Water Strider Research Articles

Chinches patinadoras marinas (Hemiptera: Heteroptera: Gerromorpha): diversidad de los hábitats oceánicos del Neotrópico

Las chinches acuaticas del infraorden Gerromorpha son especies adaptadas a caminar o patinar sobre la pelicula superficial del agua principalmente en ambientes de agua dulce, sin embargo, algunas especies se han adaptado a vivir en ambiente marinos y actualmente no se cuenta con un inventario de la riqueza y composicion de la fauna de chinches patinadoras marinas para el Neotropico. A partir de la revision bibliografica, de los especimenes depositados en colecciones entomologicas y expediciones en campo, se obtuvieron los registros de chinches asociadas a ambientes marinos. A cada registro se les asigno una categoria de habitat (estuarios/ manglares, lagunas formadas por arrecifes de coral, guarida de cangrejo en manglar, charcas formadas por las mareas, mar cerca de la costa, ambientes pelagicos) y su distribucion geografica actualizada. Se registran 203 especies a nivel mundial de Gerromorpha en ambientes asociados a ecosistemas marinos. Para el Neotropico se registraron cinco familias, 13 generos y 48 especies que representan el 23 % de las especies a nivel mundial. En orden de riqueza de especies la familia Gerridae tuvo la mayor con 22 especies distribuidas en tres generos, seguida de Veliidae con 17 especies de cinco generos, Mesoveliidae con seis especies y tres generos, Hermatobatidae con dos especies y un genero, y por ultimo Hebridae con un genero y una especie.

Bio-inspired hierarchical hair arrays with tunable adhesive superhydrophobicity

Inspired by the hierarchical seta arrays on the feet of gecko and the legs of water strider, two different microstructures including cylindrical hair arrays and coniform hair arrays have been fabricated by reactive ion etching combined with colloidal lithography. Interestingly, all the artificial hair arrays are sculptured with elaborate nanogrooves, leading to a unique hierarchical structure. Inspired by the novel hierarchical structures, the contrastive experimental research for their wetting properties was carried out by means of optical contact angle measurement. The results show that after fluorination, both of the two hair arrays exhibit excellent superhydrophobicity, but different adhesive force towards water. These tunable adhesive superhydrophobicity may be attributed to the different morphologies of the hair arrays. Based on these properties, a “mechanical hand” to transport small water droplets from a superhydrophobic surface to a hydrophobic or a hydrophilic surface without any loss or contamination was realized.

Biogeography and diversification of Holarctic water striders: Cenozoic temperature variation, habitat shifting and multiple intercontinental dispersals

AbstractIt is now rare to find a semi‐aquatic organism group with which to vigorously test whether their diversification model and distribution pattern are closely related to the Cenozoic temperature variation. This hypothesis is explored for water striders of the generaAquariusSchellenberg,GerrisFabricius andLimnoporusStål, which comprise a monophyletic clade with primarily Holarctic distribution. We sample almost 90% of the currently recognizedAquarius,GerrisandLimnoporusspecies. Five DNA fragments from 62 species are used to reconstruct a phylogram. Divergence time is estimated using Bayesian relaxed‐clock method and three fossil calibrations. We investigate diversification dynamics, biogeography and ancestral state reconstruction by using maximum‐likelihood, Bayesian and parsimony approaches. Our results showed that the crown of the three genera originated and underwent an initial diversification in Asia at 72 Ma (HPD: 59–86 Ma) in the Late Cretaceous, subsequently expanding into other regions via dispersal. The Bering Land Bridge was the major migration route between Eurasia and North America but was interrupted before the early Oligocene (34 Ma). Ancestors most likely used lentic habitats, and a minimum of two independent shifts to lotic habitats occurred in the initial diversification. Cenozoic temperature variation regulated the evolutionary history of Holarctic water striders of the generaAquarius,GerrisandLimnoporus. Temperature warming during Stage I (52–66 Ma) was associated with the disappearance of shallow lentic habitats; this phenomenon forced certain lentic lineages to colonize new lotic habitats and promoted the diversification of lineages. Temperature cooling during Stage II (after 34 Ma) was associated with the fragmentation of water habitats of the ‘mixed‐mesophytic’ belt, resulting in the extinction of historical taxa and influencing close lineages that shaped the present disjunct Eurasian–North American distribution.

Taxon-restricted genes at the origin of a novel trait allowing access to a new environment.

