Flight Behavior Research Articles

Energy supply during nocturnal endurance flight of migrant birds: effect of energy stores and flight behaviour

BackgroundMigrating birds fly non-stop for hours or even for days. They rely mainly on fat as fuel complemented by a certain amount of protein. Studies on homing pigeons and birds flying in a wind-tunnel suggest that the shares of fat and protein on total energy expenditure vary with flight duration and body fat stores. Also, flight behaviour, such as descending flight, is expected to affect metabolism. However, studies on free flying migrant birds under natural conditions are lacking.MethodsOn a Swiss Alpine pass, we caught three species of nocturnal migrant passerines out of their natural migratory flight. Since most night migrants start soon after dusk, we used time since dusk as a measure of flight duration. We used plasma concentrations of metabolites of the fat, protein, and carbohydrate metabolism as indicators of relative fuel use. We used flight altitudes of birds tracked with radar and with atmospheric pressure loggers to characterize flight behaviour.ResultsThe indicators of fat catabolism (triglycerides, very low-density lipoproteins, glycerol) were positively correlated with body energy stores, supporting earlier findings that birds with high fat stores have a higher fat catabolism. As expected, plasma levels of triglycerides, very low-density lipoproteins, glycerol and ß-hydroxy-butyrate increased at the beginning of the night, indicating that nocturnal migrants increased their fat metabolism directly after take-off. Surprisingly, fat catabolism as well as glucose levels decreased in the second half of the night. Data from radar observations showed that the number of birds aloft, their mean height above ground and vertical flight speed decreased after midnight. Together with the findings from atmospheric pressure-loggers put on three species, this shows that nocturnal migrants migrating over continental Europe descend slowly during about 1.5 h before final landfall at night, which results in 11–30% energy savings according to current flight models.ConclusionsWe suggest that this slow descent reduces energy demands to an extent which is noticeable in the plasma concentration of lipid, protein, and carbohydrate metabolites. The slow descent may facilitate the search for a suitable resting habitat and serve to refill glycogen stores needed for foraging and predator escape when landed.

Trails of Erasure: imagining the reality of co-migrations in contemporary climate fiction

ABSTRACT In this article, I am going to trace ‘trails of erasure’ in two contemporary novels that introduce a wider trend in climate fiction: Firstly, both Barbara Kingsolver’s Flight Behaviour (2012) and Charlotte McConaghy’s Migrations (2020) indicate a tendency to envision temporalities that render climate threats more imminent and, secondly, both novels imagine spatialities that align human and non-human forms of migration. Thus, they closely connect human and non-human ways of coping with climate change, which may be considered a form of deep adaptation to our current climate crisis. However, they not only challenge but also reinscribe problematic gender and class discourses in the process.

Erratum: Modified Fear Conditioning for Inducing Flight Behaviors in Mice.

This corrects the article 10.3791/66266.

Temperature Dependency of Insect's Wingbeat Frequencies: An Empirical Approach to Temperature Correction.

This study examines the relationship between the wingbeat frequency of flying insects and ambient temperature, leveraging data from over 302,000 insect observations obtained using a near-infrared optical sensor during an eight-month field experiment. By measuring the wingbeat frequency as well as wing and body optical cross-sections of each insect in conjunction with the ambient temperature, we identified five clusters of insects and analyzed how their average wingbeat frequencies evolved over temperatures ranging from 10 °C to 38 °C. Our findings reveal a positive correlation between temperature and wingbeat frequency, with a more pronounced increase observed at higher wingbeat frequencies. Frequencies increased on average by 2.02 Hz/°C at 50 Hz, and up to 9.63 Hz/°C at 525 Hz, and a general model is proposed. This model offers a valuable tool for correcting wingbeat frequencies with temperature, enhancing the accuracy of insect clustering by optical and acoustic sensors. While this approach does not account for species-specific responses to temperature changes, our research provides a general insight, based on all species present during the field experiment, into the intricate dynamics of insect flight behavior in relation to environmental factors.

