infected cells. Influenza is a respiratory disease transmitted in the early phase of virus infection. Evasion of host innate immunity including NK cells is critical for the virus to expand and establish a successful acute infection. Previously, we showed that human influenza HIN1 virus infects NK cells and induces cell apoptosis, as well as inhibits NK cell activity. In this study, we further demonstrated that avian influenza virus also directly targeted NK cells as an immunoevasion strategy. The avian virus infected human NK cells and induced cell apoptosis. In addition, avian influenza virion and HA protein inhibited NK cell cytotoxicity. This novel strategy has obvious advantages for avian influenza virus, allowing the virus sufficient time to expand and subsequent spread before the onset of the specific immune response. Our findings provide an important clue for the immunopathogenesis of avian influenza, and also suggest that direct targeting NK cells may be a common strategy used by both human and avian influenza viruses to evade NK cell immunity.
基金We thank Kate Rose for help managing data, the survey participants for judging vividness, C. East- wood for his intellectual contributions, and Bill Cooper and one anonymous reviewer for their constructive comments on a previous version of this MS. NMH was supported by the UC Regents Special Fellowship. JPD was supported by a National Science Foundation (NSF) Graduate Research Fellowship and a fellowship from the UCLA Graduate Division during the course of this study. DTB is supported by NSF-DEB-1119660.
文摘The distance from an approaching threat at which animals initiate flight - flight-initiation distance (FID) -- is a sensitive metric of variation in risk, but the effects on FID associated with the risk of possessing highly detectable external coloration are unknown. We tested whether variation in the degree of plumage vividness in birds explained variation in flight-initiation distance. After controlling for body mass, the distance at which the experimental approach began, and phylogenetic relatedness, plumage vividness was not a predictor of FID. Contrary to the expectation that vividness affects risk, and therefore risk assess- ment, these results suggest that birds do not compensate for greater visual conspicuousness by fleeing sooner from approaching threats [Current Zoology 61 (4): 773-780, 2015].
基金supported by National Science and Technology Major Project of China (2015ZX09101044)Science & Technology Demonstration Project for Emerging Infectious Diseases Control and Prevention of Jiangsu Province, China (BE2015714 & BE2017749)Key Medical Discipline of Jiangsu Science & Technology Project of China (epidemiology,ZDXKA2016008)
文摘Human infections with influenza H7 subtypes, such as H7Ng, have raised concerns worldwide. Here, we report a human infection with a novel influenza A(HTN4) virus. A 68 years-old woman with cardiovascular and cholecystic comorbidities developed rapidly progressed pneumonia with influenza-like-illness as initial symptom, recovered after 23 days-hospitalization including 8 days in ICLI. Laboratory indicators for liver and blood coagulation dysfunction were observed. Oseltamivir phosphate, glucocorticoids and antibiotics were jointly implemented, with nasal catheterization of oxygen inhalation for this patient. We obtained the medical records and collected serial respiratory and blood specimens from her. We col- lected throat, cloacal and/or feces samples of poultry and wild birds from the patient's backyard, neigh- borhood, local live poultry markets (LPMs) and the nearest lake. All close contacts of the patient were followed up and sampled with throat swabs and sera. Influenza viruses and other respiratory pathogens were tested by real-time RT-PCR, viral culturing and/or sequencing for human respiratory and bird sam- ples. Micro-neutralizing assay was performed for sera. A novel reassortant wild bird-origin H7N4 virus is identified from the patient and her backyard poultry (chickens and ducks) by sequencing, which is dis- tinct from previously-reported avian H7N4 and H7N9 viruses. At least four folds increase of neutralizing antibodies to H7N4 was detected in her convalescent sera. No samples from close contacts, wild birds or other poultry were tested positive for H7N4 by real-time RT-PCR.
