风电场对盐城珍禽国家自然保护区鸟类的影响

利用保护区历年鸟类监测数据,以及短期野外实地调查数据,结合保护区生态环境特点,研究了风电场建设对盐城珍禽国家自然保护区鸟类的影响。结果表明:风电场建立通过占用鸟类栖息地而间接影响风电场周围鸟类的栖息和觅食,但总体来说,其影响较小;风机转速较慢及保护区鸟类飞行高度均高于风机高度,风机与鸟类的碰撞风险较低;为了保护鸟类的安全及保障其正常生存,需要采取合理布局风电场、建立鸟类观测站、协调区域滩涂及邻近地区的开发建设等措施。     

Does avian malaria reduce fledging success: an experimental test of the selection hypothesis

Like many parasites, avian haematozoa are often found at lower infection intensities in older birds than young birds. One explanation, known as the “selection” hypothesis, is that infected young birds die before reaching adulthood, thus removing the highest infection intensities from the host population. We tested this hypothesis in the field by experimentally infecting nestling rock pigeons (Columba livia) with the malaria parasite Haemoproteus columbae. We compared the condition and fledging success of infected nestlings to that of uninfected controls. There was no significant difference in the body mass, fledging success, age at fledging, or post-fledging survival of experimental versus control birds. These results were unexpected, given that long-term studies of older pigeons have demonstrated chronic effects of H. columbae. We conclude that H. columbae has little impact on nestling pigeons, even when they are directly infected with the parasite. Our study provides no support for the selection hypothesis that older birds have lower parasite loads because parasites are removed from the population by infected nestlings dying. To our knowledge, this is the first study to test the impact of avian malaria using experimental inoculations under natural conditions.     

Avian Magnetoreception: Elaborate Iron Mineral Containing Dendrites in the Upper Beak Seem to Be a Common Feature of Birds

The magnetic field sensors enabling birds to extract orientational information from the Earth''s magnetic field have remained enigmatic. Our previously published results from homing pigeons have made us suggest that the iron containing sensory dendrites in the inner dermal lining of the upper beak are a candidate structure for such an avian magnetometer system. Here we show that similar structures occur in two species of migratory birds (garden warbler, Sylvia borin and European robin, Erithacus rubecula) and a non-migratory bird, the domestic chicken (Gallus gallus). In all these bird species, histological data have revealed dendrites of similar shape and size, all containing iron minerals within distinct subcellular compartments of nervous terminals of the median branch of the Nervus ophthalmicus. We also used microscopic X-ray absorption spectroscopy analyses to identify the involved iron minerals to be almost completely Fe III-oxides. Magnetite (Fe II/III) may also occur in these structures, but not as a major Fe constituent. Our data suggest that this complex dendritic system in the beak is a common feature of birds, and that it may form an essential sensory basis for the evolution of at least certain types of magnetic field guided behavior.     

Does weather affect biting fly abundance in avian nests?

Environmental factors may strongly affect avian‐biting fly interactions in different ways because insects are heterothermic organisms that depend greatly on environmental variables to activate their metabolism and behaviour. We studied the effects of weather on both blackfly (Simuliidae) and biting midge Culicoides (Ceratopogonidae) abundance in nests of three passerine species: blue tits Cyanistes caeruleus, great tits Parus major and pied flycatchers Ficedula hypoleuca, breeding in the same area. We controlled for different host‐related factors (hatching date, brood size and host species). Blackfly abundance was negatively related to minimum temperature. In addition, blackfly and biting midge abundances were negatively affected by wind speed measured at 07.00 h, but blackfly abundance was positively associated to wind speed at 18.00 h. We found higher blackfly and biting midge abundances in nests with larger broods breeding later in the season, and significantly higher biting midge abundance in pied flycatcher nests as compared to tit nests. These results represent, to our knowledge, the first report of both environmental and host‐related effects on haematophagous fly abundance in the nests of wild hole‐nesting birds.     

