Dragonfly flight: morphology, performance and behaviour

Abstract

Odonata flight performance capabilities and behaviour and their body and wing form diversity are explored, and their interrelationships discussed theoretically and from observational evidence. Overall size and particularly wing loading appear predictably to be related to speed range. In Anisoptera at least, relatively short bodies and long wings should favour high speed manoeuvrability, though further information is needed. Medium and low aspect ratio wings are associated with gliding and soaring, but the significance of aspect ratio in flapping flight is less straightforward, and much depends on kinematics. Narrow wing bases, petiolation, basal vein fusion, distal concentration of area and a proximally positioned nodus -described by a newly defined variable, the "nodal index" -all allow high torsion between half-strokes and favour habitually slow flight, while broad wing bases are useful at higher speeds. The "basal complex" in all families seems to be a mechanism for automatic lowering of the trailing edge and maintenance of an effective angle of attack, but the relative merits of different configurations are not yet clear. There is serious need for more quantitative information on a wider range of species and families.

Amazonian Odonata Trait Bank

“…The literature indicates that morphometrics can be transformed into indices and ratios that, in turn, give rise to insights that only raw values could not provide. Some of these indices are already relatively well–studied and known to science, such as Wing Load and Wing Stroke, both linked to flight performance and dispersion (Hall & Willmott, 2000; McCauley, 2013; Resende et al, 2021; Wootton, 2020) and widely used in the aeronautical industry (Liang et al, 2014).…”

“…Since significant ecological and climatic differences arise across biomes, the range of zones dominated by a species can provide us with information linked to dispersal capacity and environmental tolerance (Renner et al, 2019). In some cases, this distribution pattern may be related to morphological traits of these species, such as body size, or even the shape, size, and venation of the wings (Hefler et al, 2018; Wootton, 2020). In fact, morphology has been considered an important element to understand the biological mechanisms of the group.…”

Relatively large wings facilitate life at higher elevations among Nearctic dragonflies

“…It is also likely to be a major threat to dragonflies since oxygen availability at sea level is insufficient to maximally power their flight (Harrison et al, 2018; Harrison & Lighton, 1998). Because relatively large wings enable individuals to takeoff and manoeuvre more efficiently (Dudley, 2002; Wootton, 2020), relatively large wings could plausibly be one solution that dragonflies employ to meet the already extreme aerobic demands of their locomotion (Weis‐Fogh, 1967). Research into the biomechanics and energetics of dragonfly flight at high altitude will be necessary to understand if either low air pressure or low oxygen availability are the greater challenge to overcome.…”

“…By studying what traits allow dragonfly species to overcome their clade‐wide altitudinal restrictions, we can more generally clarify which characteristics are most beneficial to life at high elevations for other completely volant species. In particular, since dragonfly flight is extremely aerobically and aerodynamically taxing even at sea level (Harrison & Lighton, 1998; Weis‐Fogh, 1967; Wootton, 2020), relatively large wings might be especially advantageous for alleviating the atmospheric constraints on high‐elevation life as predicted by Mayr (1963). Under this scenario, we should observe that species with relatively larger wings live at higher elevations across the Nearctic.…”

The interplay of kinematics and aerodynamics in multiple flight modes of a dragonfly

“…As one of the most successful aerial predators on Earth, dragonflies have survived and evolved for millions of years (Combes et al 2012). Unlike wings of birds or bats, the dragonfly wing is a complex mechanical structure without muscle or bone, and the wing morphology of a dragonfly is characterized by multiscale wings, such as the resilin, wing corrugation, nodus and pterostigma, which greatly affect the structural dynamics of the flapping wings and, hence, flight performance (Rajabi & Gorb 2020;Wootton 2020).…”