Taxon-restricted genes make up a considerable proportion of genomes, yet their contribution to phenotypic evolution is poorly understood. We combined gene expression with functional and behavioral assays to study the origin and adaptive value of an evolutionary innovation exclusive to the water strider genus Rhagovelia: the propelling fan. We discovered that two taxon-restricted genes, which we named geisha and mother-of-geisha, specifically control fan development. geisha originated through a duplication event at the base of the Rhagovelia lineage, and both duplicates acquired a novel expression in a specific cell population prefiguring fan development. These gene duplicates played a central role in Rhagovelia's adaptation to a new physical environment, demonstrating that the evolution of taxon-restricted genes can contribute directly to evolutionary novelties that allow access to unexploited ecological niches.

Mechanics of jumping on water

Some semi-aquatic insects, such as water striders and springtails, can jump off the water surface by exploiting the interfacial tension to escape from predators. We present a theoretical framework to analyze and predict the jumping of those insects.

The study of water bug fauna (Insecta: Hemiptera) in My Son Sanctuary, Quang Nam Province

My Son was listed as a UNESCO World Cultural Heritage Site in 1999. However, My Son is now negatively affected by on-going human activities. One of the solutions to conserve the My Son sanctuary is based on the ecosystem approach. The ecosystem approach is based on the application of appropriate scientific methodologies focused on levels of biological organization, providing a scientific basis for developing solution to the ecosystem structure. The results of presented in this paper, focusing on the fauna of water bugs (Insecta: Hemiptera), is a part of the study to investigate the species composition in the area, in order to compile a baseline data for proposing and developing a model for applying ecological and irrigation solutions in My Son sanctuary, Quang Nam province. Field surveys conducted along Khe The stream, in the area of My Son sanctuary in August 2016 and April 2017 have yielded a total of 36 water bug species, belonging to 29 genera, 13 families of two infraorders Gerromorpha and Nepomorpha. Among 13 families found in the studied area, the family Gerridae has the highest number of species, 14 species belonging to nine genera, followed by the family Veliidae with four species. Nepidae and Naucoridae have three species each. The remaining families contain only one or two species each. This study has provided the first inventory on water bug fauna of the area of the My Son sanctuary.

A biomimetic vibration sensor using a symmetric electrodes metal core piezoelectric fiber

A biomimetic vibration sensor to sense external vibrations was designed based on the hair receptor of insects similar to the water strider. Platinum core piezoelectric ceramic fiber body was prepared by squeeze and press method. This was followed by high-temperature sintering, surface electrode coating, and polarizing to fabricate the symmetric coated metal core piezoelectric fiber vibration sensor. A cantilever beam structure with two surface electrodes was designed as the theoretical sensor model. The fiber was fixed on a matrix structure. Experiments were performed to verify sensing characteristics under impact vibration and simple harmonic excitation. Results showed that the symmetric coated metal core piezoelectric fiber was able to sense amplitude and direction of impact vibration along with frequency, amplitude, and direction under simple harmonic excitation. Such a biomimetic vibration sensor can be effectively used to sense vibration amplitude and direction for a wide range of applications.

Slippery and never wet

Superhydrophobic surfaces let water droplets roll off with low friction and falling droplets rebound, leaving the surfaces completely dry. Such extremely water repellent surfaces are found in nature on lotus leaves, the legs of water striders and feather coatings of birds, and portray a beautiful example of ingenious biological design. They provide an exciting research avenue for physicists and materials scientists aspiring to understand and mimic nature.

Conditions for Barrel and Clam-Shell Liquid Drops to Move on Bio-inspired Conical Wires

It has been reported that, in a foggy environment, water drops with either barrel or clam-shell shapes are capable of self-running on conical wire-like structures, such as cactus spines, spider silk, and water striders’ legs. On the other hand, the corresponding moving mechanisms are still not quite understood. For instance, it is unclear under what conditions clam-shell drops would move from the tip towards the root on a conical wire. In this work, based on the balance of forces, we derive conditions for a drop to self-transport towards or away from the root. We find that, although barrel and clam-shell drops have different shapes, these conditions are applicable to both of them, which thus provide good guidelines for developing artificial fog collectors. Furthermore, based on the derived conditions, we interpret drop movements on both hydrophilic and hydrophobic wires, with the support of experimental results on cactus spines. Finally, our results indicate that not all the cacti are able to harvest water from fog.