文摘Recently-developed capabilities for tracking the movements of individual birds over the course of a year or longer has provided increasing evidence for consistent individual differences in migration schedules and destinations. This raises questions about the relative importance of individual consistency versus flexibility in the evolution of migration strategies, and has implications for the ability of populations to respond to climatic change. Using geolocators, we tracked the migrations of Scopoli's shearwaters Calonectris diomedea breeding in Linosa (Italy) across three years, and analysed timing and spatial aspects of their movements. Birds showed remarkable variation in their main wintering destination along the western coast of Africa. We found significant individual consistency in the total distance traveled, time spent in transit, and time that individuals spent in the win- tering areas. We found extensive sex differences in scheduling, duration, distances and destinations of migratory journeys. We also found sex differences in the degree of individual consistency in aspects of migration behaviour. Despite strong evidence for individual consistency, which indicates that migration journeys from the same bird tended to be more similar than those of dif- ferent birds, there remained substantial intra-individual variation between years. Indeed, we also found clear annual differences in departure dates, return dates, wintering period, the total distance traveled and re^rn routes from wintering grounds back to the colony. These findings show that this population flexibly shifts migration schedules as well as routes between years in response to direct or indirect effects of heterogeneity in the environment, while maintaining consistent individual migration strategies [Current Zoology 60 (5): 631-641, 2014].
文摘The level of genetic variation among individuals may affect performance by reducing the ability of prey to detect and escape from predators if lack of genetic variation reduces flight ability directly or indirectly through reduced parasite resistance. We investigated vulnerability of common avian prey species to predation by the sparrowhawk Accipiter nisus and the goshawk A. gentilis in relation to an index of genetic similarity among adults of potential prey species. We estimated a prey vulnerability in- dex that reflects the abundance of prey relative to the expected abundance according to local population density, and related this index to band sharing coefficients based on analyses of minisatellites for adults in local breeding populations. The prey vulnera- bility index was positively correlated with the band sharing coefficient in both predators, even when controlling for potentially confounding variables. These findings indicate that prey species with high band sharing coefficients, and hence low levels of genetic variation, are more readily caught by avian predators. Therefore, predation may constitute a major cost of low levels of genetic variation in extant populations of prey [Current Zoology 61(1): 1-9, 2015].
基金Field work and initial data analysis was supported by the Tropical Center (project Ekolan E-1.2) and partially by the Russian Foundation for Basic Research (RFBR Grant nos 12-04-01440, 15-04-07407, and 15-04-08407).The maintenance of the database and final data analysis was financially supported by the Russian Science Foundation (RSF Grant no. 14-50-00029).
文摘The majority of our knowledge of avian energetics is based on studies of birds from temperate and high latitudes. Using the largest existing sample of wild-caught Old World tropical species, we showed that birds from Southern Vietnam had lower basal metabolic rate (BMR) than temperate species. The strongest dissimilarity between tropical and temperate species was the low scaling exponent in the allometric relation between BMR and body mass in tropical birds (the regression slope was 0.573). The passerine migrants to temperate and high latitudes had higher BMR than tropical sedentary passerines. Body mass alone accounted for 93% of the variation in BMR (body mass ranged from 5 to 252 g). Contrary to some other studies, we did not find evidence besides the above mentioned that phylogeny, taxonomy, behavior, or ecology have a significant influence on BMR variation among tropical birds.
基金financially supported by the US National Science Foundation(NSF,MCB-0824837)the Georgia Cancer Coalition(GCC)Distinguished Cancer Clinicians and Scientists Awards
文摘We have developed a simple method to synthesize 6-seleno-2′-deoxyguanosine(SedG)by selectively replacing the 6-oxygen atom with selenium.This selenium-atom-specific modification(SAM)alters the optical properties of the naturally occurring2′-deoxyguanosine(dG).Unlike the native dG,the UVabsorption ofSedG is significantly influenced by the pH of the aqueous solution.Moreover,SedG is fluorescent at the physiological pH and exhibits pH-dependent fluorescence in aqueous solutions.Furthermore,SedG has noticeable fluorescence in non-aqueous solutions,indicating its sensitivity to environmental changes.This is the first time a fluorescent nucleoside by single-atom alteration has been observed.Fluorescent nucleosides modified by a single atom have great potential as molecular probes with minimal perturbations to investigate nucleoside interactions with proteins,such as membrane-transporter proteins.