The Eye in the Sky: Combined Use of Unmanned Aerial Systems and GPS Data Loggers for Ecological Research and Conservation of Small Birds

Technological advances for wildlife monitoring have expanded our ability to study behavior and space use of many species. But biotelemetry is limited by size, weight, data memory and battery power of the attached devices, especially in animals with light body masses, such as the majority of bird species. In this study, we describe the combined use of GPS data logger information obtained from free-ranging birds, and environmental information recorded by unmanned aerial systems (UASs). As a case study, we studied habitat selection of a small raptorial bird, the lesser kestrel Falco naumanni, foraging in a highly dynamic landscape. After downloading spatio-temporal information from data loggers attached to the birds, we programmed the UASs to fly and take imagery by means of an onboard digital camera documenting the flight paths of those same birds shortly after their recorded flights. This methodology permitted us to extract environmental information at quasi-real time. We demonstrate that UASs are a useful tool for a wide variety of wildlife studies.     

Microsporidian Species Known To Infect Humans Are Present in Aquatic Birds: Implications for Transmission via Water?

Human microsporidiosis, a serious disease of immunocompetent and immunosuppressed people, can be due to zoonotic and environmental transmission of microsporidian spores. A survey utilizing conventional and molecular techniques for examining feces from 570 free-ranging, captive, and livestock birds demonstrated that 21 animals shed microsporidian spores of species known to infect humans, including Encephalitozoon hellem (20 birds; 3.5%) and Encephalitozoon intestinalis (1 bird; 0.2%). Of 11 avian species that shed E. hellem and E. intestinalis, 8 were aquatic birds (i.e., common waterfowl). The prevalence of microsporidian infections in waterfowl (8.6%) was significantly higher than the prevalence of microsporidian infections in other birds (1.1%) (P < 0.03); waterfowl fecal droppings contained significantly more spores (mean, 3.6 × 10⁵ spores/g) than nonaquatic bird droppings contained (mean, 4.4 × 10⁴ spores/g) (P < 0.003); and the presence of microsporidian spores of species known to infect humans in fecal samples was statistically associated with the aquatic status of the avian host (P < 0.001). We demonstrated that a single visit of a waterfowl flock can introduce into the surface water approximately 9.1 × 10⁸ microsporidian spores of species known to infect humans. Our findings demonstrate that waterborne microsporidian spores of species that infect people can originate from common waterfowl, which usually occur in large numbers and have unlimited access to surface waters, including waters used for production of drinking water.     

Maps in birds: representational mechanisms and neural bases

The often extraordinary navigational behavior of birds is based in part on their ability to learn map-like representations of the heterogeneous distribution of environmental stimuli in space. Whether navigating small-scale laboratory environments or large-scale field environments, birds appear to be reliant on a directional framework, for example that provided by the sun, to learn how stimuli are distributed in space and to represent them as a map. The avian hippocampus plays a critical role in some aspects of map learning. Recent results from electrophysiological studies hint at the possibility that different aspects of space may be represented in the activity of different neuronal types in the avian hippocampus.     

New data on the brain and cognitive abilities of birds

New evidence of functional analogies and homologies of avian and mammalian brains is presented, as is a revised nomenclature of the most important brain structures. Comparative characteristics of the avian brain and criteria for its progressive development in the phylogeny have been considered. We studied the possibility to use Portmann??s index as one of the indicators of brain development in different avian species. We substantiated the necessity to chose for investigation new sets of avian species with medium (Parus caeruleus and Loxia curvirostra) and low (Larus glaucescens) levels of brain complexity to maintain fully valuable grounds for comparing the cognitive abilities in birds. The main experimentally supported proofs of the existence of elementary thinking and some other cognitive functions in the higher birds have been reviewed. The high levels of cognitive processes that underlie the tool using ability in birds, as well as the similarity to those processes in apes, have been demonstrated from the results obtained in the first decade of the 21st century. Comparative studies on proto-instrumental activity confirmed the ability of hooded crows and ravens to find urgent solution of tool-using tasks. Although birds with a medium level of brain complexity display seemingly rational behavior, it is plausible that they use simpler rules being unable to understand the task logic. It was shown that birds of different orders with a high level of brain complexity demonstrate similar dynamics in the development of abstract concepts. Crossbills, which have a medium level of brain complexity, were able to develop the same concepts at a lower level than the corvids; whereas the seagulls and pigeons, which possess a low level of cognitive abilities, were not able to operate any abstractions and were incapable of solving other cognitive tests. The fact that corvids, parrots, and apes have similar abilities to solve some cognitive tasks supports the hypothesis of the convergent evolution of the brain and cognition in birds and primates.     

