Free-ranging Van Gelder’s bat Bauerus dubiaquercus (Chiroptera: Vespertilionidae) preying on dung beetles in southern Mexico

We report the first prey species consumed by the free-ranging Van Gelder’s bat Bauerus dubiaquercus. We trapped four pregnant individuals of this species carrying freshly captured dung beetles. We describe the wing morphology and flight descriptors (wing loading and wing aspect ratio) of the species, which presents wings more suitable for capturing insects by aerial hawking, although the evidence suggests that is able to capture dung beetles of nearly 10% of its body mass in flight close to the ground. The species could obtain their prey while foraging on uncluttered pasture near forest edges.

Morphological variables restrict flower choice of Lycaenid butterfly species: implication for pollination and conservation

Background Butterflies make an important part for plant-pollinator guild. These are nectar feeder or occasionally pollen feeder and thus proboscis of the butterfly species are considered as one of the most important variable in relation to the collection of food from plants. In butterfly-plant association, nectar source is principally determined by quality of nectar, corolla length, and nectar quantity. For the butterfly, nectar uptake is determined by proboscis length because flowers with long corolla restrict butterfly species containing shorter proboscis. Empirical studies proved that butterfly species with high wing loading visit clustered flowers and species with low wing loading confined their visit to solitary or less nectar rich flowers. The present study tries to investigate the flower preference of butterfly species from Lycaenidae family having very short proboscis, lower body length, lower body weight and wing span than the most species belonging from Nymphalidae, Pieridae, Papilionidae, and Hesperiidae. Results Butterflies with shorter proboscis cannot access nectar from deeper flower. Although they mainly visit on less deeper flower to sucking nectar, butterflies with high wing loading visits clustered flowers to fulfill their energy requirements. In this study, we demonstrated flower choice of seven butterfly species belonging to Lycanidiae family. The proboscis length maintains a positive relationship with body length and body weight. Body length maintains a positive relationship with body weight and wing span. Wing span indicate a strong positive relationship with body weight. This study proved that these seven butterfly species namely Castalius rosimon (CRN), Taracus nara (TNA), Zizinia otis (ZOT), Zizula hylax (ZHY), Jamides celeno (JCE), Chilades laius (CLA), and Psuedozizeeria maha (PMA) visit frequently in Tridax procumbens (TPR), Ocimum americanum (OAM) and Syndrella nodiflora (SNO). The species do not visit Lantana camara (LCA) and Catharanthus roseus (CRO) plants. Conclusion The present study proved that butterfly species visits frequently in Tridax procumbens (TPR), Ocimum americanum (OAM) but less frequently in Syndrella nodiflora (SNO). So, that study determined the butterfly species helps in pollination of these herbs that in turn helps the conservation of these butterfly species.

Divergence in Body Mass, Wing Loading, and Population Structure Reveals Species-Specific and Potentially Adaptive Trait Variation Across Elevations in Montane Bumble Bees

Biogeographic clines in morphology along environmental gradients can illuminate forces influencing trait evolution within and between species. Latitude has long been studied as a driver of morphological clines, with a focus on body size and temperature. However, counteracting environmental pressures may impose constraints on body size. In montane landscapes, declines in air density with elevation can negatively impact flight performance in volant species, which may contribute to selection for reduced body mass despite declining temperatures. We examine morphology in two bumble bee (Hymenoptera: Apidae: Bombus Latreille) species, Bombus vancouverensis Cresson and Bombus vosnesenskii Radoszkowski, across mountainous regions of California, Oregon, and Washington, United States. We incorporate population genomic data to investigate the relationship between genomic ancestry and morphological divergence. We find that B. vancouverensis, which tends to be more specialized for high elevations, exhibits stronger spatial-environmental variation, being smaller in the southern and higher elevation parts of its range and having reduced wing loading (mass relative to wing area) at high elevations. Bombus vosnesenskii, which is more of an elevational generalist, has substantial trait variation, but spatial-environmental correlations are weak. Population structure is stronger in the smaller B. vancouverensis, and we find a significant association between elevation and wing loading after accounting for genetic structure, suggesting the possibility of local adaptation for this flight performance trait. Our findings suggest that some conflicting results for body size trends may stem from distinct environmental pressures that impact different aspects of bumble bee ecology, and that different species show different morphological clines in the same region.

Caste and wing loading in a social wasp (Hymenoptera, Vespidae, Dolichovespula maculata)

Variation in wing design and wing loading according to body weight is well studied across taxa of birds and flying insects. Comparable studies have not been made in the few insects that show substantial size variation within the same phenon of a single species. We examine body measures of adults of the social wasp Dolichovespula maculata (Linnaeus, 1763), with particular attention to the limbs and wing loading. As expected, measures of the length of the legs scales isometrically with overall body weight and size. Against expectation, wing size also scales isometrically with body weight and size. This does not match the general pattern of comparison across species of flying animals, in which larger individuals have relatively larger wings, as a partial compensation for greater wing loading. We suggest that wing size in D. maculata may be constrained by the demands of life in a crowded nest.