A Quick View on Biology of Near Threatened Peacock Eel (<i>Macrognathus aculeatus</i>) in Khulna Region of Bangladesh

The Peacock eel, Macrognathus aculeatus is a near threatened highly valuable small indigenous species in Bangladesh. It is not only toothsome nutritive table fish but also notable aquarium species but still rely on natural stock. Keeping in mind the paucity of information on the biology which is crucial to develop artificial propagation and culture technique of this species, the present research was performed as an attempt to contribute to the information on the taxonomy and other biological aspects of M. aculeatus. Total 50 samples were collected from Khulna region during April to May 2014 to assay. The taxonomical study revealed that the total length, standard length, head length, eye diameter, pre and post orbital length; length of dorsal, anal and caudal fin; length of upper and lower jaw; body depth and width, distance between dorsal fin to caudal fin ranged from 17.00-21.00, 15.00-19.00, 0.80-3.00, 0.20-0.40, 0.50-2.10, 0.30-1.70, 3.10-6.70, 3.50-6.30, 0.50-1.50, 0.30-1.00, 0.70-1.80, 0.90-2.30, 0.60-1.20, 0.70-2.40 cm respectively, additionally meristic character’s formula appeared like D. 19 - 39, A. 11 - 18, C. 29 – 52, L. 11-15 and number of eye spots on dorsal fin, 3-10. Turning to the biological inquiry which showed that the fish weight (g), gonad weight (g), liver weight (g), gut weight (g), gonadosomatic, alimentosomatic and hepatosomatic index and condition factor ranged from 15.10-28.60, 2.32-3.18, 0.029-0.044, 0.64-1.08, 9.69-14.79, 2.58-4.15, 0.11-0.19 and 0.30-0.40 respectably. The mean values of hepatosomatic and alimentosomatic indices persuaded greater liver activity and feeding intensity in M. aculeatus. Moreover, stomach content depicted that the diet of peacock eel composed of small fish species, small prawn, prawn larvae, earthworm, water strider, insects pupae, Metaphire posthuma, Caenorhabditis, sand and mud for instance, which in brief expressed that M. aculeatus is omnivorous in its feeding habits. Indeed, this preliminary research outcome would be utile for the species identification, seed production, developing culture technologies as well as biodiversity conservation of this near threatened fish species.

Development of water surface mobile robot inspired by water striders

This work describes a water surface mobile robot utilising surface tension forces. Recent biological studies on water striders revealed how they stay afloat and move on the surface of water. By using their hairy legs coated with hydrophobic substance produced, they increase the water repellency and float by the surface tension. This work focuses on understanding the static and dynamic interactions between supporting legs and the surface of water. First, microstructured wire legs were fabricated by using femtosecond laser machining to enhance the water repellency. Then the supporting force, the pull-off force and the drag force were measured to find the suitable legs for water strider robot. Finally, by assembling the legs optimised for supporting load and propulsion, a water strider robot weighing 4.39 g was developed. The robot successfully moved on the surface of water at a speed of 59.2 mm/s.

A Miniature Water Surface Jumping Robot

Many small insects such as water striders can leap from water surface. Inspired by their jumping capability, we present the design of a novel, miniature, water surface jumping robot in this paper. Jumping from water surface is more challenging than jumping from ground due to the liquid water surface. We address this problem by using carbon fiber strip to store energy, two wings to flap the water surface, a hollow body to initially support the robot, and an intermittent gear train to charge and release energy. With such a design, the final robot weighs around 12.5 g and has a maximum size of 10 cm. Experimental results show that the robot can jump up to 9.5 cm in height, which is close to the predicted results from a dynamic model developed by us to capture the hydrodynamic behaviors of the robot during the whole jumping process. The research presented in this paper offers a new design of tiny robots for mimicking the water-jumping capability of aquatic insects. The robot, if equipped with sensors, can be employed for aquatic environmental monitoring of water quality.

Microstructures and grease layer of water strider and its influence on superhydrophobicity

In this paper, the microstructures of the water strider surface were observed by scanning electron microscopy. The surfaces, including wings, legs, back and abdomen, all exhibited various compound microstructures, which are the important factors influencing the superhydrophobicity with a contact angle (CA) of up to 153°. Furthermore, the grease of the water strider on different substrates was studied by self-assembly of the grease for 14 d. Images of the grease indicated that the morphology and spatial orientation of the grease depend on the substrate chosen. The grease decreased the substrate wettability by approximately 30° on highly ordered pyrolytic graphite and about 23° on the silicon substrates. Gas chromatography combined with mass spectrometry was also used to study the chemical composition of the grease layer of water strider surface. The grease layer is composed of a mixture of aliphatic compounds, which possess hydrophobicity based on the chemical structure. Grease protects the microstructures of water strider surfaces and thus results in higher CAs and hydrophobic properties. The microstructure and the grease of the water strider jointly render the hydrophobic properties of the water strider surface.