Flight capacity and behavior of Ephestia kuehniella (Lepidoptera: Pyralidae) in response to kairomonal and pheromonal stimuli.

Flight behavior is an important component to understand in the context of pest management. However, because of their small size, little is known about the flight capacity of most stored-product insects, and when a flight has been assessed, it usually consists of a propensity for initiating flight. Despite a priori expectations of the importance of flight for moths, there are no data about the flight capacity and little on the flight behavior of the Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae). As a result, the objective of the current study was to (i) characterize the baseline flight capacity of E. kuehniella and (ii) determine how flight capacity is affected by the presence of kairomonal, pheromonal, or no stimuli. We found adult E. kuehniella flew a mean of 24-34 km in a 24-h period, and the distance flown per bout increased from 91 to 207 m in the presence of pheromones but decreased to 41 m when food was nearby compared to a negative control. The total number of flight bouts was 1.6-fold higher in the presence of pheromone compared to the negative control, but E. kuehniella flew significantly slower with pheromone and food cues present, suggesting they may be exhibiting an optimal foraging strategy. Our data on flight capacity results in qualitatively and quantitatively different conclusions about flight than those conclusions formed if only flight initiation is considered. Overall, this novel information is useful for understanding the spread within facilities and in the landscape (between facilities), as well as parameterizing ecological modeling.

Effect of Fungi Presence on Wing Morphometry and Flight Behaviour in the Common Pipistrelle Bats (Pipistrellus pipistrellus)

Effect of Fungi Presence on Wing Morphometry and Flight Behaviour in the Common Pipistrelle Bats (Pipistrellus pipistrellus)

Exploring the Significance of Nature in Literature: Eco Critical Themes in the Selected Work of Barbara Kingslover

The present article deals with an analysis of the eco-critic elements in Barbara Kingsolver’s Flight Behaviour. The article explores the perspectives of eco-critical along with ecological speculations in order to deal with the climate change and cultural aspects of the novel. Critical, unlike the conventional eco-critic in literary genre, discards the genre constraints the last happenstances and becomes impressive for endless critical examination. Ecology offers the supreme impulse, which is concealed in traditional ecology. The eco-critical enclaves in the novel closely surround the aspects of the current world’s concerned environment, which is why the novel becomes appropriate to be analyzed as an ecocritical. The deteriorating environmental circumstances in the contemporary world and a much similar one in the novel provide an optimal space to study ecology beside ecocriticism. An ecocritical analysis of the text not only focuses on the need for ecological consciousness in the characters. But in a sustainable way of saving the earth for the future

Control Authority of a Single-Surface Parafoil with Bleed-Air Spoilers

Bleed-air control of ram-air parafoils is a lightweight and cost-effective mechanism that enables significant landing accuracy improvements compared to traditional trailing edge brake control due to the addition of direct glide slope control. Single-surface parafoil canopies have been shown to be lightweight and possess similar flight behavior as their ram-air counterparts. The design of bleed-air spoilers is more challenging for single-surface canopies, which lack the internal ram-air that provides a high pressure differential at any chordwise location. This paper explores bleed-air spoilers on single-surface parafoils with a focus on turn rate and glide slope control capabilities. Through a flight test campaign, it was shown that bleed-air spoilers on a single-surface parafoil provide both turn rate control from asymmetric vent opening and glide slope change from symmetric vent opening. Vents located far forward at the 10% chord location yield substantial control response with a maximum turn rate response of 38 deg/s and a maximum glide slope change of 58%. Vents located farther aft at 30, 50, and 70% chords demonstrated diminished control authority. Varying the spanwise locations of the spoilers revealed that the outermost vents had negligible lateral and longitudinal control authority.

