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Summary The seed shadow created by wind dispersal around parent trees may be affected by functional traits, as well as wind conditions and surrounding vegetation. This study of one mature tree each of 12 Neotropical species determined the extent to which species variation in diaspore traits vs. tree height and crop size explains (i) rate of diaspore descent in still air, (ii) distributions of diaspores dispersed from a 40‐m tower in the forest, and (iii) natural seed shadows around the parent tree. A model of diaspore wing‐loading to a fitted power explained 66·9% of the variation among species in the geometric mean rate of descent in still air. For a subset of four species, expected dispersal distance was not correlated with actual dispersal distance from the forest tower. For a subset of seven species, variation in wing‐loading0·5 of individual diaspores explained ≤4·3% of the dispersal distance from the parent tree. Measured seed shadows, particularly their distribution edges and area, differed significantly among the 12 species (range in maximum tree height 19–42 m) and were best fit by 12 separate anisotropic dispersal kernels and surveyed fecundities. Measured mean distance was highly correlated with simulated distances from the kernels. The best models, explaining 57·6% of the variation among species in shadow area, and 59·6, 61·6 and 61·7% of variation in mean, median and maximum distances, included maximum tree height, either alone or in combination with crop size, and not diaspore rate of descent. Among 10 species, seed shadow area was not related to rank of seedling shade tolerance. In their highly skewed distributions, most seeds were much closer than the distance of greatest seedling recruitment and in very high density, thus enhancing later density‐ and/or distance‐related seedling mortality. Tree functional traits, rather than the historically emphasized diaspore traits, explain distance distributions of these wind‐dispersed species. Additional exploration of diaspore abscission in relation to wind and the influence of wind patterns after release are needed. A lay summary is available for this article. Lay Summary

Seed dispersal governs the distribution of plant propagules in the landscape and hence forms the template on which density‐dependent processes act. Dispersal is therefore a vital component of many species coexistence and forest dynamics models and is of applied value in understanding forest regeneration. Research on the processes that facilitate forest regeneration and restoration is given further weight in the context of widespread loss and degradation of tropical forests, and provides impetus to improve estimates of seed dispersal for tropical forest trees. South‐East Asian lowland rainforests, which have been subject to severe degradation, are dominated by trees of the Dipterocarpaceae family which constitute over 40% of forest biomass. Dipterocarp dispersal is generally considered to be poor given their large, gyration‐dispersed fruits. However, there is wide variability in fruit size and morphology which we hypothesize mechanistically underpins dispersal potential through the lift provided to seeds mediated by the wings. We explored experimentally how the ratio of fruit wing area to mass (“inverse wing loading,” IWL) explains variation in seed dispersal kernels among 13 dipterocarp species by releasing fruit from a canopy tower. Horizontal seed dispersal distances increased with IWL, especially at high wind speeds. Seed dispersal of all species was predominantly local, with 90% of seed dispersing <10 m, although maximum dispersal distances varied widely among species. We present a generic seed dispersal model for dipterocarps based on attributes of seed morphology and provide modeled seed dispersal kernels for all dipterocarp species with IWLs of 1–50, representing 75% of species in Borneo. This article experimentally investigates seed dispersal potential in the Dipterocarpaceae, a family of trees with winged, wind dispersed fruit which dominates the tropical forests of Southeast Asia. Seed dispersal of all species was predominantly local, with 90% of seed dispersing <10 m. We present a generic seed dispersal model for dipterocarps based on attributes of seed morphology, and provide modelled seed dispersal kernels for all dipterocarp species with inverse wing loadings (area of fruit wings/mass of fruit) of 1–50, representing 75% of species in Borneo.

We measured the terminal velocity of helicopter‐like fruit from the Dipterocarpaceae family and present a model predicting the terminal velocities for all dipterocarp species in the Malesiana region. A ballistic model of seed dispersal using the observed terminal velocities predicted dispersal distances of 17–77 m under normal atmospheric conditions. These data are of applied use in parametizing models of species coexistence, forest regeneration and habitat connectivity in Southeast Asian tropical forests.