Determining fine‐scale migratory connectivity and habitat selection for a migratory songbird by using new GPS technology

Migratory aerial insectivores are among the fastest declining avian groups, but our understanding of these trends has been limited by poor knowledge of migratory connectivity and the identification of critical habitat across the vast distances they travel annually. Using new, archival GPS loggers, we tracked individual purple martins Progne subis from breeding colonies across North America to determine precise (< > 10 m) locations of migratory and overwintering roost locations in South America and to test hypotheses for fine‐scale migratory connectivity and habitat use. We discovered weak migratory connectivity at the roost scale, and extensive, fine‐scale mixing of birds in the Amazon from distant (> 2000 km) breeding sites, with some individuals sharing the same roosting trees. Despite vast tracts of contiguous forest in this region, birds occupied a much more limited habitat, with most (56%) roosts occurring on small habitat islands that were strongly associated with water. Only 17% of these roosts were in current protected areas. These data reflect a critical advance in our ability to remotely determine precise migratory connectivity and habitat selection across vast spatial scales, enhancing our understanding of population dynamics and enabling more effective conservation of species at risk.     

Physiological responses in rufous-collared sparrows to thermal acclimation and seasonal acclimatization

A large number of physiological acclimation studies assume that flexibility in a certain trait is both adaptive and functionally important for organisms in their natural environment; however, it is not clear how an organism’s capacity for temperature acclimation translates to the seasonal acclimatization that these organisms must accomplish. To elucidate this relationship, we measured BMR and TEWL rates in both field-acclimatized and laboratory-acclimated adult rufous-collared sparrows (Zonotrichia capensis). Measurements in field-acclimatized birds were taken during the winter and summer seasons; in the laboratory-acclimated birds, we took our measurements following 4 weeks at either 15 or 30°C. Although BMR and TEWL rates did not differ between winter and summer in the field-acclimatized birds, laboratory-acclimated birds exposed to 15°C exhibited both a higher BMR and TEWL rate when compared to the birds acclimated to 30°C and the field-acclimatized birds. Because organ masses seem to be similar between field and cold-acclimated birds whereas BMR is higher in cold-acclimated birds, the variability in BMR cannot be explained completely by adjustments in organ masses. Our findings suggest that, although rufous-collared sparrows can exhibit thermal acclimation of physiological traits, sparrows do not use this capacity to cope with minor to moderate fluctuations in environmental conditions. Our data support the hypothesis that physiological flexibility in energetic traits is a common feature of avian metabolism.     

Effects of weather on avian migration at proposed ridgeline wind energy sites

With the popularity of wind energy increasing globally, concerns surfaced in the 1980s as to the potential adverse effects of wind turbines on migrating birds. Understanding how weather conditions influence passage rates can help determine the potential for increased avian–turbine collisions. Using vertical and horizontal mounted marine radars, raptor stand watch observations, and portable handheld weather stations, we studied how temperature, cloud cover, barometric pressure, wind direction, and wind speed affected avian passage rates and height of migrants over 3 ridges (Wartenbe, North Dokie, and South Dokie) being developed for wind energy in northern British Columbia. Using an Akaike's Information Criterion (AIC), we determined that a reduced model combining wind speed, barometric pressure, and cloud cover was best at explaining and predicting higher passage rates (expressed as no. birds/hr) in the fall migration for both diurnal and nocturnal migrants. Wind speed proved the most important predictor of passage rates for spring nocturnal migrants and a combination of cloud cover, temperature, and wind direction for diurnal spring migrants. Wind speed also predicted decreases in flight altitude among nocturnal migrants but increased altitude in diurnal migrants. This information coupled with migration timing and topographical areas of higher migrant activity can be useful to wind energy proponents who wish to mitigate collision risk with migrating birds. © 2011 The Wildlife Society.     