Enhanced Whale Optimization Algorithm for Fuzzy Proportional–Integral–Derivative Control Optimization in Unmanned Aerial Vehicles

The traditional PID controller in quadrotor UAVs has poor performance, a large overshoot, and a long adjustment time, which limit its stability and accuracy in practical applications. In order to solve this problem, an improved whale optimization fuzzy PID control strategy based on CRICLE chaos map initialization is proposed, and a detailed simulation analysis was carried out using MATLAB software (MATLAB R2022B). Firstly, to more realistically reflect quadrotor UAVs’ flight behavior, a dynamic simulation model was established, and the dynamics and kinematic characteristics of the aircraft were considered. Then, CRICLE chaotic mapping initialization was introduced to improve the global search ability of the whale optimization algorithm and to effectively initialize the parameters of the fuzzy PID controller. This improved initialization method helped to speed up the convergence process and improve the stability of the control system. In the simulation experiments, we compared the performance indicators of the improved CRICLE chaotic mapping initialization whale optimization fuzzy PID controller to the traditional PID and fuzzy PID controllers, including overshoot, adjustment time, etc. The results show that the proposed control strategy has better performance than the traditional PID and fuzzy PID controllers, significantly reduces overshoot, and achieves a significant improvement in adjustment time. Therefore, the improved CRICLE chaotic mapping initialization whale optimization fuzzy PID control strategy proposed in this study provides an effective solution for improving the performance of the quadrotor control system and has practical application potential.

Scouts vs. usurpers: alternative foraging strategies facilitate coexistence between neotropical Cathartid vultures

Understanding how diverse assemblages of scavengers can coexist on shared ecological resources is a fundamental challenge in community ecology. However, current approaches typically focus on behaviour at carcass provisioning sites, missing how important differences in movement behaviour and foraging strategies can facilitate sympatric species coexistence. Such information is particularly important for vultures – obligate scavengers representing the most endangered avian foraging guild. Their loss from ecosystems can trigger trophic cascades, mesopredator release and disease outbreaks. We provide the first‐ever analyses of GPS location data from wild King Vultures Sarcoramphus papa and Greater Yellow‐headed Vultures Cathartes melambrotus, coupled with trait data (from both wild‐living and museum specimens) and visitation data from camera traps deployed at provisioned carcasses, to characterize vulture flight behaviour and strategies in the Peruvian Amazon. We found marked species differences in several key movement characteristics, including: King Vultures having home‐ranges five times larger, average flight heights four times greater and ground speeds 40% faster than those of Greater Yellow‐headed Vultures. Despite these differences, both species flew similar distances each day (on average), probably due to King Vultures taking 50% fewer flights and spending 40% less time in the air per day. Consistent with these patterns, King Vulture body mass was more than double that of the Greater Yellow‐headed Vulture, with a substantially larger hang wing index (a measure of long‐distance flight efficiency). At carcasses, Greater Yellow‐headed Vultures typically arrived first but were rapidly outnumbered by both King and Black Vultures Coragyps atratus. We find that the movement behaviour of obligate apex scavengers in the western Amazon is linked to their ability to coexist – Greater Yellow‐headed Vultures, a smaller stature ‘scouting’ species adapted to fly low, forage early and arrive first at carcasses, are ultimately displaced by larger‐bodied, wider ranging King Vultures at large ephemeral carrion resources. Expansion of future GPS tracking initiatives could facilitate the exploration of direct facultative interactions from animal movement data and give further insight into how diverse communities assemble and interact.

Plant invasion alters movement behaviour in endangered butterflies but not their morphology or genetic variability

Invasions of alien plants often result in biodiversity loss and may impact the biology of native species. However, the effects of biological invasions on the behavioural responses of native species have rarely been investigated. We studied how the alteration of habitat due to the invasion of alien goldenrod (Solidago spp) affects a native butterfly, the scarce large blue Phengaris teleius, which is a flagship species for grassland biodiversity conservation. To better understand immediate responses in flight behaviour (daily movements, resting, and dispersal) to a new habitat, we performed observations of experimentally translocated butterflies of two origins (invaded vs. non-invaded habitats) to four different environments: invaded habitat, non-invaded habitat, invaded matrix, non-invaded matrix. Moreover, we tested whether the level of invasion may be related to the variation in morphological traits associated with flight (wing size, body mass) and genetic variability. Flight behaviour was affected by the high goldenrod cover and the sex of the butterflies, regardless of the butterflies’ origin. In the habitat and matrix invaded by goldenrod, the butterflies tended to display dispersal behaviour more often compared to the non-invaded ones. Flight distances were longest in the matrix with goldenrod and resting time was longest in habitats invaded by goldenrod. Analysis of morphological traits as well as eight microsatellite loci did not reveal significant differences in morphology or genetic variation among the populations studied.