Aiming at the problems of the conventional design method is not applicable and multiple coupling factors in the conceptual parameter of solar-powered unmanned aerial vehicles (UAVs), this paper proposes an overall parameters design method using an algorithm. Firstly, according to the energy principles of solar-powered UAVs, the multi-disciplinary parameter models were established. This model incorporates the study of motion conditions and power required calculations for various parts of the flight profile which are based on the principle of variable altitude flight path. Secondly, minimizing the weight and wing loading of the solar-powered UAV is the design objective. Based on the lift-to-weight ratio balance, thrust-to-drag ratio balance, and energy balance relationships within the flight profile, an analysis of the influencing factors on the conceptual parameters is conducted. Finally, optimization design is performed using the algorithm to obtain the preliminary conceptual parameter.

Hummingbirds are well known for their impressive maneuvering during flight. Dakin et al. used a computer vision approach to characterize the details of flight in >200 hummingbirds from 25 species (see the Perspective by Wainwright). Larger species had enhanced agility owing to increased muscle mass. In all species, muscles dictated transitional movement, whereas wing shape facilitated sharp turns and rapid rotations. Species, and individuals within species, played on their strengths by combining inherent traits and learned skills. Science , this issue p. 653 ; see also p. 636 Hummingbirds use strength and skill to shape their rapid movements. How does agility evolve? This question is challenging because natural movement has many degrees of freedom and can be influenced by multiple traits. We used computer vision to record thousands of translations, rotations, and turns from more than 200 hummingbirds from 25 species, revealing that distinct performance metrics are correlated and that species diverge in their maneuvering style. Our analysis demonstrates that the enhanced maneuverability of larger species is explained by their proportionately greater muscle capacity and lower wing loading. Fast acceleration maneuvers evolve by recruiting changes in muscle capacity, whereas fast rotations and sharp turns evolve by recruiting changes in wing morphology. Both species and individuals use turns that play to their strengths. These results demonstrate how both skill and biomechanical traits shape maneuvering behavior.

Early members of the clade Pygostylia (birds with a short tail ending in a compound bone termed “pygostyle”) are critical for understanding how the modern avian bauplan evolved from long-tailed basal birds like Archaeopteryx. However, the currently limited known diversity of early branching pygostylians obscures our understanding of this major transition in avian evolution. Here, we describe a basal pygostylian, Jinguofortis perplexus gen. et sp. nov., from the Early Cretaceous of China that adds important information about early members of the short-tailed bird group. Phylogenetic analysis recovers a clade (Jinguofortisidae fam. nov.) uniting Jinguofortis and the enigmatic basal avian taxon Chongmingia that represents the second earliest diverging group of the Pygostylia. Jinguofortisids preserve a mosaic combination of plesiomorphic nonavian theropod features such as a fused scapulocoracoid (a major component of the flight apparatus) and more derived flight-related morphologies including the earliest evidence of reduction in manual digits among birds. The presence of a fused scapulocoracoid in adult individuals independently evolved in Jinguofortisidae and Confuciusornithiformes may relate to an accelerated osteogenesis during chondrogenesis and likely formed through the heterochronic process of peramorphosis by which these basal taxa retain the scapulocoracoid of the nonavian theropod ancestors with the addition of flight-related modifications. With wings having a low aspect ratio and wing loading, Jinguofortis may have been adapted particularly to dense forest environments. The discovery of Jinguofortis increases the known ecomorphological diversity of basal pygostylians and highlights the importance of developmental plasticity for understanding mosaic evolution in early birds.