The Development of ‘Water strider’ Inquiry Learning Program for Improving Scientific Inquiry Learning Ability in the Chapter ‘the Little Creatures World’ of the Korea Elementary School 5th Grade Science Textbook

The purpose of this study was to develop a ‘Water strider’ Inquiry Learning Program for improved inquiry learning, and to analyze the validity of the ‘Water strider.’ The Inquiry Learning Program’s goal was to create an application for finding out an on-site applicability for the ‘Water strider’ Inquiry Learning Program through the Elementary school teachers’ workshop. The following are the summarizations of the main issues of study. First, the ‘Water strider’ Inquiry Learning Program, (or W.S.I.L.P. for short) consisted of five subjects: comprehension of surface tension, collecting and raising water striders, the secret of water striders’ body, the condition of floating water striders, and making the model of water striders. There were 10 small group activities which were organized by themes including Prediction, Observation, Explanation, Reflection, and an Additional questions stage. Using these, the students could then comprehend the water strider’s structural features and the scientific principles. Secondly, in the assessment of on-site applicability, which elementary school teachers directly implemented, each activity consisted of immediate manipulation activities to help increase the students’ interest. They were not only able to easily comprehend the scientific inquiry ability, but also the inquiry ability of the W.S.I.L.P. The ‘Water strider’ Inquiry Learning Program can also be useful for science club activities in addition to the regular curriculum time because of the integrative lessons that will be available by using the ‘Water strider’ Inquiry Learning Program.

Effects of the group’s mix of sizes and personalities on the emergence of alternative mating systems in water striders

Lay SummaryWe still understand poorly why different groups of individuals within a given species differ in their mating behaviour. We investigated how the composition in size and behavioural tendencies of individuals in a group affected mating behaviour in water striders. In groups where striders were active, bigger, and more flexible, a single male guarded multiple females. In contrast, in groups where striders were inactive, smaller, and exhibited a more rigid behaviour, individuals mated with several partners.Twitter: @POMontiglio

Water skating robots take off?

An insect-inspired microbot that uses the motion of its wings to skate across the surface of water at high speed is presented in work from China aimed at creating microbots that can also fly. The water strider-inspired microbot's hydrophobic legs allow it to stand on the surface of the water thanks to surface tension. Bioinspired engineering seeks to create technology based on ideas taken from the amazing and varied biology we see around us everyday. Insects are a rich source of that inspiration, with their wide range of specialised abilities, including the ability to walk on water using surface tension displayed by gerridae such as the water strider. A group of researchers at Shanghai Jiao Tong University have been working on robots that can copy this feat, because, as team member Prof. Weiping Zhang explained, “Water striders can support themselves stably and move rapidly on the water. We feel that this is a very low energy consumption mechanism, especially in insect-scale.” In this issue of Electronics Letters, Prof. Zhang and his colleagues present a micro-bionic robot that can move quickly on the water, using flapping-wings and skating-legs, and is, they say, the lightest and one of the fastest water skating robots ever developed. Weighing just 165mg, their robot can skate across the surface of water at 151mm/s but Prof. Zhang tells us that these achievements are only a part of the significance of this work, “First, the study develops an efficient movement for aquatic robots, which can significantly improve the robot's working duration and cruising radius. Second, this study successfully combines the large thrust generation mechanism of flapping-wings flight and the low resistance movement form of surface tension skating to lay the technical foundation for further development of flight-skating amphibious robots.” This study was also the world's first attempt to combine these two forms of motion, and achieved a certain degree of movement performance. Previous studies have focused on actively driving a robot's legs to achieve water skating. The leg-driving approach produces motion through direct interaction with the water surface, using a rowing-like motion to push the robot forward. Unfortunately, at higher driving frequencies it is easy to break the water surface with this skating method, so it is difficult to increase the skating speed. The Shanghai team have avoided this problem by decoupling the drive mechanism from their robot's legs. Instead of driving the legs directly they use the flapping mechanism of the robot's flexible wings as the drive mechanism; producing aerodynamic force to move the robot across the water's surface. This increases stability and allows a higher skating speed, it also improves manoeuvrability. All of which can be controlled by adjusting the frequency of flapping motion. The motion of the robot's wings is produced by lead zirconate titanate (PZT) piezoelectric actuators; a method already used in flying robot designs. The wings themselves are made from polyester film with carbon fibre ‘veins’. The microbot stands on the water surface thanks to titanium alloy legs with a hydrophobic coating. The flapping wing laser displacement test equipment in the lab at Shanghai Jiao Tong University. Inset: The robot's polyester film wings incorporate carbon fibre 'veins'. These wings, rather than the legs, are used to drive the robot's water skating. The exact details of these tiny components in combination are key to the success of the work. “The major challenges we faced were the design of the wings and legs,” says Zhang. “Aerodynamic elastic deformation of flexible wings occurs when they flap at a high frequency, while large deflection elastic deformation of the titanium alloy legs treated with hydrophobic coating also happens when it undertakes a load during the movement of robot. We must ensure the stability of the forces produced by these two kinds of deformation, through the bionic design of veins, symmetrical distribution and horizontal assembly of wings, symmetrical PZT bimorph actuator design, periodic alternating signal and centre of gravity design.” The Shangai team are now working to further optimise the structural design of their microbot and develop their multi-DOF control technology; with the ultimate aim of producing an amphibious robot that can fly and skate with multiple degrees of freedom. The next step in the work is to further study the aerodynamic control mechanism and attempt to change the amplitude and direction of the aerodynamic forces produced in order to achieve transition between flight and water-skating. In terms of using such robots they foresee applications in aquatic detection, signal collection, military reconnaissance, marine meteorology and water pollution monitoring. “With such low-cost, low-power, fast-moving microbots as a platform, a mobile sensor network can be built up, effective distributed operations can be achieved as well.”