Red deer responses to drive hunts are related to habitat and landscape characteristics

AbstractHunting triggers behavioral responses in wildlife that may have important consequences for conservation and wildlife management. We studied movement and habitat selection in 51 global positioning system‐collared red deer (Cervus elaphus) in response to 63 large‐scale (x̄ = 18.8 km2) drive hunts conducted in 2015‐2022 on a military training area in southern Germany. The drive hunts were characterized by a low density of beaters and dogs to avoid rapid and long‐distance displacement of red deer. We determined if red deer spatial responses to drive hunts differed in various forest covers, between sexes, and in relation to the individual position prior to the hunt. On the hunting days, red deer increased their hourly displacement rates and shifted their preference for forest versus open habitats from early morning to late morning hours. Individuals initially located within the boundaries of the hunted areas exhibited longer maximum net displacements, had a greater probability of leaving their home ranges, and spent longer times outside of their home ranges than individuals outside the hunted areas. All these parameters were greater in the more forested site than in the less forested site. Males displayed shorter net displacements than females. Red deer moved away (i.e., fled) from their initial positions for variable periods, either only during the hunt or until the next day. The probability of prolonged flight was greater in the more forested site and more likely if the individuals were deeper in the forest in the less forested site. The prolonged flight behavior was desired from the hunters' perspective because red deer displaying this type of response were less likely to leave the hunted area during the hunt. Prolonged flight was associated with greater costs for the red deer, such as greater movement distances after the hunt and longer times outside of home ranges. Wildlife managers should consider that drive hunts may cause prolonged behavioral responses in game that occur both inside and outside the hunted areas. These responses depend on habitat characteristics and may be stronger in more forested landscapes.

Decoding Typical Flight States Based on Neural Signals from the Midbrain Motor Nuclei of Pigeons.

Exploring the neural encoding mechanism and decoding of motion state switching during flight can advance our knowledge of avian behavior control and contribute to the development of avian robots. However, limited acquisition equipment and neural signal quality have posed challenges, thus we understand little about the neural mechanisms of avian flight. We used chronically implanted micro-electrode arrays to record the local field potentials (LFPs) in the formation reticularis medialis mesencephali (FRM) of pigeons during various motion states in their natural outdoor flight. Subsequently, coherence-based functional connectivity networks under different bands were constructed and the topological features were extracted. Finally, we used a support vector machine model to decode different flight states. Our findings indicate that the gamma band (80-150 Hz) in the FRM exhibits significant power for identifying different states in pigeons. Specifically, the avian brain transmitted flight related information more efficiently during the accelerated take-off or decelerated landing states, compared with the uniform flight and baseline states. Finally, we achieved a best average accuracy of 0.86 using the connectivity features in the 80-150 Hz band and 0.89 using the fused features for state decoding. Our results open up possibilities for further research into the neural mechanism of avian flight and contribute to the understanding of flight behavior control in birds.

Performance Characterization of Heliotrope Solar Hot-Air Balloons during Multihour Stratospheric Flights

Abstract Heliotropes are passive solar hot-air balloons that are capable of achieving nearly level flight within the lower stratosphere for several hours. These inexpensive flight platforms enable stratospheric sensing with high cadence enabled by the low cost to manufacture, but their performance has not yet been assessed systematically. During July–September of 2021, 29 heliotropes were successfully launched from Oklahoma and achieved float altitude as part of the Balloon-based Acoustic Seismology Study (BASS). All of the heliotrope envelopes were nearly identical with only minor variations to the flight line throughout the campaign. Flight data collected during this campaign comprise a large sample to characterize the typical heliotrope flight behavior during launch, ascent, float, and descent. Each flight stage is characterized, dependence on various parameters is quantified, and a discussion of nominal and anomalous flights is provided.