Sexual dimorphism is common throughout the animal kingdom, leading to sex-specific phenotypic differences. The common whitetail skimmer dragonfly, Plathemis lydia (Drury, 1773), is sexually dichromatic, where males of this species display a conspicuous white abdomen and females display a dark brown abdomen. Differences in abdomen conspicuousness between male and female P . lydia are likely attributed to differences in selective pressure where males use their white conspicuous abdomen during male-male territorial chases. We hypothesized that male P . lydia would exhibit wing morphology adaptations to better offset the costs of predation and territoriality and that these adaptations would differ from females. We used field-collected images to quantify differences in body length, wing length, wing area, wing shape, and wing loading between male and female P . lydia . Our results show that male P . lydia have significantly shorter fore and hind wings relative to body size with a higher wing loading when compared to females. We also found that male P . lydia have narrower and pointier fore and hind wings compared to females. These results are consistent with the idea that males are adapted for faster flight, specifically higher acceleration capacity, and higher agility whereas females are adapted for higher maneuverability.

Perching (territorial) and patrolling are recognised as mate-locating tactics adopted by male butterflies. It is said that males adopting the former fly fast with high acceleration, whereas those adopting the latter fly at continuous and lower speeds. However, no previous studies have demonstrated these flight properties using quantitative data. In the present study, the flight properties of two lycaenid species, the perching L. phlaeas and the patrolling Z. maha, were investigated based on three-dimensional analysis. Males of L. phlaeas had higher flight velocities and higher relative flight time than those of Z. maha. Furthermore, the flight morphology that supports flight properties was examined. The perching L. phlaeas exhibited higher thorax-to-body mass ratios and greater wing loadings than patrolling Z. maha.

Elevation gradients pose significant challenges for flying insects due to temperature and air density shifts, which affect thermoregulation, flight abilities, and distribution patterns. Geometrid moths serve as a useful model for studying these traits. This study investigates how trait patterns in geometrid moth assemblages change across a 1500-m elevational gradient in the western Himalayas; 697 specimens from 120 geometrid moth species were examined to assess species diversity, turnover, and traits related to body size and flight capabilities. The results show a decline in species diversity with increasing elevation, accompanied by consistent turnover from low to high elevations. However, elevation did not significantly influence morphological traits such as body size (thermal sensitivity) or flight traits like wing loading and maneuverability at the assemblage level. There was high overlap in the trait spaces, thereby showing no significant trait-space differentiation among individuals across elevations. This possibly suggests that, despite species turnover within assemblages, those with similar ecological roles maintain consistent trait values, contributing to stability in the assemblage-level trait structure. This study reveals how species traits and assemblage-level trait distributions vary across an elevational gradient. The overall trait structure remained largely stable across elevations, potentially reflecting abiotic filtering, though direct environmental evidence is lacking. Further, this emphasizes the value of trait-based approaches to understanding species' responses to environmental changes, especially in paleotropical ecosystems.

The large variety of possible propulsion architectures for environmentally friendly and sustainable aircraft concepts create opportunities for the overall aircraft design. In particular, hybrid-electric aircraft have an increased number of additional components that must be implemented in the aircraft design tool. Primary and secondary energy sources can be used to achieve the necessary reduction in emissions. The preliminary aircraft design tool SUAVE offers the basic setup necessary to integrate the electrification of the propulsion system into the aircraft design. For this purpose, SUAVE has been extended to enable an iterative sizing loop for hybrid-electric aircraft. Hence, many propulsion architectures are easily adaptable. Additional components can be included and their interactions are considered. Furthermore, the fidelity levels of the models are modifiable. Moreover, the top-level aircraft requirements are transformed into a sizing chart to calculate the necessary power and wing loading. Thereby, a reasonable hybridization factor of installed power can be identified. This definition of hybridization implies a specific energy management strategy. As a result, hybridization and the energy management strategy are directly coupled and have to be considered together. Finally, in the postprocessing, the raw data is processed and can be evaluated with figures of merit. This procedure converts the results into a descriptive value and facilitates the comparison to other configurations. The figures of merit include evaluations for emissions, operational aspects and development costs and effort.