Sexual dimorphism in bat wing morphology – variation among foraging styles

Sexual dimorphism can lead to differences in foraging style among conspecifics due to morphological differences. Within bats, maneuverability and speed of flight are influenced by wing shape and size, which may differ between sexes. Female bats gain about 30% of their body mass during pregnancy, affecting their agility and flight efficiency. To fill the same foraging niche as males, pregnant female bats would require wing size and/or shape modifications to maintain maneuverability. We investigated sexual dimorphism in bat wing morphology and how it varies among foraging guilds. Wing photos of male and female adult bats (19 species) in Canada, Belize, and Dominica were analyzed using 2D geometric morphometrics, wing loading, and aspect ratios. Nonpregnant female bats had higher wing loading than males, suggesting they are less maneuverable than males. Additionally, mass increases during pregnancy may not permit female bats to forage as male conspecifics do. Wing shape differed minimally among foraging guilds with only frugivores differing significantly, from all other guilds. Further studies should investigate how female bats forage during their reproductive cycle and determine how frugivore wings differ and whether there are individual differences in wing shape that are not consistent among bat species.

A simple mechanistic model of the invasive species Heracleum sosnowskyi propagule dispersal by wind

Background Invasive species are one of the key elements of human-mediated ecosystem degradation and ecosystem services impairment worldwide. Dispersal of propagules is the first stage of plant species spread and strongly influences the dynamics of biological invasion. Therefore, distance prediction for invasive species spread is critical for invasion management. Heracleum sosnowskyi is one of the most dangerous invasive species with wind-dispersed propagules (seeds) across Eastern Europe. This study developed a simple mechanistic model for H. sosnowskyi propagule dispersal and their distances with an accuracy comparable to that of empirical measurements. Methods We measured and compared the propagule traits (terminal velocity, mass, area, and wing loading) and release height for H. sosnowskyi populations from two geographically distant regions of European Russia. We tested two simple mechanistic models: a ballistic model and a wind gradient model using identical artificial propagules. The artificial propagules were made of colored paper with a mass, area, wing loading, and terminal velocity close to those of natural H. sosnowskyi mericarps. Results The wind gradient model produced the best results. The first calculations of maximum possible propagule transfer distance by wind using the model and data from weather stations showed that the role of wind as a vector of long-distance dispersal for invasive Heracleum species was strongly underestimated. The published dataset with H. sosnowskyi propagule traits and release heights allows for modeling of the propagules’ dispersal distances by wind at any geographical point within their entire invasion range using data from the closest weather stations. The proposed simple model for the prediction of H. sosnowskyi propagule dispersal by wind may be included in planning processes for managing invasion of this species.

Domestic egg-laying hens, Gallus gallus domesticus , do not modulate flapping flight performance in response to wing condition

Wild birds modulate wing and whole-body kinematics to adjust their flight patterns and trajectories when wing loading increases flight power requirements. Domestic chickens ( Gallus gallus domesticus ) in backyards and farms exhibit feather loss, naturally high wing loading, and limited flight capabilities. Yet, housing chickens in aviaries requires birds to navigate three-dimensional spaces to access resources. To understand the impact of feather loss on laying hens' flight capabilities, we symmetrically clipped the primary and secondary feathers before measuring wing and whole-body kinematics during descent from a 1.5 m platform. We expected birds to compensate for increased wing loading by increasing wingbeat frequency, amplitude and angular velocity. Otherwise, we expected to observe an increase in descent velocity and angle and an increase in vertical acceleration. Feather clipping had a significant effect on descent velocity, descent angle and horizontal acceleration. Half-clipped hens had lower descent velocity and angle than full-clipped hens, and unclipped hens had the highest horizontal acceleration. All hens landed with a velocity two to three times greater than in bird species that are adept fliers. Our results suggest that intact laying hens operate at the maximal power output supported by their anatomy and are at the limit of their ability to control flight trajectory.

Seasonal Patterns of Fat Deposits in Relation to Migratory Strategy in Facultative Migrants

Physiological preparations for migration generally reflect migratory strategy. Migrant birds fuel long-distance flight primarily with lipids, but carrying excess fuel is costly; thus, the amount of fat deposited prior to departure often reflects the anticipated flight duration or distance between refueling bouts. Seasonal pre-migratory deposition of fat is well documented in regular seasonal migrants, but is less described for more facultative species. We analyze fat deposits of free-living birds across several taxa of facultative migrants in the songbird subfamily Carduelinae, including house finches (Haemorhous mexicanus), American goldfinches (Spinus tristis), pine siskins (Spinus pinus) and four different North American ecotypes of red crossbills (Loxia curvirostra), to evaluate seasonal fat deposition during facultative migratory periods. Our data suggest that the extent of seasonal fat deposits corresponds with migratory tendency in these facultative taxa. Specifically, nomadic red crossbills with a seasonally predictable annual movement demonstrated relatively large seasonal fat deposits coincident with the migratory periods. In contrast, pine siskins, thought to be more variable in timing and initiation of nomadic movements, had smaller peaks in fat deposits during the migratory season, and the partial migrant American goldfinch and the resident house finch showed no peaks coincident with migratory periods. Within the red crossbills, those ecotypes that are closely associated with pine habitats showed larger peaks in fat deposits coincident with autumn migratory periods and had higher wing loading, whereas those ecotypes associated with spruces, Douglas-fir and hemlocks showed larger peaks coincident with spring migratory periods and lower wing loading. We conclude that population averages of fat deposits do reflect facultative migration strategies in these species, as well as the winter thermogenic challenges at the study locations. A difference in seasonal fattening and wing loading among red crossbill ecotypes is consistent with the possibility that they differ in their migratory biology, and we discuss these differences in light of crossbill reproductive schedules and phenologies of different conifer species.