Variation in Zn, C, and N isotope ratios in three stream insects

Total Zn concentrations and Zn isotope ratios were measured, using multicollector inductively coupled plasma (ICP)-mass spectrometry (MS), in three species of aquatic insects collected from a stream in Peterborough, Ontario, Canada. Total Zn levels averaged 193 ± 88 μg/g dry weight (dw) in water striders (Heteroptera: Gerridae, Aquarius remigis) and were significantly higher than the concentrations measured in stonefly nymphs (Plecoptera: Perlidae, Acroneuria abnormis) and caddisfly larvae (Trichoptera: Limnephilidae, Pycnopsyche guttifer), i.e., 136 ± 34 μg/g dw and 125 ± 26 μg/g dw, respectively. Average delta values for 66Zn/64Zn in the water striders were approximately 0.7‰ lighter (−1.2‰ ± 1.0‰) and were significantly different than those measured for stoneflies (−0.45‰ ± 0.62‰) and caddisflies (−0.51‰ ± 0.54‰). Nitrogen isotope ratios were significantly different ( P < 0.05) among the three species suggesting differences in trophic positioning. Similar to the Zn isotope ratios, δ 13C values for the water striders (−28.61‰ ± 0.98‰) were significantly different than those of the stoneflies and caddisflies, i.e., −30.75‰ ± 1.33‰ and −30.68‰ ± 1.01‰, respectively. The data suggest that the differences observed in Zn ratios relate to food source for these insects. Similar to their carbon sources, Zn in water striders appears to be primarily of terrestrial origin, and of aquatic origin for the other two species.

Altered physical and social conditions produce rapidly reversible mating systems in water striders

Mating systems can vary within-species but the environmental drivers and behavioral mechanisms underlying this variation are seldom investigated experimentally. We experimentally assessed how individual behavioral plasticity in response to changes in pool and group size resulted in fundamental shifts in mating systems in water striders. We observed the same animals in larger and smaller pools, mimicking variation in pool size in natural streams, and observed a rapid, reversible change in the entire mating system. In large pools, striders exhibited scramble promiscuity with intense sexual conflict. Most males were active, harassing and driving females into hiding. Matings were frequent and typically lasted for more than 100 min. In contrast, when placed in small pools, the same animals often exhibited harem polygyny where the largest male drove other males into hiding, but allowed females to be relatively active. Matings were less frequent and of much shorter duration. Harem polygyny took several days to emerge after animals were moved to small pools, while these same animals returned to scramble promiscuity within hours after being moved to larger pools. Such variability in mating systems likely has important implications for the evolution of individual mating tactics.