LOAD BALANCING IN CLOUD COMPUTING VIA MAYFLY OPTIMIZATION ALGORITHM

Cloud computing is a new technology that enables users to store and retrieve data via the Internet on demand rather than using their hardware. Cloud computing comprises distinct data centers (servers) and clients (users). Load unbalancing is a multi-variant, multi-constraint issue that lowers the efficacy and performance of system resources. Therefore, a load scheduling technique is needed to distribute work among the right VMs and preserve the trade-off between them. To achieve better performance, this paper presents a novel mayfly optimization algorithm for load balancing (MFO-LB), which utilizes mayfly flight behavior and mating dynamics. The proposed technique balances the load in the cloud by managing the incoming loads by allocating resources according to user requests. The proposed work intends to increase performance by uniformly dividing the workload among the virtual machines, which will decrease utilization and reaction time. The proposed MFO-LB approach is beneficial for maintaining system stability, reducing response time (RT), and maximizing resource productivity in cloud environments. Finally, the effectiveness of the proposed technique is assessed by employing several metrics, including execution cost, RT, execution time, and makespan. The proposed method achieves up to 23.4 % low RT, a 24 %decrease in makespan, and a 31.5 % decrease in completion time, respectively.

An analytical solution and stability analysis of asymmetric non-actuator guided projectiles

PurposeOne of the challenges encountered in the design of guided projectiles is their prohibitive cost. To diminish it, an appropriate avenue many researchers have explored is the use of the non-actuator method for guiding the projectile to the target. In this method, biologically inspired by the flying concept of the single-winged seed, for instance, that of maple and ash trees, the projectile undergoes a helical motion to scan the region and meet the target in the descent phase. Indeed, the projectile is a decelerator device based on the autorotation flight while it attempts to resemble the seed’s motion using two wings of different spans. There exists a wealth of studies on the stability of the decelerators (e.g. the mono-wing, samara and pararotor), but all of them have assumed the body (exclusive of the wing) to be symmetric and paid no particular attention to the scanning quality of the region. In practice, however, the non-actuator-guided projectiles are asymmetric owing to the presence of detection sensors. This paper aims to present an analytical solution for stability analysis of asymmetric decelerators and apprise the effects of design parameters to improve the scanning quality.Design/methodology/approachThe approach of this study is to develop a theoretical model consisting of Euler equations and apply a set of non-dimensionalized equations to reduce the number of involved parameters. The obtained governing equations are readily applicable to other decelerator devices, such as the mono-wing, samara and pararotor.FindingsThe results show that the stability of the body can be preserved under certain conditions. Moreover, pertinent conclusions are outlined on the sensitivity of flight behavior to the variation of design parameters.Originality/valueThe analytical solution and sensitivity analysis presented here can efficiently reduce the design cost of the asymmetric decelerator.

Exploring the interplay between small and large scales movements in a neotropical small mammal

We record and analyze the movement patterns of the marsupial Didelphis aurita at different temporal scales. Animals trajectories are collected at a daily scale by using spool-and-line techniques and, with the help of radio-tracking devices, animals traveled distances are estimated at intervals of weeks. Small-scale movements are well described by truncated Lévy flight, while large-scale movements produce a distribution of distances which is compatible with a Brownian motion. A model of the movement behavior of these animals, based on a truncated Lévy flight calibrated on the small scale data, converges towards a Brownian behavior after a short time interval of the order of 1 week. These results show that whether Lévy flight or Brownian motion behaviors apply, will depend on the scale of aggregation of the animals paths. In this specific case, as the effect of the rude truncation present in the daily data generates a fast convergence towards Brownian behaviors, Lévy flights become of scarce interest for describing the local dispersion properties of these animals, which result well approximated by a normal diffusion process and not a fast, anomalous one. Interestingly, we are able to describe two movement phases as the consequence of a statistical effect generated by aggregation, without the necessity of introducing ecological constraints or mechanisms operating at different spatio-temporal scales. This result is of general interest, as it can be a key element for describing movement phenomenology at distinct spatio-temporal scales across different taxa and in a variety of systems.