Effect of airfoil thickness on cargo carrying capacity for high speed ship with aerodynamic unloading

В последние несколько лет, высокоскоростные суда с аэродинамической разгрузкой вызывают интерес, как в гражданском, так и военно-морском транспорте. Было проведено много исследований аэродинамических профилей около границы раздела. Но исследований грузоподъемности крыла для этого типа судов было мало. В данной работе численно оценивалось влияние толщины профиля на грузоподъемность высокоскоростного суда с аэродинамической разгрузкой. Для изучения влияния толщины аэродинамического профиля в диапазоне от 10% до 60% хорды, были проведены расчеты на движущемся экране при углах атаки от 0° до 8° и (h/c = 0,1). Все аэродинамические профили имели хорду 1 м. Профили были модифицированы и имели плоскую нижнюю поверхность, чтобы избежать присасывания на малых углах атаки при малом отстоянии от границы раздела. Поскольку это является нежелательным явлением. Модель турбулентности k-ω SST использовалась для моделирования обтекания крыла при числах Рейнольдса (R_e = 〖1×10〗^6). Для проверки результатов расчетов результаты CFD профиля NACA 4412 при движении над землей были сопоставлены с экспериментальными данными. В данной статье показано, какой тип толщины крылового профиля следует использовать для получения эффективной грузоподъемности высокоскоростного суда с аэродинамической разгрузкой при его проектировании. In the past few years, high-speed aerodynamic unloading vessels have attracted interest in both civilian and naval transport. There have been many studies of airfoils near the interface. But there has been little research on wing loading for this type of vessel. In this study, the effect of the profile thickness on the carrying capacity of a high-speed vehicle with aerodynamic unloading was numerically estimated. To study the effect of the thickness of the airfoil in the range from 10% to 60% of the chord, calculations were carried out on a moving screen at angles of attack from 0 ° to 8 ° and (h / c = 0.1). All airfoils had a chord of 1 m. The airfoils were modified to have a flat bottom surface to avoid suction at low angles of attack with a small distance from the interface. As this is an undesirable phenomenon. The k-ω SST turbulence model was used to simulate the flow around the wing at Reynolds numbers (R_e = 〖1×10〗^6). To check the calculation results, the CFD results of the NACA 4412 profile when moving above the ground were compared with the experimental data. This article shows what type of airfoil thickness should be used to obtain the effective carrying capacity of a high-speed aerodynamic craft in its design.

ВИЗНАЧЕННЯ ПОТРІБНОГО ПИТОМОГО НАВАНТА-ЖЕННЯ НА КРИЛО РАКЕТИ

Wing loading severely affects the mass of a missile as well as its flight performance. For airplanes this parameter must not exceed allowable values calculated from different requirements especially related to such cases as lift-off, landing, cruise flight and aircraft maneuverability. For missiles wing loading is determined considering launch conditions and providing the necessary maneuverability. Appropriate estimation of wing loading at the initial design stages guarantees the minimal mass of an aircraft with all tactical requirements met.Review of available literature, related to missile design, has shown that the problem of optimal wing loading estimation contains lengthy and quite approximate analytical expressions.This article is dedicated to the development of a missile wing loading estimation technique that provides minimal propellant mass fraction and total mass of an aircraft while meeting tactical requirements.Impact of wing loading onto propellant mass fraction, maximal maneuverability and total mass of a missile is considered. The algorithm of optimal wing loading estimation, which provides necessary tactical characteristics of a missile being designed, is proposed. We define simple polynomial approximations of both the trajectory and the velocity profile. Further analysis is being conducted using two considerations: for an air-based missile the value of wing loading has to provide flight during launch without fall movement as well as the maximal maneuverability at the moment when a missile intercepts the target.It is shown that for the wing loading in the range from 300 to 1000 kg/m2 the propellant mass fraction changes rapidly, and inaccurate selection of wing loading may lead to obtaining of an incorrect value of propellant mass fraction. For maximal maneuverability less than 40, inappropriate selection of wing loading may cause significant numerical error. Analysis of relation between wing loading and total mass of a missile revealed that there is a critical value of wing loading which depends on initial data and represents the low limit of an acceptable range.