Performance test and verification of an off‐the‐shelf automated avian radar tracking system

Microwave radar is an important tool for observation of birds in flight and represents a tremendous increase in observation capability in terms of amount of surveillance space that can be covered at relatively low cost. Based on off‐the‐shelf radar hardware, automated radar tracking systems have been developed for monitoring avian movements. However, radar used as an observation instrument in biological research has its limitations that are important to be aware of when analyzing recorded radar data. This article describes a method for exploring the detection capabilities of a dedicated short‐range avian radar system used inside the operational Smøla wind‐power plant. The purpose of the testing described was to find the maximum detection range for various sized birds, while controlling for the effects of flight tortuosity, flight orientation relative to the radar and ground clutter. The method was to use a dedicated test target in form of a remotely controlled unmanned aerial vehicle (UAV) with calibrated radar cross section (RCS), which enabled the design of virtually any test flight pattern within the area of interest. The UAV had a detection probability of 0.5 within a range of 2,340 m from the radar. The detection performance obtained by the RCS ‐calibrated test target (?11 dBm², 0.08 m² RCS ) was then extrapolated to find the corresponding performance of differently sized birds. Detection range depends on system sensitivity, the environment within which the radar is placed and the spatial distribution of birds. The avian radar under study enables continuous monitoring of bird activity within a maximum range up to 2 km dependent on the size of the birds in question. While small bird species may be detected up to 0.5–1 km, larger species may be detected up to 1.5–2 km distance from the radar.     

Validation of a biotelemetric technique, using ambulatory miniature black globe thermometers, to quantify thermoregulatory behaviour in ungulates

Behavioural thermoregulation is an animal's primary defence against changes in the thermal environment. We aimed to validate a remote technique to quantify the thermal environment behaviourally selected by free-ranging ungulates. First, we demonstrated that the temperature of miniature, 30 mm diameter, black globes (miniglobes) could be converted to standard, 150 mm diameter, black globe temperatures. Miniglobe temperature sensors subsequently were fitted to collars on three free-ranging ungulates, namely blue wildebeest (Connochaetes taurinus), impala (Aepyceros melampus) and horse (Equus caballus). Behavioural observations were reflected in animal miniglobe temperatures which differed from those recorded by an identical miniglobe on a nearby exposed weather station. The wildebeest often selected sites protected from the wind, whereas the impala and the horse sheltered from the sun. Nested analysis of variances revealed that the impala and horse selected significantly less variable environments than those recorded at the weather station (P<0.001) over a 20-min time interval, whereas, the microclimates selected by wildebeest tended to be more variable (P=0.08). Correlation of animal miniglobe against weather station miniglobe temperature resulted in regression slopes significantly less than one (P<0.001) for all species studied, implying that, overall, the animals selected cooler microclimates at high environmental heat loads and/or warmer microclimates at low environmental heat loads. We, therefore, have developed an ambulatory device, which can be attached to free-ranging animals, to remotely quantify thermoregulatory behaviour and selected microclimates.     

Using Nest Temperature to Estimate Nest Attendance of Piping Plovers

Abstract: Recent technological innovations allow remote monitoring of avian nest temperature that minimizes disturbance and expense without altering clutch sizes. However, the efficacy of such techniques has not been determined for ground-nesting birds. We compared the efficacy of 2 techniques, iButton® data loggers (Maxim/Dallas Semiconductor Corp., Sunnyvale, CA) and custom-built thermocouples, to measure nest temperature of piping plovers (Charadrius melodus) relative to nest attendance at Cape Cod National Seashore, Massachusetts, USA. Neither technique affected hatching success (U = 389.5, P = 0.874) or rates of predation of nests containing devices (P = 0.894). We estimated nest attendance successfully with thermocouples in nests as long as air and surface temperatures were <29° Cand 43° C, respectively. Although iButtons could not be used to determine duration of on-bouts and off-bouts of incubating piping plovers, they were effective at determining when nests were abandoned or predated. We recommend the use of thermocouples for studying nest attendance of ground-nesting birds, in general, and of threatened and endangered species, in particular, where disturbance should be minimized and altering clutch sizes is not feasible.     