Effects of blood-feeding on mosquitoes hovering kinematics and aerodynamics

Mosquitoes exhibit a distinctive and remarkable flight pattern, flapping their wings at a high frequency with relatively small stroke amplitude. However, until recently, the underlying aerodynamic mechanisms have remained unclear. Furthermore, there is a lack of understanding about their flight behaviors after blood-feeding and the corresponding aerodynamic characteristics. This study aims to explore this uncharted area, conducts experiments to acquire kinematic and morphological data and numerical simulations to obtain three-dimensional flow characteristic. Further analysis uncovers several key findings. Both before and after blood-feeding hovering exhibit a similar flapping wing pattern, characterized by downstroke and upstroke with three stages of each half stroke. After blood-feeding, there are significant increases in stroke amplitude, mid-downstroke duration, velocity, and flip angles. Additionally, body pitch, stroke plane tilt, and Reynolds number experience increments. In hovering, mosquitoes balance vertical force with weight, with substantial peaks observed in each stage, particularly during the mid-stroke. After blood-feeding, the vertical force experiences a 3.3-fold increase, with the majority of the increase occurring during the mid-downstroke. The study identifies three unsteady mechanisms for aerodynamic force generation without blood-feeding hovering, namely, added-mass force, delayed stall, and fast-pitching-up rotation. These mechanisms persist after blood-feeding, with a greater reliance on delayed stall to support increased weight.

Pervasive mimicry in flight behavior among aposematic butterflies

Flight was a key innovation in the adaptive radiation of insects. However, it is a complex trait influenced by a large number of interacting biotic and abiotic factors, making it difficult to unravel the evolutionary drivers. We investigate flight patterns in neotropical heliconiine butterflies, well known for mimicry of their aposematic wing color patterns. We quantify the flight patterns (wing beat frequency and wing angles) of 351 individuals representing 29 heliconiine and 9 ithomiine species belonging to ten color pattern mimicry groupings. For wing beat frequency and up wing angles, we show that heliconiine species group by color pattern mimicry affiliation. Convergence of down wing angles to mimicry groupings is less pronounced, indicating that distinct components of flight are under different selection pressures and constraints. The flight characteristics of the Tiger mimicry group are particularly divergent due to convergence with distantly related ithomiine species. Predator-driven selection for mimicry also explained variation in flight among subspecies, indicating that this convergence can occur over relatively short evolutionary timescales. Our results suggest that the flight convergence is driven by aposematic signaling rather than shared habitat between comimics. We demonstrate that behavioral mimicry can occur between lineages that have separated over evolutionary timescales ranging from <0.5 to 70 My.

Flight characteristics and phylogeography in three large-bodied diving beetle species: evidence that the species with expanded distribution is an active flier

Abstract Diving beetles play an important role in fishless freshwater communities. The genus Cybister is included in the Japanese Red Data List owing to its diminished population size. The phylogenetic relationships and genetic structures of Cybister chinensis and Cybister brevis, whose populations are declining, and Cybister tripunctatus lateralis, whose population and distribution is increasing, are poorly understood and must be addressed in future conservation efforts. In this study, we investigated the flight behaviour and phylogeography of the three Cybister species. Cybistyer tripunctatus lateralis and C. brevis flew well in the spring, and the proportion of flight in C. tripunctatus lateralis increased again after the reproductive season. However, C. chinensis did not fly. Relatively, among the three species, C. tripunctatus lateralis has the largest forewings. Phylogenetic analysis based on mitochondrial DNA revealed that C. chinensis showed genetic differentiation between the eastern and western regions of Japan, whereas C. tripunctatus lateralis showed no regional trends. Furthermore, C. brevis showed an intermediate trend between the two species. These findings suggest that C. tripunctatus lateralis has been expanding the area of its distribution rapidly through flight dispersal in recent years. Cybister chinensis flies infrequently, raising concerns about metapopulation fragmentation.