EAG channels expressed in microvillar photoreceptors are unsuited to diurnal vision

The principles underlying the evolutionary selection of ion channels for expression in sensory neurons are unclear. Photoreceptor depolarization in the diurnal Drosophila melanogaster is predominantly provided by light-activated transient receptor potential (TRP) channels, whereas repolarization is mediated by sustained voltage-gated K+ channels of the Shab family. In the present study, we show that phototransduction in the nocturnal cockroach Periplaneta americana is predominantly mediated by TRP-like channels, whereas membrane repolarization is based on EAG channels. Although bright light stimulates Shab channels in Drosophila, further restricting depolarization and improving membrane bandwidth, it strongly suppresses EAG conductance in Periplaneta. This light-dependent inhibition (LDI) is caused by calcium and is abolished by chelating intracellular calcium or suppressing eag gene expression. LDI increases membrane resistance, augments gain and reduces the signalling bandwidth. This makes EAG unsuitable for light response conditioning during the day and might have resulted in the evolutionary replacement of EAG by other delayed rectifiers in diurnal insects. The principles underlying evolutionary selection of ion channels for expression in sensory neurons are unclear. Among species possessing microvillar photoreceptors, the major ionic conductances have only been identified in Drosophila melanogaster. In Drosophila, depolarization is provided by light-activated transient receptor potential (TRP) channels with a minor contribution from TRP-like (TRPL) channels, whereas repolarization is mediated by sustained voltage-gated K+ (Kv) channels of the Shab family. Bright light stimulates Shab channels, further restricting depolarization and improving membrane bandwidth. In the present study, data obtained using a combination of electrophysiological, pharmacological and molecular knockdown techniques strongly suggest that in photoreceptors of the nocturnal cockroach Periplaneta americana the major excitatory channel is TRPL, whereas the predominant delayed rectifier is EAG, a ubiquitous but enigmatic Kv channel. By contrast to the diurnal Drosophila, bright light strongly suppresses EAG conductance in Periplaneta. This light-dependent inhibition (LDI) is caused by calcium entering the cytosol and is amplified following inhibition of calcium extrusion, and it can also be abolished by chelating intracellular calcium or suppressing eag gene expression by RNA interference. LDI increases membrane resistance, augments gain and reduces the signalling bandwidth, impairing information transfer. LDI is also observed in the nocturnal cricket Gryllus integer, whereas, in the diurnal water strider Gerris lacustris, the delayed rectifier is up-regulated by light. Although LDI is not expected to reduce delayed rectifier current in the normal illumination environment of nocturnal cockroaches and crickets, it makes EAG unsuitable for light response conditioning during the day, and might have resulted in the evolutionary replacement of EAG by other delayed rectifiers in diurnal insects.

Correlational selection on personality and social plasticity: morphology and social context determine behavioural effects on mating success.

Despite a central line of research aimed at quantifying relationships between mating success and sexually dimorphic traits (e.g., ornaments), individual variation in sexually selected traits often explains only a modest portion of the variation in mating success. Another line of research suggests that a significant portion of the variation in mating success observed in animal populations could be explained by correlational selection, where the fitness advantage of a given trait depends on other components of an individual's phenotype and/or its environment. We tested the hypothesis that interactions between multiple traits within an individual (phenotype dependence) or between an individual's phenotype and its social environment (context dependence) can select for individual differences in behaviour (i.e., personality) and social plasticity. To quantify the importance of phenotype- and context-dependent selection on mating success, we repeatedly measured the behaviour, social environment and mating success of about 300 male stream water striders, Aquarius remigis. Rather than explaining individual differences in long-term mating success, we instead quantified how the combination of a male's phenotype interacted with the immediate social context to explain variation in hour-by-hour mating decisions. We suggest that this analysis captures more of the mechanisms leading to differences in mating success. Males differed consistently in activity, aggressiveness and social plasticity. The mating advantage of these behavioural traits depended on male morphology and varied with the number of rival males in the pool, suggesting mechanisms selecting for consistent differences in behaviour and social plasticity. Accounting for phenotype and context dependence improved the amount of variation in male mating success we explained statistically by 30-274%. Our analysis of the determinants of male mating success provides important insights into the evolutionary forces that shape phenotypic variation. In particular, our results suggest that sexual selection is likely to favour individual differences in behaviour, social plasticity (i.e., individuals adjusting their behaviour), niche preference (i.e., individuals dispersing to particular social conditions) or social niche construction (i.e., individuals modifying the social environment). The true effect of sexual traits can only be understood in interaction with the individual's phenotype and environment.