A simple,band‐mounted device to measure behaviorally modified thermal microclimates experienced by birds

Birds encounter climate at the scale of microclimates that can vary rapidly in time and space and so understanding potential vulnerability and adaptations to those microclimates requires fine‐scale measurements that accurately track thermal exposures. However, few options exist for recording the microclimates actually experienced by birds (realized microclimates). We constructed and tested a simple, low‐cost, temperature logger for recording the realized microclimates of ground‐nesting birds. We developed attachment protocols for band‐mounting Thermochron iButtons on Ring‐billed Gull (Larus delawarensis) chicks. We tested these mounted, temperature‐logging devices on 20 chicks weighing > 200 g (device weight was 4 g), attaching devices for 48 h and observing behavior before and after attachment and removal. Devices recorded temperature immediately surrounding the leg at 2‐min intervals. Recorded temperatures were strong predictors of observed thermoregulatory behaviors (panting and sitting), outperforming predictions based on air temperatures measured by basic, static approaches. Through comparison with matched controls (chicks with just a band), we detected no adverse physiological effects of devices, no effects on social or feeding behavior, and only a short‐term decrease in inactivity immediately after device attachment (likely due to increased preening). By attaching iButtons to the legs of birds, we quantified realized thermal exposure, integrating air temperature, modes of environmental heat transfer, and bird behavior at microclimatic scales. Although not yet validated for broader use, our approach (including possible miniaturization) should be suitable to measure thermal exposure of adults, not just chicks, allowing collection of data concerning thermal exposures during flight under field conditions. At ~ $25 USD per device, our approach facilitates experimental protocols with robust sample sizes, even for relatively modest budgets.     

Effects of nonionizing radiation on birds

1. With the ability to fly comes a greater probability of direct irradiation by nonionizing radiation. The effect of nonionizing radiation on birds is, therefore, of environmental significance. 2. Most biological effects of exposure to nonionizing radiation in avian species are a result of radiation-induced temperature increases. 3. The incubating avian egg provides a model to study nonthermal effects of microwave exposure since ambient incubation temperature can be adjusted to compensate for absorbed thermal energy. 4. Some studies have shown that exposure to nonthermal levels of nonionizing radiation affect a bird's ability to recover from acute physiological stressors. 5. Although earlier research indicated that modulated radiofrequency radiation increased calcium-ion efflux in chick forebrain tissue, criticism of experimental techniques and contradictory results between related studies have made final conclusions elusive. 6. Birds have been shown to be able to reliably detect magnetic fields in both the field and laboratory. Some researchers have reported malformations in chicken embryos exposed to a sinusoidal bipolar oscillating magnetic field.     

A mathematical model of avian influenza with half-saturated incidence

The widespread impact of avian influenza viruses not only poses risks to birds, but also to humans. The viruses spread from birds to humans and from human to human In addition, mutation in the primary strain will increase the infectiousness of avian influenza. We developed a mathematical model of avian influenza for both bird and human populations. The effect of half-saturated incidence on transmission dynamics of the disease is investigated. The half-saturation constants determine the levels at which birds and humans contract avian influenza. To prevent the spread of avian influenza, the associated half-saturation constants must be increased, especially the half-saturation constant H _m for humans with mutant strain. The quantity H _m plays an essential role in determining the basic reproduction number of this model. Furthermore, by decreasing the rate β _m at which human-to-human mutant influenza is contracted, an outbreak can be controlled more effectively. To combat the outbreak, we propose both pharmaceutical (vaccination) and non-pharmaceutical (personal protection and isolation) control methods to reduce the transmission of avian influenza. Vaccination and personal protection will decrease β _m, while isolation will increase H _m. Numerical simulations demonstrate that all proposed control strategies will lead to disease eradication; however, if we only employ vaccination, it will require slightly longer to eradicate the disease than only applying non-pharmaceutical or a combination of pharmaceutical and non-pharmaceutical control methods. In conclusion, it is important to adopt a combination of control methods to fight an avian influenza outbreak.     

Seasonal occurrence and dominance of Centropages congeners in the Middle Atlantic Bight,USA

The distribution and abundance of 15 taxa of birds seen from a vessel in the region of Prydz Bay, Antarctica between November and December 1982 are presented. Antarctic petrels were by far the most frequent in the survey area while Adélie and emperor penguins made up 77% of the observed avian biomass. The distribution and abundance of birds was found to be related to ice conditions, air temperature and wind speed but not to water temperature or air pressure. The extent of species associations at sea are shown and the possibilities of diurnal fluctuations in bird numbers at sea are examined.